diff --git a/Mi/.idea/deploymentTargetSelector.xml b/Mi/.idea/deploymentTargetSelector.xml
index 6ba556a..c1546bd 100644
--- a/Mi/.idea/deploymentTargetSelector.xml
+++ b/Mi/.idea/deploymentTargetSelector.xml
@@ -4,10 +4,10 @@
     <selectionStates>
       <SelectionState runConfigName="app">
         <option name="selectionMode" value="DROPDOWN" />
-        <DropdownSelection timestamp="2025-05-29T14:05:32.256772800Z">
+        <DropdownSelection timestamp="2025-06-05T01:06:08.196508400Z">
           <Target type="DEFAULT_BOOT">
             <handle>
-              <DeviceId pluginId="LocalEmulator" identifier="path=C:\Users\Administrator\.android\avd\Pixel_9_Pro_XL.avd" />
+              <DeviceId pluginId="LocalEmulator" identifier="path=C:\Users\Administrator\.android\avd\Medium_Phone_2.avd" />
             </handle>
           </Target>
         </DropdownSelection>
diff --git a/Mi/.idea/misc.xml b/Mi/.idea/misc.xml
index b2c751a..943050d 100644
--- a/Mi/.idea/misc.xml
+++ b/Mi/.idea/misc.xml
@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">
@@ -6,4 +7,11 @@
   <component name="ProjectType">
     <option name="id" value="Android" />
   </component>
+  <component name="VisualizationToolProject">
+    <option name="state">
+      <ProjectState>
+        <option name="scale" value="0.1132844335778321" />
+      </ProjectState>
+    </option>
+  </component>
 </project>
\ No newline at end of file
diff --git a/Mi/app/build.gradle.kts b/Mi/app/build.gradle.kts
index 72c54ab..957a5ab 100644
--- a/Mi/app/build.gradle.kts
+++ b/Mi/app/build.gradle.kts
@@ -10,7 +10,7 @@ android {
 
     defaultConfig {
         applicationId = "net.micode.notes"
-        minSdk = 24
+        minSdk = 30
         targetSdk = 35
         versionCode = 1
         versionName = "1.0"
diff --git a/Mi/app/src/main/AndroidManifest.xml b/Mi/app/src/main/AndroidManifest.xml
index a3c4700..45a891f 100644
--- a/Mi/app/src/main/AndroidManifest.xml
+++ b/Mi/app/src/main/AndroidManifest.xml
@@ -23,7 +23,7 @@ Component（组件）、Extra（扩展信息）、Flag（标志位） -->
     android:versionCode="1"
     android:versionName="0.1" >
 
-    <uses-sdk android:minSdkVersion="24" />
+    <uses-sdk android:minSdkVersion="30" />
 
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT" />
diff --git a/Mi/app/src/main/java/net/micode/notes/data/NotesProvider.java b/Mi/app/src/main/java/net/micode/notes/data/NotesProvider.java
index edb0a60..dcd68fb 100644
--- a/Mi/app/src/main/java/net/micode/notes/data/NotesProvider.java
+++ b/Mi/app/src/main/java/net/micode/notes/data/NotesProvider.java
@@ -29,11 +29,15 @@ import android.net.Uri;
 import android.text.TextUtils;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import net.micode.notes.R;
 import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
+import java.util.Objects;
+
 
 public class NotesProvider extends ContentProvider {
     private static final UriMatcher mMatcher;
@@ -73,12 +77,6 @@ public class NotesProvider extends ContentProvider {
         + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
         + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
 
-    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
-        + " FROM " + TABLE.NOTE
-        + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
-        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
-        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
-
     @Override
     public boolean onCreate() {
         mHelper = NotesDatabaseHelper.getInstance(getContext());
@@ -86,8 +84,8 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
-            String sortOrder) {
+    public Cursor query(@NonNull Uri uri, String[] projection, String selection, String[] selectionArgs,
+                        String sortOrder) {
         Cursor c = null;
         SQLiteDatabase db = mHelper.getReadableDatabase();
         String id = null;
@@ -132,6 +130,11 @@ public class NotesProvider extends ContentProvider {
 
                 try {
                     searchString = String.format("%%%s%%", searchString);
+                    String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+                            + " FROM " + TABLE.NOTE
+                            + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
+                            + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+                            + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
                     c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
                             new String[] { searchString });
                 } catch (IllegalStateException ex) {
@@ -142,13 +145,13 @@ public class NotesProvider extends ContentProvider {
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         if (c != null) {
-            c.setNotificationUri(getContext().getContentResolver(), uri);
+            c.setNotificationUri(Objects.requireNonNull(getContext()).getContentResolver(), uri);
         }
         return c;
     }
 
     @Override
-    public Uri insert(Uri uri, ContentValues values) {
+    public Uri insert(@NonNull Uri uri, ContentValues values) {
         SQLiteDatabase db = mHelper.getWritableDatabase();
         long dataId = 0, noteId = 0, insertedId = 0;
         switch (mMatcher.match(uri)) {
@@ -168,13 +171,13 @@ public class NotesProvider extends ContentProvider {
         }
         // Notify the note uri
         if (noteId > 0) {
-            getContext().getContentResolver().notifyChange(
+            Objects.requireNonNull(getContext()).getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
         }
 
         // Notify the data uri
         if (dataId > 0) {
-            getContext().getContentResolver().notifyChange(
+            Objects.requireNonNull(getContext()).getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
         }
 
@@ -182,7 +185,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public int delete(Uri uri, String selection, String[] selectionArgs) {
+    public int delete(@NonNull Uri uri, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
@@ -198,7 +201,7 @@ public class NotesProvider extends ContentProvider {
                  * ID that smaller than 0 is system folder which is not allowed to
                  * trash
                  */
-                long noteId = Long.valueOf(id);
+                long noteId = Long.parseLong(id);
                 if (noteId <= 0) {
                     break;
                 }
@@ -220,15 +223,15 @@ public class NotesProvider extends ContentProvider {
         }
         if (count > 0) {
             if (deleteData) {
-                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+                Objects.requireNonNull(getContext()).getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
             }
-            getContext().getContentResolver().notifyChange(uri, null);
+            Objects.requireNonNull(getContext()).getContentResolver().notifyChange(uri, null);
         }
         return count;
     }
 
     @Override
-    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+    public int update(@NonNull Uri uri, ContentValues values, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
@@ -240,7 +243,7 @@ public class NotesProvider extends ContentProvider {
                 break;
             case URI_NOTE_ITEM:
                 id = uri.getPathSegments().get(1);
-                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                increaseNoteVersion(Long.parseLong(id), selection, selectionArgs);
                 count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs);
                 break;
@@ -260,9 +263,9 @@ public class NotesProvider extends ContentProvider {
 
         if (count > 0) {
             if (updateData) {
-                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+                Objects.requireNonNull(getContext()).getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
             }
-            getContext().getContentResolver().notifyChange(uri, null);
+            Objects.requireNonNull(getContext()).getContentResolver().notifyChange(uri, null);
         }
         return count;
     }
@@ -283,7 +286,7 @@ public class NotesProvider extends ContentProvider {
             sql.append(" WHERE ");
         }
         if (id > 0) {
-            sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+            sql.append(NoteColumns.ID + "=").append(String.valueOf(id));
         }
         if (!TextUtils.isEmpty(selection)) {
             String selectString = id > 0 ? parseSelection(selection) : selection;
@@ -297,7 +300,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public String getType(Uri uri) {
+    public String getType(@NonNull Uri uri) {
         // TODO Auto-generated method stub
         return null;
     }
diff --git a/Mi/app/src/main/java/net/micode/notes/model/Note.java b/Mi/app/src/main/java/net/micode/notes/model/Note.java
index 6706cf6..a001435 100644
--- a/Mi/app/src/main/java/net/micode/notes/model/Note.java
+++ b/Mi/app/src/main/java/net/micode/notes/model/Note.java
@@ -35,8 +35,8 @@ import java.util.ArrayList;
 
 
 public class Note {
-    private ContentValues mNoteDiffValues;
-    private NoteData mNoteData;
+    private final ContentValues mNoteDiffValues;
+    private final NoteData mNoteData;
     private static final String TAG = "Note";
     /**
      * Create a new note id for adding a new note to databases
@@ -54,10 +54,10 @@ public class Note {
 
         long noteId = 0;
         try {
-            noteId = Long.valueOf(uri.getPathSegments().get(1));
+            assert uri != null;
+            noteId = Long.parseLong(uri.getPathSegments().get(1));
         } catch (NumberFormatException e) {
             Log.e(TAG, "Get note id error :" + e.toString());
-            noteId = 0;
         }
         if (noteId == -1) {
             throw new IllegalStateException("Wrong note id:" + noteId);
@@ -97,7 +97,7 @@ public class Note {
     }
 
     public boolean isLocalModified() {
-        return mNoteDiffValues.size() > 0 || mNoteData.isLocalModified();
+        return !mNoteDiffValues.isEmpty() || mNoteData.isLocalModified();
     }
 
     public boolean syncNote(Context context, long noteId) {
@@ -122,22 +122,18 @@ public class Note {
         }
         mNoteDiffValues.clear();
 
