Part 3 of Move SelectFileDialog implementation to ui/base/dialogs/

chrome/browser/ui/views/base_shell_dialog_win.h

-// Copyright (c) 2012 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 CHROME_BROWSER_UI_VIEWS_BASE_SHELL_DIALOG_WIN_H_
-#define CHROME_BROWSER_UI_VIEWS_BASE_SHELL_DIALOG_WIN_H_
-
-#include <shlobj.h>
-#include <set>
-
-#include "ui/base/dialogs/base_shell_dialog.h"
-
-namespace base {
-class Thread;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// A base class for all shell dialog implementations that handles showing a
-// shell dialog modally on its own thread.
-class BaseShellDialogImpl {
- public:
-  BaseShellDialogImpl();
-  virtual ~BaseShellDialogImpl();
-
- protected:
-  // Represents a run of a dialog.
-  struct RunState {
-    // Owning HWND, may be null.
-    HWND owner;
-
-    // Thread dialog is run on.
-    base::Thread* dialog_thread;
-  };
-
-  // Called at the beginning of a modal dialog run. Disables the owner window
-  // and tracks it. Returns the message loop of the thread that the dialog will
-  // be run on.
-  RunState BeginRun(HWND owner);
-
-  // Cleans up after a dialog run. If the run_state has a valid HWND this makes
-  // sure that the window is enabled. This is essential because BeginRun
-  // aggressively guards against multiple modal dialogs per HWND. Must be called
-  // on the UI thread after the result of the dialog has been determined.
-  //
-  // In addition this deletes the Thread in RunState.
-  void EndRun(RunState run_state);
-
-  // Returns true if a modal shell dialog is currently active for the specified
-  // owner. Must be called on the UI thread.
-  bool IsRunningDialogForOwner(HWND owner) const;
-
-  // Disables the window |owner|. Can be run from either the ui or the dialog
-  // thread. Can be called on either the UI or the dialog thread. This function
-  // is called on the dialog thread after the modal Windows Common dialog
-  // functions return because Windows automatically re-enables the owning
-  // window when those functions return, but we don't actually want them to be
-  // re-enabled until the response of the dialog propagates back to the UI
-  // thread, so we disable the owner manually after the Common dialog function
-  // returns.
-  void DisableOwner(HWND owner);
-
- private:
-  typedef std::set<HWND> Owners;
-
-  // Creates a thread to run a shell dialog on. Each dialog requires its own
-  // thread otherwise in some situations where a singleton owns a single
-  // instance of this object we can have a situation where a modal dialog in
-  // one window blocks the appearance of a modal dialog in another.
-  static base::Thread* CreateDialogThread();
-
-  // Enables the window |owner_|. Can only be run from the ui thread.
-  void EnableOwner(HWND owner);
-
-  // A list of windows that currently own active shell dialogs for this
-  // instance. For example, if the DownloadManager owns an instance of this
-  // object and there are two browser windows open both with Save As dialog
-  // boxes active, this list will consist of the two browser windows' HWNDs.
-  // The derived class must call EndRun once the dialog is done showing to
-  // remove the owning HWND from this list.
-  // This object is static since it is maintained for all instances of this
-  // object - i.e. you can't have two file pickers open for the
-  // same owner, even though they might be represented by different instances
-  // of this object.
-  // This set only contains non-null HWNDs. NULL hwnds are not added to this
-  // list.
-  static Owners owners_;
-  static int instance_count_;
-
-  DISALLOW_COPY_AND_ASSIGN(BaseShellDialogImpl);
-};
-
-#endif  // CHROME_BROWSER_UI_VIEWS_BASE_SHELL_DIALOG_WIN_H_