Passthrough movement keys when theres no selection (#24581)

shell/platform/android/io/flutter/embedding/engine/systemchannels/TextInputChannel.java

@@ -735,5 +735,11 @@ public class TextInputChannel {
       this.composingStart = composingStart;
       this.composingEnd = composingEnd;
     }
+
+    public boolean hasSelection() {
+      // When selectionStart == -1, it's guaranteed that selectionEnd will also
+      // be -1.
+      return selectionStart >= 0;
+    }
   }
 }

shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java

@@ -306,57 +306,13 @@ class InputConnectionAdaptor extends BaseInputConnection
 
     if (event.getAction() == KeyEvent.ACTION_DOWN) {
       if (event.getKeyCode() == KeyEvent.KEYCODE_DPAD_LEFT) {
-        int selStart = Selection.getSelectionStart(mEditable);
-        int selEnd = Selection.getSelectionEnd(mEditable);
-        if (selStart == selEnd && !event.isShiftPressed()) {
-          int newSel = Math.max(flutterTextUtils.getOffsetBefore(mEditable, selStart), 0);
-          setSelection(newSel, newSel);
-        } else {
-          int newSelEnd = Math.max(flutterTextUtils.getOffsetBefore(mEditable, selEnd), 0);
-          setSelection(selStart, newSelEnd);
-        }
-        return true;
+        return handleHorizontalMovement(true, event.isShiftPressed());
       } else if (event.getKeyCode() == KeyEvent.KEYCODE_DPAD_RIGHT) {
-        int selStart = Selection.getSelectionStart(mEditable);
-        int selEnd = Selection.getSelectionEnd(mEditable);
-        if (selStart == selEnd && !event.isShiftPressed()) {
-          int newSel =
-              Math.min(flutterTextUtils.getOffsetAfter(mEditable, selStart), mEditable.length());
-          setSelection(newSel, newSel);
-        } else {
-          int newSelEnd =
-              Math.min(flutterTextUtils.getOffsetAfter(mEditable, selEnd), mEditable.length());
-          setSelection(selStart, newSelEnd);
-        }
-        return true;
+        return handleHorizontalMovement(false, event.isShiftPressed());
       } else if (event.getKeyCode() == KeyEvent.KEYCODE_DPAD_UP) {
-        int selStart = Selection.getSelectionStart(mEditable);
-        int selEnd = Selection.getSelectionEnd(mEditable);
-        if (selStart == selEnd && !event.isShiftPressed()) {
-          Selection.moveUp(mEditable, mLayout);
-          int newSelStart = Selection.getSelectionStart(mEditable);
-          setSelection(newSelStart, newSelStart);
-        } else {
-          Selection.extendUp(mEditable, mLayout);
-          int newSelStart = Selection.getSelectionStart(mEditable);
-          int newSelEnd = Selection.getSelectionEnd(mEditable);
-          setSelection(newSelStart, newSelEnd);
-        }
-        return true;
+        return handleVerticalMovement(true, event.isShiftPressed());
       } else if (event.getKeyCode() == KeyEvent.KEYCODE_DPAD_DOWN) {
-        int selStart = Selection.getSelectionStart(mEditable);
-        int selEnd = Selection.getSelectionEnd(mEditable);
-        if (selStart == selEnd && !event.isShiftPressed()) {
-          Selection.moveDown(mEditable, mLayout);
-          int newSelStart = Selection.getSelectionStart(mEditable);
-          setSelection(newSelStart, newSelStart);
-        } else {
-          Selection.extendDown(mEditable, mLayout);
-          int newSelStart = Selection.getSelectionStart(mEditable);
-          int newSelEnd = Selection.getSelectionEnd(mEditable);
-          setSelection(newSelStart, newSelEnd);
-        }
-        return true;
+        return handleVerticalMovement(false, event.isShiftPressed());
         // When the enter key is pressed on a non-multiline field, consider it a
         // submit instead of a newline.
       } else if ((event.getKeyCode() == KeyEvent.KEYCODE_ENTER
@@ -366,17 +322,20 @@ class InputConnectionAdaptor extends BaseInputConnection
         return true;
       } else {
         // Enter a character.
-        int character = event.getUnicodeChar();
-        if (character == 0) {
+        final int selStart = Selection.getSelectionStart(mEditable);
+        final int selEnd = Selection.getSelectionEnd(mEditable);
+        final int character = event.getUnicodeChar();
+        if (selStart < 0 || selEnd < 0 || character == 0) {
           return false;
         }
-        int selStart = Math.max(0, Selection.getSelectionStart(mEditable));
-        int selEnd = Math.max(0, Selection.getSelectionEnd(mEditable));
-        int selMin = Math.min(selStart, selEnd);
-        int selMax = Math.max(selStart, selEnd);
+
+        final int selMin = Math.min(selStart, selEnd);
+        final int selMax = Math.max(selStart, selEnd);
+        beginBatchEdit();
         if (selMin != selMax) mEditable.delete(selMin, selMax);
         mEditable.insert(selMin, String.valueOf((char) character));
         setSelection(selMin + 1, selMin + 1);
+        endBatchEdit();
         return true;
       }
     }
@@ -390,6 +349,60 @@ class InputConnectionAdaptor extends BaseInputConnection
     return false;
   }
 
