Re-land: NativeTextfieldViews: Show the drop cursor when dragging text

ui/views/controls/textfield/native_textfield_views.cc

Index: ui/views/controls/textfield/native_textfield_views.cc
diff --git a/ui/views/controls/textfield/native_textfield_views.cc b/ui/views/controls/textfield/native_textfield_views.cc
index bb29f06ab1257eff9d1167625c2b041d14a2b634..fc69c0d5076993e0da69fbb269c870f90182efb0 100644
--- a/ui/views/controls/textfield/native_textfield_views.cc
+++ b/ui/views/controls/textfield/native_textfield_views.cc
@@ -263,8 +263,12 @@ bool NativeTextfieldViews::CanDrop(const OSExchangeData& data) {
 
 int NativeTextfieldViews::OnDragUpdated(const ui::DropTargetEvent& event) {
   DCHECK(CanDrop(event.data()));
-  bool in_selection = GetRenderText()->IsPointInSelection(event.location());
+
+  const gfx::Point& location = event.location();
+  bool in_selection = GetRenderText()->IsPointInSelection(location);
   is_drop_cursor_visible_ = !in_selection;
+  if (is_drop_cursor_visible_)
+    drop_cursor_position_ = GetRenderText()->FindCursorPosition(location);

[msw, 2013/04/15 17:14:04]

You can optionally avoid calling both FindCursorPosition and IsPointInSelection
(which also calls FindCursorPosition), but you'd probably need to expose
RangeContainsCaret (protected->public). This is really optional for this CL,
I'll take another look if you choose to do it.

[ckocagil, 2013/04/15 20:41:15]

Done.

   // TODO(msw): Pan over text when the user drags to the visible text edge.
   OnCaretBoundsChanged();
   SchedulePaint();
@@ -278,6 +282,11 @@ int NativeTextfieldViews::OnDragUpdated(const ui::DropTargetEvent& event) {
   return ui::DragDropTypes::DRAG_COPY | ui::DragDropTypes::DRAG_MOVE;
 }
 
+void NativeTextfieldViews::OnDragExited() {
+  is_drop_cursor_visible_ = false;
+  SchedulePaint();
+}
+
 int NativeTextfieldViews::OnPerformDrop(const ui::DropTargetEvent& event) {
   DCHECK(CanDrop(event.data()));
 
@@ -1081,11 +1090,15 @@ void NativeTextfieldViews::RepaintCursor() {
 void NativeTextfieldViews::PaintTextAndCursor(gfx::Canvas* canvas) {
   TRACE_EVENT0("views", "NativeTextfieldViews::PaintTextAndCursor");
   canvas->Save();
-  GetRenderText()->set_cursor_visible(is_drop_cursor_visible_ ||
-      (is_cursor_visible_ && !model_->HasSelection()));
+  GetRenderText()->set_cursor_visible(!is_drop_cursor_visible_ &&
+      is_cursor_visible_ && !model_->HasSelection());
   // Draw the text, cursor, and selection.
   GetRenderText()->Draw(canvas);
 
+  // Draw the detached drop cursor that marks where the text will be dropped.
+  if (is_drop_cursor_visible_)
+    GetRenderText()->DrawCursor(canvas, drop_cursor_position_);
+
   // Draw placeholder text if needed.
   if (model_->GetText().empty() &&
       !textfield_->placeholder_text().empty()) {