Views: Add new SetFocusBehavior method.

ui/views/view.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.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 1181 matching lines @@
 View* View::GetPreviousFocusableView() {
   return previous_focusable_view_;
 }
 
 void View::SetNextFocusableView(View* view) {
   if (view)
     view->previous_focusable_view_ = this;
   next_focusable_view_ = view;
 }
 
-void View::SetFocusable(bool focusable) {
-  if (focusable_ == focusable)
-    return;
-
-  focusable_ = focusable;
-  AdvanceFocusIfNecessary();
+void View::SetFocusBehavior(FocusBehavior focus_behavior) {
+  switch (focus_behavior) {

[tapted, 2016/04/20 04:16:28]

since SetFocusable/SetAccessibilityFocusable are being removed from the public
API, I don't think the helpers add much.

E.g. this could be written

  bool focusable = focus_behavior == FocusBehavior::ALWAYS;
  bool accessibility_focusable = focus_behavior != FocusBehavior::NEVER;
  if (focusable == focusable_ &&
      accessibility_focusable == accessibility_focusable_)
    return;

  focusable_ = focusable;
  accessibility_focusable_ = accessibility_focusable;
  AdvanceFocusIfNecessary();


But actually I think there's no extra churn if we simply remove the two `bool`
members and replace it with a focus_behavior_ member. This method becomes even
neater, and we only need to change IsFocusable() and IsAccessibilityFocusable()
below.

i.e.

IsFocusable() {
  return focus_behaviour_ == FocusBehavior::ALWAYS && enabled_ && IsDrawn();
}

IsAccessibilityFocusable() {
  return focus_behaviour_ != FocusBehavior::NEVER && enabled_ && IsDrawn();
}


This way it's impossible to enter the meaningless state of focusable = true,
accessibilty_focusable = false.

[karandeepb, 2016/04/21 03:16:33]

Yeah should have thought of this. Thanks.

+    case FocusBehavior::ALWAYS:
+      SetFocusable(true);
+      SetAccessibilityFocusable(true);
+      break;
+    case FocusBehavior::NEVER:
+      SetFocusable(false);
+      SetAccessibilityFocusable(false);
+      break;
+    case FocusBehavior::ACCESSIBLE_ONLY:
+      SetFocusable(false);
+      SetAccessibilityFocusable(true);
+      break;
+  }
 }
 
 bool View::IsFocusable() const {
   return focusable_ && enabled_ && IsDrawn();
 }
 
 bool View::IsAccessibilityFocusable() const {
   return (focusable_ || accessibility_focusable_) && enabled_ && IsDrawn();
 }
 
-void View::SetAccessibilityFocusable(bool accessibility_focusable) {
-  if (accessibility_focusable_ == accessibility_focusable)
-    return;
-
-  accessibility_focusable_ = accessibility_focusable;
-  AdvanceFocusIfNecessary();
-}
-
 FocusManager* View::GetFocusManager() {
   Widget* widget = GetWidget();
   return widget ? widget->GetFocusManager() : NULL;
 }
 
 const FocusManager* View::GetFocusManager() const {
   const Widget* widget = GetWidget();
   return widget ? widget->GetFocusManager() : NULL;
 }
 
@@ skipping 1066 matching lines @@
     if (!leave_data_intact) {
       accelerators_->clear();
       accelerators_.reset();
     }
     registered_accelerator_count_ = 0;
   }
 }
 
 // Focus -----------------------------------------------------------------------
 
+void View::SetFocusable(bool focusable) {
+  if (focusable_ == focusable)
+    return;
+
+  focusable_ = focusable;
+  AdvanceFocusIfNecessary();
+}
+
+void View::SetAccessibilityFocusable(bool accessibility_focusable) {
+  if (accessibility_focusable_ == accessibility_focusable)
+    return;
+
+  accessibility_focusable_ = accessibility_focusable;
+  AdvanceFocusIfNecessary();
+}
+
 void View::InitFocusSiblings(View* v, int index) {
   int count = child_count();
 
   if (count == 0) {
     v->next_focusable_view_ = NULL;
     v->previous_focusable_view_ = NULL;
   } else {
     if (index == count) {
       // We are inserting at the end, but the end of the child list may not be
       // the last focusable element. Let's try to find an element with no next
@@ skipping 102 matching lines @@
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views