-        if (mNoteData.isLocalModified()
-                && (mNoteData.pushIntoContentResolver(context, noteId) == null)) {
-            return false;
-        }
-
-        return true;
+        return !mNoteData.isLocalModified()
+                || (mNoteData.pushIntoContentResolver(context, noteId) != null);
     }
 
     private class NoteData {
         private long mTextDataId;
 
-        private ContentValues mTextDataValues;
+        private final ContentValues mTextDataValues;
 
         private long mCallDataId;
 
-        private ContentValues mCallDataValues;
+        private final ContentValues mCallDataValues;
 
         private static final String TAG = "NoteData";
 
@@ -189,14 +185,15 @@ public class Note {
             ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
             ContentProviderOperation.Builder builder = null;
 
-            if(mTextDataValues.size() > 0) {
+            if(!mTextDataValues.isEmpty()) {
                 mTextDataValues.put(DataColumns.NOTE_ID, noteId);
                 if (mTextDataId == 0) {
                     mTextDataValues.put(DataColumns.MIME_TYPE, TextNote.CONTENT_ITEM_TYPE);
                     Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
                             mTextDataValues);
                     try {
-                        setTextDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                        assert uri != null;
+                        setTextDataId(Long.parseLong(uri.getPathSegments().get(1)));
                     } catch (NumberFormatException e) {
                         Log.e(TAG, "Insert new text data fail with noteId" + noteId);
                         mTextDataValues.clear();
@@ -211,14 +208,15 @@ public class Note {
                 mTextDataValues.clear();
             }
 
-            if(mCallDataValues.size() > 0) {
+            if(!mCallDataValues.isEmpty()) {
                 mCallDataValues.put(DataColumns.NOTE_ID, noteId);
                 if (mCallDataId == 0) {
                     mCallDataValues.put(DataColumns.MIME_TYPE, CallNote.CONTENT_ITEM_TYPE);
                     Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
                             mCallDataValues);
                     try {
-                        setCallDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                        assert uri != null;
+                        setCallDataId(Long.parseLong(uri.getPathSegments().get(1)));
                     } catch (NumberFormatException e) {
                         Log.e(TAG, "Insert new call data fail with noteId" + noteId);
                         mCallDataValues.clear();
@@ -233,16 +231,13 @@ public class Note {
                 mCallDataValues.clear();
             }
 
-            if (operationList.size() > 0) {
+            if (!operationList.isEmpty()) {
                 try {
                     ContentProviderResult[] results = context.getContentResolver().applyBatch(
                             Notes.AUTHORITY, operationList);
-                    return (results == null || results.length == 0 || results[0] == null) ? null
+                    return results.length == 0 || results[0] == null ? null
                             : ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId);
-                } catch (RemoteException e) {
-                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
-                    return null;
-                } catch (OperationApplicationException e) {
+                } catch (RemoteException | OperationApplicationException e) {
                     Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
                     return null;
                 }
diff --git a/Mi/app/src/main/java/net/micode/notes/model/WorkingNote.java b/Mi/app/src/main/java/net/micode/notes/model/WorkingNote.java
index be081e4..8ff86cf 100644
--- a/Mi/app/src/main/java/net/micode/notes/model/WorkingNote.java
+++ b/Mi/app/src/main/java/net/micode/notes/model/WorkingNote.java
@@ -34,7 +34,7 @@ import net.micode.notes.tool.ResourceParser.NoteBgResources;
 
 public class WorkingNote {
     // Note for the working note
-    private Note mNote;
+    private final Note mNote;
     // Note Id
     private long mNoteId;
     // Note content
@@ -54,7 +54,7 @@ public class WorkingNote {
 
     private long mFolderId;
 
-    private Context mContext;
+    private final Context mContext;
 
     private static final String TAG = "WorkingNote";
 
@@ -217,12 +217,8 @@ public class WorkingNote {
     }
 
     private boolean isWorthSaving() {
-        if (mIsDeleted || (!existInDatabase() && TextUtils.isEmpty(mContent))
-                || (existInDatabase() && !mNote.isLocalModified())) {
-            return false;
-        } else {
-            return true;
-        }
+        return !mIsDeleted && (existInDatabase() || !TextUtils.isEmpty(mContent))
+                && (!existInDatabase() || mNote.isLocalModified());
     }
 
     public void setOnSettingStatusChangedListener(NoteSettingChangedListener l) {
@@ -295,7 +291,7 @@ public class WorkingNote {
     }
 
     public boolean hasClockAlert() {
-        return (mAlertDate > 0 ? true : false);
+        return (mAlertDate > 0);
     }
 
     public String getContent() {
diff --git a/Mi/app/src/main/java/net/micode/notes/tool/BackupUtils.java b/Mi/app/src/main/java/net/micode/notes/tool/BackupUtils.java
index 39f6ec4..797fa32 100644
--- a/Mi/app/src/main/java/net/micode/notes/tool/BackupUtils.java
+++ b/Mi/app/src/main/java/net/micode/notes/tool/BackupUtils.java
@@ -36,7 +36,7 @@ import java.io.IOException;
 import java.io.PrintStream;
 
 
-public class BackupUtils {
+    public class BackupUtils {
     private static final String TAG = "BackupUtils";
     // Singleton stuff
     private static BackupUtils sInstance;
@@ -63,7 +63,7 @@ public class BackupUtils {
     // Backup or restore success
     public static final int STATE_SUCCESS                      = 4;
 
-    private TextExport mTextExport;
+    private final TextExport mTextExport;
 
     private BackupUtils(Context context) {
         mTextExport = new TextExport(context);
@@ -121,7 +121,7 @@ public class BackupUtils {
         private static final int FORMAT_NOTE_DATE            = 1;
         private static final int FORMAT_NOTE_CONTENT         = 2;
 
-        private Context mContext;
+        private final Context mContext;
         private String mFileName;
         private String mFileDirectory;
 
@@ -267,9 +267,9 @@ public class BackupUtils {
             if (noteCursor != null) {
                 if (noteCursor.moveToFirst()) {
                     do {
-                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
+                        ps.printf((getFormat(FORMAT_NOTE_DATE)) + "%n", DateFormat.format(
                                 mContext.getString(R.string.format_datetime_mdhm),
-                                noteCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
+                                noteCursor.getLong(NOTE_COLUMN_MODIFIED_DATE)));
                         // Query data belong to this note
                         String noteId = noteCursor.getString(NOTE_COLUMN_ID);
                         exportNoteToText(noteId, ps);
@@ -298,10 +298,7 @@ public class BackupUtils {
             try {
                 FileOutputStream fos = new FileOutputStream(file);
                 ps = new PrintStream(fos);
-            } catch (FileNotFoundException e) {
-                e.printStackTrace();
-                return null;
-            } catch (NullPointerException e) {
+            } catch (FileNotFoundException | NullPointerException e) {
                 e.printStackTrace();
                 return null;
             }
@@ -331,9 +328,7 @@ public class BackupUtils {
                 file.createNewFile();
             }
             return file;
-        } catch (SecurityException e) {
-            e.printStackTrace();
-        } catch (IOException e) {
+        } catch (SecurityException | IOException e) {
             e.printStackTrace();
         }
 
diff --git a/Mi/app/src/main/java/net/micode/notes/tool/DataUtils.java b/Mi/app/src/main/java/net/micode/notes/tool/DataUtils.java
index 2a14982..4856083 100644
--- a/Mi/app/src/main/java/net/micode/notes/tool/DataUtils.java
+++ b/Mi/app/src/main/java/net/micode/notes/tool/DataUtils.java
@@ -42,7 +42,7 @@ public class DataUtils {
             Log.d(TAG, "the ids is null");
             return true;
         }
-        if (ids.size() == 0) {
+        if (ids.isEmpty()) {
             Log.d(TAG, "no id is in the hashset");
             return true;
         }
@@ -59,14 +59,12 @@ public class DataUtils {
         }
         try {
             ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
-            if (results == null || results.length == 0 || results[0] == null) {
+            if (results.length == 0 || results[0] == null) {
                 Log.d(TAG, "delete notes failed, ids:" + ids.toString());
                 return false;
             }
             return true;
-        } catch (RemoteException e) {
-            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
-        } catch (OperationApplicationException e) {
+        } catch (RemoteException | OperationApplicationException e) {
             Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
         }
         return false;
@@ -98,14 +96,12 @@ public class DataUtils {
 
         try {
             ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
-            if (results == null || results.length == 0 || results[0] == null) {
+            if (results.length == 0 || results[0] == null) {
                 Log.d(TAG, "delete notes failed, ids:" + ids.toString());
                 return false;
             }
             return true;
-        } catch (RemoteException e) {
-            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
-        } catch (OperationApplicationException e) {
+        } catch (RemoteException | OperationApplicationException e) {
             Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
         }
         return false;
@@ -232,12 +228,10 @@ public class DataUtils {
                 null);
 
         if (cursor != null && cursor.moveToFirst()) {
-            try {
+            try (cursor) {
                 return cursor.getString(0);
             } catch (IndexOutOfBoundsException e) {
                 Log.e(TAG, "Get call number fails " + e.toString());
-            } finally {
-                cursor.close();
             }
         }
         return "";
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/AlarmAlertActivity.java b/Mi/app/src/main/java/net/micode/notes/ui/AlarmAlertActivity.java
index 85723be..6fbfd79 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/AlarmAlertActivity.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/AlarmAlertActivity.java
@@ -38,6 +38,7 @@ import net.micode.notes.data.Notes;
 import net.micode.notes.tool.DataUtils;
 
