basictabbedpaneui.java

gcc的组建

      Insets tabAreaInsets = getTabAreaInsets(tabPlacement);
      Insets insets = tabPane.getInsets();

      height -= tabAreaInsets.top + tabAreaInsets.bottom + insets.top
      + insets.bottom;
      int fontHeight = fm.getHeight();

      for (int i = 0; i < tabPane.getTabCount(); i++)
        {
          tabHeight = calculateTabHeight(tabPlacement, i, fontHeight);
          if (runHeight + tabHeight > height)
            {
              runHeight = tabHeight;
              runs++;
            }
          else
            runHeight += tabHeight;
        }
      runs++;

      int maxTabWidth = calculateMaxTabWidth(tabPlacement);
      int tabAreaWidth = calculateTabAreaWidth(tabPlacement, runs, maxTabWidth);
      return tabAreaWidth;
    }

    /**
     * This method rotates the places each run in the correct place  the
     * tabRuns array. See the comment for tabRuns for how the runs are placed
     * in the array.
     *
     * @param tabPlacement The JTabbedPane's tab placement.
     * @param selectedRun The run the current selection is in.
     */
    protected void rotateTabRuns(int tabPlacement, int selectedRun)
    {
      if (runCount == 1 || selectedRun == 1 || selectedRun == -1)
        return;
      int[] newTabRuns = new int[tabRuns.length];
      int currentRun = selectedRun;
      int i = 1;
      do
        {
          newTabRuns[i] = tabRuns[currentRun];
          currentRun = getNextTabRun(currentRun);
          i++;
        }
      while (i < runCount);
      if (runCount > 1)
        newTabRuns[0] = tabRuns[currentRun];

      tabRuns = newTabRuns;
      BasicTabbedPaneUI.this.selectedRun = 1;
    }

    /**
     * This method is called when a component is removed  from the
     * JTabbedPane.
     *
     * @param comp The component removed.
     */
    public void removeLayoutComponent(Component comp)
    {
      // Do nothing.
    }
  }

  /**
   * This class acts as the LayoutManager for the JTabbedPane in
   * SCROLL_TAB_MODE.
   */
  private class TabbedPaneScrollLayout extends TabbedPaneLayout
  {
    /**
     * This method returns the preferred layout size for the given container.
     *
     * @param parent The container to calculate a size for.
     *
     * @return The preferred layout size.
     */
    public Dimension preferredLayoutSize(Container parent)
    {
      return super.calculateSize(true);
    }

    /**
     * This method returns the minimum layout size for the given container.
     *
     * @param parent The container to calculate a size for.
     *
     * @return The minimum layout size.
     */
    public Dimension minimumLayoutSize(Container parent)
    {
      return super.calculateSize(true);
    }

    /**
     * This method calculates the tab area height given  a desired width.
     *
     * @param tabPlacement The JTabbedPane's tab placement.
     * @param width The expected width.
     *
     * @return The tab area height given the width.
     */
    protected int preferredTabAreaHeight(int tabPlacement, int width)
    {
      if (tabPane.getTabCount() == 0)
        return calculateTabAreaHeight(tabPlacement, 0, 0);

      int runs = 1;

      int maxTabHeight = calculateMaxTabHeight(tabPlacement);
      int tabAreaHeight = calculateTabAreaHeight(tabPlacement, runs,
                                                 maxTabHeight);
      return tabAreaHeight;
    }

    /**
     * This method calculates the tab area width given a desired height.
     *
     * @param tabPlacement The JTabbedPane's tab placement.
     * @param height The expected height.
     *
     * @return The tab area width given the height.
     */
    protected int preferredTabAreaWidth(int tabPlacement, int height)
    {
      if (tabPane.getTabCount() == 0)
        return calculateTabAreaHeight(tabPlacement, 0, 0);

      int runs = 1;

      int maxTabWidth = calculateMaxTabWidth(tabPlacement);
      int tabAreaWidth = calculateTabAreaWidth(tabPlacement, runs, maxTabWidth);
      return tabAreaWidth;
    }

    /**
     * This method is called to calculate the tab rectangles.  This method
     * will calculate the size and position of all  rectangles (taking into
     * account which ones should be in which tab run). It will pad them and
     * normalize them  as necessary.
     *
     * @param tabPlacement The JTabbedPane's tab placement.
     * @param tabCount The number of tabs.
     */
    protected void calculateTabRects(int tabPlacement, int tabCount)
    {
      if (tabCount == 0)
        return;
      assureRectsCreated(tabCount);

