Support modal windows

athena/screen/modal_window_controller.cc

+// Copyright 2014 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 "athena/screen/modal_window_controller.h"
+
+#include "athena/screen/public/screen_manager.h"
+#include "base/message_loop/message_loop.h"
+#include "ui/aura/window.h"
+#include "ui/aura/window_property.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/layer_animation_observer.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/wm/core/window_animations.h"
+
+namespace athena {
+namespace {
+
+DEFINE_OWNED_WINDOW_PROPERTY_KEY(ModalWindowController,
+                                 kModalWindowControllerKey,
+                                 NULL);
+
+}  // namespace
+
+// static
+ModalWindowController* ModalWindowController::Get(aura::Window* container) {
+  ModalWindowController* controller =
+      container->GetProperty(kModalWindowControllerKey);
+  CHECK(controller);
+  return controller;
+}
+
+ModalWindowController::ModalWindowController(int priority)
+    : modal_container_(NULL),
+      dimmer_window_(new aura::Window(NULL)),
+      dimmed_(false) {
+  ScreenManager::ContainerParams params("ModalContainer", priority);
+  params.can_activate_children = true;
+  params.block_events = true;
+  modal_container_ = ScreenManager::Get()->CreateContainer(params);
+  modal_container_->SetProperty(kModalWindowControllerKey, this);
+
+  dimmer_window_->SetType(ui::wm::WINDOW_TYPE_NORMAL);
+  dimmer_window_->Init(aura::WINDOW_LAYER_SOLID_COLOR);
+  dimmer_window_->layer()->SetColor(SK_ColorBLACK);
+  dimmer_window_->layer()->SetOpacity(0.0f);
+  dimmer_window_->Show();
+
+  modal_container_->AddChild(dimmer_window_);
+  modal_container_->AddObserver(this);
+
+  UpdateDimmerWindowBounds();
+}
+
+ModalWindowController::~ModalWindowController() {
+  if (modal_container_)
+    modal_container_->RemoveObserver(this);
+}
+
+void ModalWindowController::OnWindowAdded(aura::Window* child) {
+  DCHECK_NE(child, dimmer_window_);
+  if (IsChildWindow(child)) {
+    child->AddObserver(this);
+    UpdateDimming(NULL);
+  }
+}
+
+void ModalWindowController::OnWindowVisibilityChanged(aura::Window* window,
+                                                      bool visible) {
+  if (IsChildWindow(window))
+    UpdateDimming(NULL);
+}
+
+void ModalWindowController::OnWindowBoundsChanged(aura::Window* window,
+                                                  const gfx::Rect& old_bounds,
+                                                  const gfx::Rect& new_bounds) {
+  if (window == modal_container_)
+    UpdateDimmerWindowBounds();
+}
+
+void ModalWindowController::OnWindowDestroyed(aura::Window* window) {
+  UpdateDimming(window);
+}
+
+bool ModalWindowController::IsChildWindow(aura::Window* child) const {
+  return child->parent() == modal_container_ && child != dimmer_window_;
+}
+
+void ModalWindowController::UpdateDimmerWindowBounds() {
+  gfx::Rect bounds(modal_container_->bounds().size());
+  dimmer_window_->SetBounds(bounds);
+}
+
+void ModalWindowController::UpdateDimming(aura::Window* ignore) {
+  if (!modal_container_ || !dimmer_window_)
+    return;
+  bool should_delete = true;
+  for (aura::Window* window : modal_container_->children()) {
+    if (window == dimmer_window_ || window == ignore)
+      continue;
+    should_delete = false;
+    if (window->TargetVisibility()) {
+      SetDimmed(true);
+      return;
+    }
+  }
+  SetDimmed(false);
+
+  if (should_delete) {
+    // Remove the container from root so that the container becomes
+    // invisible, but don't delete it until next event execution
+    // because the call stack may still have and use the pointer.
+    modal_container_->RemoveObserver(this);
+    modal_container_->parent()->RemoveChild(modal_container_);
+    base::MessageLoopForUI::current()->DeleteSoon(FROM_HERE, modal_container_);
+    modal_container_ = NULL;
+    dimmer_window_ = NULL;
+  }
+}
+
+void ModalWindowController::SetDimmed(bool dimmed) {
+  const float kDimmedOpacity = 0.4f;
+
+  if (!dimmer_window_ || dimmed_ == dimmed)
+    return;
+  dimmed_ = dimmed;
+
+  const int kDimmAnimationDurationMs = 500;
+  if (dimmed) {
+    ui::ScopedLayerAnimationSettings settings(
+        dimmer_window_->layer()->GetAnimator());
+    settings.SetTransitionDuration(
+        base::TimeDelta::FromMilliseconds(kDimmAnimationDurationMs));
+    dimmer_window_->layer()->SetOpacity(kDimmedOpacity);
+  } else {
+    // ScopedHidingAnimationSettings will detach the animating and
+    // recreate layers for the container so that animation can continue
+    // even if the container is removed immediately.
+    wm::ScopedHidingAnimationSettings settings(modal_container_);
+    settings.layer_animation_settings()->SetTransitionDuration(
+        base::TimeDelta::FromMilliseconds(kDimmAnimationDurationMs));
+    modal_container_->layer()->SetOpacity(0.0f);
+  }
+}
+
+}  // namespace athena