 import java.io.IOException;
+import java.util.Objects;
 
 
 public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
@@ -64,7 +65,7 @@ public class AlarmAlertActivity extends Activity implements OnClickListener, OnD
         Intent intent = getIntent();
 
         try {
-            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
+            mNoteId = Long.parseLong(Objects.requireNonNull(intent.getData()).getPathSegments().get(1));
             mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);
             mSnippet = mSnippet.length() > SNIPPET_PREW_MAX_LEN ? mSnippet.substring(0,
                     SNIPPET_PREW_MAX_LEN) + getResources().getString(R.string.notelist_string_info)
@@ -104,16 +105,8 @@ public class AlarmAlertActivity extends Activity implements OnClickListener, OnD
             mPlayer.prepare();
             mPlayer.setLooping(true);
             mPlayer.start();
-        } catch (IllegalArgumentException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (SecurityException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (IllegalStateException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (IOException e) {
+        } catch (IllegalArgumentException | SecurityException | IOException |
+                 IllegalStateException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
@@ -131,15 +124,11 @@ public class AlarmAlertActivity extends Activity implements OnClickListener, OnD
     }
 
     public void onClick(DialogInterface dialog, int which) {
-        switch (which) {
-            case DialogInterface.BUTTON_NEGATIVE:
-                Intent intent = new Intent(this, NoteEditActivity.class);
-                intent.setAction(Intent.ACTION_VIEW);
-                intent.putExtra(Intent.EXTRA_UID, mNoteId);
-                startActivity(intent);
-                break;
-            default:
-                break;
+        if (which == DialogInterface.BUTTON_NEGATIVE) {
+            Intent intent = new Intent(this, NoteEditActivity.class);
+            intent.setAction(Intent.ACTION_VIEW);
+            intent.putExtra(Intent.EXTRA_UID, mNoteId);
+            startActivity(intent);
         }
     }
 
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/AlarmInitReceiver.java b/Mi/app/src/main/java/net/micode/notes/ui/AlarmInitReceiver.java
index f221202..85c7a69 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/AlarmInitReceiver.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/AlarmInitReceiver.java
@@ -16,6 +16,7 @@
 
 package net.micode.notes.ui;
 
+import android.annotation.SuppressLint;
 import android.app.AlarmManager;
 import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
@@ -38,6 +39,7 @@ public class AlarmInitReceiver extends BroadcastReceiver {
     private static final int COLUMN_ID                = 0;
     private static final int COLUMN_ALERTED_DATE      = 1;
 
+    @SuppressLint("UnsafeProtectedBroadcastReceiver")
     @Override
     public void onReceive(Context context, Intent intent) {
         long currentDate = System.currentTimeMillis();
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/DateTimePicker.java b/Mi/app/src/main/java/net/micode/notes/ui/DateTimePicker.java
index 496b0cd..36c858b 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/DateTimePicker.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/DateTimePicker.java
@@ -50,9 +50,9 @@ public class DateTimePicker extends FrameLayout {
     private final NumberPicker mHourSpinner;
     private final NumberPicker mMinuteSpinner;
     private final NumberPicker mAmPmSpinner;
-    private Calendar mDate;
+    private final Calendar mDate;
 
-    private String[] mDateDisplayValues = new String[DAYS_IN_ALL_WEEK];
+    private final String[] mDateDisplayValues = new String[DAYS_IN_ALL_WEEK];
 
     private boolean mIsAm;
 
@@ -64,100 +64,6 @@ public class DateTimePicker extends FrameLayout {
 
     private OnDateTimeChangedListener mOnDateTimeChangedListener;
 
-    private NumberPicker.OnValueChangeListener mOnDateChangedListener = new NumberPicker.OnValueChangeListener() {
-        @Override
-        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
-            mDate.add(Calendar.DAY_OF_YEAR, newVal - oldVal);
-            updateDateControl();
-            onDateTimeChanged();
-        }
-    };
-
-    private NumberPicker.OnValueChangeListener mOnHourChangedListener = new NumberPicker.OnValueChangeListener() {
-        @Override
-        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
-            boolean isDateChanged = false;
-            Calendar cal = Calendar.getInstance();
-            if (!mIs24HourView) {
-                if (!mIsAm && oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY) {
-                    cal.setTimeInMillis(mDate.getTimeInMillis());
-                    cal.add(Calendar.DAY_OF_YEAR, 1);
-                    isDateChanged = true;
-                } else if (mIsAm && oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
-                    cal.setTimeInMillis(mDate.getTimeInMillis());
-                    cal.add(Calendar.DAY_OF_YEAR, -1);
-                    isDateChanged = true;
-                }
-                if (oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY ||
-                        oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
-                    mIsAm = !mIsAm;
-                    updateAmPmControl();
-                }
-            } else {
-                if (oldVal == HOURS_IN_ALL_DAY - 1 && newVal == 0) {
-                    cal.setTimeInMillis(mDate.getTimeInMillis());
-                    cal.add(Calendar.DAY_OF_YEAR, 1);
-                    isDateChanged = true;
-                } else if (oldVal == 0 && newVal == HOURS_IN_ALL_DAY - 1) {
-                    cal.setTimeInMillis(mDate.getTimeInMillis());
-                    cal.add(Calendar.DAY_OF_YEAR, -1);
-                    isDateChanged = true;
-                }
-            }
-            int newHour = mHourSpinner.getValue() % HOURS_IN_HALF_DAY + (mIsAm ? 0 : HOURS_IN_HALF_DAY);
-            mDate.set(Calendar.HOUR_OF_DAY, newHour);
-            onDateTimeChanged();
-            if (isDateChanged) {
-                setCurrentYear(cal.get(Calendar.YEAR));
-                setCurrentMonth(cal.get(Calendar.MONTH));
-                setCurrentDay(cal.get(Calendar.DAY_OF_MONTH));
-            }
-        }
-    };
-
-    private NumberPicker.OnValueChangeListener mOnMinuteChangedListener = new NumberPicker.OnValueChangeListener() {
-        @Override
-        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
-            int minValue = mMinuteSpinner.getMinValue();
-            int maxValue = mMinuteSpinner.getMaxValue();
-            int offset = 0;
-            if (oldVal == maxValue && newVal == minValue) {
-                offset += 1;
-            } else if (oldVal == minValue && newVal == maxValue) {
-                offset -= 1;
-            }
-            if (offset != 0) {
-                mDate.add(Calendar.HOUR_OF_DAY, offset);
-                mHourSpinner.setValue(getCurrentHour());
-                updateDateControl();
-                int newHour = getCurrentHourOfDay();
-                if (newHour >= HOURS_IN_HALF_DAY) {
-                    mIsAm = false;
-                    updateAmPmControl();
-                } else {
-                    mIsAm = true;
-                    updateAmPmControl();
-                }
-            }
-            mDate.set(Calendar.MINUTE, newVal);
-            onDateTimeChanged();
-        }
-    };
-
-    private NumberPicker.OnValueChangeListener mOnAmPmChangedListener = new NumberPicker.OnValueChangeListener() {
-        @Override
-        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
-            mIsAm = !mIsAm;
-            if (mIsAm) {
-                mDate.add(Calendar.HOUR_OF_DAY, -HOURS_IN_HALF_DAY);
-            } else {
-                mDate.add(Calendar.HOUR_OF_DAY, HOURS_IN_HALF_DAY);
-            }
-            updateAmPmControl();
-            onDateTimeChanged();
-        }
-    };
-
     public interface OnDateTimeChangedListener {
         void onDateTimeChanged(DateTimePicker view, int year, int month,
                 int dayOfMonth, int hourOfDay, int minute);
@@ -181,14 +87,91 @@ public class DateTimePicker extends FrameLayout {
         mDateSpinner = (NumberPicker) findViewById(R.id.date);
         mDateSpinner.setMinValue(DATE_SPINNER_MIN_VAL);
         mDateSpinner.setMaxValue(DATE_SPINNER_MAX_VAL);
+        NumberPicker.OnValueChangeListener mOnDateChangedListener = new NumberPicker.OnValueChangeListener() {
+            @Override
+            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
+                mDate.add(Calendar.DAY_OF_YEAR, newVal - oldVal);
+                updateDateControl();
+                onDateTimeChanged();
+            }
+        };
         mDateSpinner.setOnValueChangedListener(mOnDateChangedListener);
 
