gecko-dev/view/src/nsViewManager.h

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#ifndef nsViewManager_h___
#define nsViewManager_h___
#include "nsCOMPtr.h"
#include "nsIViewManager.h"
#include "nsCRT.h"
#include "nsITimer.h"
#include "prtime.h"
#include "prinrval.h"
#include "nsVoidArray.h"
#include "nsThreadUtils.h"
#include "nsIScrollableView.h"
#include "nsIRegion.h"
#include "nsView.h"
#include "nsIViewObserver.h"

//Uncomment the following line to enable generation of viewmanager performance data.
//#define NS_VM_PERF_METRICS 1


/**
   Invalidation model:

   1) Callers call into the view manager and ask it to update a view.
   
   2) The view manager finds the "right" widget for the view, henceforth called
      the root widget.

   3) The view manager traverses descendants of the root widget and for each
      one that needs invalidation either

      a)  Calls Invalidate() on the widget (no batching)
    or
      b)  Stores the rect to invalidate on the widget's view (batching)

   // XXXbz we want to change this a bit.  See bug 243726

   4) When batching, the call to end the batch either processes the pending
      Invalidate() calls on the widgets or posts an event to do so.

   It's important to note that widgets associated to views outside this view
   manager can end up being invalidated during step 3.  Therefore, the end of a
   view update batch really needs to traverse the entire view tree, to ensure
   that those invalidates happen.

   To cope with this, invalidate event processing and view update batch
   handling should only happen on the root viewmanager.  This means the root
   view manager is the only thing keeping track of mUpdateCnt.  As a result,
   Composite() calls should also be forwarded to the root view manager.
*/

class nsViewManagerEvent : public nsRunnable {
public:
  nsViewManagerEvent(class nsViewManager *vm) : mViewManager(vm) {
    NS_ASSERTION(mViewManager, "null parameter");
  }
  void Revoke() { mViewManager = nsnull; }
protected:
  class nsViewManager *mViewManager;
};

class nsViewManager : public nsIViewManager {
public:
  nsViewManager();

  NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW

  NS_DECL_ISUPPORTS

  NS_IMETHOD  Init(nsIDeviceContext* aContext);

  NS_IMETHOD_(nsIView*) CreateView(const nsRect& aBounds,
                                   const nsIView* aParent,
                                   nsViewVisibility aVisibilityFlag = nsViewVisibility_kShow);

  NS_IMETHOD_(nsIScrollableView*) CreateScrollableView(const nsRect& aBounds,
                                                       const nsIView* aParent);

  NS_IMETHOD  GetRootView(nsIView *&aView);
  NS_IMETHOD  SetRootView(nsIView *aView);

  NS_IMETHOD  GetWindowDimensions(nscoord *width, nscoord *height);
  NS_IMETHOD  SetWindowDimensions(nscoord width, nscoord height);
  NS_IMETHOD  FlushDelayedResize();

  NS_IMETHOD  Composite(void);

  NS_IMETHOD  UpdateView(nsIView *aView, PRUint32 aUpdateFlags);
  NS_IMETHOD  UpdateView(nsIView *aView, const nsRect &aRect, PRUint32 aUpdateFlags);
  NS_IMETHOD  UpdateAllViews(PRUint32 aUpdateFlags);

  NS_IMETHOD  DispatchEvent(nsGUIEvent *aEvent,
      nsIView* aTargetView, nsEventStatus* aStatus);

  NS_IMETHOD  InsertChild(nsIView *parent, nsIView *child, nsIView *sibling,
                          PRBool above);

  NS_IMETHOD  InsertChild(nsIView *parent, nsIView *child,
                          PRInt32 zindex);

  NS_IMETHOD  RemoveChild(nsIView *parent);

  NS_IMETHOD  MoveViewBy(nsIView *aView, nscoord aX, nscoord aY);

  NS_IMETHOD  MoveViewTo(nsIView *aView, nscoord aX, nscoord aY);

