Remote assistance on Chrome OS Part V - It2MeHost Continue Window

remoting/host/chromeos/message_box.h

+// 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.
+
+#ifndef REMOTING_HOST_CHROMEOS_MESSAGE_BOX_H_
+#define REMOTING_HOST_CHROMEOS_MESSAGE_BOX_H_
+
+#include "base/memory/ref_counted.h"
+#include "ui/views/window/dialog_delegate.h"
+
+namespace remoting {
+
+// Overview:
+// Shows a system modal message box with ok and cancel buttons. This class
+// is not thread-safe.

[dcaiafa, 2014/10/31 18:05:49]

Does it have to run in a specific thread?

[kelvinp, 2014/10/31 21:12:53]

Comments added.

+//
+// Implementation details:
+// The MessageBox 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 MessageBox using the
+// DialogDelegateView interface.  DialogDelegateView must remain valid until
+// DeleteDelegate() is called, at which the DialogDelegateView deletes itself.
+// To abstract this awkward ownership model, the MessageBox object is
+// RefCounted.  It calls AddRef() on itself when the widget is created and calls
+// Release() when DeleteDelegate() is called.
+class MessageBox : public views::DialogDelegateView,
+                   public base::RefCounted<MessageBox> {
+ public:
+  enum Result {
+    OK,
+    CANCEL
+  };
+
+  // ResultCallback will be invoked with Result::Cancel if the user closes the
+  // MessageBox without clicking on any buttons.
+  typedef base::Callback<void(Result)> ResultCallback;
+
+  MessageBox(const base::string16& message_label,
+             const base::string16& ok_label,
+             const base::string16& cancel_label,
+             ResultCallback result_callback);
+
+  // Shows the message box.
+  void Show();
+  // Hides the message box.
+  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;
+  void DeleteDelegate() override;
+
+ private:
+  friend class base::RefCounted<MessageBox>;
+  ~MessageBox();

[dcaiafa, 2014/10/31 18:05:49]

~MessageBox() override;

[kelvinp, 2014/10/31 21:12:53]

Done.

+
+  const base::string16 message_label_;
+  const base::string16 ok_label_;
+  const base::string16 cancel_label_;
+  ResultCallback result_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageBox);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_CHROMEOS_MESSAGE_BOX_H_