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

ui/views/controls/textfield/textfield.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/textfield/textfield.h"
 
 #include <string>
 #include <utility>
 
 #include "base/trace_event/trace_event.h"
@@ skipping 220 matching lines @@
       read_only_(false),
       default_width_in_chars_(0),
       use_default_text_color_(true),
       use_default_background_color_(true),
       use_default_selection_text_color_(true),
       use_default_selection_background_color_(true),
       text_color_(SK_ColorBLACK),
       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),
       text_input_flags_(0),
       performing_user_action_(false),
       skip_input_method_cancel_composition_(false),
       drop_cursor_visible_(false),
       initiating_drag_(false),
       selection_controller_(this),
       drag_start_display_offset_(0),
@@ skipping 17 matching lines @@
   AddAccelerator(ui::Accelerator(ui::VKEY_X, ui::EF_CONTROL_DOWN));
   AddAccelerator(ui::Accelerator(ui::VKEY_C, ui::EF_CONTROL_DOWN));
   AddAccelerator(ui::Accelerator(ui::VKEY_V, ui::EF_CONTROL_DOWN));
 }
 
 Textfield::~Textfield() {
   if (GetInputMethod()) {
     // The textfield should have been blurred before destroy.
     DCHECK(this != GetInputMethod()->GetTextInputClient());
   }
+  DCHECK(!focus_manager_);
 }
 
 void Textfield::SetReadOnly(bool read_only) {
   // Update read-only without changing the focusable state (or active, etc.).
   read_only_ = read_only;
   if (GetInputMethod())
     GetInputMethod()->OnTextInputTypeChanged(this);
   SetColor(GetTextColor());
   UpdateBackgroundColor();
 }
@@ skipping 127 matching lines @@
 SkColor Textfield::GetSelectionBackgroundColor() const {
   return use_default_selection_background_color_ ?
       GetNativeTheme()->GetSystemColor(
           ui::NativeTheme::kColorId_TextfieldSelectionBackgroundFocused) :
       selection_background_color_;
 }
 
 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();
 }
 
 void Textfield::SetCursorEnabled(bool enabled) {
   GetRenderText()->SetCursorEnabled(enabled);
 }
 
 const gfx::FontList& Textfield::GetFontList() const {
   return GetRenderText()->font_list();
@@ skipping 473 matching lines @@
     touch_selection_controller_->SelectionChanged();
 }
 
 void Textfield::OnEnabledChanged() {
   View::OnEnabledChanged();
   if (GetInputMethod())
     GetInputMethod()->OnTextInputTypeChanged(this);
   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);
   OnPaintBorder(canvas);
 }
 
 void Textfield::OnFocus() {
   GetRenderText()->set_focused(true);
   if (ShouldShowCursor())
     GetRenderText()->set_cursor_visible(true);
@@ skipping 33 matching lines @@
 gfx::Point Textfield::GetKeyboardContextMenuLocation() {
   return GetCaretBounds().bottom_right();
 }
 
 void Textfield::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   gfx::RenderText* render_text = GetRenderText();
   render_text->SetColor(GetTextColor());
   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());
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Textfield, TextfieldModel::Delegate overrides:
 
 void Textfield::OnCompositionTextConfirmedOrCleared() {
   if (!skip_input_method_cancel_composition_)
     GetInputMethod()->CancelComposition(this);
 }
 
@@ skipping 56 matching lines @@
   return drag_operations;
 }
 
 bool Textfield::CanStartDragForView(View* sender,
                                     const gfx::Point& press_pt,
                                     const gfx::Point& p) {
   return initiating_drag_ && GetRenderText()->IsPointInSelection(press_pt);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// 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,
                                         gfx::DecoratedText* decorated_word,
                                         gfx::Point* baseline_point) {
   return GetRenderText()->GetDecoratedWordAtPoint(point, decorated_word,
                                                   baseline_point);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 746 matching lines @@
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
   if (text_input_type_ != ui::TEXT_INPUT_TYPE_PASSWORD) {
     ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_SELECTION)
         .WriteText(GetSelectedText());
     if (controller_)
       controller_->OnAfterCutOrCopy(ui::CLIPBOARD_TYPE_SELECTION);
   }
 #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())
     return;
   if (!clear_first)
     InsertOrReplaceText(new_value);
   else
     SetText(new_value);
   ClearSelection();
 }
@@ skipping 208 matching lines @@
 }
 
 void Textfield::OnCursorBlinkTimerFired() {
   DCHECK(ShouldBlinkCursor());
   gfx::RenderText* render_text = GetRenderText();
   render_text->set_cursor_visible(!render_text->cursor_visible());
   RepaintCursor();
 }
 
 }  // namespace views