         mHourSpinner = (NumberPicker) findViewById(R.id.hour);
+        NumberPicker.OnValueChangeListener mOnHourChangedListener = new NumberPicker.OnValueChangeListener() {
+            @Override
+            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
+                boolean isDateChanged = false;
+                Calendar cal = Calendar.getInstance();
+                if (!mIs24HourView) {
+                    if (!mIsAm && oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY) {
+                        cal.setTimeInMillis(mDate.getTimeInMillis());
+                        cal.add(Calendar.DAY_OF_YEAR, 1);
+                        isDateChanged = true;
+                    } else if (mIsAm && oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
+                        cal.setTimeInMillis(mDate.getTimeInMillis());
+                        cal.add(Calendar.DAY_OF_YEAR, -1);
+                        isDateChanged = true;
+                    }
+                    if (oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY ||
+                            oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
+                        mIsAm = !mIsAm;
+                        updateAmPmControl();
+                    }
+                } else {
+                    if (oldVal == HOURS_IN_ALL_DAY - 1 && newVal == 0) {
+                        cal.setTimeInMillis(mDate.getTimeInMillis());
+                        cal.add(Calendar.DAY_OF_YEAR, 1);
+                        isDateChanged = true;
+                    } else if (oldVal == 0 && newVal == HOURS_IN_ALL_DAY - 1) {
+                        cal.setTimeInMillis(mDate.getTimeInMillis());
+                        cal.add(Calendar.DAY_OF_YEAR, -1);
+                        isDateChanged = true;
+                    }
+                }
+                int newHour = mHourSpinner.getValue() % HOURS_IN_HALF_DAY + (mIsAm ? 0 : HOURS_IN_HALF_DAY);
+                mDate.set(Calendar.HOUR_OF_DAY, newHour);
+                onDateTimeChanged();
+                if (isDateChanged) {
+                    setCurrentYear(cal.get(Calendar.YEAR));
+                    setCurrentMonth(cal.get(Calendar.MONTH));
+                    setCurrentDay(cal.get(Calendar.DAY_OF_MONTH));
+                }
+            }
+        };
         mHourSpinner.setOnValueChangedListener(mOnHourChangedListener);
         mMinuteSpinner =  (NumberPicker) findViewById(R.id.minute);
         mMinuteSpinner.setMinValue(MINUT_SPINNER_MIN_VAL);
         mMinuteSpinner.setMaxValue(MINUT_SPINNER_MAX_VAL);
         mMinuteSpinner.setOnLongPressUpdateInterval(100);
+        NumberPicker.OnValueChangeListener mOnMinuteChangedListener = new NumberPicker.OnValueChangeListener() {
+            @Override
+            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
+                int minValue = mMinuteSpinner.getMinValue();
+                int maxValue = mMinuteSpinner.getMaxValue();
+                int offset = 0;
+                if (oldVal == maxValue && newVal == minValue) {
+                    offset += 1;
+                } else if (oldVal == minValue && newVal == maxValue) {
+                    offset -= 1;
+                }
+                if (offset != 0) {
+                    mDate.add(Calendar.HOUR_OF_DAY, offset);
+                    mHourSpinner.setValue(getCurrentHour());
+                    updateDateControl();
+                    int newHour = getCurrentHourOfDay();
+                    if (newHour >= HOURS_IN_HALF_DAY) {
+                        mIsAm = false;
+                        updateAmPmControl();
+                    } else {
+                        mIsAm = true;
+                        updateAmPmControl();
+                    }
+                }
+                mDate.set(Calendar.MINUTE, newVal);
+                onDateTimeChanged();
+            }
+        };
         mMinuteSpinner.setOnValueChangedListener(mOnMinuteChangedListener);
 
         String[] stringsForAmPm = new DateFormatSymbols().getAmPmStrings();
@@ -196,6 +179,19 @@ public class DateTimePicker extends FrameLayout {
         mAmPmSpinner.setMinValue(AMPM_SPINNER_MIN_VAL);
         mAmPmSpinner.setMaxValue(AMPM_SPINNER_MAX_VAL);
         mAmPmSpinner.setDisplayedValues(stringsForAmPm);
+        NumberPicker.OnValueChangeListener mOnAmPmChangedListener = new NumberPicker.OnValueChangeListener() {
+            @Override
+            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
+                mIsAm = !mIsAm;
+                if (mIsAm) {
+                    mDate.add(Calendar.HOUR_OF_DAY, -HOURS_IN_HALF_DAY);
+                } else {
+                    mDate.add(Calendar.HOUR_OF_DAY, HOURS_IN_HALF_DAY);
+                }
+                updateAmPmControl();
+                onDateTimeChanged();
+            }
+        };
         mAmPmSpinner.setOnValueChangedListener(mOnAmPmChangedListener);
 
         // update controls to initial state
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/DateTimePickerDialog.java b/Mi/app/src/main/java/net/micode/notes/ui/DateTimePickerDialog.java
index 2c47ba4..68f5523 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/DateTimePickerDialog.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/DateTimePickerDialog.java
@@ -31,10 +31,9 @@ import android.text.format.DateUtils;
 
 public class DateTimePickerDialog extends AlertDialog implements OnClickListener {
 
-    private Calendar mDate = Calendar.getInstance();
+    private final Calendar mDate = Calendar.getInstance();
     private boolean mIs24HourView;
     private OnDateTimeSetListener mOnDateTimeSetListener;
-    private DateTimePicker mDateTimePicker;
 
     public interface OnDateTimeSetListener {
         void OnDateTimeSet(AlertDialog dialog, long date);
@@ -42,7 +41,7 @@ public class DateTimePickerDialog extends AlertDialog implements OnClickListener
 
     public DateTimePickerDialog(Context context, long date) {
         super(context);
-        mDateTimePicker = new DateTimePicker(context);
+        DateTimePicker mDateTimePicker = new DateTimePicker(context);
         setView(mDateTimePicker);
         mDateTimePicker.setOnDateTimeChangedListener(new OnDateTimeChangedListener() {
             public void onDateTimeChanged(DateTimePicker view, int year, int month,
@@ -77,7 +76,7 @@ public class DateTimePickerDialog extends AlertDialog implements OnClickListener
             DateUtils.FORMAT_SHOW_YEAR |
             DateUtils.FORMAT_SHOW_DATE |
             DateUtils.FORMAT_SHOW_TIME;
-        flag |= mIs24HourView ? DateUtils.FORMAT_24HOUR : DateUtils.FORMAT_24HOUR;
+        flag |= DateUtils.FORMAT_24HOUR;
         setTitle(DateUtils.formatDateTime(this.getContext(), date, flag));
     }
 
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/DropdownMenu.java b/Mi/app/src/main/java/net/micode/notes/ui/DropdownMenu.java
index 613dc74..e0613fe 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/DropdownMenu.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/DropdownMenu.java
@@ -28,9 +28,9 @@ import android.widget.PopupMenu.OnMenuItemClickListener;
 import net.micode.notes.R;
 
 public class DropdownMenu {
-    private Button mButton;
-    private PopupMenu mPopupMenu;
-    private Menu mMenu;
+    private final Button mButton;
+    private final PopupMenu mPopupMenu;
+    private final Menu mMenu;
 
     public DropdownMenu(Context context, Button button, int menuId) {
         mButton = button;
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/FoldersListAdapter.java b/Mi/app/src/main/java/net/micode/notes/ui/FoldersListAdapter.java
index 96b77da..f9c8c97 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/FoldersListAdapter.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/FoldersListAdapter.java
@@ -63,8 +63,8 @@ public class FoldersListAdapter extends CursorAdapter {
                 .getString(R.string.menu_move_parent_folder) : cursor.getString(NAME_COLUMN);
     }
 
-    private class FolderListItem extends LinearLayout {
-        private TextView mName;
+    private static class FolderListItem extends LinearLayout {
+        private final TextView mName;
 
         public FolderListItem(Context context) {
             super(context);
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NoteEditActivity.java b/Mi/app/src/main/java/net/micode/notes/ui/NoteEditActivity.java
index a674d7a..840e96d 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NoteEditActivity.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NoteEditActivity.java
@@ -16,6 +16,7 @@
 
 package net.micode.notes.ui;
 
+import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.app.AlarmManager;
 import android.app.AlertDialog;
@@ -52,6 +53,8 @@ import android.widget.LinearLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+
 import net.micode.notes.R;
 import net.micode.notes.data.Notes;
 import net.micode.notes.data.Notes.TextNote;
@@ -68,13 +71,14 @@ import net.micode.notes.widget.NoteWidgetProvider_4x;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Objects;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 
 public class NoteEditActivity extends Activity implements OnClickListener,
         NoteSettingChangedListener, OnTextViewChangeListener {
-    private class HeadViewHolder {
+    private static class HeadViewHolder {
         public TextView tvModified;
 
         public ImageView ivAlertIcon;
@@ -147,7 +151,6 @@ public class NoteEditActivity extends Activity implements OnClickListener,
     private LinearLayout mEditTextList;
 
     private String mUserQuery;
-    private Pattern mPattern;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -166,9 +169,9 @@ public class NoteEditActivity extends Activity implements OnClickListener,
      * user load this activity, we should restore the former state
      */
     @Override
-    protected void onRestoreInstanceState(Bundle savedInstanceState) {
+    protected void onRestoreInstanceState(@NonNull Bundle savedInstanceState) {
         super.onRestoreInstanceState(savedInstanceState);
-        if (savedInstanceState != null && savedInstanceState.containsKey(Intent.EXTRA_UID)) {
+        if (savedInstanceState.containsKey(Intent.EXTRA_UID)) {
             Intent intent = new Intent(Intent.ACTION_VIEW);
             intent.putExtra(Intent.EXTRA_UID, savedInstanceState.getLong(Intent.EXTRA_UID));
             if (!initActivityState(intent)) {
@@ -193,7 +196,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
              * Starting from the searched result
              */
             if (intent.hasExtra(SearchManager.EXTRA_DATA_KEY)) {
-                noteId = Long.parseLong(intent.getStringExtra(SearchManager.EXTRA_DATA_KEY));
+                noteId = Long.parseLong(Objects.requireNonNull(intent.getStringExtra(SearchManager.EXTRA_DATA_KEY)));
                 mUserQuery = intent.getStringExtra(SearchManager.USER_QUERY);
             }
 
