basictreeui.java

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   *          is the height to set this.rowHeight to.
   */
  protected void setRowHeight(int rowHeight)
  {
    if (rowHeight == 0)
      rowHeight = Math.max(getMaxHeight(tree), 20);
    treeState.setRowHeight(rowHeight);
  }

  /**
   * Returns the current row height.
   * 
   * @return current row height.
   */
  protected int getRowHeight()
  {
    return treeState.getRowHeight();
  }

  /**
   * Sets the TreeCellRenderer to <code>tcr</code>. This invokes
   * <code>updateRenderer</code>.
   * 
   * @param tcr
   *          is the new TreeCellRenderer.
   */
  protected void setCellRenderer(TreeCellRenderer tcr)
  {
    currentCellRenderer = tcr;
    updateRenderer();
  }

  /**
   * Return currentCellRenderer, which will either be the trees renderer, or
   * defaultCellRenderer, which ever was not null.
   * 
   * @return the current Cell Renderer
   */
  protected TreeCellRenderer getCellRenderer()
  {
    if (currentCellRenderer != null)
      return currentCellRenderer;

    return createDefaultCellRenderer();
  }

  /**
   * Sets the tree's model.
   * 
   * @param model
   *          to set the treeModel to.
   */
  protected void setModel(TreeModel model)
  {
    tree.setModel(model);
    treeModel = tree.getModel();
  }

  /**
   * Returns the tree's model
   * 
   * @return treeModel
   */
  protected TreeModel getModel()
  {
    return treeModel;
  }

  /**
   * Sets the root to being visible.
   * 
   * @param newValue
   *          sets the visibility of the root
   */
  protected void setRootVisible(boolean newValue)
  {
    tree.setRootVisible(newValue);
  }

  /**
   * Returns true if the root is visible.
   * 
   * @return true if the root is visible.
   */
  protected boolean isRootVisible()
  {
    return tree.isRootVisible();
  }

  /**
   * Determines whether the node handles are to be displayed.
   * 
   * @param newValue
   *          sets whether or not node handles should be displayed.
   */
  protected void setShowsRootHandles(boolean newValue)
  {
    tree.setShowsRootHandles(newValue);
  }

  /**
   * Returns true if the node handles are to be displayed.
   * 
   * @return true if the node handles are to be displayed.
   */
  protected boolean getShowsRootHandles()
  {
    return tree.getShowsRootHandles();
  }

  /**
   * Sets the cell editor.
   * 
   * @param editor
   *          to set the cellEditor to.
   */
  protected void setCellEditor(TreeCellEditor editor)
  {
    cellEditor = editor;
    createdCellEditor = true;
  }

  /**
   * Returns the <code>TreeCellEditor</code> for this tree.
   * 
   * @return the cellEditor for this tree.
   */
  protected TreeCellEditor getCellEditor()
  {
    return cellEditor;
  }

  /**
   * Configures the receiver to allow, or not allow, editing.
   * 
   * @param newValue
   *          sets the receiver to allow editing if true.
   */
  protected void setEditable(boolean newValue)
  {
    tree.setEditable(newValue);
  }

  /**
   * Returns true if the receiver allows editing.
   * 
   * @return true if the receiver allows editing.
   */
  protected boolean isEditable()
  {
    return tree.isEditable();
  }

  /**
   * Resets the selection model. The appropriate listeners are installed on the
   * model.
   * 
   * @param newLSM
   *          resets the selection model.
   */
  protected void setSelectionModel(TreeSelectionModel newLSM)
  {
    if (newLSM != null)
      {
        treeSelectionModel = newLSM;
        tree.setSelectionModel(treeSelectionModel);
      }
  }

  /**
   * Returns the current selection model.
   * 
   * @return the current selection model.
   */
  protected TreeSelectionModel getSelectionModel()
  {
    return treeSelectionModel;
  }

  /**
   * Returns the Rectangle enclosing the label portion that the last item in
   * path will be drawn to. Will return null if any component in path is
   * currently valid.
   * 
   * @param tree
   *          is the current tree the path will be drawn to.
   * @param path
   *          is the current path the tree to draw to.
   * @return the Rectangle enclosing the label portion that the last item in the
   *         path will be drawn to.
   */
  public Rectangle getPathBounds(JTree tree, TreePath path)
  {
    int row = -1;
    Object cell = null;
    if (path != null)
      {
        row = getRowForPath(tree, path);
        cell = path.getLastPathComponent();
      }
    return nodeDimensions.getNodeDimensions(cell, row, getLevel(cell),
                                            tree.isExpanded(path),
                                            new Rectangle());
  }

  /**
   * Returns the max height of all the nodes in the tree.
   * 
   * @param tree -
   *          the current tree
   * @return the max height.
   */
  private int getMaxHeight(JTree tree)
  {
    if (maxHeight != 0)
      return maxHeight;

    Icon e = UIManager.getIcon("Tree.openIcon");
    Icon c = UIManager.getIcon("Tree.closedIcon");
    Icon l = UIManager.getIcon("Tree.leafIcon");
    int rc = getRowCount(tree);
    int iconHeight = 0;

    for (int row = 0; row < rc; row++)
      {
        if (isLeaf(row))
          iconHeight = l.getIconHeight();
        else if (tree.isExpanded(row))
          iconHeight = e.getIconHeight();
        else
          iconHeight = c.getIconHeight();

        maxHeight = Math.max(maxHeight, iconHeight + gap);
      }

    return maxHeight;
  }

  /**
   * Returns the path for passed in row. If row is not visible null is returned.
   * 
   * @param tree
   *          is the current tree to return path for.
   * @param row
   *          is the row number of the row to return.
   * @return the path for passed in row. If row is not visible null is returned.
   */
  public TreePath getPathForRow(JTree tree, int row)
  {
    if (treeModel != null && currentVisiblePath != null)
      {
        Object[] nodes = currentVisiblePath.getPath();
        if (row < nodes.length)
          return new TreePath(getPathToRoot(nodes[row], 0));
      }
    return null;
  }

