Name: sdC67446 Date: 06/08/99


The method
   protected boolean canPathsBeAdded(TreePath[] paths)
of class javax.swing.tree.DefaultTreeSelectionModel
returns true if 'paths' cant be added without breaking the continuity
of the model. This happens in case when array of TreePaths with the
hole inside has been selected before. (see example).

The doc says:
--------------------------------------------------
    /**
     * Returns true if the paths can be added without breaking the
     * continuity of the model.
     */
    protected boolean canPathsBeAdded(TreePath[] paths)

The test demonstrating the bug:
-----------------Test.java------------------------
import javax.swing.tree.*;

public class Test {

    public static class DummyDefaultTreeSelectionModel extends DefaultTreeSelectionModel {
        public boolean canPathsBeAdded(TreePath[] paths) {
            return super.canPathsBeAdded(paths);
        }
    }

    public static class DummyRowMapper implements RowMapper {

        // this is it - returning row of the path is the count of path's components
        // ["1"] -> 1
        // ["1", "2"] -> 2
        // ["1", "2", "3"] -> 3
        
        public int[] getRowsForPaths(TreePath[] path) {
            int rows[] = new int[path.length];
            for (int i=0;i<path.length;i++) {
                String userObject = (String)path[i].getPathComponent(0);
                rows[i] = path[i].getPathCount();
            }
            return rows;
        }
    }
    public static void main(String[] args) {
        Object objs1[] = {"1"};
        Object objs2[] = {"1", "2"};
        Object objs3[] = {"1", "2", "3"};
        Object objs4[] = {"1", "2", "3", "4"};
   
        DummyDefaultTreeSelectionModel model = new DummyDefaultTreeSelectionModel();
    
        // this is the "array of TreePaths with the hole inside":
        // so the array of its rows is: [[1], [3]]
        TreePath sPaths[] = {
            new TreePath(objs1),
            new TreePath(objs3)
        };

        TreePath paths[] = {
            new TreePath(objs4)
        };

        model.setSelectionPaths(sPaths);
        model.setRowMapper(new DummyRowMapper());
        model.setSelectionMode(TreeSelectionModel.CONTIGUOUS_TREE_SELECTION);

        System.out.println(" [[1], [3]] + [[4]] isn't continual, ");
        System.out.println(" but canPathsBeAdded(..) == "+model.canPathsBeAdded(paths));
    };
}
---------Output from the test---------------------
 [[1], [3]] + [[4]] isn't continual,
 but canPathsBeAdded(..) == true
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