basictreeui.java

gcc的组建

    completeUIUninstall();
  }

  /**
   * Paints the specified component appropriate for the look and feel. This
   * method is invoked from the ComponentUI.update method when the specified
   * component is being painted. Subclasses should override this method and use
   * the specified Graphics object to render the content of the component.
   * 
   * @param g
   *          the Graphics context in which to paint
   * @param c
   *          the component being painted; this argument is often ignored, but
   *          might be used if the UI object is stateless and shared by multiple
   *          components
   */
  public void paint(Graphics g, JComponent c)
  {
    JTree tree = (JTree) c;
    if (currentVisiblePath == null)
      updateCurrentVisiblePath();

    Rectangle clip = g.getClipBounds();
    Insets insets = tree.getInsets();

    if (clip != null && treeModel != null && currentVisiblePath != null)
      {
        int startIndex = tree.getClosestRowForLocation(clip.x, clip.y);
        int endIndex = tree.getClosestRowForLocation(clip.x + clip.width,
                                                     clip.y + clip.height);

        paintVerticalPartOfLeg(g, clip, insets, currentVisiblePath);
        for (int i = startIndex; i <= endIndex; i++)
          {
            Object curr = currentVisiblePath.getPathComponent(i);
            boolean isLeaf = treeModel.isLeaf(curr);
            TreePath path = new TreePath(getPathToRoot(curr, 0));

            boolean isExpanded = tree.isExpanded(path);
            Rectangle bounds = getPathBounds(tree, path);
            paintHorizontalPartOfLeg(g, clip, insets, bounds, path, i,
                                     isExpanded, false, isLeaf);
            paintRow(g, clip, insets, bounds, path, i, isExpanded, false,
                     isLeaf);
          }
      }
  }

  /**
   * Ensures that the rows identified by beginRow through endRow are visible.
   * 
   * @param beginRow
   *          is the first row
   * @param endRow
   *          is the last row
   */
  protected void ensureRowsAreVisible(int beginRow, int endRow)
  {
    if (beginRow < endRow)
      {
        int temp = endRow;
        endRow = beginRow;
        beginRow = temp;
      }
    
    for (int i = beginRow; i < endRow; i++)
      {
        TreePath path = getPathForRow(tree, i);
        if (!tree.isVisible(path))
          tree.makeVisible(path);
      }
  }

  /**
   * Sets the preferred minimum size.
   * 
   * @param newSize
   *          is the new preferred minimum size.
   */
  public void setPreferredMinSize(Dimension newSize)
  {
    preferredMinSize = newSize;
  }

  /**
   * Gets the preferred minimum size.
   * 
   * @returns the preferred minimum size.
   */
  public Dimension getPreferredMinSize()
  {
    return preferredMinSize;
  }

  /**
   * Returns the preferred size to properly display the tree, this is a cover
   * method for getPreferredSize(c, false).
   * 
   * @param c
   *          the component whose preferred size is being queried; this argument
   *          is often ignored but might be used if the UI object is stateless
   *          and shared by multiple components
   * @return the preferred size
   */
  public Dimension getPreferredSize(JComponent c)
  {
    return getPreferredSize(c, false);
  }

  /**
   * Returns the preferred size to represent the tree in c. If checkConsistancy
   * is true, checkConsistancy is messaged first.
   * 
   * @param c
   *          the component whose preferred size is being queried.
   * @param checkConsistancy
   *          if true must check consistancy
   * @return the preferred size
   */
  public Dimension getPreferredSize(JComponent c, boolean checkConsistancy)
  {
    // FIXME: checkConsistancy not implemented, c not used 
    if(!validCachedPreferredSize) 
      updateCachedPreferredSize();
    return preferredSize;
  }

  /**
   * Returns the minimum size for this component. Which will be the min
   * preferred size or (0,0).
   * 
   * @param c
   *          the component whose min size is being queried.
   * @returns the preferred size or null
   */
  public Dimension getMinimumSize(JComponent c)
  {
    Dimension min = getPreferredMinSize(); 
    if (min == null)
      return new Dimension();
    return min;
  }

  /**
   * Returns the maximum size for the component, which will be the preferred
   * size if the instance is currently in JTree or (0,0).
   * 
   * @param c
   *          the component whose preferred size is being queried
   * @return the max size or null
   */
  public Dimension getMaximumSize(JComponent c)
  {
    if (c instanceof JTree)
      return ((JTree) c).getPreferredSize();
    return new Dimension();
  }

