gecko-dev/layout/generic/nsGfxScrollFrame.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is
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 *
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#ifndef nsGfxScrollFrame_h___
#define nsGfxScrollFrame_h___

#include "nsHTMLContainerFrame.h"
#include "nsIAnonymousContentCreator.h"
#include "nsBoxFrame.h"
#include "nsIScrollableFrame.h"
#include "nsIScrollPositionListener.h"
#include "nsIPresState.h"
#include "nsIStatefulFrame.h"

class nsISupportsArray;
class nsIScrollableView;
class nsPresContext;
class nsIPresShell;
class nsIContent;
class nsIAtom;
class nsIDocument;
class nsIScrollFrameInternal;

class nsGfxScrollFrameInner : public nsIScrollPositionListener {
public:
  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr);
  NS_IMETHOD_(nsrefcnt) AddRef(void);
  NS_IMETHOD_(nsrefcnt) Release(void);

  nsGfxScrollFrameInner(nsBoxFrame* aOuter);

  typedef nsIScrollableFrame::ScrollbarStyles ScrollbarStyles;
  ScrollbarStyles GetScrollbarStylesFromFrame() const;

  // If a child frame was added or removed on the scrollframe,
  // reload our child frame list.
  // We need this if a scrollbar frame is recreated.
  void ReloadChildFrames();

  void CreateAnonymousContent(nsISupportsArray& aAnonymousChildren);

  // nsIScrollPositionListener

  NS_IMETHOD ScrollPositionWillChange(nsIScrollableView* aScrollable, nscoord aX, nscoord aY);
  NS_IMETHOD ScrollPositionDidChange(nsIScrollableView* aScrollable, nscoord aX, nscoord aY);

  // This gets called when the 'curpos' attribute on one of the scrollbars changes
  void CurPosAttributeChanged(nsIContent* aChild, PRInt32 aModType);

  void SetScrollbarEnabled(nsIBox* aBox, nscoord aMaxPos, PRBool aReflow=PR_TRUE);
  PRBool SetAttribute(nsIBox* aBox, nsIAtom* aAtom, nscoord aSize, PRBool aReflow=PR_TRUE);
  PRInt32 GetIntegerAttribute(nsIBox* aFrame, nsIAtom* atom, PRInt32 defaultValue);

  nsresult Layout(nsBoxLayoutState& aState);
  nsresult LayoutBox(nsBoxLayoutState& aState, nsIBox* aBox, const nsRect& aRect);
  
  // Like ScrollPositionDidChange, but initiated by this frame rather than from the
  // scrolling view
  void InternalScrollPositionDidChange(nscoord aX, nscoord aY);

   PRBool AddRemoveScrollbar       (PRBool& aHasScrollbar, 
                                  nscoord& aXY, 
                                  nscoord& aSize, 
                                  nscoord aSbSize, 
                                  PRBool aOnRightOrBottom, 
                                  PRBool aAdd);

   PRBool AddRemoveScrollbar(nsBoxLayoutState& aState, 
                           nsRect& aScrollAreaSize, 
                           PRBool aOnTop, 
                           PRBool aHorizontal, 
                           PRBool aAdd);

   PRBool AddHorizontalScrollbar   (nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnBottom);
   PRBool AddVerticalScrollbar     (nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnRight);
   void RemoveHorizontalScrollbar(nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnBottom);
   void RemoveVerticalScrollbar  (nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnRight);

   nsIScrollableView* GetScrollableView() const;

  void ScrollToRestoredPosition();

  already_AddRefed<nsIPresState> SaveState();
  void RestoreState(nsIPresState* aState);

  nsIFrame* GetScrolledFrame() const {
    nsIFrame* childBox;
    mScrollAreaBox->GetChildBox(&childBox);
    return childBox;
  }

  void ScrollbarChanged(nsPresContext* aPresContext, nscoord aX, nscoord aY, PRUint32 aFlags);

  void SetScrollbarVisibility(nsIBox* aScrollbar, PRBool aVisible);

