chrome/browser/tab_contents/infobar_delegate.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_TAB_CONTENTS_INFOBAR_DELEGATE_H_
#define CHROME_BROWSER_TAB_CONTENTS_INFOBAR_DELEGATE_H_
#pragma once

#include "base/basictypes.h"
#include "base/string16.h"
#include "content/browser/tab_contents/navigation_controller.h"
#include "webkit/glue/window_open_disposition.h"

class ConfirmInfoBarDelegate;
class ExtensionInfoBarDelegate;
class InfoBar;
class LinkInfoBarDelegate;
class PluginInstallerInfoBarDelegate;
class SkBitmap;
class ThemeInstalledInfoBarDelegate;
class TranslateInfoBarDelegate;

// An interface implemented by objects wishing to control an InfoBar.
// Implementing this interface is not sufficient to use an InfoBar, since it
// does not map to a specific InfoBar type. Instead, you must implement either
// LinkInfoBarDelegate or ConfirmInfoBarDelegate, or override with your own
// delegate for your own InfoBar variety.
//
// --- WARNING ---
// When creating your InfoBarDelegate subclass, it is recommended that you
// design it such that you instantiate a brand new delegate for every call to
// AddInfoBar, rather than re-using/sharing a delegate object. Otherwise,
// you need to consider the fact that more than one InfoBar instance can exist
// and reference the same delegate -- even though it is also true that we only
// ever fully show one infobar (they don't stack). The dual-references occur
// because a second InfoBar can be added while the first one is in the process
// of closing (the animations). This can cause problems because when the first
// one does finally fully close InfoBarDelegate::InfoBarClosed() is called,
// and the delegate is free to clean itself up or reset state, which may have
// fatal consequences for the InfoBar that was in the process of opening (or is
// now fully opened) -- it is referencing a delegate that may not even exist
// anymore.
// As such, it is generally much safer to dedicate a delegate instance to
// AddInfoBar!
class InfoBarDelegate {
 public:
  // The type of the infobar. It controls its appearance, such as its background
  // color.
  enum Type {
    WARNING_TYPE,
    PAGE_ACTION_TYPE,
  };

  virtual ~InfoBarDelegate();

  // Called to create the InfoBar. Implementation of this method is
  // platform-specific.
  virtual InfoBar* CreateInfoBar() = 0;

  // Returns true if the supplied |delegate| is equal to this one. Equality is
  // left to the implementation to define. This function is called by the
  // TabContents when determining whether or not a delegate should be added
  // because a matching one already exists. If this function returns true, the
  // TabContents will not add the new delegate because it considers one to
  // already be present.
  virtual bool EqualsDelegate(InfoBarDelegate* delegate) const;

  // Returns true if the InfoBar should be closed automatically after the page
  // is navigated. The default behavior is to return true if the page is
  // navigated somewhere else or reloaded.
  virtual bool ShouldExpire(
      const NavigationController::LoadCommittedDetails& details) const;

  // Called when the user clicks on the close button to dismiss the infobar.
  virtual void InfoBarDismissed();

  // Called after the InfoBar is closed. The delegate is free to delete itself
  // at this point.
  virtual void InfoBarClosed();

  // Return the icon to be shown for this InfoBar. If the returned bitmap is
  // NULL, no icon is shown.
  virtual SkBitmap* GetIcon() const;

  // Returns the type of the infobar.  The type determines the appearance (such
  // as background color) of the infobar.
  virtual Type GetInfoBarType() const;

  // Type-checking downcast routines:
  virtual ConfirmInfoBarDelegate* AsConfirmInfoBarDelegate();
  virtual ExtensionInfoBarDelegate* AsExtensionInfoBarDelegate();
  virtual LinkInfoBarDelegate* AsLinkInfoBarDelegate();
  virtual PluginInstallerInfoBarDelegate* AsPluginInstallerInfoBarDelegate();
  virtual ThemeInstalledInfoBarDelegate* AsThemePreviewInfobarDelegate();
  virtual TranslateInfoBarDelegate* AsTranslateInfoBarDelegate();

 protected:
  // Provided to subclasses as a convenience to initialize the state of this
  // object. If |contents| is non-NULL, its active entry's unique ID will be
  // stored using StoreActiveEntryUniqueID automatically.
  explicit InfoBarDelegate(TabContents* contents);

  // Store the unique id for the active entry in the specified TabContents, to
  // be used later upon navigation to determine if this InfoBarDelegate should
  // be expired from |contents_|.
  void StoreActiveEntryUniqueID(TabContents* contents);

 private:
  // The unique id of the active NavigationEntry of the TabContents that we were
  // opened for. Used to help expire on navigations.
  int contents_unique_id_;

  DISALLOW_COPY_AND_ASSIGN(InfoBarDelegate);
};

#endif  // CHROME_BROWSER_TAB_CONTENTS_INFOBAR_DELEGATE_H_