// Copyright (c) 2006-2008 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_INFOBAR_DELEGATE_H_
#define CHROME_BROWSER_INFOBAR_DELEGATE_H_

#include <string>

#include "base/basictypes.h"
#include "chrome/browser/navigation_controller.h"
#include "skia/include/SkBitmap.h"

class AlertInfoBarDelegate;
class ConfirmInfoBarDelegate;
class InfoBar;
class LinkInfoBarDelegate;

// 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
// AlertInfoBarDelegate or ConfirmInfoBarDelegate, or override with your own
// delegate for your own InfoBar variety.
class InfoBarDelegate {
 public:
  // 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 {
    return false;
  }

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

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

  // Returns a pointer to the AlertInfoBarDelegate interface, if implemented.
  virtual AlertInfoBarDelegate* AsAlertInfoBarDelegate() {
    return NULL;
  }

  // Returns a pointer to the LinkInfoBarDelegate interface, if implemented.
  virtual LinkInfoBarDelegate* AsLinkInfoBarDelegate() {
    return NULL;
  }

  // Returns a pointer to the ConfirmInfoBarDelegate interface, if implemented.
  virtual ConfirmInfoBarDelegate* AsConfirmInfoBarDelegate() {
    return NULL;
  }

 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 taht we were
  // opened for. Used to help expire on navigations.
  int contents_unique_id_;

  DISALLOW_COPY_AND_ASSIGN(InfoBarDelegate);
};

// An interface derived from InfoBarDelegate implemented by objects wishing to
// control an AlertInfoBar.
class AlertInfoBarDelegate : public InfoBarDelegate {
 public:
  // Returns the message string to be displayed for the InfoBar.
  virtual std::wstring GetMessageText() const = 0;

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

  // Overridden from InfoBarDelegate:
  virtual bool EqualsDelegate(InfoBarDelegate* delegate) const;
  virtual InfoBar* CreateInfoBar();
  virtual AlertInfoBarDelegate* AsAlertInfoBarDelegate() { return this; }

 protected:
  explicit AlertInfoBarDelegate(TabContents* contents);

  DISALLOW_COPY_AND_ASSIGN(AlertInfoBarDelegate);
};

// An interface derived from InfoBarDelegate implemented by objects wishing to
// control a LinkInfoBar.
class LinkInfoBarDelegate : public InfoBarDelegate {
 public:
  // Returns the message string to be displayed in the InfoBar. |link_offset|
  // is the position where the link should be inserted. If |link_offset| is set
  // to std::wstring::npos (it is by default), the link is right aligned within
  // the InfoBar rather than being embedded in the message text.
  virtual std::wstring GetMessageTextWithOffset(size_t* link_offset) const {
    *link_offset = std::wstring::npos;
    return std::wstring();
  }

  // Returns the text of the link to be displayed.
  virtual std::wstring GetLinkText() const = 0;

  // Returns the icon that should be shown for this InfoBar, or NULL if there is
  // none.
  virtual SkBitmap* GetIcon() const { return NULL; }

  // Called when the Link is clicked. The |disposition| specifies how the
  // resulting document should be loaded (based on the event flags present when
  // the link was clicked). This function returns true if the InfoBar should be
  // closed now or false if it should remain until the user explicitly closes
  // it.
  virtual bool LinkClicked(WindowOpenDisposition disposition) {
    return true; 
  }

  // Overridden from InfoBarDelegate:
  virtual InfoBar* CreateInfoBar();
  virtual LinkInfoBarDelegate* AsLinkInfoBarDelegate() {
    return this;
  }

 protected:
  explicit LinkInfoBarDelegate(TabContents* contents);

  DISALLOW_COPY_AND_ASSIGN(LinkInfoBarDelegate);
};

// An interface derived from InfoBarDelegate implemented by objects wishing to
// control a ConfirmInfoBar.
class ConfirmInfoBarDelegate : public AlertInfoBarDelegate {
 public:
  enum InfoBarButton {
    BUTTON_NONE = 0,
    BUTTON_OK,
    BUTTON_CANCEL
  };

  // Return the buttons to be shown for this InfoBar.
  virtual int GetButtons() const {
    return BUTTON_NONE;
  }

  // Return the label for the specified button. The default implementation
  // returns "OK" for the OK button and "Cancel" for the Cancel button.
  virtual std::wstring GetButtonLabel(InfoBarButton button) const;

  // Called when the OK button is pressed. If the function returns true, the
  // InfoBarDelegate should be removed from the associated TabContents.
  virtual bool Accept() { return true; }

  // Called when the Cancel button is pressed.  If the function returns true,
  // the InfoBarDelegate should be removed from the associated TabContents.
  virtual bool Cancel() { return true; }

  // Overridden from InfoBarDelegate:
  virtual InfoBar* CreateInfoBar();
  virtual ConfirmInfoBarDelegate* AsConfirmInfoBarDelegate() {
    return this;
  }

 protected:
  explicit ConfirmInfoBarDelegate(TabContents* contents);

  DISALLOW_COPY_AND_ASSIGN(ConfirmInfoBarDelegate);
};

// Simple implementations for common use cases ---------------------------------

class SimpleAlertInfoBarDelegate : public AlertInfoBarDelegate {
 public:
  SimpleAlertInfoBarDelegate(TabContents* contents,
                             const std::wstring& message,
                             SkBitmap* icon);

  // Overridden from AlertInfoBarDelegate:
  virtual std::wstring GetMessageText() const;
  virtual SkBitmap* GetIcon() const;
  virtual void InfoBarClosed();

 private:
  std::wstring message_;
  SkBitmap* icon_;

  DISALLOW_COPY_AND_ASSIGN(SimpleAlertInfoBarDelegate);
};

#endif  // #ifndef CHROME_BROWSER_INFOBAR_DELEGATE_H_