+  private boolean handleHorizontalMovement(boolean isLeft, boolean isShiftPressed) {
+    final int selStart = Selection.getSelectionStart(mEditable);
+    final int selEnd = Selection.getSelectionEnd(mEditable);
+
+    if (selStart < 0 || selEnd < 0) {
+      return false;
+    }
+
+    final int newSelectionEnd =
+        isLeft
+            ? Math.max(flutterTextUtils.getOffsetBefore(mEditable, selEnd), 0)
+            : Math.min(flutterTextUtils.getOffsetAfter(mEditable, selEnd), mEditable.length());
+
+    final boolean shouldCollapse = selStart == selEnd && !isShiftPressed;
+
+    if (shouldCollapse) {
+      setSelection(newSelectionEnd, newSelectionEnd);
+    } else {
+      setSelection(selStart, newSelectionEnd);
+    }
+    return true;
+  };
+
+  private boolean handleVerticalMovement(boolean isUp, boolean isShiftPressed) {
+    final int selStart = Selection.getSelectionStart(mEditable);
+    final int selEnd = Selection.getSelectionEnd(mEditable);
+
+    if (selStart < 0 || selEnd < 0) {
+      return false;
+    }
+
+    final boolean shouldCollapse = selStart == selEnd && !isShiftPressed;
+
+    beginBatchEdit();
+    if (shouldCollapse) {
+      if (isUp) {
+        Selection.moveUp(mEditable, mLayout);
+      } else {
+        Selection.moveDown(mEditable, mLayout);
+      }
+      final int newSelection = Selection.getSelectionStart(mEditable);
+      setSelection(newSelection, newSelection);
+    } else {
+      if (isUp) {
+        Selection.extendUp(mEditable, mLayout);
+      } else {
+        Selection.extendDown(mEditable, mLayout);
+      }
+      setSelection(Selection.getSelectionStart(mEditable), Selection.getSelectionEnd(mEditable));
+    }
+    endBatchEdit();
+    return true;
+  }
+
   @Override
   public boolean performContextMenuAction(int id) {
     beginBatchEdit();

shell/platform/android/io/flutter/plugin/editing/ListenableEditingState.java

@@ -137,7 +137,7 @@ class ListenableEditingState extends SpannableStringBuilder {
     beginBatchEdit();
     replace(0, length(), newState.text);
 
-    if (newState.selectionStart >= 0) {
+    if (newState.hasSelection()) {
       Selection.setSelection(this, newState.selectionStart, newState.selectionEnd);
     } else {
       Selection.removeSelection(this);

shell/platform/android/test/io/flutter/plugin/editing/InputConnectionAdaptorTest.java

@@ -84,6 +84,7 @@ public class InputConnectionAdaptorTest {
     TextInputChannel textInputChannel = new TextInputChannel(dartExecutor);
     AndroidKeyProcessor mockKeyProcessor = mock(AndroidKeyProcessor.class);
     ListenableEditingState mEditable = new ListenableEditingState(null, testView);
+    Selection.setSelection(mEditable, 0, 0);
     ListenableEditingState spyEditable = spy(mEditable);
     EditorInfo outAttrs = new EditorInfo();
     outAttrs.inputType = InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_FLAG_MULTI_LINE;
@@ -911,6 +912,37 @@ public class InputConnectionAdaptorTest {
     assertTrue(Selection.getSelectionStart(editable) > selStart);
   }
 
+  @Test
+  public void testSendKeyEvent_MovementKeysAreNopWhenNoSelection() {
+    // Regression test for https://github.com/flutter/flutter/issues/76283.
+    ListenableEditingState editable = sampleEditable(-1, -1);
+    InputConnectionAdaptor adaptor = sampleInputConnectionAdaptor(editable);
+
+    KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_DOWN);
+    boolean didConsume = adaptor.sendKeyEvent(keyEvent);
+    assertFalse(didConsume);
+    assertEquals(Selection.getSelectionStart(editable), -1);
+    assertEquals(Selection.getSelectionEnd(editable), -1);
+
+    keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_UP);
+    didConsume = adaptor.sendKeyEvent(keyEvent);
+    assertFalse(didConsume);
+    assertEquals(Selection.getSelectionStart(editable), -1);
+    assertEquals(Selection.getSelectionEnd(editable), -1);
+
+    keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_LEFT);
+    didConsume = adaptor.sendKeyEvent(keyEvent);
+    assertFalse(didConsume);
+    assertEquals(Selection.getSelectionStart(editable), -1);
+    assertEquals(Selection.getSelectionEnd(editable), -1);
+
+    keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_RIGHT);
+    didConsume = adaptor.sendKeyEvent(keyEvent);
+    assertFalse(didConsume);
+    assertEquals(Selection.getSelectionStart(editable), -1);
+    assertEquals(Selection.getSelectionEnd(editable), -1);
+  }
+
   @Test
   public void testMethod_getExtractedText() {
     int selStart = 5;