basictabbedpaneui.java

gcc的组建

        {
          int maxWidth = calculateMaxTabWidth(tabPlacement);
          calcRect.height -= tabAreaInsets.top + tabAreaInsets.bottom;
          max = calcRect.height + tabAreaInsets.top + insets.top;

          int height = 0;
          start += tabAreaInsets.top + insets.top;
          int runHeight = start;

          int fontHeight = fm.getHeight();

          for (int i = 0; i < tabCount; i++)
            {
              height = calculateTabHeight(tabPlacement, i, fontHeight);
              if (runHeight + height > max)
                {
                  runHeight = tabAreaInsets.top + insets.top
                  + getTabRunIndent(tabPlacement, ++runs);
                  rects[i] = new Rectangle(insets.left + tabAreaInsets.left,
                                           runHeight, maxWidth, height);
                  runHeight += height;
                  if (runs > tabRuns.length - 1)
                    expandTabRunsArray();
                  tabRuns[runs] = i;
                }
              else
                {
                  rects[i] = new Rectangle(insets.left + tabAreaInsets.left,
                                           runHeight, maxWidth, height);
                  runHeight += height;
                }
            }
          runs++;

          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;

      tabRuns[0] = 0;
      normalizeTabRuns(tabPlacement, tabCount, start, max);
      selectedRun = getRunForTab(tabCount, tabPane.getSelectedIndex());
      if (shouldRotateTabRuns(tabPlacement))
        rotateTabRuns(tabPlacement, selectedRun);

      // Need to pad the runs and move them to the correct location.
      for (int i = 0; i < runCount; i++)
        {
          int first = lastTabInRun(tabCount, getPreviousTabRun(i)) + 1;
          if (first == tabCount)
            first = 0;
          int last = lastTabInRun(tabCount, i);
          if (shouldPadTabRun(tabPlacement, i))
            padTabRun(tabPlacement, first, last, max);

          // Done padding, now need to move it.
          if (tabPlacement == SwingConstants.TOP && i > 0)
            {
              for (int j = first; j <= last; j++)
                rects[j].y += (runCount - i) * maxTabHeight
                - (runCount - i) * tabRunOverlay;
            }

          if (tabPlacement == SwingConstants.BOTTOM)
            {
              int height = tabPane.getBounds().height - insets.bottom
              - tabAreaInsets.bottom;
              int adjustment;
              if (i == 0)
                adjustment = height - maxTabHeight;
              else
                adjustment = height - (runCount - i + 1) * maxTabHeight
                - (runCount - i) * tabRunOverlay;

              for (int j = first; j <= last; j++)
                rects[j].y = adjustment;
            }

          if (tabPlacement == SwingConstants.LEFT && i > 0)
            {
              for (int j = first; j <= last; j++)
                rects[j].x += (runCount - i) * maxTabWidth
                - (runCount - i) * tabRunOverlay;
            }

          if (tabPlacement == SwingConstants.RIGHT)
            {
              int width = tabPane.getBounds().width - insets.right
              - tabAreaInsets.right;
              int adjustment;
              if (i == 0)
                adjustment = width - maxTabWidth;
              else
                adjustment = width - (runCount - i + 1) * maxTabWidth
                + (runCount - i) * tabRunOverlay;

              for (int j = first; j <= last; j++)
                rects[j].x = adjustment;
            }
        }
      padSelectedTab(tabPlacement, tabPane.getSelectedIndex());
    }

    /**
     * This method is called when the JTabbedPane is laid out in
     * WRAP_TAB_LAYOUT. It calls calculateLayoutInfo to  find the positions
     * of all its components.
     *
     * @param parent The Container to lay out.
     */
    public void layoutContainer(Container parent)
    {
      calculateLayoutInfo();
    }

    /**
     * This method returns the minimum layout size for the given container.
     *
     * @param parent The container that is being sized.
     *
     * @return The minimum size.
     */
    public Dimension minimumLayoutSize(Container parent)
    {
      return calculateSize(false);
    }

    // If there is more free space in an adjacent run AND the tab in the run can fit in the 
    // adjacent run, move it. This method is not perfect, it is merely an approximation.
    // If you play around with Sun's JTabbedPane, you'll see that 
    // it does do some pretty strange things with regards to not moving tabs 
    // that should be moved. 
    // start = the x position where the tabs will begin
    // max = the maximum position of where the tabs can go to (tabAreaInsets.left + the width of the tab area)

    /**
     * This method tries to "even out" the number of tabs in each run based on
     * their widths.
     *
     * @param tabPlacement The JTabbedPane's tab placement.
     * @param tabCount The number of tabs.
     * @param start The x position where the tabs will begin.
     * @param max The maximum x position where the tab can run to.
     */
    protected void normalizeTabRuns(int tabPlacement, int tabCount, int start,
                                    int max)
    {
      Insets tabAreaInsets = getTabAreaInsets(tabPlacement);
      if (tabPlacement == SwingUtilities.TOP
          || tabPlacement == SwingUtilities.BOTTOM)
        {
          // We should only do this for runCount - 1, cause we can only shift that many times between
          // runs.
          for (int i = 1; i < runCount; i++)
            {
              Rectangle currRun = rects[lastTabInRun(tabCount, i)];
              Rectangle nextRun = rects[lastTabInRun(tabCount, getNextTabRun(i))];
              int spaceInCurr = currRun.x + currRun.width;
              int spaceInNext = nextRun.x + nextRun.width;

              int diffNow = spaceInCurr - spaceInNext;
              int diffLater = (spaceInCurr - currRun.width)
              - (spaceInNext + currRun.width);
              while (Math.abs(diffLater) < Math.abs(diffNow)
                  && spaceInNext + currRun.width < max)
                {
                  tabRuns[i]--;
                  spaceInNext += currRun.width;
                  spaceInCurr -= currRun.width;
                  currRun = rects[lastTabInRun(tabCount, i)];
                  diffNow = spaceInCurr - spaceInNext;
                  diffLater = (spaceInCurr - currRun.width)
                  - (spaceInNext + currRun.width);
                }

