view/public/nsIScrollableView.h

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  37
  38 #ifndef nsIScrollableView_h___
  39 #define nsIScrollableView_h___
  40
  41 #include "nsCoord.h"
  42
  43 class nsIView;
  44 class nsIScrollPositionListener;
  45 struct nsSize;
  46
  47 // IID for the nsIScrollableView interface
  48 #define NS_ISCROLLABLEVIEW_IID    \
  49 { 0x00bba69f, 0xbbef, 0x4725, \
  50 { 0x8b, 0xee, 0xec, 0xfe, 0x82, 0xf7, 0xbd, 0xb0 } }
  51
  52 /**
  53  * A scrolling view allows an arbitrary view that you supply to be scrolled
  54  * vertically or horizontally (or both). The scrolling view creates and
  55  * manages the scrollbars.
  56  *
  57  * You must use SetScrolledView() to specify the view that is to be scrolled,
  58  * because the scrolled view is made a child of the clip view (an internal
  59  * child view created by the scrolling view).
  60  *
  61  */
  62 class nsIScrollableView {
  63 public:
  64   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISCROLLABLEVIEW_IID)
  65
  66   /**
  67    * Create the controls used to allow scrolling. Call this method
  68    * before anything else is done with the scrollable view.
  69    * @param aNative native widget to use as parent for control widgets
  70    * @return error status
  71    */
  72   NS_IMETHOD  CreateScrollControls(nsNativeWidget aNative = nsnull) = 0;
  73
  74   /**
  75    * Get the dimensions of the container
  76    * @param aWidth return value for width of container
  77    * @param aHeight return value for height of container
  78    */
  79   NS_IMETHOD  GetContainerSize(nscoord *aWidth, nscoord *aHeight) const = 0;
  80
  81   /**
  82    * Set the view that we are scrolling within the scrolling view.
  83    */
  84   NS_IMETHOD  SetScrolledView(nsIView *aScrolledView) = 0;
  85
  86   /**
  87    * Get the view that we are scrolling within the scrolling view.
  88    * @result child view
  89    */
  90   NS_IMETHOD  GetScrolledView(nsIView *&aScrolledView) const = 0;
  91
  92   /**
  93    * Get the position of the scrolled view.
  94    */
  95   NS_IMETHOD  GetScrollPosition(nscoord &aX, nscoord& aY) const = 0;
  96
  97   /**
  98    * Scroll the view to the given x,y, update's the scrollbar's thumb
  99    * positions and the view's offset. Clamps the values to be
 100    * legal. Updates the display based on aUpdateFlags.
 101    * @param aX left edge to scroll to
 102    * @param aY top edge to scroll to
 103    * @param aUpdateFlags indicate smooth or async scrolling
 104    * @return error status
 105    */
 106   NS_IMETHOD ScrollTo(nscoord aX, nscoord aY, PRUint32 aUpdateFlags) = 0;
 107
 108   /**
 109    * Set the properties describing how scrolling can be performed
 110    * in this scrollable.
 111    * @param aProperties new properties
 112    * @return error status
 113    */
 114   NS_IMETHOD SetScrollProperties(PRUint32 aProperties) = 0;
 115
 116   /**
 117    * Get the properties describing how scrolling can be performed
 118    * in this scrollable.
 119    * @param aProperties out parameter for current properties
 120    * @return error status
 121    */
 122   NS_IMETHOD GetScrollProperties(PRUint32 *aProperties) = 0;
 123
 124   /**
 125    * Set the height of a line used for line scrolling.
 126    * @param aHeight new line height in app units. the default
 127    *        height is 12 points.
 128    * @return error status
 129    */
 130   NS_IMETHOD SetLineHeight(nscoord aHeight) = 0;
 131
 132   /**
 133    * Get the height of a line used for line scrolling.
 134    * @param aHeight out parameter for line height
 135    * @return error status
 136    */
 137   NS_IMETHOD GetLineHeight(nscoord *aHeight) = 0;
 138
 139   /**
 140    * Scroll the view left or right by aNumLinesX columns. Positive values move right.
