view/public/nsIViewManager.h
author mats.palmgren@bredband.net
Fri, 27 Apr 2007 04:06:22 -0700
changeset 867 77a55fdcc9291735905f4dd17bb506badd4daeb2
parent 139 8c536b29e8f09b7864e6c9a452d7aabdb7d9b1f2
child 1097 4029aeb5bacf2b0721d3eacb27c1d9388f98ad44
permissions -rw-r--r--
Crash [@ nsPresContext::GetContainerInternal]. b=378682 r+sr=bzbarsky

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 *
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 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
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 *
 * Contributor(s):
 *
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#ifndef nsIViewManager_h___
#define nsIViewManager_h___

#include "nscore.h"
#include "nsIView.h"
#include "nsColor.h"
#include "nsEvent.h"
#include "nsIRenderingContext.h"

class nsIScrollableView;
class nsIWidget;
class nsIBlender;
class nsICompositeListener;
struct nsRect;
class nsRegion;
class nsIDeviceContext;
class nsIViewObserver;

enum nsRectVisibility { 
  nsRectVisibility_kVisible, 
  nsRectVisibility_kAboveViewport, 
  nsRectVisibility_kBelowViewport, 
  nsRectVisibility_kLeftOfViewport, 
  nsRectVisibility_kRightOfViewport, 
  nsRectVisibility_kZeroAreaRect
}; 

// 143945d0-0a20-4bf0-a04d-ad212ab9acc2
#define NS_IVIEWMANAGER_IID   \
{ 0x143945d0, 0x0a20, 0x4bf0, \
  { 0xa0, 0x4d, 0xad, 0x21, 0x2a, 0xb9, 0xac, 0xc2 } }

class nsIViewManager : public nsISupports
{
public:

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IVIEWMANAGER_IID)
  /**
   * Initialize the ViewManager
   * Note: this instance does not hold a reference to the viewobserver
   * because it holds a reference to this instance.
   * @result The result of the initialization, NS_OK if no errors
   */
  NS_IMETHOD  Init(nsIDeviceContext* aContext) = 0;

  /**
   * Create an ordinary view
   * @param aBounds initial bounds for view
   *        XXX We should eliminate this parameter; you can set the bounds after CreateView
   * @param aParent intended parent for view. this is not actually set in the
   *        nsIView through this method. it is only used by the initialization
   *        code to walk up the view tree, if necessary, to find resources.
   *        XXX We should eliminate this parameter!
   * @param aVisibilityFlag initial visibility state of view
   *        XXX We should eliminate this parameter; you can set it after CreateView
   * @result The new view
   */
  NS_IMETHOD_(nsIView*) CreateView(const nsRect& aBounds,
                                   const nsIView* aParent,
                                   nsViewVisibility aVisibilityFlag = nsViewVisibility_kShow) = 0;

  /**
   * Create an scrollable view
   * @param aBounds initial bounds for view
   *        XXX We should eliminate this parameter; you can set the bounds after CreateScrollableView
   * @param aParent intended parent for view. this is not actually set in the
   *        nsIView through this method. it is only used by the initialization
   *        code to walk up the view tree, if necessary, to find resources.
   *        XXX We should eliminate this parameter!
   * @result The new view
   */
  NS_IMETHOD_(nsIScrollableView*) CreateScrollableView(const nsRect& aBounds,
                                                       const nsIView* aParent) = 0;

  /**
   * Get the root of the view tree.
   * @result the root view
   */
  NS_IMETHOD  GetRootView(nsIView *&aView) = 0;

  /**
   * Set the root of the view tree. Does not destroy the current root view.
   * aView may have a parent view managed by a different view manager.
   * aView may have a widget (anything but printing) or may not (printing).
   * @param aView view to set as root
   */
  NS_IMETHOD  SetRootView(nsIView *aView) = 0;

  /**
   * Get the dimensions of the root window. The dimensions are in
   * twips
   * @param aWidth out parameter for width of window in twips
   * @param aHeight out parameter for height of window in twips
   */
  NS_IMETHOD  GetWindowDimensions(nscoord *aWidth, nscoord *aHeight) = 0;