  NS_IMETHOD GetScrolledSize(nsPresContext* aPresContext, 
                         nscoord *aWidth, 
                         nscoord *aHeight) const;
  void AdjustReflowStateForPrintPreview(nsBoxLayoutState& aState, PRBool& aSetBack);
  void AdjustReflowStateBack(nsBoxLayoutState& aState, PRBool aSetBack);

  nsIBox* mHScrollbarBox;
  nsIBox* mVScrollbarBox;
  nsIBox* mScrollAreaBox;
  nsIBox* mScrollCornerBox;
  nscoord mOnePixel;
  nsBoxFrame* mOuter;
  nscoord mMaxElementWidth;

  nsRect mRestoreRect;
  nsPoint mLastPos;

  // The last dir value we saw in AddHorizontalScrollbar.  Use PRInt16
  // so we can fit all the possible values of a PRUint8 and have a -1
  // value that indicates "not set")
  PRInt16     mLastDir;
  
  PRPackedBool mNeverHasVerticalScrollbar;   
  PRPackedBool mNeverHasHorizontalScrollbar; 

  PRPackedBool mHasVerticalScrollbar;
  PRPackedBool mHasHorizontalScrollbar;
  PRPackedBool mViewInitiatedScroll;
  PRPackedBool mFrameInitiatedScroll;
  PRPackedBool mDidHistoryRestore;
};

/**
 * The scroll frame creates and manages the scrolling view
 *
 * It only supports having a single child frame that typically is an area
 * frame, but doesn't have to be. The child frame must have a view, though
 *
 * Scroll frames don't support incremental changes, i.e. you can't replace
 * or remove the scrolled frame
 */
class nsHTMLScrollFrame : public nsBoxFrame,
                          public nsIScrollableFrame,
                          public nsIAnonymousContentCreator,
                          public nsIStatefulFrame {
public:
  friend nsresult NS_NewHTMLScrollFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame, 
                                        PRBool aIsRoot);

  // Called to set the child frames. We typically have three: the scroll area,
  // the vertical scrollbar, and the horizontal scrollbar.
  NS_IMETHOD SetInitialChildList(nsPresContext* aPresContext,
                                 nsIAtom*        aListName,
                                 nsIFrame*       aChildList);

  NS_IMETHOD Reflow(nsPresContext*          aPresContext,
                  nsHTMLReflowMetrics&     aDesiredSize,
                  const nsHTMLReflowState& aReflowState,
                  nsReflowStatus&          aStatus);

  // Because there can be only one child frame, these two function return
  // NS_ERROR_FAILURE
  NS_IMETHOD AppendFrames(nsPresContext* aPresContext,
                          nsIPresShell&   aPresShell,
                          nsIAtom*        aListName,
                          nsIFrame*       aFrameList);
  NS_IMETHOD InsertFrames(nsPresContext* aPresContext,
                          nsIPresShell&   aPresShell,
                          nsIAtom*        aListName,
                          nsIFrame*       aPrevFrame,
                          nsIFrame*       aFrameList);

  NS_IMETHOD ReplaceFrame(nsPresContext* aPresContext,
                     nsIPresShell&   aPresShell,
                     nsIAtom*        aListName,
                     nsIFrame*       aOldFrame,
                     nsIFrame*       aNewFrame);

  NS_IMETHOD Destroy(nsPresContext* aPresContext);

  NS_IMETHOD RemoveFrame(nsPresContext* aPresContext,
                         nsIPresShell&   aPresShell,
                         nsIAtom*        aListName,
                         nsIFrame*       aOldFrame);


  NS_IMETHOD GetContentAndOffsetsFromPoint(nsPresContext* aCX,
                                           const nsPoint&  aPoint,
                                           nsIContent **   aNewContent,
                                           PRInt32&        aContentOffset,
                                           PRInt32&        aContentOffsetEnd,
                                           PRBool&         aBeginFrameContent);

  virtual nsIFrame* GetContentInsertionFrame() {
    return mInner.GetScrolledFrame()->GetContentInsertionFrame();
  }

  // nsIAnonymousContentCreator
  NS_IMETHOD CreateAnonymousContent(nsPresContext* aPresContext,
                                    nsISupportsArray& aAnonymousItems);
  NS_IMETHOD CreateFrameFor(nsPresContext*   aPresContext,
                            nsIContent *      aContent,
                            nsIFrame**        aFrame) { if (aFrame) *aFrame = nsnull; return NS_ERROR_FAILURE; }

