Bug 283263

Description Jeff 2009-07-12 22:20:19 EDT

As an example let say I have a table with 2 rows and the row height is 20 pixels each.  The first row is the header, since the height is 20 pixels the y coordinate goes from 0 to 19 and the y coordinate of the 2nd row goes from 20 to 39.

If I click on the table where the y coordinate = 20, I would get a ArrayIndexOutofBoundsException in my log, with the following stacktrace:

java.lang.ArrayIndexOutOfBoundsException: -1
	at org.eclipse.swt.widgets.Table._getItem(Table.java:2101)
	at org.eclipse.swt.widgets.Table.getItem(Table.java:676)
	at org.eclipse.jface.viewers.TableViewer.getItemAt(TableViewer.java:197)
	at org.eclipse.jface.viewers.ColumnViewer.getViewerRow(ColumnViewer.java:150)
	at org.eclipse.jface.viewers.ColumnViewer.getCell(ColumnViewer.java:133)
	at org.eclipse.jface.viewers.ColumnViewer.handleMouseDown(ColumnViewer.java:649)
	at org.eclipse.jface.viewers.ColumnViewer.access$0(ColumnViewer.java:648)
	at org.eclipse.jface.viewers.ColumnViewer$1.mouseDown(ColumnViewer.java:88)


The problem I believe is with the following code in the Table class.

  public TableItem getItem( final Point point ) {
    checkWidget();
    TableItem result = null;
    int headerHeight = getHeaderHeight();
    Rectangle itemArea = getClientArea();
    itemArea.y += headerHeight;
    if( itemArea.contains( point ) ) {
      int itemHeight = getItemHeight();
      int index = ( ( point.y - headerHeight ) / itemHeight ) - 1;
      if( point.y == 0 || point.y % itemHeight != 0 ) {
        index++;
      }
      index += topIndex;
      if( index < itemCount ) {
        result = _getItem( index );
      }
    }
    return result;
  }

The itemArea contains the point which is correct, but the calculation of the index is incorrect.  In this case where point.y = 20, if u step through the above code u will see the index value at the end is -1, causing the exception.  (topIndex is 0)