  /**
   * Set the dimensions of the root window.
   * Called if the root window is resized. The dimensions are in
   * twips
   * @param aWidth of window in twips
   * @param aHeight of window in twips
   */
  NS_IMETHOD  SetWindowDimensions(nscoord aWidth, nscoord aHeight) = 0;

  /**
   * Called to force a redrawing of any dirty areas.
   */
  // XXXbz why is this exposed?  Shouldn't update view batches handle this?
  // It's not like Composite() does what's expected inside a view update batch
  // anyway, since dirty areas may not have been invalidated on the widget yet
  // and widget changes may not have been propagated yet.  Maybe this should
  // call FlushPendingInvalidates()?
  NS_IMETHOD  Composite(void) = 0;

  /**
   * Called to inform the view manager that the entire area of a view
   * is dirty and needs to be redrawn.
   * @param aView view to paint. should be root view
   * @param aUpdateFlags see bottom of nsIViewManager.h for description
   */
  NS_IMETHOD  UpdateView(nsIView *aView, PRUint32 aUpdateFlags) = 0;

  /**
   * Called to inform the view manager that some portion of a view
   * is dirty and needs to be redrawn. The rect passed in
   * should be in the view's coordinate space.
   * @param aView view to paint. should be root view
   * @param rect rect to mark as damaged
   * @param aUpdateFlags see bottom of nsIViewManager.h for description
   */
  NS_IMETHOD  UpdateView(nsIView *aView, const nsRect &aRect, PRUint32 aUpdateFlags) = 0;

  /**
   * Called to inform the view manager that it should redraw all views.
   * @param aView view to paint. should be root view
   * @param aUpdateFlags see bottom of nsIViewManager.h for description
   */
  NS_IMETHOD  UpdateAllViews(PRUint32 aUpdateFlags) = 0;

  /**
   * Called to dispatch an event to the appropriate view. Often called
   * as a result of receiving a mouse or keyboard event from the widget
   * event system.
   * @param event event to dispatch
   * @result event handling status
   */
  NS_IMETHOD  DispatchEvent(nsGUIEvent *aEvent, nsEventStatus* aStatus) = 0;

  /**
   * Used to grab/capture all mouse events for a specific view,
   * irrespective of the cursor position at which the
   * event occurred.
   * @param aView view to capture mouse events
   * @result event handling status
   */
  NS_IMETHOD  GrabMouseEvents(nsIView *aView, PRBool& aResult) = 0;

  /**
   * Get the current view, if any, that's capturing mouse events.
   * @result view that is capturing mouse events or nsnull
   */
  NS_IMETHOD  GetMouseEventGrabber(nsIView *&aView) = 0;

  /**
   * Given a parent view, insert another view as its child.
   * aSibling and aAbove control the "document order" for the insertion.
   * If aSibling is null, the view is inserted at the end of the document order
   * if aAfter is PR_TRUE, otherwise it is inserted at the beginning.
   * If aSibling is non-null, then if aAfter is PR_TRUE, the view is inserted
   * after the sibling in document order (appearing above the sibling unless
   * overriden by z-order).
   * If it is PR_FALSE, the view is inserted before the sibling.
   * The view manager generates the appopriate dirty regions.
   * @param aParent parent view
   * @param aChild child view
   * @param aSibling sibling view
   * @param aAfter after or before in the document order
   */
  NS_IMETHOD  InsertChild(nsIView *aParent, nsIView *aChild, nsIView *aSibling,
                          PRBool aAfter) = 0;

  /**
   * Given a parent view, insert a placeholder for a view that logically
   * belongs to this parent but has to be moved somewhere else for geometry
   * reasons ("fixed" positioning).
   * @param aParent parent view
   * @param aChild child view
   * @param aSibling sibling view
   * @param aAfter after or before in the document order
   */
  NS_IMETHOD  InsertZPlaceholder(nsIView *aParent, nsIView *aChild, nsIView *aSibling,
                                 PRBool aAfter) = 0;