  NS_IMETHOD  ResizeView(nsIView *aView, const nsRect &aRect, PRBool aRepaintExposedAreaOnly = PR_FALSE);

  NS_IMETHOD  SetViewFloating(nsIView *aView, PRBool aFloating);

  NS_IMETHOD  SetViewVisibility(nsIView *aView, nsViewVisibility aVisible);

  NS_IMETHOD  SetViewZIndex(nsIView *aView, PRBool aAuto, PRInt32 aZIndex, PRBool aTopMost=PR_FALSE);

  NS_IMETHOD  SetViewObserver(nsIViewObserver *aObserver);
  NS_IMETHOD  GetViewObserver(nsIViewObserver *&aObserver);

  NS_IMETHOD  GetDeviceContext(nsIDeviceContext *&aContext);

  NS_IMETHOD  DisableRefresh(void);
  NS_IMETHOD  EnableRefresh(PRUint32 aUpdateFlags);

  virtual nsIViewManager* BeginUpdateViewBatch(void);
  NS_IMETHOD  EndUpdateViewBatch(PRUint32 aUpdateFlags);

  NS_IMETHOD  SetRootScrollableView(nsIScrollableView *aScrollable);
  NS_IMETHOD  GetRootScrollableView(nsIScrollableView **aScrollable);

  NS_IMETHOD GetRootWidget(nsIWidget **aWidget);
  NS_IMETHOD ForceUpdate();
 
  NS_IMETHOD IsPainting(PRBool& aIsPainting);
  NS_IMETHOD GetLastUserEventTime(PRUint32& aTime);
  void ProcessInvalidateEvent();
  static PRUint32 gLastUserEventTime;

  /**
   * Determine if a rectangle specified in the view's coordinate system 
   * is completely, or partially visible.
   * @param aView view that aRect coordinates are specified relative to
   * @param aRect rectangle in twips to test for visibility 
   * @param aMinTwips is the min. pixel rows or cols at edge of screen 
   *                  needed for object to be counted visible
   * @param aRectVisibility returns eVisible if the rect is visible, 
   *                        otherwise it returns an enum indicating why not
   */
  NS_IMETHOD GetRectVisibility(nsIView *aView, const nsRect &aRect, 
                               nscoord aMinTwips,
                               nsRectVisibility *aRectVisibility);

  NS_IMETHOD SynthesizeMouseMove(PRBool aFromScroll);
  void ProcessSynthMouseMoveEvent(PRBool aFromScroll);

  /* Update the cached RootViewManager pointer on this view manager. */
  void InvalidateHierarchy();

protected:
  virtual ~nsViewManager();

private:

  void FlushPendingInvalidates();
  void ProcessPendingUpdates(nsView *aView, PRBool aDoInvalidate);
  void ReparentChildWidgets(nsIView* aView, nsIWidget *aNewWidget);
  void ReparentWidgets(nsIView* aView, nsIView *aParent);
  already_AddRefed<nsIRenderingContext> CreateRenderingContext(nsView &aView);
  void UpdateWidgetArea(nsView *aWidgetView, nsIWidget* aWidget,
                        const nsRegion &aDamagedRegion,
                        nsView* aIgnoreWidgetView);

  void UpdateViews(nsView *aView, PRUint32 aUpdateFlags);

  void Refresh(nsView *aView, nsIRenderingContext *aContext,
               nsIRegion *region, PRUint32 aUpdateFlags);
  void RenderViews(nsView *aRootView, nsIRenderingContext& aRC,
                   const nsRegion& aRegion);

  void InvalidateRectDifference(nsView *aView, const nsRect& aRect, const nsRect& aCutOut, PRUint32 aUpdateFlags);
  void InvalidateHorizontalBandDifference(nsView *aView, const nsRect& aRect, const nsRect& aCutOut,
                                          PRUint32 aUpdateFlags, nscoord aY1, nscoord aY2, PRBool aInCutOut);

