增设撤回功能，优化布局

src/main/java/ui/NoteEditActivity.java

@@ -86,11 +86,14 @@ import net.micode.notes.ui.NoteEditText.OnTextViewChangeListener;
 import net.micode.notes.widget.NoteWidgetProvider_2x;
 import net.micode.notes.widget.NoteWidgetProvider_4x;
 
+import org.w3c.dom.Text;
+
 import java.io.FileNotFoundException;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Vector;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -177,7 +180,7 @@ public class NoteEditActivity extends AppCompatActivity implements OnClickListen
     private static final int SHORTCUT_ICON_TITLE_MAX_LEN = 10;
 
     private static final int PHOTO_REQUEST=1;
-
+    private boolean mIsRvoke=false;
     public static final String TAG_CHECKED = String.valueOf('\u221A');
     public static final String TAG_UNCHECKED = String.valueOf('\u25A1');
 
@@ -190,6 +193,7 @@ public class NoteEditActivity extends AppCompatActivity implements OnClickListen
     private TextView textView;
 
 
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -220,6 +224,32 @@ public class NoteEditActivity extends AppCompatActivity implements OnClickListen
 
             }
         });
+        final ImageButton revoke = (ImageButton) findViewById(R.id.revoke);
+        revoke.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                doRevoke();
+                return;
+            }
+        });
+        mNoteEditor.addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+            }
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+
+            }
+            @Override
+            public void afterTextChanged(Editable s) {//文本更改后
+                if(!mIsRvoke) {
+                    saveMyChanged();
+                }else {
+                    mIsRvoke = false;
+                }
+            }
+
+        });
     }
 
     /**
@@ -1182,7 +1212,33 @@ public class NoteEditActivity extends AppCompatActivity implements OnClickListen
         }while (flag1 != -1);
         return stringBuffer.toString();
     }
+    private String Text_revoke(String oriText){
+        StringBuffer stringBuffer = new StringBuffer(oriText);
+        int flag1 = -1;
+        int flag2 = -1;
+        do{//不计入表示图片的字符
+            flag1 = stringBuffer.indexOf("/n");
+            flag2 = stringBuffer.indexOf("[/local]")+7;
+            if (flag1 != -1 && flag2 != -1){
+                stringBuffer = stringBuffer.replace(flag1,flag2+1,"");
+            }
+        }while (flag1 != -1 && flag2 != -1);
+
+        do{//不计入换行字符
+            flag1 = stringBuffer.indexOf("\n");
+            if (flag1 != -1){
+                stringBuffer = stringBuffer.replace(flag1,flag1+1,"");
+            }
+        }while (flag1 != -1);
 
+        do{//不计入空格字符
+            flag1 = stringBuffer.indexOf(" ");
+            if (flag1 != -1){
+                stringBuffer = stringBuffer.replace(flag1,flag1+1,"");
+            }
+        }while (flag1 != -1);
+        return stringBuffer.toString();
+    }
 