  /**
   * Remove a specific child view from its parent. This will NOT remove its placeholder
   * if there is one.
   * The view manager generates the appropriate dirty regions.
   * @param aParent parent view
   * @param aChild child view
   */
  NS_IMETHOD  RemoveChild(nsIView *aChild) = 0;

  /**
   * Move a view to the specified position, provided in parent coordinates.
   * The new position is the (0, 0) origin for the view's coordinate system.
   * The view's bounds may extend above or to the left of this point.
   * The view manager generates the appropriate dirty regions.
   * @param aView view to move
   * @param aX x value for new view position
   * @param aY y value for new view position
   */
  NS_IMETHOD  MoveViewTo(nsIView *aView, nscoord aX, nscoord aY) = 0;

  /**
   * Resize a view. In addition to setting the width and height, you can
   * set the x and y of its bounds relative to its position. Negative x and y
   * will let the view extend above and to the left of the (0,0) point in its
   * coordinate system.
   * The view manager generates the appropriate dirty regions.
   * @param aView view to move
   * @param the new bounds relative to the current position
   * @param RepaintExposedAreaOnly
   *     if PR_TRUE Repaint only the expanded or contracted region,
   *     if PR_FALSE Repaint the union of the old and new rectangles.
   */
  NS_IMETHOD  ResizeView(nsIView *aView, const nsRect &aRect,
                         PRBool aRepaintExposedAreaOnly = PR_FALSE) = 0;

  /**
   * Set the visibility of a view.
   * The view manager generates the appropriate dirty regions.
   * @param aView view to change visibility state of
   * @param visible new visibility state
   */
  NS_IMETHOD  SetViewVisibility(nsIView *aView, nsViewVisibility aVisible) = 0;

  /**
   * Set the z-index of a view. Positive z-indices mean that a view
   * is above its parent in z-order. Negative z-indices mean that a
   * view is below its parent.
   * The view manager generates the appropriate dirty regions.
   * @param aAutoZIndex indicate that the z-index of a view is "auto". An "auto" z-index
   * means that the view does not define a new stacking context,
   * which means that the z-indicies of the view's children are
   * relative to the view's siblings.
   * @param aView view to change z depth of
   * @param aZindex explicit z depth
   * @param aTopMost used when this view is z-index:auto to compare against 
   *        other z-index:auto views.
   *        PR_TRUE if the view should be topmost when compared with 
   *        other z-index:auto views.
   */
  NS_IMETHOD  SetViewZIndex(nsIView *aView, PRBool aAutoZIndex, PRInt32 aZindex, PRBool aTopMost = PR_FALSE) = 0;

  /**
   * Set whether the view "floats" above all other views,
   * which tells the compositor not to consider higher views in
   * the view hierarchy that would geometrically intersect with
   * this view. This is a hack, but it fixes some problems with
   * views that need to be drawn in front of all other views.
   */
  NS_IMETHOD  SetViewFloating(nsIView *aView, PRBool aFloatingView) = 0;

  /**
   * Set whether the view's children should be searched during event processing.
   */
  NS_IMETHOD  SetViewCheckChildEvents(nsIView *aView, PRBool aEnable) = 0;

  /**
   * Set the view observer associated with this manager
   * @param aObserver - new observer
   * @result error status
   */
  NS_IMETHOD SetViewObserver(nsIViewObserver *aObserver) = 0;

  /**
   * Get the view observer associated with this manager
   * @param aObserver - out parameter for observer
   * @result error status
   */
  NS_IMETHOD GetViewObserver(nsIViewObserver *&aObserver) = 0;

  /**
   * Get the device context associated with this manager
   * @result device context
   */
  NS_IMETHOD  GetDeviceContext(nsIDeviceContext *&aContext) = 0;

  /**
   * prevent the view manager from refreshing.
   * @return error status
   */
  // XXXbz callers of this function don't seem to realize that it disables
  // refresh for the entire view manager hierarchy.... Maybe it shouldn't do
  // that?
  NS_IMETHOD DisableRefresh(void) = 0;

  /**
   * allow the view manager to refresh. this may cause a synchronous
   * paint to occur inside the call.
   * @param aUpdateFlags see bottom of nsIViewManager.h for description
   * @return error status
   */
  NS_IMETHOD EnableRefresh(PRUint32 aUpdateFlags) = 0;

