[[ Bug 18876 ]] Fix character duplication when deleting text on Android

livecodeian · livecodeian · commit a0219a715f92 · 2020-02-20T15:16:27.000Z
This patch fixes an issue where using the backspace key to delete text
previously entered using a virtual keyboard on Android would result in extra
text being added to the field. This was due to both our own method overrides and
the underlying BaseInputConnection class sending synthesised KeyEvents to the
field. The implementation has been revised to prevent this.
diff --git a/engine/src/java/com/runrev/android/Engine.java b/engine/src/java/com/runrev/android/Engine.java
@@ -449,17 +449,16 @@ public void setDisplayOrientation(int p_orientation)
 
 ////////////////////////////////////////////////////////////////////////////////
 
-	protected CharSequence m_composing_text;
-	
     @Override
     public InputConnection onCreateInputConnection(EditorInfo outAttrs)
     {
 		Log.i(TAG, "onCreateInputConnection()");
 		if (!m_text_editor_visible)
 			return null;
 		
-		m_composing_text = null;
-        InputConnection t_connection = new BaseInputConnection(this, false) {
+        InputConnection t_connection = new BaseInputConnection(this, true) {
+        	String m_current_text = "";
+        	
 			void handleKey(int keyCode, int charCode)
 			{
 				if (charCode == 0)
@@ -533,25 +532,26 @@ else if (key.getAction() == KeyEvent.ACTION_MULTIPLE)
 				return true;
             }
 			
-			// IM-2013-02-25: [[ BZ 10684 ]] - updated to show text changes in the field
-			// as software keyboards modify the composing text.
-			void updateComposingText(CharSequence p_new)
+			// Show text changes in the field as the composing text is modified.
+			// We do this by removing edited text with fake backspace key events
+			// and sending key events for each new character.
+			void updateComposingText()
 			{
+				String t_new = getEditable().toString();
+				
 				// send changes to the engine as a sequence of key events.
 				int t_match_length = 0;
 				int t_current_length = 0;
 				int t_new_length = 0;
 				int t_max_length = 0;
 				
-				if (m_composing_text != null)
-					t_current_length = m_composing_text.length();
-				if (p_new != null)
-					t_new_length = p_new.length();
+				t_current_length = m_current_text.length();
+				t_new_length = t_new.length();
 				
 				t_max_length = Math.min(t_current_length, t_new_length);
 				for (int i = 0; i < t_max_length; i++)
 				{
-					if (p_new.charAt(i) != m_composing_text.charAt(i))
+					if (t_new.charAt(i) != m_current_text.charAt(i))
 						break;
 					t_match_length += 1;
 				}
@@ -561,9 +561,9 @@ void updateComposingText(CharSequence p_new)
 					handleKey(KeyEvent.KEYCODE_DEL, 0);
 				// send new text
 				for (int i = t_match_length; i < t_new_length; i++)
-					handleKey(KeyEvent.KEYCODE_UNKNOWN, p_new.charAt(i));
+					handleKey(KeyEvent.KEYCODE_UNKNOWN, t_new.charAt(i));
 				
-				m_composing_text = p_new;
+				m_current_text = t_new;
 				
 				if (m_wake_on_event)
 					doProcess(false);
@@ -573,30 +573,38 @@ void updateComposingText(CharSequence p_new)
 			@Override
 			public boolean commitText(CharSequence text, int newCursorPosition)
 			{
-				updateComposingText(text);
-				m_composing_text = null;
-				getEditable().clear();
-				return true;
+				boolean t_return_value = super.commitText(text, newCursorPosition);
+				updateComposingText();
+				return t_return_value;
 			}
 			@Override
 			public boolean finishComposingText()
 			{
-				m_composing_text = null;
-				getEditable().clear();
-				return true;
+				boolean t_return_value = super.finishComposingText();
+				updateComposingText();
+				return t_return_value;
 			}
 			@Override
 			public boolean setComposingText(CharSequence text, int newCursorPosition)
 			{
-				updateComposingText(text);
-				return super.setComposingText(text, newCursorPosition);
+				boolean t_return_value =  super.setComposingText(text, newCursorPosition);
+				updateComposingText();
+				return t_return_value;
 			}
             @Override
             public boolean performEditorAction (int editorAction)
             {
                 handleKey(0, 10);
                 return true;
             }
+            
+            @Override
+            public boolean deleteSurroundingText(int beforeLength, int afterLength)
+            {
+            	boolean t_return_value = super.deleteSurroundingText(beforeLength, afterLength);
+            	updateComposingText();
+            	return t_return_value;
+            }
         };
         
 		int t_type = getInputType(false);
