athena: Add the concept of Activity and related managers.

athena/task/task_manager_impl.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/task/public/task_manager.h"
+
+#include "athena/screen/public/screen_manager.h"
+#include "athena/task/public/task.h"
+#include "base/strings/utf_string_conversions.h"
+#include "ui/aura/window.h"
+#include "ui/views/background.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/controls/native/native_view_host.h"
+#include "ui/views/layout/layout_manager.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
+
+namespace athena {
+
+namespace {
+
+class TaskWidget : public views::LayoutManager {
+ public:
+  explicit TaskWidget(Task* task)
+      : task_(task),
+        container_(NULL),
+        title_(NULL),
+        host_(NULL),
+        widget_(NULL) {
+    container_ = new views::View;
+
+    title_ = new views::Label();
+    title_->SetHorizontalAlignment(gfx::ALIGN_CENTER);
+    const gfx::FontList& font_list = title_->font_list();
+    title_->SetFontList(font_list.Derive(1, gfx::Font::BOLD));
+    title_->SetEnabledColor(SK_ColorBLACK);
+    title_->SetShadowColors(SK_ColorWHITE, SK_ColorWHITE);
+    title_->set_shadow_blur(.5);
+    container_->AddChildView(title_);
+    container_->SetLayoutManager(this);
+
+    host_ = new views::NativeViewHost();
+    container_->AddChildView(host_);
+
+    widget_ = new views::Widget;
+    views::Widget::InitParams params(
+        views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
+    params.parent = ScreenManager::Get()->GetContext();
+    params.delegate = NULL;
+    params.activatable = views::Widget::InitParams::ACTIVATABLE_YES;
+    widget_->Init(params);
+    widget_->SetContentsView(container_);
+
+    host_->Attach(task->GetNativeWindow());
+  }
+
+  virtual ~TaskWidget() {}
+
+  void Show() {
+    Update();
+    widget_->Show();
+  }
+
+  void Update() {
+    title_->SetText(base::UTF8ToUTF16(task_->GetTitle()));
+    title_->set_background(views::Background::CreateSolidBackground(
+        task_->GetRepresentativeColor()));
+  }
+
+ private:
+  // views::LayoutManager:
+  virtual void Layout(views::View* host) OVERRIDE {
+    CHECK_EQ(container_, host);
+    const gfx::Rect& host_bounds = host->bounds();
+    const int kTitleHeight = 25;
+    title_->SetBounds(0, 0, host_bounds.width(), kTitleHeight);
+    host_->SetBounds(0, kTitleHeight, host_bounds.width(),
+                     host_bounds.height() - kTitleHeight);
+  }
+
+  virtual gfx::Size GetPreferredSize(const views::View* host) const OVERRIDE {
+    CHECK_EQ(container_, host);
+    gfx::Size size;
+    gfx::Size label_size = title_->GetPreferredSize();
+    gfx::Size host_size = host_->GetPreferredSize();
+
+    size.set_width(std::max(label_size.width(), host_size.width()));
+    size.set_height(label_size.height() + host_size.height());
+    return size;
+  }
+
+  Task* task_;
+  views::View* container_;
+  views::Label* title_;
+  views::NativeViewHost* host_;
+  views::Widget* widget_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskWidget);
+};
+
+class TaskManagerImpl : public TaskManager {
+ public:
+  TaskManagerImpl() {}
+  virtual ~TaskManagerImpl() {}
+
+  // TaskManager:
+  virtual void AddTask(Task* task) OVERRIDE {
+    CHECK(task_widgets_.end() == task_widgets_.find(task));
+    TaskWidget* container = new TaskWidget(task);
+    task_widgets_[task] = container;
+    container->Show();
+  }
+
+  virtual void RemoveTask(Task* task) OVERRIDE {
+    std::map<Task*, TaskWidget*>::iterator find = task_widgets_.find(task);
+    if (find != task_widgets_.end())
+      task_widgets_.erase(task);
+  }
+
+  virtual void UpdateTask(Task* task) OVERRIDE {
+    std::map<Task*, TaskWidget*>::iterator find = task_widgets_.find(task);
+    if (find != task_widgets_.end())
+      find->second->Update();
+  }
+
+ private:
+  std::map<Task*, TaskWidget*> task_widgets_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskManagerImpl);
+};
+
+static TaskManagerImpl* g_instance;
+
+}  // namespace
+
+// static
+TaskManager* TaskManager::Create() {
+  CHECK(!g_instance);
+  g_instance = new TaskManagerImpl();
+  return g_instance;
+}
+
+TaskManager* TaskManager::Get() {
+  return g_instance;
+}
+
+void TaskManager::Shutdown() {
+  CHECK(g_instance);
+  delete g_instance;
+  g_instance = NULL;
+}
+
+}  // namespace athena