Added labels under the windows in OverviewMode displaying their current name.

ash/wm/overview/window_selector_item.cc

 // Copyright 2013 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 "ash/wm/overview/window_selector_item.h"
+
+#include "ash/shell.h"
+#include "ash/shell_window_ids.h"
+#include "ash/wm/overview/scoped_transform_overview_window.h"
 #include "base/auto_reset.h"
+#include "base/memory/scoped_ptr.h"
+#include "third_party/skia/include/core/SkColor.h"
 #include "ui/aura/window.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/box_layout.h"
+#include "ui/views/widget/widget.h"
 
 namespace ash {
 
+// Foreground label color.
+static const SkColor kLabelColor = SK_ColorWHITE;
+
+// Background label color.
+static const SkColor kLabelBackground = SK_ColorTRANSPARENT;
+
+// Label shadow color.
+static const SkColor kLabelShadow = 0xB0000000;
+
+// Vertical padding for the label, both over and beneath it.
+static const int kVerticalLabelPadding = 20;
+
+// Label height, i.e. distance from the border of the window to the label
+// bottom.
+static const int kLabelHeight = 20;
+
+views::Widget* CreateWindowLabel(aura::Window* root_window,
+                                 const base::string16 title) {
+  views::Widget* widget = new views::Widget;
+  views::Widget::InitParams params;
+  params.type = views::Widget::InitParams::TYPE_POPUP;
+  params.can_activate = false;
+  params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
+  params.parent =
+      Shell::GetContainer(root_window, ash::kShellWindowId_OverlayContainer);
+  params.accept_events = false;
+  widget->set_focus_on_creation(false);
+  widget->Init(params);
+  views::Label* label = new views::Label;
+  label->SetEnabledColor(kLabelColor);
+  label->SetBackgroundColor(kLabelBackground);
+  label->SetShadowColors(kLabelShadow, kLabelShadow);
+  label->SetShadowOffset(0, 1);
+  label->set_shadow_blur(10);

[flackr, 2014/04/16 02:37:10]

Seems like these should be constants as well, i.e. shadow blur and offset.

[Nina, 2014/04/16 18:19:12]

Done.

+  ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
+  label->SetFontList(bundle.GetFontList(ui::ResourceBundle::BoldFont));
+  label->SetText(title);
+  views::BoxLayout* layout = new views::BoxLayout(views::BoxLayout::kVertical,
+                                                  0,
+                                                  kVerticalLabelPadding,
+                                                  0);
+  label->SetLayoutManager(layout);
+  widget->SetContentsView(label);
+  widget->Show();
+  return widget;
+}
+
 WindowSelectorItem::WindowSelectorItem()
     : root_window_(NULL),
       in_bounds_update_(false) {
 }
 
 WindowSelectorItem::~WindowSelectorItem() {
 }
 
 void WindowSelectorItem::SetBounds(aura::Window* root_window,
                                    const gfx::Rect& target_bounds) {
   if (in_bounds_update_)
     return;
   base::AutoReset<bool> auto_reset_in_bounds_update(&in_bounds_update_, true);
   root_window_ = root_window;
   target_bounds_ = target_bounds;
   SetItemBounds(root_window, target_bounds, true);
+  UpdateWindowLabels(target_bounds);
 }
 
 void WindowSelectorItem::RecomputeWindowTransforms() {
   if (in_bounds_update_ || target_bounds_.IsEmpty())
     return;
   DCHECK(root_window_);
   base::AutoReset<bool> auto_reset_in_bounds_update(&in_bounds_update_, true);
   SetItemBounds(root_window_, target_bounds_, false);
 }
 
+void WindowSelectorItem::UpdateWindowLabels(const gfx::Rect& window_bounds) {
+  aura::Window* root_window = GetRootWindow();
+
+  gfx::Rect label_bounds(window_bounds.x(),
+                         window_bounds.y() + window_bounds.height(),
+                         window_bounds.width(),
+                         kLabelHeight);
+
+  // If the root window has changed, force the window label to be recreated
+  // and faded in on the new root window.
+  if (window_label_ &&
+      window_label_->GetNativeWindow()->GetRootWindow() != root_window) {
+    window_label_.reset();
+  }
+
+  if (!window_label_) {
+    window_label_.reset(CreateWindowLabel(GetRootWindow(),
+                                          SelectionWindow()->title()));
+    window_label_->GetNativeWindow()->SetBounds(label_bounds);
+    ui::Layer* layer = window_label_->GetNativeWindow()->layer();
+
+    layer->SetOpacity(0);
+    layer->GetAnimator()->StopAnimating();
+
+    layer->GetAnimator()->SchedulePauseForProperties(
+        base::TimeDelta::FromMilliseconds(
+            ScopedTransformOverviewWindow::kTransitionMilliseconds),
+        ui::LayerAnimationElement::OPACITY);
+
+    ui::ScopedLayerAnimationSettings settings(layer->GetAnimator());
+    settings.SetPreemptionStrategy(
+        ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
+    settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
+          ScopedTransformOverviewWindow::kFadeInMilliseconds));
+    layer->SetOpacity(1);
+  } else {
+    ui::ScopedLayerAnimationSettings settings(
+        window_label_->GetNativeWindow()->layer()->GetAnimator());
+    settings.SetPreemptionStrategy(
+        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+    settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
+        ScopedTransformOverviewWindow::kTransitionMilliseconds));
+    window_label_->GetNativeWindow()->SetBounds(label_bounds);
+  }
+
+}
+
 }  // namespace ash