  /**
   * prevents the view manager from refreshing. allows UpdateView()
   * to notify widgets of damaged regions that should be repainted
   * when the batch is ended.
   * @return error status
   */
  NS_IMETHOD BeginUpdateViewBatch(void) = 0;

  /**
   * allow the view manager to refresh any damaged areas accumulated
   * after the BeginUpdateViewBatch() call.  this may cause a
   * synchronous paint to occur inside the call if aUpdateFlags
   * NS_VMREFRESH_IMMEDIATE is set.
   *
   * If this is not the outermost view batch command, then this does
   * nothing except that the specified flags are remembered. When the
   * outermost batch finally ends, we merge together all the flags for the
   * inner batches in the following way:
   * -- If any batch specified NS_VMREFRESH_IMMEDIATE, then we use that flag
   * (i.e. there is a synchronous paint under the last EndUpdateViewBatch)
   * -- Otherwise if any batch specified NS_VMREFERSH_DEFERRED, then we use
   * that flag (i.e. invalidation is deferred until the processing of an
   * Invalidate PLEvent)
   * -- Otherwise all batches specified NS_VMREFRESH_NO_SYNC and we honor
   * that; all widgets are invalidated normally and will be painted the next
   * time the toolkit chooses to update them.
   *
   * @param aUpdateFlags see bottom of nsIViewManager.h for
   * description @return error status
   */
  NS_IMETHOD EndUpdateViewBatch(PRUint32 aUpdateFlags) = 0;

  /**
   * set the view that is is considered to be the root scrollable
   * view for the document.
   * @param aScrollable root scrollable view
   * @return error status
   */
  NS_IMETHOD SetRootScrollableView(nsIScrollableView *aScrollable) = 0;

  /**
   * get the view that is is considered to be the root scrollable
   * view for the document.
   * @param aScrollable out parameter for root scrollable view
   * @return error status
   */
  NS_IMETHOD GetRootScrollableView(nsIScrollableView **aScrollable) = 0;

  /**
   * Dump the specified view into a new offscreen rendering context.
   * @param aRect is the region to capture into the offscreen buffer, in the view's
   * coordinate system
   * @param aUntrusted set to PR_TRUE if the contents may be passed to malicious
   * agents. E.g. we might choose not to paint the contents of sensitive widgets
   * such as the file name in a file upload widget, and we might choose not
   * to paint themes.
   * @param aIgnoreViewportScrolling ignore clipping/scrolling/scrollbar painting
   * due to scrolling in the viewport
   * @param aBackgroundColor a background color to render onto
   * @param aRenderedContext gets set to a rendering context whose offscreen
   * buffer can be locked to get the data. The buffer's size will be aRect's size.
   * In all cases the caller must clean it up by calling
   * cx->DestroyDrawingSurface(cx->GetDrawingSurface()).
   */
  NS_IMETHOD RenderOffscreen(nsIView* aView, nsRect aRect, PRBool aUntrusted,
                             PRBool aIgnoreViewportScrolling,
                             nscolor aBackgroundColor,
                             nsIRenderingContext** aRenderedContext) = 0;

  /**
   * Add a listener to the view manager's composite listener list.
   * @param aListener - new listener
   * @result error status
   */
  NS_IMETHOD AddCompositeListener(nsICompositeListener *aListener) = 0;

  /**
   * Remove a listener from the view manager's composite listener list.
   * @param aListener - listener to remove
   * @result error status
   */
  NS_IMETHOD RemoveCompositeListener(nsICompositeListener *aListener) = 0;

  /**
   * Retrieve the widget at the root of the view manager. This is the
   * widget associated with the root view, if the root view exists and has
   * a widget.
   */
  NS_IMETHOD GetWidget(nsIWidget **aWidget) = 0;

  /**
   * Force update of view manager widget
   * Callers should use UpdateView(view, NS_VMREFRESH_IMMEDIATE) in most cases instead
   * @result error status
   */
  // XXXbz Callers seem to be confused about this one... and it doesn't play
  // right with view update batching at all (will miss updates).  Maybe this
  // should call FlushPendingInvalidates()?
  NS_IMETHOD ForceUpdate() = 0;

