src/tim/prune/undo/UndoDeleteOperation.java

   1 package tim.prune.undo;
   2
   3 import tim.prune.data.TrackInfo;
   4
   5 /**
   6  * Abstract class to hold the selection handling required by all
   7  * Undo operations which have undeleted something
   8  */
   9 public abstract class UndoDeleteOperation implements UndoOperation
  10 {
  11         /** Flag to remember whether the deleted point was at the beginning or end of the selected range */
  12         private boolean _isAtBoundaryOfSelectedRange = false;
  13
  14         /**
  15          * @param inAtBoundary true if deleted point was at the beginning or end of the selected range
  16          */
  17         public void setAtBoundaryOfSelectedRange(boolean inAtBoundary)
  18         {
  19                 _isAtBoundaryOfSelectedRange = inAtBoundary;
  20         }
  21
  22         /**
  23          * Modify the current point/range selection after the delete operation is undone
  24          * @param inTrackInfo track info object
  25          * @param inStartIndex start index of reinserted range
  26          * @param inEndIndex end index of reinserted range
  27          */
  28         protected void modifySelection(TrackInfo inTrackInfo, int inStartIndex, int inEndIndex)
  29         {
  30                 final int numPointsInserted = inEndIndex - inStartIndex + 1;
  31                 // See if there is a currently selected point, if so does it need to be modified
  32                 final int currentPoint = inTrackInfo.getSelection().getCurrentPointIndex();
  33                 if (currentPoint >= inStartIndex)
  34                 {
  35                         inTrackInfo.selectPoint(currentPoint + numPointsInserted);
  36                 }
  37                 // Same for currently selected range
  38                 int rangeStart = inTrackInfo.getSelection().getStart();
  39                 int rangeEnd   = inTrackInfo.getSelection().getEnd();
  40                 // Was the deleted point at the start or end of the selected range?
  41                 final boolean wasAtStart = numPointsInserted == 1 && inStartIndex == rangeStart && _isAtBoundaryOfSelectedRange;
  42                 final boolean wasAtEnd   = numPointsInserted == 1 && inStartIndex == (rangeEnd+1) && _isAtBoundaryOfSelectedRange;
  43                 if (rangeEnd >= inStartIndex && rangeEnd > rangeStart || wasAtStart || wasAtEnd)
  44                 {
  45                         rangeEnd += numPointsInserted;
  46                         if (rangeStart >= inStartIndex) {
  47                                 rangeStart += numPointsInserted;
  48                         }
  49                         // Extend selection if the deleted point was at the start or end
  50                         if (wasAtStart) {
  51                                 rangeStart--;
  52                         }
  53                         inTrackInfo.getSelection().selectRange(rangeStart, rangeEnd);
  54                 }
  55         }
  56 }