@@ -205,11 +208,6 @@ public class NoteEditActivity extends Activity implements OnClickListener,
                 return false;
             } else {
                 mWorkingNote = WorkingNote.load(this, noteId);
-                if (mWorkingNote == null) {
-                    Log.e(TAG, "load note failed with note id" + noteId);
-                    finish();
-                    return false;
-                }
             }
             getWindow().setSoftInputMode(
                     WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN
@@ -235,11 +233,6 @@ public class NoteEditActivity extends Activity implements OnClickListener,
                 if ((noteId = DataUtils.getNoteIdByPhoneNumberAndCallDate(getContentResolver(),
                         phoneNumber, callDate)) > 0) {
                     mWorkingNote = WorkingNote.load(this, noteId);
-                    if (mWorkingNote == null) {
-                        Log.e(TAG, "load call note failed with note id" + noteId);
-                        finish();
-                        return false;
-                    }
                 } else {
                     mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId,
                             widgetType, bgResId);
@@ -309,7 +302,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         } else {
             mNoteHeaderHolder.tvAlertDate.setVisibility(View.GONE);
             mNoteHeaderHolder.ivAlertIcon.setVisibility(View.GONE);
-        };
+        }
     }
 
     @Override
@@ -319,7 +312,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
     }
 
     @Override
-    protected void onSaveInstanceState(Bundle outState) {
+    protected void onSaveInstanceState(@NonNull Bundle outState) {
         super.onSaveInstanceState(outState);
         /**
          * For new note without note id, we should firstly save it to
@@ -354,13 +347,10 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         view.getLocationOnScreen(location);
         int x = location[0];
         int y = location[1];
-        if (ev.getX() < x
-                || ev.getX() > (x + view.getWidth())
-                || ev.getY() < y
-                || ev.getY() > (y + view.getHeight())) {
-                    return false;
-                }
-        return true;
+        return !(ev.getX() < x)
+                && !(ev.getX() > (x + view.getWidth()))
+                && !(ev.getY() < y)
+                && !(ev.getY() > (y + view.getHeight()));
     }
 
     private void initResources() {
@@ -383,7 +373,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         for (int id : sFontSizeBtnsMap.keySet()) {
             View view = findViewById(id);
             view.setOnClickListener(this);
-        };
+        }
         mSharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
         mFontSizeId = mSharedPrefs.getInt(PREFERENCE_FONT_SIZE, ResourceParser.BG_DEFAULT_FONT_SIZE);
         /**
@@ -439,7 +429,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         } else if (sFontSizeBtnsMap.containsKey(id)) {
             findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.GONE);
             mFontSizeId = sFontSizeBtnsMap.get(id);
-            mSharedPrefs.edit().putInt(PREFERENCE_FONT_SIZE, mFontSizeId).commit();
+            mSharedPrefs.edit().putInt(PREFERENCE_FONT_SIZE, mFontSizeId).apply();
             findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
             if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
                 getWorkingText();
@@ -505,6 +495,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         return true;
     }
 
+    @SuppressLint("NonConstantResourceId")
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
@@ -609,7 +600,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
     }
 
     private boolean isSyncMode() {
-        return NotesPreferenceActivity.getSyncAccountName(this).trim().length() > 0;
+        return !NotesPreferenceActivity.getSyncAccountName(this).trim().isEmpty();
     }
 
     public void onClockAlertChanged(long date, boolean set) {
@@ -711,7 +702,8 @@ public class NoteEditActivity extends Activity implements OnClickListener,
     private Spannable getHighlightQueryResult(String fullText, String userQuery) {
         SpannableString spannable = new SpannableString(fullText == null ? "" : fullText);
         if (!TextUtils.isEmpty(userQuery)) {
-            mPattern = Pattern.compile(userQuery);
+            Pattern mPattern = Pattern.compile(userQuery);
+            assert fullText != null;
             Matcher m = mPattern.matcher(fullText);
             int start = 0;
             while (m.find(start)) {
@@ -726,7 +718,7 @@ public class NoteEditActivity extends Activity implements OnClickListener,
     }
 
     private View getListItem(String item, int index) {
-        View view = LayoutInflater.from(this).inflate(R.layout.note_edit_list_item, null);
+        @SuppressLint("InflateParams") View view = LayoutInflater.from(this).inflate(R.layout.note_edit_list_item, null);
         final NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
         edit.setTextAppearance(this, TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
         CheckBox cb = ((CheckBox) view.findViewById(R.id.cb_edit_item));
@@ -743,11 +735,11 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         if (item.startsWith(TAG_CHECKED)) {
             cb.setChecked(true);
             edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
-            item = item.substring(TAG_CHECKED.length(), item.length()).trim();
+            item = item.substring(TAG_CHECKED.length()).trim();
         } else if (item.startsWith(TAG_UNCHECKED)) {
             cb.setChecked(false);
             edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);
-            item = item.substring(TAG_UNCHECKED.length(), item.length()).trim();
+            item = item.substring(TAG_UNCHECKED.length()).trim();
         }
 
         edit.setOnTextViewChangeListener(this);
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NoteEditText.java b/Mi/app/src/main/java/net/micode/notes/ui/NoteEditText.java
index 2afe2a8..bc616e1 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NoteEditText.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NoteEditText.java
@@ -16,6 +16,7 @@
 
 package net.micode.notes.ui;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.Rect;
 import android.text.Layout;
@@ -32,6 +33,8 @@ import android.view.MenuItem.OnMenuItemClickListener;
 import android.view.MotionEvent;
 import android.widget.EditText;
 
+import androidx.annotation.NonNull;
+
 import net.micode.notes.R;
 
 import java.util.HashMap;
@@ -99,23 +102,21 @@ public class NoteEditText extends EditText {
         // TODO Auto-generated constructor stub
     }
 
+    @SuppressLint("ClickableViewAccessibility")
     @Override
     public boolean onTouchEvent(MotionEvent event) {
-        switch (event.getAction()) {
-            case MotionEvent.ACTION_DOWN:
-
-                int x = (int) event.getX();
-                int y = (int) event.getY();
-                x -= getTotalPaddingLeft();
-                y -= getTotalPaddingTop();
-                x += getScrollX();
-                y += getScrollY();
-
-                Layout layout = getLayout();
-                int line = layout.getLineForVertical(y);
-                int off = layout.getOffsetForHorizontal(line, x);
-                Selection.setSelection(getText(), off);
-                break;
+        if (event.getAction() == MotionEvent.ACTION_DOWN) {
+            int x = (int) event.getX();
+            int y = (int) event.getY();
+            x -= getTotalPaddingLeft();
+            y -= getTotalPaddingTop();
+            x += getScrollX();
+            y += getScrollY();
+
+            Layout layout = getLayout();
+            int line = layout.getLineForVertical(y);
+            int off = layout.getOffsetForHorizontal(line, x);
+            Selection.setSelection(getText(), off);
         }
 
         return super.onTouchEvent(event);
@@ -170,18 +171,14 @@ public class NoteEditText extends EditText {
     @Override
     protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
         if (mOnTextViewChangeListener != null) {
-            if (!focused && TextUtils.isEmpty(getText())) {
-                mOnTextViewChangeListener.onTextChange(mIndex, false);
-            } else {
-                mOnTextViewChangeListener.onTextChange(mIndex, true);
-            }
+            mOnTextViewChangeListener.onTextChange(mIndex, focused || !TextUtils.isEmpty(getText()));
         }
         super.onFocusChanged(focused, direction, previouslyFocusedRect);
     }
 
     @Override
     protected void onCreateContextMenu(ContextMenu menu) {
-        if (getText() instanceof Spanned) {
+        if (getText() != null) {
             int selStart = getSelectionStart();
             int selEnd = getSelectionEnd();
 
@@ -192,7 +189,7 @@ public class NoteEditText extends EditText {
             if (urls.length == 1) {
                 int defaultResId = 0;
                 for(String schema: sSchemaActionResMap.keySet()) {
-                    if(urls[0].getURL().indexOf(schema) >= 0) {
+                    if(urls[0].getURL().contains(schema)) {
                         defaultResId = sSchemaActionResMap.get(schema);
                         break;
                     }
@@ -204,7 +201,7 @@ public class NoteEditText extends EditText {
 
                 menu.add(0, 0, 0, defaultResId).setOnMenuItemClickListener(
                         new OnMenuItemClickListener() {
-                            public boolean onMenuItemClick(MenuItem item) {
+                            public boolean onMenuItemClick(@NonNull MenuItem item) {
                                 // goto a new intent
                                 urls[0].onClick(NoteEditText.this);
                                 return true;
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NoteItemData.java b/Mi/app/src/main/java/net/micode/notes/ui/NoteItemData.java
index 0f5a878..73698ea 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NoteItemData.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NoteItemData.java
@@ -26,7 +26,7 @@ import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.tool.DataUtils;
 
