添加了画板，并实现了画板的撤销，恢复，清空功能

src/main/AndroidManifest.xml

@@ -139,6 +139,13 @@
             android:theme="@android:style/Theme.Holo.Light" >
         </activity>
 
+        <activity
+            android:name="net.micode.notes.ui.BoardActivity"
+            android:label="@string/app_name"
+            android:launchMode="singleTop"
+            android:theme="@android:style/Theme.Holo.Light" >
+        </activity>
+
         <service
             android:name="net.micode.notes.gtask.remote.GTaskSyncService"
             android:exported="false" >

src/main/java/net/micode/notes/ui/NoteEditActivity.java

@@ -1002,23 +1002,23 @@ public class NoteEditActivity extends Activity implements OnClickListener,
         // DocumentProvider
         if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
             // ExternalStorageProvider
-//            if (isExternalStorageDocument(uri)) {
-//                final String docId = DocumentsContract.getDocumentId(uri);
-//                final String[] split = docId.split(":");
-//                final String type = split[0];
-//
-//                if ("primary".equalsIgnoreCase(type)) {
-//                    return Environment.getExternalStorageDirectory() + "/" + split[1];
-//                }
-//            }
-//            // DownloadsProvider
-//            else if (isDownloadsDocument(uri)) {
-//                final String id = DocumentsContract.getDocumentId(uri);
-//                final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
-//                return getDataColumn(context, contentUri, null, null);
-//            }
+            if (isExternalStorageDocument(uri)) {
+                final String docId = DocumentsContract.getDocumentId(uri);
+                final String[] split = docId.split(":");
+                final String type = split[0];
+
+                if ("primary".equalsIgnoreCase(type)) {
+                   return Environment.getExternalStorageDirectory() + "/" + split[1];
+                }
+            }
+            // DownloadsProvider
+            else if (isDownloadsDocument(uri)) {
+                final String id = DocumentsContract.getDocumentId(uri);
+                final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
+                return getDataColumn(context, contentUri, null, null);
+            }
             // MediaProvider
-//            else
+            else
                 if (isMediaDocument(uri)) {
                 final String docId = DocumentsContract.getDocumentId(uri);
                 final String[] split = docId.split(":");
@@ -1069,14 +1069,14 @@ public class NoteEditActivity extends Activity implements OnClickListener,
 
 
     //是否为外部存储文件
-//    public boolean isExternalStorageDocument(Uri uri) {
-//        return "com.android.externalstorage.documents".equals(uri.getAuthority());
-//    }
-//
-//    //是否为下载文件
-//    public boolean isDownloadsDocument(Uri uri) {
-//        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
-//    }
+    public boolean isExternalStorageDocument(Uri uri) {
+        return "com.android.externalstorage.documents".equals(uri.getAuthority());
+    }
+
+    //是否为下载文件
+    public boolean isDownloadsDocument(Uri uri) {
+        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
+    }
 
     //是否为媒体文件
     public boolean isMediaDocument(Uri uri) {

src/main/java/net/micode/notes/ui/NotesListActivity.java

@@ -55,11 +55,13 @@ import android.widget.AdapterView.OnItemClickListener;
 import android.widget.AdapterView.OnItemLongClickListener;
 import android.widget.Button;
 import android.widget.EditText;
+import android.widget.GridView;
 import android.widget.ListView;
 import android.widget.PopupMenu;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import net.micode.notes.PaintView;
 import net.micode.notes.R;
 import net.micode.notes.data.Notes;
 import net.micode.notes.data.Notes.NoteColumns;
@@ -119,6 +121,10 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
     private ModeCallback mModeCallBack;
 
+    private PaintView paintView;
+
+    private GridView paint_bottomMenu;
+
     private static final String TAG = "NotesListActivity";
 
     public static final int NOTES_LISTVIEW_SCROLL_RATE = 30;
@@ -812,6 +818,18 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             case R.id.menu_search:
                 onSearchRequested();
                 break;
+            case R.id.menu_board: {
+
+                /* 新建一个Intent对象 */
+                Intent intent = new Intent();
+                /* 指定intent要启动的类 */
+                intent.setClass(NotesListActivity.this, BoardActivity.class);
+                /* 启动一个新的Activity */
+                startActivity(intent);
+                /* 关闭当前的Activity */
+                NotesListActivity.this.finish();
+                break;
+            }
             default:
                 break;
         }

src/main/res/menu/note_list.xml

@@ -36,4 +36,8 @@
     <item
         android:id="@+id/menu_search"
         android:title="@string/menu_search"/>
+
+    <item
+        android:id="@+id/menu_board"
+        android:title="Board"/>
 </menu>