Views: Draw Textfield selected text in gray when top-level Widget loses focus.

ui/views/controls/textfield/textfield.cc

Index: ui/views/controls/textfield/textfield.cc
diff --git a/ui/views/controls/textfield/textfield.cc b/ui/views/controls/textfield/textfield.cc
index 2ab27564ee4b4354f377bcfe825d7b0d4949d4b7..7ec42e57aeae82c7cbfc8cf868bdf2467885cc92 100644
--- a/ui/views/controls/textfield/textfield.cc
+++ b/ui/views/controls/textfield/textfield.cc
@@ -238,6 +238,7 @@ Textfield::Textfield()
       background_color_(SK_ColorWHITE),
       selection_text_color_(SK_ColorWHITE),
       selection_background_color_(SK_ColorBLUE),
+      focus_manager_(nullptr),
       placeholder_text_color_(kDefaultPlaceholderTextColor),
       invalid_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_TEXT),
@@ -275,6 +276,7 @@ Textfield::~Textfield() {
     // The textfield should have been blurred before destroy.
     DCHECK(this != GetInputMethod()->GetTextInputClient());
   }
+  DCHECK(!focus_manager_);
 }
 
 void Textfield::SetReadOnly(bool read_only) {
@@ -422,18 +424,23 @@ SkColor Textfield::GetSelectionBackgroundColor() const {
 void Textfield::SetSelectionBackgroundColor(SkColor color) {
   selection_background_color_ = color;
   use_default_selection_background_color_ = false;
-  GetRenderText()->set_selection_background_focused_color(
+  GetRenderText()->set_selection_background_color(
       GetSelectionBackgroundColor());
   SchedulePaint();
 }
 
 void Textfield::UseDefaultSelectionBackgroundColor() {
   use_default_selection_background_color_ = true;
-  GetRenderText()->set_selection_background_focused_color(
+  GetRenderText()->set_selection_background_color(
       GetSelectionBackgroundColor());
   SchedulePaint();
 }
 
+SkColor Textfield::GetUnfocusedSelectionBackgroundColor() const {
+  return GetNativeTheme()->GetSystemColor(
+      ui::NativeTheme::kColorId_TextfieldSelectionBackgroundUnfocused);
+}
+
 bool Textfield::GetCursorEnabled() const {
   return GetRenderText()->cursor_enabled();
 }
@@ -927,6 +934,30 @@ void Textfield::OnEnabledChanged() {
   SchedulePaint();
 }
 
+void Textfield::ViewHierarchyChanged(
+    const ViewHierarchyChangedDetails& details) {
+  // Textfields only care about focus changes if the entire Widget has lost
+  // focus, so don't bother listening if there is no Widget.
+  if (!GetWidget())

[tapted, 2016/11/02 03:59:14]

actually I think this `if` can be omitted. -- we can rely on GetFocusManager
will returning null. Then we don't have to worry about the case that
focus_manager_ might be non-nil here

[Patti Lor, 2016/11/07 05:34:26]

Done.

[tapted, 2016/11/07 06:14:50]

ping? (this should be redundant with the changes in ObserveWidgetFocusChanges)

But also I think it's important to be calling RemoveFocusChangeListener(this) to
handle the case where GetWidget() has _become_ null when previously it wasn't.
Otherwise |focus_manager_| may refer to a deleted object.

[Patti Lor, 2016/11/08 01:47:31]

Oops, thank you - forgot to reapply the latest patch after switching OSes.

+    return;
+
+  if (details.parent->Contains(this) && details.move_view == nullptr)
+    AddOrRemoveAsFocusChangeListener(details.is_add);
+}
+
+void Textfield::NativeViewHierarchyChanged() {
+  if (!GetWidget()) {

[tapted, 2016/11/02 03:59:14]

same here. In fact I think we can just make this entire method.

ObserveWidgetFocusChanges(true);

This should be called only rarely, and it's fine to unsubscribe, then
re-subscribe to the same FocusManager

[Patti Lor, 2016/11/07 05:34:26]

Done.