 
-public class NoteItemData {
+    public class NoteItemData {
     static final String [] PROJECTION = new String [] {
         NoteColumns.ID,
         NoteColumns.ALERTED_DATE,
@@ -55,13 +55,13 @@ public class NoteItemData {
     private static final int WIDGET_ID_COLUMN             = 10;
     private static final int WIDGET_TYPE_COLUMN           = 11;
 
-    private long mId;
-    private long mAlertDate;
-    private int mBgColorId;
-    private long mCreatedDate;
-    private boolean mHasAttachment;
-    private long mModifiedDate;
-    private int mNotesCount;
+    private final long mId;
+    private final long mAlertDate;
+    private final int mBgColorId;
+    private final long mCreatedDate;
+    private final boolean mHasAttachment;
+    private final long mModifiedDate;
+    private final int mNotesCount;
     private long mParentId;
     private String mSnippet;
     private int mType;
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NotesListActivity.java b/Mi/app/src/main/java/net/micode/notes/ui/NotesListActivity.java
index e843aec..3ae6c10 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NotesListActivity.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NotesListActivity.java
@@ -16,6 +16,7 @@
 
 package net.micode.notes.ui;
 
+import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Dialog;
@@ -60,6 +61,8 @@ import android.widget.PopupMenu;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+
 import net.micode.notes.R;
 import net.micode.notes.data.Notes;
 import net.micode.notes.data.Notes.NoteColumns;
@@ -93,7 +96,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
     private enum ListEditState {
         NOTE_LIST, SUB_FOLDER, CALL_RECORD_FOLDER
-    };
+    }
 
     private ListEditState mState;
 
@@ -164,17 +167,12 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             InputStream in = null;
             try {
                  in = getResources().openRawResource(R.raw.introduction);
-                if (in != null) {
-                    InputStreamReader isr = new InputStreamReader(in);
-                    BufferedReader br = new BufferedReader(isr);
-                    char [] buf = new char[1024];
-                    int len = 0;
-                    while ((len = br.read(buf)) > 0) {
-                        sb.append(buf, 0, len);
-                    }
-                } else {
-                    Log.e(TAG, "Read introduction file error");
-                    return;
+                InputStreamReader isr = new InputStreamReader(in);
+                BufferedReader br = new BufferedReader(isr);
+                char [] buf = new char[1024];
+                int len = 0;
+                while ((len = br.read(buf)) > 0) {
+                    sb.append(buf, 0, len);
                 }
             } catch (IOException e) {
                 e.printStackTrace();
@@ -195,7 +193,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
                     ResourceParser.RED);
             note.setWorkingText(sb.toString());
             if (note.saveNote()) {
-                sp.edit().putBoolean(PREFERENCE_ADD_INTRODUCTION, true).commit();
+                sp.edit().putBoolean(PREFERENCE_ADD_INTRODUCTION, true).apply();
             } else {
                 Log.e(TAG, "Save introduction note error");
                 return;
@@ -209,6 +207,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         startAsyncNotesListQuery();
     }
 
+    @SuppressLint({"ClickableViewAccessibility", "InflateParams"})
     private void initResources() {
         mContentResolver = this.getContentResolver();
         mBackgroundQueryHandler = new BackgroundQueryHandler(this.getContentResolver());
@@ -234,12 +233,11 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     private class ModeCallback implements ListView.MultiChoiceModeListener, OnMenuItemClickListener {
         private DropdownMenu mDropDownMenu;
         private ActionMode mActionMode;
-        private MenuItem mMoveMenu;
 
         public boolean onCreateActionMode(ActionMode mode, Menu menu) {
             getMenuInflater().inflate(R.menu.note_list_options, menu);
             menu.findItem(R.id.delete).setOnMenuItemClickListener(this);
-            mMoveMenu = menu.findItem(R.id.move);
+            MenuItem mMoveMenu = menu.findItem(R.id.move);
             if (mFocusNoteDataItem.getParentId() == Notes.ID_CALL_RECORD_FOLDER
                     || DataUtils.getUserFolderCount(mContentResolver) == 0) {
                 mMoveMenu.setVisible(false);
@@ -252,7 +250,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             mNotesListView.setLongClickable(false);
             mAddNewNote.setVisibility(View.GONE);
 
-            View customView = LayoutInflater.from(NotesListActivity.this).inflate(
+            @SuppressLint("InflateParams") View customView = LayoutInflater.from(NotesListActivity.this).inflate(
                     R.layout.note_list_dropdown_menu, null);
             mode.setCustomView(customView);
             mDropDownMenu = new DropdownMenu(NotesListActivity.this,
@@ -312,7 +310,8 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             updateMenu();
         }
 
-        public boolean onMenuItemClick(MenuItem item) {
+        @SuppressLint("NonConstantResourceId")
+        public boolean onMenuItemClick(@NonNull MenuItem item) {
             if (mNotesListAdapter.getSelectedCount() == 0) {
                 Toast.makeText(NotesListActivity.this, getString(R.string.menu_select_none),
                         Toast.LENGTH_SHORT).show();
@@ -348,6 +347,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
     private class NewNoteOnTouchListener implements OnTouchListener {
 
+        @SuppressLint("ClickableViewAccessibility")
         public boolean onTouch(View v, MotionEvent event) {
             switch (event.getAction()) {
                 case MotionEvent.ACTION_DOWN: {
@@ -406,7 +406,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             return false;
         }
 
-    };
+    }
 
     private void startAsyncNotesListQuery() {
         String selection = (mCurrentFolderId == Notes.ID_ROOT_FOLDER) ? ROOT_FOLDER_SELECTION
@@ -417,6 +417,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
                 }, NoteColumns.TYPE + " DESC," + NoteColumns.MODIFIED_DATE + " DESC");
     }
 
+    @SuppressLint("HandlerLeak")
     private final class BackgroundQueryHandler extends AsyncQueryHandler {
         public BackgroundQueryHandler(ContentResolver contentResolver) {
             super(contentResolver);
@@ -469,6 +470,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         this.startActivityForResult(intent, REQUEST_CODE_NEW_NODE);
     }
 
+    @SuppressLint("StaticFieldLeak")
     private void batchDelete() {
         new AsyncTask<Void, Void, HashSet<AppWidgetAttribute>>() {
             protected HashSet<AppWidgetAttribute> doInBackground(Void... unused) {
@@ -557,13 +559,10 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         mTitleBar.setVisibility(View.VISIBLE);
     }
 
+    @SuppressLint("NonConstantResourceId")
     public void onClick(View v) {
-        switch (v.getId()) {
-            case R.id.btn_new_note:
-                createNewNote();
-                break;
-            default:
-                break;
+        if (v.getId() == R.id.btn_new_note) {
+            createNewNote();
         }
     }
 
@@ -719,7 +718,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     };
 
     @Override
-    public void onContextMenuClosed(Menu menu) {
+    public void onContextMenuClosed(@NonNull Menu menu) {
         if (mNotesListView != null) {
             mNotesListView.setOnCreateContextMenuListener(null);
         }
@@ -727,7 +726,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     }
 
     @Override
-    public boolean onContextItemSelected(MenuItem item) {
+    public boolean onContextItemSelected(@NonNull MenuItem item) {
         if (mFocusNoteDataItem == null) {
             Log.e(TAG, "The long click data item is null");
             return false;
@@ -778,6 +777,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         return true;
     }
 
+    @SuppressLint("NonConstantResourceId")
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
@@ -824,6 +824,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         return true;
     }
 
+    @SuppressLint("StaticFieldLeak")
     private void exportNoteToText() {
         final BackupUtils backup = BackupUtils.getInstance(NotesListActivity.this);
         new AsyncTask<Void, Void, Integer>() {
@@ -867,7 +868,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     }
 
     private boolean isSyncMode() {
-        return NotesPreferenceActivity.getSyncAccountName(this).trim().length() > 0;
+        return !NotesPreferenceActivity.getSyncAccountName(this).trim().isEmpty();
     }
 
     private void startPreferenceActivity() {
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NotesListAdapter.java b/Mi/app/src/main/java/net/micode/notes/ui/NotesListAdapter.java
index 51c9cb9..1a1a16b 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NotesListAdapter.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NotesListAdapter.java
@@ -33,15 +33,15 @@ import java.util.Iterator;
 
 public class NotesListAdapter extends CursorAdapter {
     private static final String TAG = "NotesListAdapter";
-    private Context mContext;
-    private HashMap<Integer, Boolean> mSelectedIndex;
+    private final Context mContext;
+    private final HashMap<Integer, Boolean> mSelectedIndex;
     private int mNotesCount;
     private boolean mChoiceMode;
 
     public static class AppWidgetAttribute {
         public int widgetId;
         public int widgetType;
-    };
+    }
 
     public NotesListAdapter(Context context) {
         super(context, null);
@@ -92,8 +92,8 @@ public class NotesListAdapter extends CursorAdapter {
     public HashSet<Long> getSelectedItemIds() {
         HashSet<Long> itemSet = new HashSet<Long>();
         for (Integer position : mSelectedIndex.keySet()) {
-            if (mSelectedIndex.get(position) == true) {
-                Long id = getItemId(position);
+            if (Boolean.TRUE.equals(mSelectedIndex.get(position))) {
+                long id = getItemId(position);
                 if (id == Notes.ID_ROOT_FOLDER) {
                     Log.d(TAG, "Wrong item id, should not happen");
                 } else {
@@ -108,7 +108,7 @@ public class NotesListAdapter extends CursorAdapter {
     public HashSet<AppWidgetAttribute> getSelectedWidget() {
         HashSet<AppWidgetAttribute> itemSet = new HashSet<AppWidgetAttribute>();
         for (Integer position : mSelectedIndex.keySet()) {
-            if (mSelectedIndex.get(position) == true) {
+            if (Boolean.TRUE.equals(mSelectedIndex.get(position))) {
                 Cursor c = (Cursor) getItem(position);
                 if (c != null) {
                     AppWidgetAttribute widget = new AppWidgetAttribute();
@@ -130,13 +130,10 @@ public class NotesListAdapter extends CursorAdapter {
 
     public int getSelectedCount() {
         Collection<Boolean> values = mSelectedIndex.values();
-        if (null == values) {
-            return 0;
-        }
         Iterator<Boolean> iter = values.iterator();
         int count = 0;
         while (iter.hasNext()) {
-            if (true == iter.next()) {
+            if (iter.next()) {
                 count++;
             }
         }
@@ -152,7 +149,7 @@ public class NotesListAdapter extends CursorAdapter {
         if (null == mSelectedIndex.get(position)) {
             return false;
         }
-        return mSelectedIndex.get(position);
+        return Boolean.TRUE.equals(mSelectedIndex.get(position));
     }
 