  /**
   * Messages to stop the editing session. If the UI the receiver is providing
   * the look and feel for returns true from
   * <code>getInvokesStopCellEditing</code>, stopCellEditing will be invoked
   * on the current editor. Then completeEditing will be messaged with false,
   * true, false to cancel any lingering editing.
   */
  protected void completeEditing()
  {
    completeEditing(false, true, false);
  }

  /**
   * Stops the editing session. If messageStop is true, the editor is messaged
   * with stopEditing, if messageCancel is true the editor is messaged with
   * cancelEditing. If messageTree is true, the treeModel is messaged with
   * valueForPathChanged.
   * 
   * @param messageStop
   *          message to stop editing
   * @param messageCancel
   *          message to cancel editing
   * @param messageTree
   *          message to treeModel
   */
  protected void completeEditing(boolean messageStop, boolean messageCancel,
                                 boolean messageTree)
  {
    if (messageStop)
      {
        getCellEditor().stopCellEditing();
        stopEditingInCompleteEditing = true;
      }

    if (messageCancel)
      {
        getCellEditor().cancelCellEditing();
        stopEditingInCompleteEditing = true;
      }

    if (messageTree)
      treeModel.valueForPathChanged(tree.getLeadSelectionPath(), newVal);
  }

  /**
   * Will start editing for node if there is a cellEditor and shouldSelectCall
   * returns true. This assumes that path is valid and visible.
   * 
   * @param path
   *          is the path to start editing
   * @param event
   *          is the MouseEvent performed on the path
   * @return true if successful
   */
  protected boolean startEditing(TreePath path, MouseEvent event)
  {
    int x;
    int y;
    if (event == null)
      {
        Rectangle bounds = getPathBounds(tree, path);
        x = bounds.x;
        y = bounds.y;
      }
    else
      {
        x = event.getX();
        y = event.getY();
      }

    updateCellEditor();
    TreeCellEditor ed = getCellEditor();
    if (ed != null && ed.shouldSelectCell(event) && ed.isCellEditable(event))
      {
        editingPath = path;
        editingRow = tree.getRowForPath(editingPath);

        Object val = editingPath.getLastPathComponent();
        cellEditor.addCellEditorListener(cellEditorListener);
        stopEditingInCompleteEditing = false;
        boolean expanded = tree.isExpanded(editingPath);
        isEditing = true;
        editingComponent = ed.getTreeCellEditorComponent(tree, val, true,
                                                         expanded,
                                                         isLeaf(editingRow),
                                                         editingRow);
        editingComponent.getParent().setVisible(true);
        editingComponent.getParent().validate();
        tree.add(editingComponent.getParent());
        editingComponent.getParent().validate();
        validCachedPreferredSize = false;
        tree.revalidate();
        ((JTextField) editingComponent).requestFocusInWindow(false);
        editorTimer.start();
        return true;
      }
    return false;
  }

  /**
   * If the <code>mouseX</code> and <code>mouseY</code> are in the expand or
   * collapse region of the row, this will toggle the row.
   * 
   * @param path
   *          the path we are concerned with
   * @param mouseX
   *          is the cursor's x position
   * @param mouseY
   *          is the cursor's y position
   */
  protected void checkForClickInExpandControl(TreePath path, int mouseX,
                                              int mouseY)
  {
    if (isLocationInExpandControl(path, mouseX, mouseY))
      toggleExpandState(path);
  }

  /**
   * Returns true if the <code>mouseX</code> and <code>mouseY</code> fall in
   * the area of row that is used to expand/collpse the node and the node at row
   * does not represent a leaf.
   * 
   * @param path
   *          the path we are concerned with
   * @param mouseX
   *          is the cursor's x position
   * @param mouseY
   *          is the cursor's y position
   * @return true if the <code>mouseX</code> and <code>mouseY</code> fall in
   *         the area of row that is used to expand/collpse the node and the
   *         node at row does not represent a leaf.
   */
  protected boolean isLocationInExpandControl(TreePath path, int mouseX,
                                              int mouseY)
  {
    boolean cntlClick = false;
    int row = getRowForPath(tree, path);
    
    if (!isLeaf(row))
      {
        Rectangle bounds = getPathBounds(tree, path);

        if (hasControlIcons() && (mouseX < bounds.x) 
            && (mouseX > (bounds.x - getCurrentControlIcon(path).getIconWidth() - gap)))
          cntlClick = true;
      }
    return cntlClick;
  }