  // nsIBox methods
  NS_DECL_ISUPPORTS

  NS_IMETHOD GetPrefSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize);
  NS_IMETHOD GetMinSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize);
  NS_IMETHOD GetMaxSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize);
  NS_IMETHOD GetAscent(nsBoxLayoutState& aBoxLayoutState, nscoord& aAscent);

  NS_IMETHOD DoLayout(nsBoxLayoutState& aBoxLayoutState);
  NS_IMETHOD GetPadding(nsMargin& aPadding);

  // nsIScrollableFrame
  virtual nsIFrame* GetScrolledFrame() const;
  virtual nsIScrollableView* GetScrollableView();

  virtual nsPoint GetScrollPosition() const;
  virtual void ScrollTo(nsPoint aScrollPosition, PRUint32 aFlags);

  virtual void SetScrollbarVisibility(PRBool aVerticalVisible, PRBool aHorizontalVisible);

  virtual nsIBox* GetScrollbarBox(PRBool aVertical);

  virtual void CurPosAttributeChanged(nsIContent* aChild, PRInt32 aModType);

  // nsIStatefulFrame
  NS_IMETHOD SaveState(nsPresContext* aPresContext, nsIPresState** aState) {
    NS_ENSURE_ARG_POINTER(aState);
    *aState = mInner.SaveState().get();
    return NS_OK;
  }
  NS_IMETHOD RestoreState(nsPresContext* aPresContext, nsIPresState* aState) {
    NS_ENSURE_ARG_POINTER(aState);
    mInner.RestoreState(aState);
    return NS_OK;
  }

  virtual void ScrollToRestoredPosition() {
    mInner.ScrollToRestoredPosition();
  }

  virtual nsMargin GetActualScrollbarSizes() const;
  virtual nsMargin GetDesiredScrollbarSizes(nsBoxLayoutState* aState);
  virtual nsGfxScrollFrameInner::ScrollbarStyles GetScrollbarStyles() const;

  /**
   * Get the "type" of the frame
   *
   * @see nsLayoutAtoms::scrollFrame
   */
  virtual nsIAtom* GetType() const;
  
#ifdef NS_DEBUG
  NS_IMETHOD GetFrameName(nsAString& aResult) const;
#endif

  virtual nsresult GetContentOf(nsIContent** aContent);

  PRBool DidHistoryRestore() { return mInner.mDidHistoryRestore; }

#ifdef ACCESSIBILITY
  NS_IMETHOD GetAccessible(nsIAccessible** aAccessible);
#endif

protected:
  nsHTMLScrollFrame(nsIPresShell* aShell, PRBool aIsRoot);
  virtual PRIntn GetSkipSides() const;

private:
  friend class nsGfxScrollFrameInner;
  nsGfxScrollFrameInner mInner;
};

/**
 * The scroll frame creates and manages the scrolling view
 *
 * It only supports having a single child frame that typically is an area
 * frame, but doesn't have to be. The child frame must have a view, though
 *
 * Scroll frames don't support incremental changes, i.e. you can't replace
 * or remove the scrolled frame
 */
class nsXULScrollFrame : public nsBoxFrame,
                         public nsIScrollableFrame,
                         public nsIAnonymousContentCreator,
                         public nsIStatefulFrame {
public:
  friend nsresult NS_NewXULScrollFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame, 
                                       PRBool aIsRoot);

  // Called to set the child frames. We typically have three: the scroll area,
  // the vertical scrollbar, and the horizontal scrollbar.
  NS_IMETHOD SetInitialChildList(nsPresContext* aPresContext,
                                 nsIAtom*        aListName,
                                 nsIFrame*       aChildList);

  NS_IMETHOD Reflow(nsPresContext*          aPresContext,
                  nsHTMLReflowMetrics&     aDesiredSize,
                  const nsHTMLReflowState& aReflowState,
                  nsReflowStatus&          aStatus);

  // Because there can be only one child frame, these two function return
  // NS_ERROR_FAILURE
  NS_IMETHOD AppendFrames(nsPresContext* aPresContext,
                          nsIPresShell&   aPresShell,
                          nsIAtom*        aListName,
                          nsIFrame*       aFrameList);
  NS_IMETHOD InsertFrames(nsPresContext* aPresContext,
                          nsIPresShell&   aPresShell,
                          nsIAtom*        aListName,
                          nsIFrame*       aPrevFrame,
                          nsIFrame*       aFrameList);