     /*
        函数功能：实现在编辑小米便签的时候计数
@@ -1416,5 +1472,40 @@ public class NoteEditActivity extends AppCompatActivity implements OnClickListen
         }
         return null;
     }
-
+    private static final int MAX_TIME_OF_RVOKE_TIME=100;
+    private int MAX_OF_RVOKE_TIME=100;
+    private Vector<SpannableString> mChanged = new Vector<SpannableString>(MAX_OF_RVOKE_TIME);
+    private void saveMyChanged(){
+        SpannableString text = new SpannableString(mNoteEditor.getText());//用getText方法获取每次编辑的内容
+        if(mChanged.size()>=MAX_TIME_OF_RVOKE_TIME){//如果栈中的数据大于最大撤销次数，就把第一次修改的内容删除
+            mChanged.removeElementAt(0);
+        }
+        mChanged.add(text);//然后把本次修改的内容加入栈中
+    }
+    private void doRevoke(){
+        int size = mChanged.size();//获取当前栈大小
+        AlertDialog.Builder dialog = new AlertDialog.Builder(this);//创建一个alertdialog窗口
+        dialog.setTitle(R.string.tips_of_revoke);//设置title信息
+        dialog.setCancelable(true);//设置为可取消
+        dialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {//只需要设置一个OK键即可
+            @Override
+            public void onClick(DialogInterface dialog, int which) {
+            }
+        });
+        mIsRvoke = true;//把是否已执行撤销的标记设置为true
+        if(size<=1){//如果栈中元素过少，打印提示信息
+            dialog.setMessage(R.string.have_not_input_anything);//提示用户您还没有输入任何信息
+            dialog.show();//显示当前alertdialog
+            return;
+        }
+        else {
+            mNoteEditor.setText((CharSequence) mChanged.elementAt(size-2));//在textview中设置撤销的内容
+            mNoteEditor.setSelection(mNoteEditor.length());
+            mChanged.removeElementAt(size-1);//删除元素
+            if(size==2){
+                dialog.setMessage(R.string.can_not_revoke);//如果只有一次操作，那么提示用户不能再撤销了
+                dialog.show();//显示当前alertdialog
+            }
+        }
+    }
 }

src/main/res/layout/note_edit.xml

@@ -42,6 +42,13 @@
 
                 android:layout_marginRight="8dip"
                 android:textAppearance="@style/TextAppearanceSecondaryItem" />
+
+            <ImageView
+                android:id="@+id/iv_alert_icon"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_gravity="center_vertical"
+                android:background="@drawable/title_alert" />
             <ImageButton
                 android:id="@+id/add_img_btn"
                 android:layout_width="30dp"
@@ -51,19 +58,15 @@
                 android:layout_gravity="center|center_vertical"
                 android:layout_marginHorizontal="@dimen/text_font_size_large"/>
             <ImageButton
-                android:id="@+id/read_note"
+                android:id="@+id/revoke"
                 android:layout_width="25dp"
                 android:layout_height="25dp"
-                android:background="@drawable/laba1"
+                android:layout_marginLeft="7dp"
+                android:background="@drawable/cehui3"
                 android:layout_gravity="center|center_vertical"
-                android:layout_marginHorizontal="@dimen/text_font_size_large" />
+                android:layout_marginHorizontal="@dimen/text_font_size_large"/>
+
 
-            <ImageView
-                android:id="@+id/iv_alert_icon"
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:layout_gravity="center_vertical"
-                android:background="@drawable/title_alert" />
 
             <TextView
                 android:id="@+id/tv_alert_date"
@@ -140,7 +143,9 @@
                         android:orientation="vertical"
                         android:layout_marginLeft="-10dip"
                         android:visibility="gone" />
+
                 </LinearLayout>
+
             </ScrollView>
 
             <ImageView
@@ -149,7 +154,13 @@
                 android:background="@drawable/bg_color_btn_mask" />
         </LinearLayout>
     </LinearLayout>
-
+    <ImageButton
+        android:id="@+id/read_note"
+        android:layout_width="100dp"
+        android:layout_height="100dp"
+        android:background="@drawable/laba1"
+        android:layout_gravity="bottom|left"
+        android:layout_marginHorizontal="@dimen/text_font_size_large" />
     <LinearLayout
         android:id="@+id/note_bg_color_selector"
         android:layout_width="wrap_content"

src/main/res/values/strings.xml

@@ -37,6 +37,9 @@
     <string name="note_link_web">Browse web</string>
     <string name="note_link_other">Open map</string>
     <!-- Text export file information -->
+    <string name="tips_of_revoke">提示</string>
+    <string name="can_not_revoke">您不能再执行撤销了</string>
+    <string name="have_not_input_anything">您还没有输入任何内容</string>
     <string name="read_note">read_note</string>
     <string name="file_path">/MIUI/notes/</string>
     <string name="file_name_txt_format">notes_%s.txt</string>