gecko/layout/xul/base/src/nsMenuFrame.h

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
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 *
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 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
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 * Contributor(s):
 *   Original Author: David W. Hyatt (hyatt@netscape.com)
 *
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//
// nsMenuFrame
//

#ifndef nsMenuFrame_h__
#define nsMenuFrame_h__

#include "prtypes.h"
#include "nsIAtom.h"
#include "nsCOMPtr.h"

#include "nsBoxFrame.h"
#include "nsFrameList.h"
#include "nsGkAtoms.h"
#include "nsMenuParent.h"
#include "nsIMenuFrame.h"
#include "nsXULPopupManager.h"
#include "nsITimer.h"
#include "nsIDOMText.h"
#include "nsIContent.h"
#include "nsIScrollableViewProvider.h"

nsIFrame* NS_NewMenuFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
nsIFrame* NS_NewMenuItemFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);

class nsMenuBarFrame;
class nsIScrollableView;

#define NS_STATE_ACCELTEXT_IS_DERIVED  NS_STATE_BOX_CHILD_RESERVED

// the type of menuitem
enum nsMenuType {
  // a normal menuitem where a command is carried out when activated
  eMenuType_Normal = 0,
  // a menuitem with a checkmark that toggles when activated
  eMenuType_Checkbox = 1,
  // a radio menuitem where only one of it and its siblings with the same
  // name attribute can be checked at a time
  eMenuType_Radio = 2
};

class nsMenuFrame;

/**
 * nsMenuTimerMediator is a wrapper around an nsMenuFrame which can be safely
 * passed to timers. The class is reference counted unlike the underlying
 * nsMenuFrame, so that it will exist as long as the timer holds a reference
 * to it. The callback is delegated to the contained nsMenuFrame as long as
 * the contained nsMenuFrame has not been destroyed.
 */
class nsMenuTimerMediator : public nsITimerCallback
{
public:
  nsMenuTimerMediator(nsMenuFrame* aFrame);
  ~nsMenuTimerMediator();

  NS_DECL_ISUPPORTS
  NS_DECL_NSITIMERCALLBACK

  void ClearFrame();

private:

  // Pointer to the wrapped frame.
  nsMenuFrame* mFrame;
};

class nsMenuFrame : public nsBoxFrame, 
                    public nsIMenuFrame,
                    public nsIScrollableViewProvider
{
public:
  nsMenuFrame(nsIPresShell* aShell, nsStyleContext* aContext);

  NS_DECL_QUERYFRAME

  // nsIBox
  NS_IMETHOD DoLayout(nsBoxLayoutState& aBoxLayoutState);
  virtual nsSize GetMinSize(nsBoxLayoutState& aBoxLayoutState);
  virtual nsSize GetPrefSize(nsBoxLayoutState& aBoxLayoutState);

  NS_IMETHOD Init(nsIContent*      aContent,
                  nsIFrame*        aParent,
                  nsIFrame*        aPrevInFlow);

#ifdef DEBUG_LAYOUT
  NS_IMETHOD SetDebug(nsBoxLayoutState& aState, PRBool aDebug);
#endif

  NS_IMETHOD IsActive(PRBool& aResult) { aResult = PR_TRUE; return NS_OK; }

  // The following methods are all overridden so that the menupopup
  // can be stored in a separate list, so that it doesn't impact reflow of the
  // actual menu item at all.
  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
  NS_IMETHOD SetInitialChildList(nsIAtom*        aListName,
                                 nsIFrame*       aChildList);
  virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
  virtual void Destroy();

  // Overridden to prevent events from going to children of the menu.
  NS_IMETHOD BuildDisplayListForChildren(nsDisplayListBuilder*   aBuilder,
                                         const nsRect&           aDirtyRect,
                                         const nsDisplayListSet& aLists);
                                         
  // this method can destroy the frame
  NS_IMETHOD HandleEvent(nsPresContext* aPresContext, 
                         nsGUIEvent*     aEvent,
                         nsEventStatus*  aEventStatus);

  NS_IMETHOD  AppendFrames(nsIAtom*        aListName,
                           nsIFrame*       aFrameList);

  NS_IMETHOD  InsertFrames(nsIAtom*        aListName,
                           nsIFrame*       aPrevFrame,
                           nsIFrame*       aFrameList);

  NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                          nsIFrame*       aOldFrame);

  virtual nsIAtom* GetType() const { return nsGkAtoms::menuFrame; }

  NS_IMETHOD SelectMenu(PRBool aActivateFlag);

  /**
   * NOTE: OpenMenu will open the menu asynchronously.
   */
  void OpenMenu(PRBool aSelectFirstItem);
  // CloseMenu closes the menu asynchronously
  void CloseMenu(PRBool aDeselectMenu);

  PRBool IsChecked() { return mChecked; }

  NS_IMETHOD GetActiveChild(nsIDOMElement** aResult);
  NS_IMETHOD SetActiveChild(nsIDOMElement* aChild);