  // Utilities

  PRBool IsViewInserted(nsView *aView);

  /**
   * Function to recursively call Update() on all widgets belonging to
   * a view or its kids.
   */
  void UpdateWidgetsForView(nsView* aView);

  /**
   * Transforms a rectangle from aView's coordinate system to the coordinate
   * system of the widget attached to aWidgetView, which should be an ancestor
   * of aView.
   */
  nsIntRect ViewToWidget(nsView *aView, nsView* aWidgetView, const nsRect &aRect) const;

  /**
   * Transforms a rectangle from specified view's coordinate system to
   * an absolute coordinate rectangle which can be compared against the
   * rectangle returned by GetVisibleRect to determine visibility.
   * @param aView view that aRect coordinates are specified relative to
   * @param aRect rectangle in twips to convert to absolute coordinates
   * @param aAbsRect rectangle in absolute coorindates.
   * @returns NS_OK if successful otherwise, NS_ERROR_FAILURE 
   */

  nsresult GetAbsoluteRect(nsView *aView, const nsRect &aRect, 
                           nsRect& aAbsRect);
  /**
   * Determine the visible rect 
   * @param aVisibleRect visible rectangle in twips
   * @returns NS_OK if successful, otherwise NS_ERROR_FAILURE.
   */

  nsresult GetVisibleRect(nsRect& aVisibleRect);

  void DoSetWindowDimensions(nscoord aWidth, nscoord aHeight)
  {
    nsRect oldDim;
    nsRect newDim(0, 0, aWidth, aHeight);
    mRootView->GetDimensions(oldDim);
    // We care about resizes even when one dimension is already zero.
    if (!oldDim.IsExactEqual(newDim)) {
      // Don't resize the widget. It is already being set elsewhere.
      mRootView->SetDimensions(newDim, PR_TRUE, PR_FALSE);
      if (mObserver)
        mObserver->ResizeReflow(mRootView, aWidth, aHeight);
    }
  }

  // Safety helpers
  void IncrementUpdateCount() {
    NS_ASSERTION(IsRootVM(),
                 "IncrementUpdateCount called on non-root viewmanager");
    ++mUpdateCnt;
  }

  void DecrementUpdateCount() {
    NS_ASSERTION(IsRootVM(),
                 "DecrementUpdateCount called on non-root viewmanager");
    --mUpdateCnt;
  }

  PRInt32 UpdateCount() const {
    NS_ASSERTION(IsRootVM(),
                 "DecrementUpdateCount called on non-root viewmanager");
    return mUpdateCnt;
  }

  void ClearUpdateCount() {
    NS_ASSERTION(IsRootVM(),
                 "DecrementUpdateCount called on non-root viewmanager");
    mUpdateCnt = 0;
  }

  PRBool IsPainting() const {
    return RootViewManager()->mPainting;
  }

  void SetPainting(PRBool aPainting) {
    RootViewManager()->mPainting = aPainting;
  }

public: // NOT in nsIViewManager, so private to the view module
  nsView* GetRootView() const { return mRootView; }
  nsViewManager* RootViewManager() const { return mRootViewManager; }
  PRBool IsRootVM() const { return this == RootViewManager(); }

  nsEventStatus HandleEvent(nsView* aView, nsPoint aPoint, nsGUIEvent* aEvent);

  /**
   * Called to inform the view manager that a view is about to bit-blit.
   * @param aView the view that will bit-blit
   * @param aScrollAmount how much aView will scroll by
   * @return always returns NS_OK
   * @note
   * This method used to return void, but MSVC 6.0 SP5 (without the
   * Processor Pack) and SP6, and the MS eMbedded Visual C++ 4.0 SP4
   * (for WINCE) hit an internal compiler error when compiling this
   * method:
   *
   * @par
@verbatim
       fatal error C1001: INTERNAL COMPILER ERROR
                   (compiler file 'E:\8966\vc98\p2\src\P2\main.c', line 494)
@endverbatim
   *
   * @par
   * Making the method return nsresult worked around the internal
   * compiler error.  See Bugzilla bug 281158.  (The WINCE internal
   * compiler error was addressed by the patch in bug 291229 comment
   * 14 although the bug report did not mention the problem.)
   */
  nsresult WillBitBlit(nsView* aView, nsPoint aScrollAmount);
  
