Support dragging panels to stack and snap.

chrome/browser/ui/views/panels/panel_stack_view.cc

Index: chrome/browser/ui/views/panels/panel_stack_view.cc
diff --git a/chrome/browser/ui/views/panels/panel_stack_view.cc b/chrome/browser/ui/views/panels/panel_stack_view.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0f98ead8974c9ca0bb278b88c5c9a87cccbfe256
--- /dev/null
+++ b/chrome/browser/ui/views/panels/panel_stack_view.cc
@@ -0,0 +1,159 @@
+// Copyright (c) 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 "chrome/browser/ui/views/panels/panel_stack_view.h"
+
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/panels/panel.h"
+#include "chrome/browser/ui/panels/stacked_panel_collection.h"
+#include "chrome/common/extensions/extension.h"
+#include "ui/gfx/rect.h"
+#include "ui/views/widget/widget.h"
+
+#if defined(OS_WIN)
+#include "chrome/browser/shell_integration.h"
+#include "ui/base/win/shell.h"
+#endif
+
+// static
+NativePanelStack* NativePanelStack::Create(
+    scoped_ptr<StackedPanelCollection> stacked_collection) {
+#if defined(OS_WIN)
+  return new PanelStackView(stacked_collection.Pass());
+#else
+  NOTIMPLEMENTED();
+  return NULL;
+#endif
+}
+
+PanelStackView::PanelStackView(
+    scoped_ptr<StackedPanelCollection> stacked_collection)
+    : stacked_collection_(stacked_collection.Pass()),
+      delay_initialized_(false),
+      window_(NULL) {
+  window_ = new views::Widget;
+  views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
+  params.delegate = this;
+  params.remove_standard_frame = true;
+  params.transparent = true;
+  // Empty size is not allowed so a temporary small size is passed. SetBounds
+  // will be called later to update the bounds.
+  params.bounds = gfx::Rect(0, 0, 1, 1);
+  window_->Init(params);
+  window_->set_frame_type(views::Widget::FRAME_TYPE_FORCE_CUSTOM);
+  window_->set_focus_on_creation(false);
+  window_->AddObserver(this);
+  window_->ShowInactive();
+}
+
+PanelStackView::~PanelStackView() {
+}
+
+void PanelStackView::EnsureInitialized() {
+  // The stack view cannot be fully initialized until the first panel has been
+  // added to the stack because we need the information from that panel.
+  if (delay_initialized_)
+    return;
+  Panel* panel = stacked_collection_->top_panel();
+  if (!panel)
+    return;
+  delay_initialized_ = true;
+
+#if defined(OS_WIN) && !defined(USE_AURA)
+  ui::win::SetAppIdForWindow(
+      ShellIntegration::GetAppModelIdForProfile(UTF8ToWide(panel->app_name()),
+                                                panel->profile()->GetPath()),
+      window_->GetNativeWindow());
+#endif
+}
+
+void PanelStackView::Close() {
+  window_->Close();
+}
+
+void PanelStackView::OnPanelAddedOrRemoved(Panel* panel) {
+  EnsureInitialized();
+
+  UpdateWindowOwnerForTaskbarIconAppearance(panel);
+
+  window_->UpdateWindowTitle();
+  window_->UpdateWindowIcon();
+}
+
+void PanelStackView::SetBounds(const gfx::Rect& bounds) {
+  window_->SetBounds(bounds);
+}
+
+string16 PanelStackView::GetWindowTitle() const {
+  Panel* panel = stacked_collection_->top_panel();
+  if (!panel)
+    return string16();
+
+  const extensions::Extension* extension = panel->GetExtension();
+  return UTF8ToUTF16(extension && !extension->name().empty() ?
+      extension->name() : panel->app_name());
+}
+
+gfx::ImageSkia PanelStackView::GetWindowAppIcon() {
+  Panel* panel = stacked_collection_->top_panel();
+  if (panel) {
+    gfx::Image app_icon = panel->app_icon();
+    if (!app_icon.IsEmpty())
+      return *app_icon.ToImageSkia();
+  }
+  return gfx::ImageSkia();
+}
+
+gfx::ImageSkia PanelStackView::GetWindowIcon() {
+  return GetWindowAppIcon();
+}
+
+views::Widget* PanelStackView::GetWidget() {
+  return window_;
+}
+
+const views::Widget* PanelStackView::GetWidget() const {
+  return window_;
+}
+
+void PanelStackView::DeleteDelegate() {
+  delete this;
+}
+
+void PanelStackView::OnWidgetClosing(views::Widget* widget) {
+  window_ = NULL;
+}
+
+void PanelStackView::UpdateWindowOwnerForTaskbarIconAppearance(Panel* panel) {
+#if defined(OS_WIN) && !defined(USE_AURA)
+  HWND panel_window = panel->GetNativeWindow();
+
+  HWND stack_window = NULL;
+  StackedPanelCollection* stack = panel->stack();
+  if (stack) {
+    stack_window = static_cast<PanelStackView*>(stack->native_stack())->
+        window_->GetNativeWindow();
+  }
+
+  // The extended style WS_EX_APPWINDOW is used to force a top-level window onto
+  // the taskbar. In order for multiple stacked panels to appear as one, this
+  // bit needs to be cleared.
+  int value = ::GetWindowLong(panel_window, GWL_EXSTYLE);
+  ::SetWindowLong(
+      panel_window,
+      GWL_EXSTYLE,
+      stack_window ? (value & ~WS_EX_APPWINDOW) : (value | WS_EX_APPWINDOW));
+
+  // All the windows that share the same owner window will appear as a single
+  // window on the taskbar.
+  ::SetWindowLong(panel_window,
+                  GWL_HWNDPARENT,
+                  reinterpret_cast<LONG>(stack_window));
+
+#else
+  NOTIMPLEMENTED();
+#endif
+}