view/public/nsIViewObserver.h

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  37
  38 #ifndef nsIViewObserver_h___
  39 #define nsIViewObserver_h___
  40
  41 #include "nsISupports.h"
  42 #include "nsEvent.h"
  43 #include "nsColor.h"
  44 #include "nsRect.h"
  45
  46 class nsIRenderingContext;
  47 class nsGUIEvent;
  48
  49 #define NS_IVIEWOBSERVER_IID   \
  50 { 0x63ae23ee, 0xe251, 0x4005, \
  51 { 0xaf, 0xe4, 0x5b, 0x0f, 0xa1, 0x5a, 0xb4, 0x99 } }
  52
  53 class nsIViewObserver : public nsISupports
  54 {
  55 public:
  56
  57   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IVIEWOBSERVER_IID)
  58
  59   /* called when the observer needs to paint. This paints the entire
  60    * frame subtree rooted at the view, including frame subtrees from
  61    * subdocuments.
  62    * @param aRenderingContext rendering context to paint to; the origin
  63    * of the view is painted at (0,0) in the rendering context's current
  64    * transform. For best results this should transform to pixel-aligned
  65    * coordinates.
  66    * @param aDirtyRegion the region to be painted, in the coordinates of aRootView
  67    * @return error status
  68    */
  69   NS_IMETHOD Paint(nsIView*             aRootView,
  70                    nsIRenderingContext* aRenderingContext,
  71                    const nsRegion&      aDirtyRegion) = 0;
  72
  73   /**
  74    * @see nsLayoutUtils::ComputeRepaintRegionForCopy
  75    */
  76   NS_IMETHOD ComputeRepaintRegionForCopy(nsIView*      aRootView,
  77                                          nsIView*      aMovingView,
  78                                          nsPoint       aDelta,
  79                                          const nsRect& aCopyRect,
  80                                          nsRegion*     aRepaintRegion) = 0;
  81
  82   /* called when the observer needs to handle an event
  83    * @param aView  - where to start processing the event; the root view,
  84    * or the view that's currently capturing this sort of event; must be a view
  85    * for this presshell
  86    * @param aEvent - event notification
  87    * @param aEventStatus - out parameter for event handling
  88    *                       status
  89    * @param aHandled - whether the correct frame was found to
  90    *                   handle the event
  91    * @return error status
  92    */
  93   NS_IMETHOD HandleEvent(nsIView*       aView,
  94                          nsGUIEvent*    aEvent,
  95                          nsEventStatus* aEventStatus) = 0;
  96
  97   /* called when the view has been resized and the
  98    * content within the view needs to be reflowed.
  99    * @param aWidth - new width of view
 100    * @param aHeight - new height of view
 101    * @return error status
 102    */
 103   NS_IMETHOD ResizeReflow(nsIView * aView, nscoord aWidth, nscoord aHeight) = 0;
 104
 105   /**
 106    * Hack to find out if the view observer is itself visible, in lieu
 107    * of having the view trees linked.
 108    */
 109   NS_IMETHOD_(PRBool) IsVisible() = 0;
 110
 111   /**
 112    * Notify the observer that we're about to start painting.  This
 113    * gives the observer a chance to make some last-minute invalidates
 114    * and geometry changes if it wants to.
 115    */
 116   NS_IMETHOD_(void) WillPaint() = 0;
 117
 118   /**
 119    * Notify the observer that it should invalidate the frame bounds for
 120    * the frame associated with this view.
 121    */
 122   NS_IMETHOD_(void) InvalidateFrameForView(nsIView *aView) = 0;
 123 };
 124
 125 NS_DEFINE_STATIC_IID_ACCESSOR(nsIViewObserver, NS_IVIEWOBSERVER_IID)
 126
 127 #endif