Remote assistance on Chrome OS Part V - It2MeHost Continue Window

remoting/host/chromeos/message_box.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 "remoting/host/chromeos/message_box.h"
+
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/views/controls/message_box_view.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/window/dialog_delegate.h"
+
+namespace remoting {
+
+// MessageBox::Core creates the dialog using the views::DialogWidget.  The
+// DialogWidget is created by the caller but its lifetime is managed by the
+// NativeWidget.  The DialogWidget communicates with the caller using the
+//.DialogDelegateView interface, which must remain valid until DeleteDelegate()
+// is called, at which the DialogDelegateView deletes itself.
+//
+// The Core class is introduced to abstract this awkward ownership model.  The
+// Core and the MessageBox hold a raw references to each other, which is
+// invalidated when either side are destroyed.
+class MessageBox::Core : public views::DialogDelegateView {
+ public:
+  Core(const base::string16& title_label,
+       const base::string16& message_label,
+       const base::string16& ok_label,
+       const base::string16& cancel_label,
+       ResultCallback result_callback,
+       MessageBox* message_box);
+
+  // Mirrors the public MessageBox interface.
+  void Show();
+  void Hide();
+
+  // views::DialogDelegateView interface.
+  bool Accept() override;
+  bool Cancel() override;
+  ui::ModalType GetModalType() const override;
+  base::string16 GetWindowTitle() const override;
+  base::string16 GetDialogButtonLabel(ui::DialogButton button) const override;
+
+  // views::WidgetDelegate interface.
+  views::View* GetContentsView() override;
+  views::Widget* GetWidget() override;
+  const views::Widget* GetWidget() const override;
+  void DeleteDelegate() override;
+
+  // Called by MessageBox::Core when it is destroyed.
+  void OnMessageBoxDestroyed();
+
+ private:
+  const base::string16 title_label_;
+  const base::string16 ok_label_;
+  const base::string16 cancel_label_;
+  ResultCallback result_callback_;
+  MessageBox* message_box_;
+
+  // Owned by the native widget hierarchy.
+  views::MessageBoxView* message_box_view_;
+
+  DISALLOW_COPY_AND_ASSIGN(Core);
+};
+
+MessageBox::Core::Core(const base::string16& title_label,
+                       const base::string16& message_label,
+                       const base::string16& ok_label,
+                       const base::string16& cancel_label,
+                       ResultCallback result_callback,
+                       MessageBox* message_box)
+    : title_label_(title_label),
+      ok_label_(ok_label),
+      cancel_label_(cancel_label),
+      result_callback_(result_callback),
+      message_box_(message_box),
+      message_box_view_(new views::MessageBoxView(
+          views::MessageBoxView::InitParams(message_label))) {
+  DCHECK(message_box_);
+}
+
+void MessageBox::Core::Show() {
+  // The widget is owned by the NativeWidget.  See  comments in widget.h.
+  views::Widget* widget =
+      CreateDialogWidget(this, /* delegate */
+                         nullptr /* parent window*/,
+                         nullptr /* parent view */);
+
+  if (widget) {
+    widget->Show();
+  }
+}
+
+void MessageBox::Core::Hide() {
+  if (GetWidget()) {
+    GetWidget()->Close();
+  }
+}
+
+bool MessageBox::Core::Accept() {
+  if (!result_callback_.is_null()) {
+    base::ResetAndReturn(&result_callback_).Run(OK);
+  }
+  return true /* close the window*/;
+}
+
+bool MessageBox::Core::Cancel() {
+  if (!result_callback_.is_null()) {
+    base::ResetAndReturn(&result_callback_).Run(CANCEL);
+  }
+  return true /* close the window*/;
+}
+
+ui::ModalType MessageBox::Core::GetModalType() const {
+  return ui::MODAL_TYPE_SYSTEM;
+}
+
+base::string16 MessageBox::Core::GetWindowTitle() const {
+  return title_label_;
+}
+
+base::string16 MessageBox::Core::GetDialogButtonLabel(
+    ui::DialogButton button) const {
+  switch (button) {
+    case ui::DIALOG_BUTTON_OK:
+      return ok_label_;
+    case ui::DIALOG_BUTTON_CANCEL:
+      return cancel_label_;
+    default:
+      NOTREACHED();
+      return base::string16();
+  }
+}
+
+views::View* MessageBox::Core::GetContentsView() {
+  return message_box_view_;
+}
+
+views::Widget* MessageBox::Core::GetWidget() {
+  return message_box_view_->GetWidget();
+}
+
+const views::Widget* MessageBox::Core::GetWidget() const {
+  return message_box_view_->GetWidget();
+}
+
+void MessageBox::Core::DeleteDelegate() {
+  if (message_box_) {
+    message_box_->core_ = nullptr;
+  }
+  delete this;
+}
+
+void MessageBox::Core::OnMessageBoxDestroyed() {
+  DCHECK(message_box_);
+  message_box_ = nullptr;
+  // The callback should not be invoked after MessageBox is destroyed.
+  result_callback_.Reset();
+}
+
+MessageBox::MessageBox(const base::string16& title_label,
+                       const base::string16& message_label,
+                       const base::string16& ok_label,
+                       const base::string16& cancel_label,
+                       ResultCallback result_callback)
+    : core_(new Core(title_label,
+                     message_label,
+                     ok_label,
+                     cancel_label,
+                     result_callback,
+                     this)) {
+  thread_checker_.DetachFromThread();
+}
+
+MessageBox::~MessageBox() {
+  if (core_) {
+    core_->OnMessageBoxDestroyed();
+    core_->Hide();
+    core_ = nullptr;
+  }
+}
+
+void MessageBox::Show() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  core_->Show();
+}
+
+void MessageBox::Hide() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (core_) {
+    core_->Hide();
+  }
+}
+
+}  // namespace remoting