Cache floating cursor location on start event instead of update (#62415)

packages/flutter/lib/src/widgets/editable_text.dart

@@ -1623,7 +1623,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
   // cursor.
   TextPosition _lastTextPosition;
 
-  // The offset of the floating cursor as determined from the first update call.
+  // The offset of the floating cursor as determined from the start call.
   Offset _pointOffsetOrigin;
 
   // The most recent position of the floating cursor.
@@ -1642,22 +1642,24 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
           _floatingCursorResetController.stop();
           _onFloatingCursorResetTick();
         }
+        // We want to send in points that are centered around a (0,0) origin, so
+        // we cache the position.
+        _pointOffsetOrigin = point.offset;
+
         final TextPosition currentTextPosition = TextPosition(offset: renderEditable.selection.baseOffset);
         _startCaretRect = renderEditable.getLocalRectForCaret(currentTextPosition);
-        renderEditable.setFloatingCursor(point.state, _startCaretRect.center - _floatingCursorOffset, currentTextPosition);
+
+        _lastBoundedOffset = _startCaretRect.center - _floatingCursorOffset;
+        _lastTextPosition = currentTextPosition;
+        renderEditable.setFloatingCursor(point.state, _lastBoundedOffset, _lastTextPosition);
         break;
       case FloatingCursorDragState.Update:
-        // We want to send in points that are centered around a (0,0) origin, so we cache the
-        // position on the first update call.
-        if (_pointOffsetOrigin != null) {
-          final Offset centeredPoint = point.offset - _pointOffsetOrigin;
-          final Offset rawCursorOffset = _startCaretRect.center + centeredPoint - _floatingCursorOffset;
-          _lastBoundedOffset = renderEditable.calculateBoundedFloatingCursorOffset(rawCursorOffset);
-          _lastTextPosition = renderEditable.getPositionForPoint(renderEditable.localToGlobal(_lastBoundedOffset + _floatingCursorOffset));
-          renderEditable.setFloatingCursor(point.state, _lastBoundedOffset, _lastTextPosition);
-        } else {
-          _pointOffsetOrigin = point.offset;
-        }
+        final Offset centeredPoint = point.offset - _pointOffsetOrigin;
+        final Offset rawCursorOffset = _startCaretRect.center + centeredPoint - _floatingCursorOffset;
+
+        _lastBoundedOffset = renderEditable.calculateBoundedFloatingCursorOffset(rawCursorOffset);
+        _lastTextPosition = renderEditable.getPositionForPoint(renderEditable.localToGlobal(_lastBoundedOffset + _floatingCursorOffset));
+        renderEditable.setFloatingCursor(point.state, _lastBoundedOffset, _lastTextPosition);
         break;
       case FloatingCursorDragState.End:
         // We skip animation if no update has happened.

packages/flutter/test/widgets/editable_text_cursor_test.dart

@@ -398,13 +398,9 @@ void main() {
     expect(controller.selection.baseOffset, 29);
 
     final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start));
-
-    expect(controller.selection.baseOffset, 29);
 
     // Sets the origin.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
-        offset: const Offset(20, 20)));
+    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start, offset: const Offset(20, 20)));
 
     expect(controller.selection.baseOffset, 29);
 
@@ -427,10 +423,9 @@ void main() {
     expect(controller.selection.baseOffset, 8);
 
     // Go in the other direction.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start));
+
     // Sets the origin.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
-        offset: const Offset(20, 20)));
+    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start, offset: const Offset(20, 20)));
 
     editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
         offset: const Offset(-5000, 20)));
@@ -482,13 +477,9 @@ void main() {
     expect(controller.selection.baseOffset, 29);
 
     final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start));
-
-    expect(controller.selection.baseOffset, 29);
 
     // Sets the origin.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
-      offset: const Offset(20, 20)));
+    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start, offset: const Offset(20, 20)));
 
     expect(controller.selection.baseOffset, 29);
 
@@ -583,13 +574,9 @@ void main() {
     expect(controller.selection.baseOffset, 29);
 
     final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start));
-
-    expect(controller.selection.baseOffset, 29);
 
     // Sets the origin.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
-      offset: const Offset(20, 20)));
+    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start, offset: const Offset(20, 20)));
 
     expect(controller.selection.baseOffset, 29);
 
@@ -603,13 +590,11 @@ void main() {
     editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.End));
     // Immediately start a new floating cursor, in the same way as happens when
     // the user tries to select text in trackpad mode.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start));
+    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Start, offset: const Offset(20, 20)));
     await tester.pumpAndSettle();
 
     // Set and move the second cursor like a selection. Previously, the second
     // Update here caused a crash.
-    editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
-      offset: const Offset(20, 20)));
     editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.Update,
       offset: const Offset(-250, 20)));
     editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.End));
@@ -676,13 +661,7 @@ void main() {
 
     final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
     editableTextState.updateFloatingCursor(
-      RawFloatingCursorPoint(state: FloatingCursorDragState.Start),
-    );
-    editableTextState.updateFloatingCursor(
-      RawFloatingCursorPoint(
-        state: FloatingCursorDragState.Update,
-        offset: const Offset(20, 20),
-      ),
+      RawFloatingCursorPoint(state: FloatingCursorDragState.Start, offset: const Offset(20, 20)),
     );
     await tester.pump();