  /**
   * Indicate whether the viewmanager is currently painting
   *
   * @param aPainting PR_TRUE if the viewmanager is painting
   *                  PR_FALSE otherwise
   */
  NS_IMETHOD IsPainting(PRBool& aIsPainting)=0;

  /**
   * Set the default background color that the view manager should use
   * to paint otherwise unowned areas. If the color isn't known, just set
   * it to zero (which means 'transparent' since the color is RGBA).
   *
   * @param aColor the default background color
   */
  NS_IMETHOD SetDefaultBackgroundColor(nscolor aColor)=0;

  /**
   * Retrieve the default background color.
   *
   * @param aColor the default background color
   */
  NS_IMETHOD GetDefaultBackgroundColor(nscolor* aColor)=0;

  /**
   * Retrieve the time of the last user event. User events
   * include mouse and keyboard events. The viewmanager
   * saves the time of the last user event.
   *
   * @param aTime Last user event time in microseconds
   */
  NS_IMETHOD GetLastUserEventTime(PRUint32& aTime)=0;

  /**
   * 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, 
                               PRUint16 aMinTwips, 
                               nsRectVisibility *aRectVisibility)=0;

  /**
   * Dispatch a mouse move event based on the most recent mouse
   * position.  This is used when the contents of the page moved
   * (aFromScroll is false) or scrolled (aFromScroll is true).
   */
  NS_IMETHOD SynthesizeMouseMove(PRBool aFromScroll)=0;
  
  /**
   TEMPORARY. Expose BlendingBuffers to layout so layout can
   paint with opacity. This will go away with cairo/thebes, or be moved
   to layout, depending on what happens first.
   
    This class represents an offscreen buffer which may have an alpha channel.
    Currently, if an alpha channel is required, we implement it by rendering into
    two buffers: one with a black background, one with a white background. We can
    recover the alpha values by comparing corresponding final values for each pixel.
  */
  class BlendingBuffers {
  public:
    BlendingBuffers(nsIRenderingContext* aCleanupContext);
    ~BlendingBuffers();
  
    // used by the destructor to cleanup resources
    nsCOMPtr<nsIRenderingContext> mCleanupContext;
    // The primary rendering context. When an alpha channel is in use, this
    // holds the black background.
    nsCOMPtr<nsIRenderingContext> mBlackCX;
    // Only used when an alpha channel is required; holds the white background.
    nsCOMPtr<nsIRenderingContext> mWhiteCX;
  
    PRBool mOwnBlackSurface;
    // drawing surface for mBlackCX
    nsIDrawingSurface*  mBlack;
    // drawing surface for mWhiteCX
    nsIDrawingSurface*  mWhite;
  
    // The offset within the current widget at which this buffer will
    // eventually be composited
    nsPoint mOffset;
  };

  virtual BlendingBuffers* CreateBlendingBuffers(nsIRenderingContext *aRC, PRBool aBorrowContext,
                                                 nsIDrawingSurface* aBorrowSurface, PRBool aNeedAlpha,
                                                 const nsRect& aArea) = 0;
  virtual nsIBlender* GetBlender() = 0;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIViewManager, NS_IVIEWMANAGER_IID)

// Paint timing mode flags

// intermediate: do no special timing processing; repaint when the
// toolkit issues an expose event (which will happen *before* PLEvent
// processing). This is essentially the default.
#define NS_VMREFRESH_NO_SYNC            0

// least immediate: we suppress invalidation, storing dirty areas in
// views, and post an Invalidate PLEvent. The Invalidate event gets
// processed after toolkit events such as window resize events!
// This is only usable with EndUpdateViewBatch and EnableRefresh.
#define NS_VMREFRESH_DEFERRED           0x0001

// most immediate: force a call to nsViewManager::Composite, which
// synchronously updates the window(s) right away before returning
#define NS_VMREFRESH_IMMEDIATE          0x0002

//animate scroll operation
#define NS_VMREFRESH_SMOOTHSCROLL       0x0008

#endif  // nsIViewManager_h___