     @Override
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NotesListItem.java b/Mi/app/src/main/java/net/micode/notes/ui/NotesListItem.java
index 1221e80..d347fb1 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NotesListItem.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NotesListItem.java
@@ -16,6 +16,7 @@
 
 package net.micode.notes.ui;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.text.format.DateUtils;
 import android.view.View;
@@ -31,12 +32,12 @@ import net.micode.notes.tool.ResourceParser.NoteItemBgResources;
 
 
 public class NotesListItem extends LinearLayout {
-    private ImageView mAlert;
-    private TextView mTitle;
-    private TextView mTime;
-    private TextView mCallName;
+    private final ImageView mAlert;
+    private final TextView mTitle;
+    private final TextView mTime;
+    private final TextView mCallName;
     private NoteItemData mItemData;
-    private CheckBox mCheckBox;
+    private final CheckBox mCheckBox;
 
     public NotesListItem(Context context) {
         super(context);
@@ -48,6 +49,7 @@ public class NotesListItem extends LinearLayout {
         mCheckBox = (CheckBox) findViewById(android.R.id.checkbox);
     }
 
+    @SuppressLint("SetTextI18n")
     public void bind(Context context, NoteItemData data, boolean choiceMode, boolean checked) {
         if (choiceMode && data.getType() == Notes.TYPE_NOTE) {
             mCheckBox.setVisibility(View.VISIBLE);
diff --git a/Mi/app/src/main/java/net/micode/notes/ui/NotesPreferenceActivity.java b/Mi/app/src/main/java/net/micode/notes/ui/NotesPreferenceActivity.java
index 07c5f7e..707b263 100644
--- a/Mi/app/src/main/java/net/micode/notes/ui/NotesPreferenceActivity.java
+++ b/Mi/app/src/main/java/net/micode/notes/ui/NotesPreferenceActivity.java
@@ -18,6 +18,7 @@ package net.micode.notes.ui;
 
 import android.accounts.Account;
 import android.accounts.AccountManager;
+import android.annotation.SuppressLint;
 import android.app.ActionBar;
 import android.app.AlertDialog;
 import android.content.BroadcastReceiver;
@@ -47,6 +48,8 @@ import net.micode.notes.data.Notes;
 import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.gtask.remote.GTaskSyncService;
 
+import java.util.Objects;
+
 
 public class NotesPreferenceActivity extends PreferenceActivity {
     public static final String PREFERENCE_NAME = "notes_preferences";
@@ -69,12 +72,13 @@ public class NotesPreferenceActivity extends PreferenceActivity {
 
     private boolean mHasAddedAccount;
 
+    @SuppressLint("UnspecifiedRegisterReceiverFlag")
     @Override
     protected void onCreate(Bundle icicle) {
         super.onCreate(icicle);
 
         /* using the app icon for navigation */
-        getActionBar().setDisplayHomeAsUpEnabled(true);
+        Objects.requireNonNull(getActionBar()).setDisplayHomeAsUpEnabled(true);
 
         addPreferencesFromResource(R.xml.preferences);
         mAccountCategory = (PreferenceCategory) findPreference(PREFERENCE_SYNC_ACCOUNT_KEY);
@@ -292,12 +296,8 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         if (!getSyncAccountName(this).equals(account)) {
             SharedPreferences settings = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
             SharedPreferences.Editor editor = settings.edit();
-            if (account != null) {
-                editor.putString(PREFERENCE_SYNC_ACCOUNT_NAME, account);
-            } else {
-                editor.putString(PREFERENCE_SYNC_ACCOUNT_NAME, "");
-            }
-            editor.commit();
+            editor.putString(PREFERENCE_SYNC_ACCOUNT_NAME, Objects.requireNonNullElse(account, ""));
+            editor.apply();
 
             // clean up last sync time
             setLastSyncTime(this, 0);
@@ -327,7 +327,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         if (settings.contains(PREFERENCE_LAST_SYNC_TIME)) {
             editor.remove(PREFERENCE_LAST_SYNC_TIME);
         }
-        editor.commit();
+        editor.apply();
 
         // clean up local gtask related info
         new Thread(new Runnable() {
@@ -351,7 +351,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
                 Context.MODE_PRIVATE);
         SharedPreferences.Editor editor = settings.edit();
         editor.putLong(PREFERENCE_LAST_SYNC_TIME, time);
-        editor.commit();
+        editor.apply();
     }
 
     public static long getLastSyncTime(Context context) {
@@ -375,14 +375,12 @@ public class NotesPreferenceActivity extends PreferenceActivity {
     }
 
     public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case android.R.id.home:
-                Intent intent = new Intent(this, NotesListActivity.class);
-                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
-                startActivity(intent);
-                return true;
-            default:
-                return false;
+        if (item.getItemId() == android.R.id.home) {
+            Intent intent = new Intent(this, NotesListActivity.class);
+            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+            startActivity(intent);
+            return true;
         }
+        return false;
     }
 }
diff --git a/Mi/app/src/main/java/net/micode/notes/widget/NoteWidgetProvider_4x.java b/Mi/app/src/main/java/net/micode/notes/widget/NoteWidgetProvider_4x.java
index c12a02e..a31bd1b 100644
--- a/Mi/app/src/main/java/net/micode/notes/widget/NoteWidgetProvider_4x.java
+++ b/Mi/app/src/main/java/net/micode/notes/widget/NoteWidgetProvider_4x.java
@@ -24,7 +24,7 @@ import net.micode.notes.data.Notes;
 import net.micode.notes.tool.ResourceParser;
 
 
-public class NoteWidgetProvider_4x extends NoteWidgetProvider {
+    public class NoteWidgetProvider_4x extends NoteWidgetProvider {
     @Override
     public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
         super.update(context, appWidgetManager, appWidgetIds);
diff --git a/Mi/app/src/main/res/layout/datetime_picker.xml b/Mi/app/src/main/res/layout/datetime_picker.xml
index f10d592..ec27d1b 100644
--- a/Mi/app/src/main/res/layout/datetime_picker.xml
+++ b/Mi/app/src/main/res/layout/datetime_picker.xml
@@ -31,7 +31,7 @@
         android:id="@+id/hour"
         android:layout_width="50dip"
         android:layout_height="wrap_content"
-        android:layout_marginLeft="5dip"
+        android:layout_marginStart="5dip"
         android:focusable="true"
         android:focusableInTouchMode="true"
         />
@@ -40,7 +40,7 @@
         android:id="@+id/minute"
         android:layout_width="50dip"
         android:layout_height="wrap_content"
-        android:layout_marginLeft="5dip"
+        android:layout_marginStart="5dip"
         android:focusable="true"
         android:focusableInTouchMode="true"
         />
@@ -49,7 +49,7 @@
         android:id="@+id/amPm"
         android:layout_width="50dip"
         android:layout_height="wrap_content"
-        android:layout_marginLeft="5dip"
+        android:layout_marginStart="5dip"
         android:focusable="true"
         android:focusableInTouchMode="true"
         />
diff --git a/Mi/app/src/main/res/layout/note_edit.xml b/Mi/app/src/main/res/layout/note_edit.xml
index 10b2aa7..4538062 100644
--- a/Mi/app/src/main/res/layout/note_edit.xml
+++ b/Mi/app/src/main/res/layout/note_edit.xml
@@ -15,7 +15,7 @@
      limitations under the License.
 -->
 
-<FrameLayout
+<FrameLayout xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:background="@drawable/list_background"
@@ -37,8 +37,9 @@
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
                 android:layout_gravity="left|center_vertical"
-                android:layout_marginRight="8dip"
-                android:textAppearance="@style/TextAppearanceSecondaryItem" />
+                android:layout_marginEnd="8dip"
+                android:textAppearance="@style/TextAppearanceSecondaryItem"
+                tools:ignore="RtlHardcoded" />
 