  // called when the Enter key is pressed while the menuitem is the current
  // one in its parent popup. This will carry out the command attached to
  // the menuitem. If the menu should be opened, this frame will be returned,
  // otherwise null will be returned.
  nsMenuFrame* Enter();

  NS_IMETHOD SetParent(const nsIFrame* aParent);

  virtual nsMenuParent *GetMenuParent() { return mMenuParent; }
  const nsAString& GetRadioGroupName() { return mGroupName; }
  nsMenuType GetMenuType() { return mType; }
  nsMenuPopupFrame* GetPopup() { return mPopupFrame; }

  // nsIScrollableViewProvider methods

  virtual nsIScrollableView* GetScrollableView();

  // nsMenuFrame methods 

  nsresult DestroyPopupFrames(nsPresContext* aPresContext);

  virtual PRBool IsOnMenuBar() { return mMenuParent && mMenuParent->IsMenuBar(); }
  virtual PRBool IsOnActiveMenuBar() { return IsOnMenuBar() && mMenuParent->IsActive(); }
  virtual PRBool IsOpen();
  virtual PRBool IsMenu();
  PRBool IsDisabled();
  PRBool IsGenerated();
  void ToggleMenuState();

  // indiciate that the menu's popup has just been opened, so that the menu
  // can update its open state. This method modifies the open attribute on
  // the menu, so the frames could be gone after this call.
  void PopupOpened();
  // indiciate that the menu's popup has just been closed, so that the menu
  // can update its open state. The menu should be unhighlighted if
  // aDeselectedMenu is true. This method modifies the open attribute on
  // the menu, so the frames could be gone after this call.
  void PopupClosed(PRBool aDeselectMenu);

  // returns true if this is a menu on another menu popup. A menu is a submenu
  // if it has a parent popup or menupopup.
  PRBool IsOnMenu() { return mMenuParent && mMenuParent->IsMenu(); }
  void SetIsMenu(PRBool aIsMenu) { mIsMenu = aIsMenu; }

#ifdef DEBUG
  NS_IMETHOD GetFrameName(nsAString& aResult) const
  {
      return MakeFrameName(NS_LITERAL_STRING("Menu"), aResult);
  }
#endif

  static PRBool IsSizedToPopup(nsIContent* aContent, PRBool aRequireAlways);

protected:
  friend class nsMenuTimerMediator;
  friend class nsASyncMenuInitialization;

  // initialize mPopupFrame to the first popup frame within aChildList. Returns
  // aChildList with the popup frame removed.
  nsIFrame* SetPopupFrame(nsIFrame* aChildList);

  // set mMenuParent to the nearest enclosing menu bar or menupopup frame of
  // aParent (or aParent itself). This is called when initializing the frame,
  // so aParent should be the expected parent of this frame.
  void InitMenuParent(nsIFrame* aParent);

  // Update the menu's type (normal, checkbox, radio).
  // This method can destroy the frame.
  void UpdateMenuType(nsPresContext* aPresContext);
  // Update the checked state of the menu, and for radios, clear any other
  // checked items. This method can destroy the frame.
  void UpdateMenuSpecialState(nsPresContext* aPresContext);

  // Examines the key node and builds the accelerator.
  void BuildAcceleratorText();

  // Called to execute our command handler. This method can destroy the frame.
  void Execute(nsGUIEvent *aEvent);

  // This method can destroy the frame
  NS_IMETHOD AttributeChanged(PRInt32 aNameSpaceID,
                              nsIAtom* aAttribute,
                              PRInt32 aModType);
  virtual ~nsMenuFrame();

  PRBool SizeToPopup(nsBoxLayoutState& aState, nsSize& aSize);

protected:
#ifdef DEBUG_LAYOUT
  nsresult SetDebug(nsBoxLayoutState& aState, nsIFrame* aList, PRBool aDebug);
#endif
  NS_HIDDEN_(nsresult) Notify(nsITimer* aTimer);

  PRPackedBool mIsMenu; // Whether or not we can even have children or not.
  PRPackedBool mChecked;              // are we checked?
  nsMenuType mType;

  nsMenuParent* mMenuParent; // Our parent menu.

  // the popup for this menu, owned
  nsMenuPopupFrame* mPopupFrame;

  // Reference to the mediator which wraps this frame.
  nsRefPtr<nsMenuTimerMediator> mTimerMediator;

  nsCOMPtr<nsITimer> mOpenTimer;

  nsString mGroupName;
  
  //we load some display strings from platformKeys.properties only once
  static nsrefcnt gRefCnt; 
  static nsString *gShiftText;
  static nsString *gControlText;
  static nsString *gMetaText;
  static nsString *gAltText;
  static nsString *gModifierSeparator;

}; // class nsMenuFrame

#endif