  /**
   * Returns the row that the last item identified in path is visible at. Will
   * return -1 if any of the elments in the path are not currently visible.
   * 
   * @param tree
   *          is the current tree to return the row for.
   * @param path
   *          is the path used to find the row.
   * @return the row that the last item identified in path is visible at. Will
   *         return -1 if any of the elments in the path are not currently
   *         visible.
   */
  public int getRowForPath(JTree tree, TreePath path)
  {
    int row = 0;
    Object dest = path.getLastPathComponent();
    int rowCount = getRowCount(tree);
    if (currentVisiblePath != null)
      {
        Object[] nodes = currentVisiblePath.getPath();
        while (row < rowCount)
          {
            if (dest.equals(nodes[row]))
              return row;
            row++;
          }
      }
    return -1;
  }

  /**
   * Returns the number of rows that are being displayed.
   * 
   * @param tree
   *          is the current tree to return the number of rows for.
   * @return the number of rows being displayed.
   */
  public int getRowCount(JTree tree)
  {
    if (currentVisiblePath != null)
      return currentVisiblePath.getPathCount();
    return 0;
  }

  /**
   * Returns the path to the node that is closest to x,y. If there is nothing
   * currently visible this will return null, otherwise it'll always return a
   * valid path. If you need to test if the returned object is exactly at x,y
   * you should get the bounds for the returned path and test x,y against that.
   * 
   * @param tree
   *          the tree to search for the closest path
   * @param x
   *          is the x coordinate of the location to search
   * @param y
   *          is the y coordinate of the location to search
   * @return the tree path closes to x,y.
   */
  public TreePath getClosestPathForLocation(JTree tree, int x, int y)
  {
    int row = Math.round(y / getMaxHeight(tree));
    TreePath path = getPathForRow(tree, row);

    // no row is visible at this node
    while (row > 0 && path == null)
      {
        --row;
        path = getPathForRow(tree, row);
      }

    return path;
  }

  /**
   * Returns true if the tree is being edited. The item that is being edited can
   * be returned by getEditingPath().
   * 
   * @param tree
   *          is the tree to check for editing.
   * @return true if the tree is being edited.
   */
  public boolean isEditing(JTree tree)
  {
    return isEditing;
  }

  /**
   * Stops the current editing session. This has no effect if the tree is not
   * being edited. Returns true if the editor allows the editing session to
   * stop.
   * 
   * @param tree
   *          is the tree to stop the editing on
   * @return true if the editor allows the editing session to stop.
   */
  public boolean stopEditing(JTree tree)
  {
    if (isEditing(tree))
      {
        completeEditing(false, false, true);
        finish();
      }
    return !isEditing(tree);
  }

  /**
   * Cancels the current editing session.
   * 
   * @param tree
   *          is the tree to cancel the editing session on.
   */
  public void cancelEditing(JTree tree)
  {   
      // There is no need to send the cancel message to the editor,
      // as the cancellation event itself arrives from it. This would
      // only be necessary when cancelling the editing programatically.
      completeEditing(false, false, false);
      finish();
  }

  /**
   * Selects the last item in path and tries to edit it. Editing will fail if
   * the CellEditor won't allow it for the selected item.
   * 
   * @param tree
   *          is the tree to edit on.
   * @param path
   *          is the path in tree to edit on.
   */
  public void startEditingAtPath(JTree tree, TreePath path)
  {
    startEditing(path, null);
  }

  /**
   * Returns the path to the element that is being editted.
   * 
   * @param tree
   *          is the tree to get the editing path from.
   * @return the path that is being edited.
   */
  public TreePath getEditingPath(JTree tree)
  {
    return editingPath;
  }

  /**
   * Invoked after the tree instance variable has been set, but before any
   * default/listeners have been installed.
   */
  protected void prepareForUIInstall()
  {
    // TODO: Implement this properly.
  }

  /**
   * Invoked from installUI after all the defaults/listeners have been
   * installed.
   */
  protected void completeUIInstall()
  {
    // TODO: Implement this properly.
  }

  /**
   * Invoked from uninstallUI after all the defaults/listeners have been
   * uninstalled.
   */
  protected void completeUIUninstall()
  {
    // TODO: Implement this properly.
  }

  /**
   * Installs the subcomponents of the tree, which is the renderer pane.
   */
  protected void installComponents()
  {
    currentCellRenderer = createDefaultCellRenderer();
    rendererPane = createCellRendererPane();
    createdRenderer = true;
    setCellRenderer(currentCellRenderer);
  }

  /**
   * Creates an instance of NodeDimensions that is able to determine the size of
   * a given node in the tree.
   * 
   * @return the NodeDimensions of a given node in the tree
   */
  protected AbstractLayoutCache.NodeDimensions createNodeDimensions()
  {
    return new NodeDimensionsHandler();
  }

  /**
   * Creates a listener that is reponsible for the updates the UI based on how
   * the tree changes.
   * 
   * @return the PropertyChangeListener that is reposnsible for the updates
   */
  protected PropertyChangeListener createPropertyChangeListener()