package bluej.stride.generic;

import java.util.List;

public interface CursorFinder
{        



| Finds a cursor for this Y coordinate (in scene coordinates).  Essentially there are three cases:
|
| 1. The point is before this block.  Because we scan down the blocks in order
|    using this method, it should return the given prevCursor.
|
| 2. The point is within this block.  This method should return the nearest
|    cursor, e.g. the cursor before if the point is in the top half of the block
|    and the cursor after if it is in the bottom half, or a similar appropriate heuristic.
|
| 3. The point is after this block.  This method should still return the last cursor.
|
| @param sceneY The Y in scene coordinates at which to find the nearest cursor
| @param prevCursor The cursor before this frame, or null
| @param nextCursor The cursor after this frame, or null
| @param exclude Cursors in this frame that are not a valid answer (e.g. because they are being dragged and we are looking for a drag target).
| @param canDescend If true, can go into subframes to find a closest cursor.  If false, only look
|                   at cursors at the top level.
|
public FrameCursor findCursor(double sceneX, double sceneY, FrameCursor prevCursor, FrameCursor nextCursor, List<Frame> exclude, boolean isDrag, boolean canDescend); 
   }