              // Fix the bounds.
              int first = lastTabInRun(tabCount, i) + 1;
              int last = lastTabInRun(tabCount, getNextTabRun(i));
              int currX = tabAreaInsets.left;
              for (int j = first; j <= last; j++)
                {
                  rects[j].x = currX;
                  currX += rects[j].width;
                }
            }
        }
      else
        {
          for (int i = 1; i < runCount; i++)
            {
              Rectangle currRun = rects[lastTabInRun(tabCount, i)];
              Rectangle nextRun = rects[lastTabInRun(tabCount, getNextTabRun(i))];
              int spaceInCurr = currRun.y + currRun.height;
              int spaceInNext = nextRun.y + nextRun.height;

              int diffNow = spaceInCurr - spaceInNext;
              int diffLater = (spaceInCurr - currRun.height)
              - (spaceInNext + currRun.height);
              while (Math.abs(diffLater) < Math.abs(diffNow)
                  && spaceInNext + currRun.height < max)
                {
                  tabRuns[i]--;
                  spaceInNext += currRun.height;
                  spaceInCurr -= currRun.height;
                  currRun = rects[lastTabInRun(tabCount, i)];
                  diffNow = spaceInCurr - spaceInNext;
                  diffLater = (spaceInCurr - currRun.height)
                  - (spaceInNext + currRun.height);
                }

              int first = lastTabInRun(tabCount, i) + 1;
              int last = lastTabInRun(tabCount, getNextTabRun(i));
              int currY = tabAreaInsets.top;
              for (int j = first; j <= last; j++)
                {
                  rects[j].y = currY;
                  currY += rects[j].height;
                }
            }
        }
    }

    /**
     * This method pads the tab at the selected index by the  selected tab pad
     * insets (so that it looks larger).
     *
     * @param tabPlacement The placement of the tabs.
     * @param selectedIndex The selected index.
     */
    protected void padSelectedTab(int tabPlacement, int selectedIndex)
    {
      Insets insets = getSelectedTabPadInsets(tabPlacement);
      rects[selectedIndex].x -= insets.left;
      rects[selectedIndex].y -= insets.top;
      rects[selectedIndex].width += insets.left + insets.right;
      rects[selectedIndex].height += insets.top + insets.bottom;
    }

    // If the tabs on the run don't fill the width of the window, make it fit now.
    // start = starting index of the run
    // end = last index of the run
    // max = tabAreaInsets.left + width (or equivalent)
    // assert start <= end.

    /**
     * This method makes each tab in the run larger so that the  tabs expand
     * to fill the runs width/height (depending on tabPlacement).
     *
     * @param tabPlacement The placement of the tabs.
     * @param start The index of the first tab.
     * @param end The last index of the tab
     * @param max The amount of space in the run (width for TOP and BOTTOM
     *        tabPlacement).
     */
    protected void padTabRun(int tabPlacement, int start, int end, int max)
    {
      if (tabPlacement == SwingConstants.TOP
          || tabPlacement == SwingConstants.BOTTOM)
        {
          int runWidth = rects[end].x + rects[end].width;
          int spaceRemaining = max - runWidth;
          int numTabs = end - start + 1;

          // now divvy up the space.
          int spaceAllocated = spaceRemaining / numTabs;
          int currX = rects[start].x;
          for (int i = start; i <= end; i++)
            {
              rects[i].x = currX;
              rects[i].width += spaceAllocated;
              currX += rects[i].width;
              // This is used because since the spaceAllocated 
              // variable is an int, it rounds down. Sometimes,
              // we don't fill an entire row, so we make it do
              // so now.
              if (i == end && rects[i].x + rects[i].width != max)
                rects[i].width = max - rects[i].x;
            }
        }
      else
        {
          int runHeight = rects[end].y + rects[end].height;
          int spaceRemaining = max - runHeight;
          int numTabs = end - start + 1;

          int spaceAllocated = spaceRemaining / numTabs;
          int currY = rects[start].y;
          for (int i = start; i <= end; i++)
            {
              rects[i].y = currY;
              rects[i].height += spaceAllocated;
              currY += rects[i].height;
              if (i == end && rects[i].y + rects[i].height != max)
                rects[i].height = max - rects[i].y;
            }
        }
    }

    /**
     * This method returns the preferred layout size for the given container.
     *
     * @param parent The container to size.
     *
     * @return The preferred layout size.
     */
    public Dimension preferredLayoutSize(Container parent)
    {
      return calculateSize(false);
    }

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

      int runs = 0;
      int runWidth = 0;
      int tabWidth = 0;

      FontMetrics fm = getFontMetrics();

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

      // Only interested in width, this is a messed up rectangle now.
      width -= tabAreaInsets.left + tabAreaInsets.right + insets.left
      + insets.right;

      // The reason why we can't use runCount:
      // This method is only called to calculate the size request
      // for the tabbedPane. However, this size request is dependent on 
      // our desired width. We need to find out what the height would
      // be IF we got our desired width.
      for (int i = 0; i < tabPane.getTabCount(); i++)
        {
          tabWidth = calculateTabWidth(tabPlacement, i, fm);
          if (runWidth + tabWidth > width)
            {
              runWidth = tabWidth;
              runs++;
            }
          else
            runWidth += tabWidth;
        }
      runs++;

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

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

      int runs = 0;
      int runHeight = 0;
      int tabHeight = 0;

      FontMetrics fm = getFontMetrics();