  NS_IMETHOD ReplaceFrame(nsPresContext* aPresContext,
                     nsIPresShell&   aPresShell,
                     nsIAtom*        aListName,
                     nsIFrame*       aOldFrame,
                     nsIFrame*       aNewFrame);

  NS_IMETHOD Destroy(nsPresContext* aPresContext);

  NS_IMETHOD RemoveFrame(nsPresContext* aPresContext,
                         nsIPresShell&   aPresShell,
                         nsIAtom*        aListName,
                         nsIFrame*       aOldFrame);


  NS_IMETHOD GetContentAndOffsetsFromPoint(nsPresContext* aCX,
                                           const nsPoint&  aPoint,
                                           nsIContent **   aNewContent,
                                           PRInt32&        aContentOffset,
                                           PRInt32&        aContentOffsetEnd,
                                           PRBool&         aBeginFrameContent);

  virtual nsIFrame* GetContentInsertionFrame() {
    return mInner.GetScrolledFrame()->GetContentInsertionFrame();
  }

  // nsIAnonymousContentCreator
  NS_IMETHOD CreateAnonymousContent(nsPresContext* aPresContext,
                                    nsISupportsArray& aAnonymousItems);
  NS_IMETHOD CreateFrameFor(nsPresContext*   aPresContext,
                            nsIContent *      aContent,
                            nsIFrame**        aFrame) { if (aFrame) *aFrame = nsnull; return NS_ERROR_FAILURE; }

  // nsIBox methods
  NS_DECL_ISUPPORTS

  NS_IMETHOD GetPrefSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize);
  NS_IMETHOD GetMinSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize);
  NS_IMETHOD GetMaxSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize);
  NS_IMETHOD GetAscent(nsBoxLayoutState& aBoxLayoutState, nscoord& aAscent);

  NS_IMETHOD DoLayout(nsBoxLayoutState& aBoxLayoutState);
  NS_IMETHOD GetPadding(nsMargin& aPadding);

  // nsIScrollableFrame
  virtual nsIFrame* GetScrolledFrame() const;
  virtual nsIScrollableView* GetScrollableView();

  virtual nsPoint GetScrollPosition() const;
  virtual void ScrollTo(nsPoint aScrollPosition, PRUint32 aFlags);

  virtual void SetScrollbarVisibility(PRBool aVerticalVisible, PRBool aHorizontalVisible);

  virtual nsIBox* GetScrollbarBox(PRBool aVertical);

  virtual void CurPosAttributeChanged(nsIContent* aChild, PRInt32 aModType);

  // nsIStatefulFrame
  NS_IMETHOD SaveState(nsPresContext* aPresContext, nsIPresState** aState) {
    NS_ENSURE_ARG_POINTER(aState);
    *aState = mInner.SaveState().get();
    return NS_OK;
  }
  NS_IMETHOD RestoreState(nsPresContext* aPresContext, nsIPresState* aState) {
    NS_ENSURE_ARG_POINTER(aState);
    mInner.RestoreState(aState);
    return NS_OK;
  }

  virtual void ScrollToRestoredPosition() {
    mInner.ScrollToRestoredPosition();
  }

  virtual nsMargin GetActualScrollbarSizes() const;
  virtual nsMargin GetDesiredScrollbarSizes(nsBoxLayoutState* aState);
  virtual nsGfxScrollFrameInner::ScrollbarStyles GetScrollbarStyles() const;

  /**
   * Get the "type" of the frame
   *
   * @see nsLayoutAtoms::scrollFrame
   */
  virtual nsIAtom* GetType() const;
  
#ifdef NS_DEBUG
  NS_IMETHOD GetFrameName(nsAString& aResult) const;
#endif

  virtual nsresult GetContentOf(nsIContent** aContent);

protected:
  nsXULScrollFrame(nsIPresShell* aShell, PRBool aIsRoot);
  virtual PRIntn GetSkipSides() const;

private:
  friend class nsGfxScrollFrameInner;
  nsGfxScrollFrameInner mInner;
};

#endif /* nsGfxScrollFrame_h___ */