  /**
   * Messaged when the user clicks the particular row, this invokes
   * toggleExpandState.
   * 
   * @param path
   *          the path we are concerned with
   * @param mouseX
   *          is the cursor's x position
   * @param mouseY
   *          is the cursor's y position
   */
  protected void handleExpandControlClick(TreePath path, int mouseX, int mouseY)
  {
    toggleExpandState(path);
  }

  /**
   * Expands path if it is not expanded, or collapses row if it is expanded. If
   * expanding a path and JTree scroll on expand, ensureRowsAreVisible is
   * invoked to scroll as many of the children to visible as possible (tries to
   * scroll to last visible descendant of path).
   * 
   * @param path
   *          the path we are concerned with
   */
  protected void toggleExpandState(TreePath path)
  {
    if (tree.isExpanded(path))
      tree.collapsePath(path);
    else
      tree.expandPath(path);
    updateCurrentVisiblePath();
  }

  /**
   * Returning true signifies a mouse event on the node should toggle the
   * selection of only the row under the mouse.
   * 
   * @param event
   *          is the MouseEvent performed on the row.
   * @return true signifies a mouse event on the node should toggle the
   *         selection of only the row under the mouse.
   */
  protected boolean isToggleSelectionEvent(MouseEvent event)
  {
    return (tree.getSelectionModel().getSelectionMode() == 
      TreeSelectionModel.SINGLE_TREE_SELECTION);
  }

  /**
   * Returning true signifies a mouse event on the node should select from the
   * anchor point.
   * 
   * @param event
   *          is the MouseEvent performed on the node.
   * @return true signifies a mouse event on the node should select from the
   *         anchor point.
   */
  protected boolean isMultiSelectEvent(MouseEvent event)
  {
    return (tree.getSelectionModel().getSelectionMode() == 
      TreeSelectionModel.CONTIGUOUS_TREE_SELECTION);
  }

  /**
   * Returning true indicates the row under the mouse should be toggled based on
   * the event. This is invoked after checkForClickInExpandControl, implying the
   * location is not in the expand (toggle) control.
   * 
   * @param event
   *          is the MouseEvent performed on the row.
   * @return true indicates the row under the mouse should be toggled based on
   *         the event.
   */
  protected boolean isToggleEvent(MouseEvent event)
  {
    return true;
  }

  /**
   * Messaged to update the selection based on a MouseEvent over a particular
   * row. If the even is a toggle selection event, the row is either selected,
   * or deselected. If the event identifies a multi selection event, the
   * selection is updated from the anchor point. Otherwise, the row is selected,
   * and if the even specified a toggle event the row is expanded/collapsed.
   * 
   * @param path
   *          is the path selected for an event
   * @param event
   *          is the MouseEvent performed on the path.
   */
  protected void selectPathForEvent(TreePath path, MouseEvent event)
  {
    if (isToggleSelectionEvent(event))
      {
        if (tree.isPathSelected(path))
          tree.removeSelectionPath(path);
        else
          {
            tree.addSelectionPath(path);
            tree.setAnchorSelectionPath(path);
          }
      }
    else if (isMultiSelectEvent(event))
      {
        TreePath anchor = tree.getAnchorSelectionPath();
        if (anchor != null)
          {
            int aRow = getRowForPath(tree, anchor);
            tree.addSelectionInterval(aRow, getRowForPath(tree, path));
          }
        else
          tree.addSelectionPath(path);
      }
    else
      tree.addSelectionPath(path);
  }

  /**
   * Returns true if the node at <code>row</code> is a leaf.
   * 
   * @param row
   *          is the row we are concerned with.
   * @return true if the node at <code>row</code> is a leaf.
   */
  protected boolean isLeaf(int row)
  {
    TreePath pathForRow = getPathForRow(tree, row);
    if (pathForRow == null)
      return true;

    Object node = pathForRow.getLastPathComponent();
    return treeModel.isLeaf(node);
  }

  /**
   * This class implements the actions that we want to happen when specific keys
   * are pressed for the JTree. The actionPerformed method is called when a key
   * that has been registered for the JTree is received.
   */
  class TreeAction
    extends AbstractAction
  {

    /**
     * What to do when this action is called.
     * 
     * @param e
     *          the ActionEvent that caused this action.
     */
    public void actionPerformed(ActionEvent e)
    {
      TreePath lead = tree.getLeadSelectionPath();

      if (e.getActionCommand().equals("selectPreviousChangeLead")
          || e.getActionCommand().equals("selectPreviousExtendSelection")