 141    * Scroll the view up or down by aNumLinesY lines. Positive values move down.
 142    * Prevents scrolling off the end of the view.
 143    * @param aNumLinesX number of lines to scroll the view horizontally
 144    * @param aNumLinesY number of lines to scroll the view vertically
 145    * @param aUpdateFlags indicate smooth or async scrolling
 146    * @return error status
 147    */
 148   NS_IMETHOD ScrollByLines(PRInt32 aNumLinesX, PRInt32 aNumLinexY,
 149                            PRUint32 aUpdateFlags = 0) = 0;
 150
 151   /**
 152    * Get the desired size of a page scroll in each dimension.
 153    * ScrollByPages will scroll by independent multiples of these amounts
 154    * unless it hits the edge of the view.
 155    */
 156   NS_IMETHOD GetPageScrollDistances(nsSize *aDistances) = 0;
 157
 158   /**
 159    * Scroll the view left or right by aNumPagesX pages. Positive values move right.
 160    * Scroll the view up or down by aNumPagesY pages. Positive values move down.
 161    * A page is considered to be the amount displayed by the clip view.
 162    * Prevents scrolling off the end of the view.
 163    * @param aNumPagesX number of pages to scroll the view horizontally
 164    * @param aNumPagesY number of pages to scroll the view vertically
 165    * @param aUpdateFlags indicate smooth or async scrolling
 166    * @return error status
 167    */
 168   NS_IMETHOD ScrollByPages(PRInt32 aNumPagesX, PRInt32 aNumPagesY,
 169                            PRUint32 aUpdateFlags = 0) = 0;
 170
 171   /**
 172    * Scroll the view to the top or bottom of the document depending
 173    * on the value of aTop.
 174    * @param aForward indicates whether to scroll to top or bottom
 175    * @param aUpdateFlags indicate smooth or async scrolling
 176    * @return error status
 177    */
 178   NS_IMETHOD ScrollByWhole(PRBool aTop, PRUint32 aUpdateFlags = 0) = 0;
 179
 180   /**
 181    * Scroll the view left or right by aNumLinesX pixels.  Positive values move
 182    * right.  Scroll the view up or down by aNumLinesY pixels.  Positive values
 183    * move down.  Prevents scrolling off the end of the view.
 184    * @param aNumLinesX number of lines to scroll the view horizontally
 185    * @param aNumLinesY number of lines to scroll the view vertically
 186    * @param aUpdateFlags indicate smooth or async scrolling
 187    * @return error status
 188    */
 189   NS_IMETHOD ScrollByPixels(PRInt32 aNumPixelsX, PRInt32 aNumPixelsY,
 190                             PRUint32 aUpdateFlags = 0) = 0;
 191
 192   /**
 193    * Check the view can scroll from current offset.
 194    * @param aHorizontal If checking to Left or to Right, true. Otherwise, false.
 195    * @param aForward    If checking to Right or Bottom, true. Otherwise, false.
 196    * @param aResult     If the view can scroll, true. Otherwise, false.
 197    * @return            error status
 198    */
 199   NS_IMETHOD CanScroll(PRBool aHorizontal, PRBool aForward, PRBool &aResult) = 0;
 200
 201   /**
 202    * Returns the view as an nsIView*
 203    */
 204   NS_IMETHOD_(nsIView*) View() = 0;
 205
 206   /**
 207    * Adds a scroll position listener.
 208    */
 209   NS_IMETHOD AddScrollPositionListener(nsIScrollPositionListener* aListener) = 0;
 210
 211   /**
 212    * Removes a scroll position listener.
 213    */
 214   NS_IMETHOD RemoveScrollPositionListener(nsIScrollPositionListener* aListener) = 0;
 215 };
 216
 217 NS_DEFINE_STATIC_IID_ACCESSOR(nsIScrollableView, NS_ISCROLLABLEVIEW_IID)
 218
 219 //regardless of the transparency or opacity settings
 220 //for this view, it can always be scrolled via a blit
 221 #define NS_SCROLL_PROPERTY_ALWAYS_BLIT    0x0001
 222
 223 #endif