      FontMetrics fm = getFontMetrics();
      SwingUtilities.calculateInnerArea(tabPane, calcRect);
      Insets tabAreaInsets = getTabAreaInsets(tabPlacement);
      Insets insets = tabPane.getInsets();
      int max = 0;
      int runs = 1;
      int start = 0;
      int top = 0;
      if (tabPlacement == SwingConstants.TOP
          || tabPlacement == SwingConstants.BOTTOM)
        {
          int maxHeight = calculateMaxTabHeight(tabPlacement);
          calcRect.width -= tabAreaInsets.left + tabAreaInsets.right;
          max = calcRect.width + tabAreaInsets.left + insets.left;
          start = tabAreaInsets.left + insets.left;
          int width = 0;
          int runWidth = start;
          top = insets.top + tabAreaInsets.top;
          for (int i = 0; i < tabCount; i++)
            {
              width = calculateTabWidth(tabPlacement, i, fm);

              rects[i] = new Rectangle(runWidth, top, width, maxHeight);
              runWidth += width;
            }
          tabAreaRect.width = tabPane.getWidth() - insets.left - insets.right;
          tabAreaRect.height = runs * maxTabHeight
          - (runs - 1) * tabRunOverlay
          + tabAreaInsets.top + tabAreaInsets.bottom;
          contentRect.width = tabAreaRect.width;
          contentRect.height = tabPane.getHeight() - insets.top
          - insets.bottom - tabAreaRect.height;
          contentRect.x = insets.left;
          tabAreaRect.x = insets.left;
          if (tabPlacement == SwingConstants.BOTTOM)
            {
              contentRect.y = insets.top;
              tabAreaRect.y = contentRect.y + contentRect.height;
            }
          else
            {
              tabAreaRect.y = insets.top;
              contentRect.y = tabAreaRect.y + tabAreaRect.height;
            }
        }
      else
        {
          int maxWidth = calculateMaxTabWidth(tabPlacement);

          calcRect.height -= tabAreaInsets.top + tabAreaInsets.bottom;
          max = calcRect.height + tabAreaInsets.top;
          int height = 0;
          start = tabAreaInsets.top + insets.top;
          int runHeight = start;
          int fontHeight = fm.getHeight();
          top = insets.left + tabAreaInsets.left;
          for (int i = 0; i < tabCount; i++)
            {
              height = calculateTabHeight(tabPlacement, i, fontHeight);
              rects[i] = new Rectangle(top, runHeight, maxWidth, height);
              runHeight += height;
            }
          tabAreaRect.width = runs * maxTabWidth - (runs - 1) * tabRunOverlay
          + tabAreaInsets.left + tabAreaInsets.right;
          tabAreaRect.height = tabPane.getHeight() - insets.top
          - insets.bottom;
          tabAreaRect.y = insets.top;
          contentRect.width = tabPane.getWidth() - insets.left - insets.right
          - tabAreaRect.width;
          contentRect.height = tabAreaRect.height;
          contentRect.y = insets.top;
          if (tabPlacement == SwingConstants.LEFT)
            {
              tabAreaRect.x = insets.left;
              contentRect.x = tabAreaRect.x + tabAreaRect.width;
            }
          else
            {
              contentRect.x = insets.left;
              tabAreaRect.x = contentRect.x + contentRect.width;
            }
        }
      runCount = runs;

      padSelectedTab(tabPlacement, tabPane.getSelectedIndex());
    }

    /**
     * This method is called when the JTabbedPane is laid out in
     * SCROLL_TAB_LAYOUT. It finds the position for all components in the
     * JTabbedPane.
     *
     * @param pane The JTabbedPane to be laid out.
     */
    public void layoutContainer(Container pane)
    {
      super.layoutContainer(pane);
      int tabCount = tabPane.getTabCount();
      Point p = null;
      if (tabCount == 0)
        return;
      int tabPlacement = tabPane.getTabPlacement();
      incrButton.hide();
      decrButton.hide();
      if (tabPlacement == SwingConstants.TOP
          || tabPlacement == SwingConstants.BOTTOM)
        {
          if (tabAreaRect.x + tabAreaRect.width < rects[tabCount - 1].x
              + rects[tabCount - 1].width)
            {
              Dimension incrDims = incrButton.getPreferredSize();
              Dimension decrDims = decrButton.getPreferredSize();

