Implement input type=color UI

chrome/browser/ui/views/base_shell_dialog_win.h

+// Copyright (c) 2011 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_
+#pragma once
+
+#include <set>
+
+#include "chrome/browser/ui/base_shell_dialog.h"
+#include "base/threading/thread.h"
+#include <shlobj.h>
+
+// Helpers to show certain types of Windows shell dialogs in a way that doesn't
+// block the UI of the entire app.
+
+class ShellDialogThread : public base::Thread {
+ public:
+  ShellDialogThread() : base::Thread("Chrome_ShellDialogThread") { }
+  ~ShellDialogThread() {
+    Stop();
+  }
+
+ protected:
+  void Init() {
+    // Initializes the COM library on the current thread.
+    CoInitialize(NULL);
+  }
+
+  void CleanUp() {
+    // Closes the COM library on the current thread. CoInitialize must
+    // be balanced by a corresponding call to CoUninitialize.
+    CoUninitialize();
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ShellDialogThread);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// 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:
+  // 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.
+  typedef std::set<HWND> Owners;
+  static Owners owners_;
+  static int instance_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(BaseShellDialogImpl);
+};
+
+#endif  // CHROME_BROWSER_UI_VIEWS_BASE_SHELL_DIALOG_WIN_H_