+    focus_manager_ = nullptr;
+    return;
+  }
+
+  // Update the focus manager if it's changed.
+  if (focus_manager_ != GetFocusManager()) {
+    AddOrRemoveAsFocusChangeListener(false);
+    AddOrRemoveAsFocusChangeListener(true);

[tapted, 2016/11/02 03:45:06]

I think calling with `true` should always behave as if it was called with
`false` prior.

[Patti Lor, 2016/11/07 05:34:26]

Done.

+  }
+}
+
 void Textfield::OnPaint(gfx::Canvas* canvas) {
   OnPaintBackground(canvas);
   PaintTextAndCursor(canvas);
@@ -980,8 +1011,12 @@ void Textfield::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   UpdateBackgroundColor();
   render_text->set_cursor_color(GetTextColor());
   render_text->set_selection_color(GetSelectionTextColor());
-  render_text->set_selection_background_focused_color(
-      GetSelectionBackgroundColor());
+  if (HasFocus()) {
+    render_text->set_selection_background_color(GetSelectionBackgroundColor());
+  } else {
+    render_text->set_selection_background_color(
+        GetUnfocusedSelectionBackgroundColor());
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1058,6 +1093,25 @@ bool Textfield::CanStartDragForView(View* sender,
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// Textfield, FocusChangeListener overrides:
+
+void Textfield::OnWillChangeFocus(View* focus_before, View* focus_after) {
+  if (focus_before != this && focus_after != this)
+    return;
+
+  SkColor selection_bg_color = focus_after
+                                   ? GetSelectionBackgroundColor()
+                                   : GetUnfocusedSelectionBackgroundColor();
+
+  // Selection is drawn if |this| has focus, or the Widget loses activation, but
+  // not if another View in this Widget is gaining focus.
+  GetRenderText()->set_draw_text_selection(focus_after == this || !focus_after);
+  GetRenderText()->set_selection_background_color(selection_bg_color);
+}
+
+void Textfield::OnDidChangeFocus(View* focused_before, View* focused_now) {}
+
+////////////////////////////////////////////////////////////////////////////////
 // Textfield, WordLookupClient overrides:
 
 bool Textfield::GetDecoratedWordAtPoint(const gfx::Point& point,
@@ -1824,6 +1878,19 @@ void Textfield::UpdateSelectionClipboard() {
 #endif
 }
 
+void Textfield::AddOrRemoveAsFocusChangeListener(bool add_as_listener) {
+  if (add_as_listener) {
+    FocusManager* focus_manager = GetFocusManager();
+    if (!focus_manager)
+      return;

[tapted, 2016/11/02 03:45:06]

Comment when this can occur?

[tapted, 2016/11/02 03:59:14]

(btw, I'm guessing this can occur only when Widget is null, or when
Widget::GetTopLevelWidget() returns null (i.e. for a TYPE_CONTROL widget not in
a parent Widget) - is that right?). If so, we can also say that we would be
expecting a call to NativeViewHierarchyChanged() to follow.

[Patti Lor, 2016/11/07 05:34:26]

Yeah, this happens when there's a TYPE_CONTROL Widget. I don't think it matters
if it has a parent Widget? I haven't really investigated that. I did add a
comment with info about the NativeViewHierarchyChanged() call though.

+    focus_manager_ = focus_manager;
+    focus_manager_->AddFocusChangeListener(this);
+  } else if (focus_manager_) {

[tapted, 2016/11/02 03:45:06]

I think this block can just go at the start of the method, then we don't have to
call with false prior to the calling with true. i.e.

if (focus_manager_) {
  focus_manager_->RemoveFocusChangeListener(this);
  focus_manager = nullptr;
}

if (add_as_listener) {
  focus_manager_ = GetFocusManager();
  if (!focus_manager) {
    // This can happen when XXX.
    return;
  }
  focus_manager_->AddFocusChangeListener(this);
}

[Patti Lor, 2016/11/07 05:34:26]

Done.

+    focus_manager_->RemoveFocusChangeListener(this);
+    focus_manager_ = nullptr;
+  }
+}
+
 void Textfield::AccessibilitySetValue(const base::string16& new_value,
                                       bool clear_first) {
   if (read_only())