              decrButton.setBounds(tabAreaRect.x + tabAreaRect.width
                                   - incrDims.width - decrDims.width,
                                   tabAreaRect.y, decrDims.width,
                                   tabAreaRect.height);
              incrButton.setBounds(tabAreaRect.x + tabAreaRect.width
                                   - incrDims.width, tabAreaRect.y,
                                   decrDims.width, tabAreaRect.height);

              tabAreaRect.width -= decrDims.width + incrDims.width;
              incrButton.show();
              decrButton.show();
            }
        }

      if (tabPlacement == SwingConstants.LEFT
          || tabPlacement == SwingConstants.RIGHT)
        {
          if (tabAreaRect.y + tabAreaRect.height < rects[tabCount - 1].y
              + rects[tabCount - 1].height)
            {
              Dimension incrDims = incrButton.getPreferredSize();
              Dimension decrDims = decrButton.getPreferredSize();

              decrButton.setBounds(tabAreaRect.x,
                                   tabAreaRect.y + tabAreaRect.height
                                   - incrDims.height - decrDims.height,
                                   tabAreaRect.width, decrDims.height);
              incrButton.setBounds(tabAreaRect.x,
                                   tabAreaRect.y + tabAreaRect.height
                                   - incrDims.height, tabAreaRect.width,
                                   incrDims.height);

              tabAreaRect.height -= decrDims.height + incrDims.height;
              incrButton.show();
              decrButton.show();
            }
        }
      viewport.setBounds(tabAreaRect.x, tabAreaRect.y, tabAreaRect.width,
                         tabAreaRect.height);
      int tabC = tabPane.getTabCount() - 1;
      if (tabCount > 0)
        {
          int w = Math.max(rects[tabC].width + rects[tabC].x, tabAreaRect.width);
          int h = Math.max(rects[tabC].height, tabAreaRect.height);
          p = findPointForIndex(currentScrollLocation);
          
          // we want to cover that entire space so that borders that run under
          // the tab area don't show up when we move the viewport around.
          panel.setSize(w + p.x, h + p.y);
        }
      viewport.setViewPosition(p);
      viewport.repaint();
    }
  }

  /**
   * This class handles ChangeEvents from the JTabbedPane.
   *
   * @specnote Apparently this class was intended to be protected,
   *           but was made public by a compiler bug and is now
   *           public for compatibility.
   */
  public class TabSelectionHandler implements ChangeListener
  {
    /**
     * This method is called whenever a ChangeEvent is fired from the
     * JTabbedPane.
     *
     * @param e The ChangeEvent fired.
     */
    public void stateChanged(ChangeEvent e)
    {
      selectedRun = getRunForTab(tabPane.getTabCount(),
                                 tabPane.getSelectedIndex());
      tabPane.revalidate();
      tabPane.repaint();
    }
  }

  /**
   * This helper class is a JPanel that fits inside the ScrollViewport. This
   * panel's sole job is to paint the tab rectangles inside the  viewport so
   * that it's clipped correctly.
   */
  private class ScrollingPanel extends JPanel
  {
    /**
     * This is a private UI class for our panel.
     */
    private class ScrollingPanelUI extends BasicPanelUI
    {
      /**
       * This method overrides the default paint method. It paints the tab
       * rectangles for the JTabbedPane in the panel.
       *
       * @param g The Graphics object to paint with.
       * @param c The JComponent to paint.
       */
      public void paint(Graphics g, JComponent c)
      {
        paintTabArea(g, tabPane.getTabPlacement(), tabPane.getSelectedIndex());
      }
    }

    /**
     * This method overrides the updateUI method. It makes the default UI for
     * this ScrollingPanel to be  a ScrollingPanelUI.
     */
    public void updateUI()
    {
      setUI((PanelUI) new ScrollingPanelUI());
    }
  }

  /**
   * This is a helper class that paints the panel that paints tabs. This
   * custom JViewport is used so that the tabs painted in the panel will be
   * clipped. This class implements UIResource so tabs are not added when
   * this objects of this class are added to the  JTabbedPane.
   */
  private class ScrollingViewport extends JViewport implements UIResource
  {
    // TODO: Maybe remove this inner class.
  }

  /**
   * This is a helper class that implements UIResource so it is not added as a
   * tab when an object of this class is added to the JTabbedPane.
   */
  private class ScrollingButton extends BasicArrowButton implements UIResource
  {
    /**
     * Creates a ScrollingButton given the direction.