  /**
   * Called to inform the view manager that a view has scrolled via a
   * bitblit.
   * The view manager will invalidate any widgets which may need
   * to be rerendered.
   * @param aView view to paint. should be the nsScrollPortView that
   * got scrolled.
   * @param aBlitRegion the region that was blitted; this is just so
   * we can notify our view observer
   * @param aUpdateRegion ensure that this part of the view is repainted
   */
  void UpdateViewAfterScroll(nsView *aView, const nsRegion& aBlitRegion,
                             const nsRegion& aUpdateRegion);

  /**
   * Given that the view aView has being moved by scrolling by aDelta
   * (so we want to blit pixels by -aDelta), compute the regions that
   * must be blitted and repainted to correctly update the screen.
   */
  void GetRegionsForBlit(nsView* aView, nsPoint aDelta,
                         nsRegion* aBlitRegion, nsRegion* aRepaintRegion);

  nsresult CreateRegion(nsIRegion* *result);

  PRBool IsRefreshEnabled() { return RootViewManager()->mRefreshEnabled; }

  nsIViewObserver* GetViewObserver() { return mObserver; }

  // Call this when you need to let the viewmanager know that it now has
  // pending updates.
  void PostPendingUpdate() { RootViewManager()->mHasPendingUpdates = PR_TRUE; }
private:
  nsIDeviceContext  *mContext;
  nsIViewObserver   *mObserver;
  nsIScrollableView *mRootScrollable;
  nsIntPoint        mMouseLocation; // device units, relative to mRootView

  // The size for a resize that we delayed until the root view becomes
  // visible again.
  nsSize            mDelayedResize;

  nsCOMPtr<nsIFactory> mRegionFactory;
  nsView            *mRootView;
  // mRootViewManager is a strong ref unless it equals |this|.  It's
  // never null (if we have no ancestors, it will be |this|).
  nsViewManager     *mRootViewManager;

  nsRevocableEventPtr<nsViewManagerEvent> mSynthMouseMoveEvent;
  nsRevocableEventPtr<nsViewManagerEvent> mInvalidateEvent;

  // The following members should not be accessed directly except by
  // the root view manager.  Some have accessor functions to enforce
  // this, as noted.
  
  // Use IncrementUpdateCount(), DecrementUpdateCount(), UpdateCount(),
  // ClearUpdateCount() on the root viewmanager to access mUpdateCnt.
  PRInt32           mUpdateCnt;
  PRInt32           mUpdateBatchCnt;
  PRUint32          mUpdateBatchFlags;
  PRInt32           mScrollCnt;
  // Use IsRefreshEnabled() to check the value of mRefreshEnabled.
  PRPackedBool      mRefreshEnabled;
  // Use IsPainting() and SetPainting() to access mPainting.
  PRPackedBool      mPainting;
  PRPackedBool      mRecursiveRefreshPending;
  PRPackedBool      mHasPendingUpdates;
  PRPackedBool      mInScroll;

  //from here to public should be static and locked... MMP
  static PRInt32           mVMCount;        //number of viewmanagers

  //Rendering context used to cleanup the blending buffers
  static nsIRenderingContext* gCleanupContext;

  //list of view managers
  static nsVoidArray       *gViewManagers;

  void PostInvalidateEvent();
};

//when the refresh happens, should it be double buffered?
#define NS_VMREFRESH_DOUBLE_BUFFER      0x0001

#endif /* nsViewManager_h___ */