             <ImageView
                 android:id="@+id/iv_alert_icon"
@@ -52,8 +53,8 @@
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_gravity="center_vertical"
-                android:layout_marginLeft="2dip"
-                android:layout_marginRight="8dip"
+                android:layout_marginStart="2dip"
+                android:layout_marginEnd="8dip"
                 android:textAppearance="@style/TextAppearanceSecondaryItem" />
 
             <ImageButton
@@ -81,11 +82,13 @@
                 android:scrollbars="none"
                 android:overScrollMode="never"
                 android:layout_gravity="left|top"
-                android:fadingEdgeLength="0dip">
+                android:fadingEdgeLength="0dip"
+                tools:ignore="RtlHardcoded">
 
                 <LinearLayout
                     android:layout_width="fill_parent"
-                    android:layout_height="fill_parent">
+                    android:layout_height="wrap_content"
+                    android:orientation="horizontal">
 
                     <net.micode.notes.ui.NoteEditText
                         android:id="@+id/note_edit_view"
@@ -97,14 +100,15 @@
                         android:linksClickable="false"
                         android:minLines="12"
                         android:textAppearance="@style/TextAppearancePrimaryItem"
-                        android:lineSpacingMultiplier="1.2" />
+                        android:lineSpacingMultiplier="1.2"
+                        tools:ignore="RtlHardcoded" />
 
                     <LinearLayout
                         android:id="@+id/note_edit_list"
                         android:layout_width="fill_parent"
                         android:layout_height="wrap_content"
                         android:orientation="vertical"
-                        android:layout_marginLeft="-10dip"
+                        android:layout_marginStart="-10dip"
                         android:visibility="gone" />
                 </LinearLayout>
             </ScrollView>
@@ -121,7 +125,8 @@
         android:layout_height="43dip"
         android:layout_width="wrap_content"
         android:background="@drawable/bg_color_btn_mask"
-        android:layout_gravity="top|right" />
+        android:layout_gravity="top|right"
+        tools:ignore="RtlHardcoded" />
 
     <LinearLayout
         android:id="@+id/note_bg_color_selector"
@@ -129,9 +134,11 @@
         android:layout_height="wrap_content"
         android:background="@drawable/note_edit_color_selector_panel"
         android:layout_marginTop="30dip"
-        android:layout_marginRight="8dip"
+        android:layout_marginEnd="8dip"
         android:layout_gravity="top|right"
-        android:visibility="gone">
+        android:baselineAligned="false"
+        android:visibility="gone"
+        tools:ignore="RtlHardcoded">
 
         <FrameLayout
             android:layout_width="0dip"
@@ -151,7 +158,8 @@
                 android:layout_marginRight="5dip"
                 android:focusable="false"
                 android:visibility="gone"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -172,7 +180,8 @@
                 android:focusable="false"
                 android:visibility="gone"
                 android:layout_marginRight="3dip"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -193,7 +202,8 @@
                 android:focusable="false"
                 android:visibility="gone"
                 android:layout_marginRight="2dip"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -213,7 +223,8 @@
                 android:layout_gravity="bottom|right"
                 android:focusable="false"
                 android:visibility="gone"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -233,7 +244,8 @@
                 android:layout_gravity="bottom|right"
                 android:focusable="false"
                 android:visibility="gone"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
     </LinearLayout>
 
@@ -243,6 +255,7 @@
         android:layout_height="wrap_content"
         android:background="@drawable/font_size_selector_bg"
         android:layout_gravity="bottom"
+        android:baselineAligned="false"
         android:visibility="gone">
 
         <FrameLayout
@@ -256,7 +269,8 @@
                 android:layout_height="wrap_content"
                 android:orientation="vertical"
                 android:layout_gravity="center"
-                android:gravity="center">
+                android:gravity="center"
+                tools:ignore="UseCompoundDrawables">
 
                 <ImageView
                     android:layout_width="wrap_content"
@@ -276,11 +290,12 @@
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_gravity="bottom|right"
-                android:layout_marginRight="6dip"
+                android:layout_marginEnd="6dip"
                 android:layout_marginBottom="-7dip"
                 android:focusable="false"
                 android:visibility="gone"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -294,7 +309,8 @@
                 android:layout_height="wrap_content"
                 android:orientation="vertical"
                 android:layout_gravity="center"
-                android:gravity="center">
+                android:gravity="center"
+                tools:ignore="UseCompoundDrawables">
 
                 <ImageView
                     android:layout_width="wrap_content"
@@ -316,9 +332,10 @@
                 android:layout_gravity="bottom|right"
                 android:focusable="false"
                 android:visibility="gone"
-                android:layout_marginRight="6dip"
+                android:layout_marginEnd="6dip"
                 android:layout_marginBottom="-7dip"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -332,7 +349,8 @@
                 android:layout_height="wrap_content"
                 android:orientation="vertical"
                 android:layout_gravity="center"
-                android:gravity="center">
+                android:gravity="center"
+                tools:ignore="UseCompoundDrawables">
 
                 <ImageView
                     android:layout_width="wrap_content"
@@ -354,9 +372,10 @@
                 android:layout_gravity="bottom|right"
                 android:focusable="false"
                 android:visibility="gone"
-                android:layout_marginRight="6dip"
+                android:layout_marginEnd="6dip"
                 android:layout_marginBottom="-7dip"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
 
         <FrameLayout
@@ -370,7 +389,8 @@
                 android:layout_height="wrap_content"
                 android:orientation="vertical"
                 android:layout_gravity="center"
-                android:gravity="center">
+                android:gravity="center"
+                tools:ignore="UseCompoundDrawables">
 
                 <ImageView
                     android:layout_width="wrap_content"
@@ -392,9 +412,10 @@
                 android:layout_gravity="bottom|right"
                 android:focusable="false"
                 android:visibility="gone"
-                android:layout_marginRight="6dip"
+                android:layout_marginEnd="6dip"
                 android:layout_marginBottom="-7dip"
-                android:src="@drawable/selected" />
+                android:src="@drawable/selected"
+                tools:ignore="RtlHardcoded" />
         </FrameLayout>
     </LinearLayout>
 </FrameLayout>
diff --git a/Mi/app/src/main/res/layout/note_edit_list_item.xml b/Mi/app/src/main/res/layout/note_edit_list_item.xml
index a885f9c..02b62d0 100644
--- a/Mi/app/src/main/res/layout/note_edit_list_item.xml
+++ b/Mi/app/src/main/res/layout/note_edit_list_item.xml
@@ -17,6 +17,7 @@
 
 <LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content">
 
@@ -26,7 +27,8 @@
         android:layout_height="28dip"
         android:checked="false"
         android:focusable="false"
-        android:layout_gravity="top|left" />
+        android:layout_gravity="top|left"
+        tools:ignore="RtlHardcoded" />
 
     <net.micode.notes.ui.NoteEditText
         android:id="@+id/et_edit_text"
diff --git a/Mi/app/src/main/res/layout/note_item.xml b/Mi/app/src/main/res/layout/note_item.xml
index d541f6a..9ce1b54 100644
--- a/Mi/app/src/main/res/layout/note_item.xml
+++ b/Mi/app/src/main/res/layout/note_item.xml
@@ -17,6 +17,7 @@
 
 <FrameLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/note_item"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent">
@@ -39,7 +40,8 @@
                 android:layout_height="0dip"
                 android:layout_weight="1"
                 android:textAppearance="@style/TextAppearancePrimaryItem"
-                android:visibility="gone" />
+                android:visibility="gone"
+                tools:ignore="NestedWeights" />
 
             <LinearLayout
                 android:layout_width="fill_parent"
@@ -74,5 +76,6 @@
         android:id="@+id/iv_alert_icon"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_gravity="top|right"/>
+        android:layout_gravity="top|right"
+        tools:ignore="RtlHardcoded" />
 </FrameLayout>
diff --git a/Mi/app/src/main/res/layout/note_list.xml b/Mi/app/src/main/res/layout/note_list.xml
index 6b25d38..bb17545 100644
--- a/Mi/app/src/main/res/layout/note_list.xml
+++ b/Mi/app/src/main/res/layout/note_list.xml
@@ -45,7 +45,7 @@
             android:cacheColorHint="@null"
             android:listSelector="@android:color/transparent"
             android:divider="@null"
-            android:fadingEdge="@null" />
+            android:fadingEdge="none" />
     </LinearLayout>
 
     <Button
diff --git a/Mi/app/src/main/res/layout/note_list_dropdown_menu.xml b/Mi/app/src/main/res/layout/note_list_dropdown_menu.xml
index 3fa271d..600ffb8 100644
--- a/Mi/app/src/main/res/layout/note_list_dropdown_menu.xml
+++ b/Mi/app/src/main/res/layout/note_list_dropdown_menu.xml
@@ -17,7 +17,8 @@
 
 <LinearLayout
         xmlns:android="http://schemas.android.com/apk/res/android"
-        android:id="@+id/navigation_bar"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/navigation_bar"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="horizontal">
@@ -28,5 +29,6 @@
             android:gravity="left|center_vertical"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
-            style="?android:attr/borderlessButtonStyle" />
+            style="?android:attr/borderlessButtonStyle"
+        tools:ignore="RtlHardcoded" />
 </LinearLayout>
\ No newline at end of file
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similarity index 100%
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rename to doc/开源软件维护方案及成果 origin.docx
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