gridbaglayout.java

gcc的组建

                                  break;
                                }
                              else
                                {
                                  constraints.gridy = Math.max (constraints.gridy,
                                                                lastConstraints.gridy + Math.max (1, lastConstraints.gridheight));
                                }
                            }
                        }
                    }
                  constraints.gridheight = max_y - constraints.gridy;
                }
              else if (constraints.gridheight == GridBagConstraints.RELATIVE)
                {
                  constraints.gridheight = max_y - constraints.gridy - 1;
                }

              // Re-sort
              sortedByHeight.remove(sortedByHeight.indexOf(component));
              sortBySpan(component, constraints.gridheight, sortedByHeight, false);
            }
        } // end of STEP 2

      // STEP 3: Determine sizes and weights for columns.
      for (int i = 0; i < sortedByWidth.size(); i++)
        {
          Component component = (Component) sortedByWidth.get(i);
			
          // If component is not visible we dont have to care about it.
          if (!component.isVisible())
            continue;

          GridBagConstraints constraints = lookupInternalConstraints (component);

          int width = (sizeflag == PREFERREDSIZE) ?
                      component.getPreferredSize().width :
                      component.getMinimumSize().width;

          if(constraints.insets != null)
            width += constraints.insets.left + constraints.insets.right;

          width += constraints.ipadx;

          distributeSizeAndWeight(width,
                                  constraints.weightx, 
                                  constraints.gridx,
                                  constraints.gridwidth,
                                  info.colWidths,
                                  info.colWeights);
        } // end of STEP 3

      // STEP 4: Determine sizes and weights for rows.
      for (int i = 0; i < sortedByHeight.size(); i++)
        {
          Component component = (Component) sortedByHeight.get(i);
			
          // If component is not visible we dont have to care about it.
          if (!component.isVisible())
            continue;

          GridBagConstraints constraints = lookupInternalConstraints (component);

          int height = (sizeflag == PREFERREDSIZE) ?
                       component.getPreferredSize().height :
                       component.getMinimumSize().height;

          if(constraints.insets != null)
            height += constraints.insets.top + constraints.insets.bottom;

          height += constraints.ipady;

          distributeSizeAndWeight(height,
                                  constraints.weighty, 
                                  constraints.gridy,
                                  constraints.gridheight,
                                  info.rowHeights,
                                  info.rowWeights);
        } // end of STEP 4

      // Adjust cell sizes iff parent size not zero.
      if (parentDim.width > 0 && parentDim.height > 0)
        {
          calcCellSizes (info.colWidths, info.colWeights, parentDim.width);
          calcCellSizes (info.rowHeights, info.rowWeights, parentDim.height);
        }

      int totalWidth = sumIntArray(info.colWidths);
      int totalHeight = sumIntArray(info.rowHeights);

      // Make sure pos_x and pos_y are never negative.
      if (totalWidth >= parentDim.width)
        info.pos_x = parentInsets.left;
      else
        info.pos_x = parentInsets.left + (parentDim.width - totalWidth) / 2;

      if (totalHeight >= parentDim.height)
        info.pos_y = parentInsets.top;
      else
        info.pos_y = parentInsets.top + (parentDim.height - totalHeight) / 2;

      // DEBUG
      //dumpLayoutInfo (info);

      return info;
    }

    /**
     * Obsolete.
     */
    protected Dimension GetMinSize (Container parent, GridBagLayoutInfo info)
    {
      if (parent == null || info == null)
        return new Dimension (0, 0);

      Insets insets = parent.getInsets();
      int width = sumIntArray (info.colWidths) + insets.left + insets.right;
      int height = sumIntArray (info.rowHeights) + insets.top + insets.bottom;
      return new Dimension (width, height);
    }

    /**
     * @since 1.4
     */
    protected Dimension getMinSize (Container parent, GridBagLayoutInfo info)
    {
      return GetMinSize (parent, info);
    }

    /**
     * Helper method used by GetLayoutInfo to keep components sorted, either
     * by gridwidth or gridheight.
     *
     * @param component   Component to add to the sorted list.
     * @param span        Either the component's gridwidth or gridheight.
     * @param list        <code>ArrayList</code> of components, sorted by
     *                    their span.
     * @param sortByWidth Flag indicating sorting index. If true, sort by
     *                    width. Otherwise, sort by height.
     * FIXME: Use a better sorting algorithm.
     */
    private void sortBySpan (Component component, int span, ArrayList list, boolean sortByWidth)
    {
      if (span == GridBagConstraints.REMAINDER
          || span == GridBagConstraints.RELATIVE)
        {
          // Put all RELATIVE and REMAINDER components at the end.
          list.add(component);
        }
      else
        {
          int i = 0;
          if (list.size() > 0)
            {
              GridBagConstraints gbc = lookupInternalConstraints((Component) list.get(i));
              int otherspan = sortByWidth ?
                              gbc.gridwidth :
                              gbc.gridheight;
              while (otherspan != GridBagConstraints.REMAINDER
                     && otherspan != GridBagConstraints.RELATIVE
                     && span >= otherspan)
                {
                  i++;
                  if (i < list.size())
                    {
                      gbc = lookupInternalConstraints((Component) list.get(i));
                      otherspan = sortByWidth ?
                                  gbc.gridwidth :
                                  gbc.gridheight;
                    }
                  else
                    break;
                }
            }
          list.add(i, component);
        }
    }

    /**
     * Helper method used by GetLayoutInfo to distribute a component's size
     * and weight.
     *
     * @param size    Preferred size of component, with inset and padding
     *                already added.
     * @param weight  Weight of component.
     * @param start   Starting position of component. Either
     *                constraints.gridx or gridy.
     * @param span    Span of component. either contraints.gridwidth or
     *                gridheight.
     * @param sizes   Sizes of rows or columns.
     * @param weights Weights of rows or columns.
     */
    private void distributeSizeAndWeight (int size, double weight,
                                          int start, int span,
                                          int[] sizes, double[] weights)
    {
      if (span == 1)
        {
          sizes[start] = Math.max(sizes[start], size);
          weights[start] = Math.max(weights[start], weight);
        }
      else if (span > 1)
        {
          int numOccupied = span;
          int lastOccupied = -1;

          for(int i = start; i < start + span; i++)
            {
              if (sizes[i] == 0.0)
                numOccupied--;
              else
                {
                  size -= sizes[i];
                  lastOccupied = i;
                }
            }

          // A component needs to occupy at least one row.
          if(numOccupied == 0)
            sizes[start + span - 1] = size;
          else if (size > 0)
            sizes[lastOccupied] += size;

          calcCellWeights(weight, weights, start, span);
        }
    }

    /**
     * Helper method used by GetLayoutInfo to calculate weight distribution.
     * @param weight  Weight of component.
     * @param weights Weights of rows/columns.
     * @param start   Starting position of component in grid (gridx/gridy).
     * @param span    Span of component (gridwidth/gridheight).
     */
    private void calcCellWeights (double weight, double[] weights, int start, int span)
    {
      double totalWeight = 0.0;
      for(int k = start; k < start + span; k++)
        totalWeight += weights[k];

      if(weight > totalWeight)
        {
          if (totalWeight == 0.0)
            {
              weights[start + span - 1] += weight;
            }
          else
            {
              double diff = weight - totalWeight ;
              double remaining = diff;

              for(int k = start; k < start + span; k++)
                {
                  double extraWeight = diff * weights[k] / totalWeight;
                  weights[k] += extraWeight;
                  remaining -= extraWeight;
                } 

              if (remaining > 0.0 && weights[start + span - 1] != 0.0)
                {
                  weights[start + span - 1] += remaining;
                }
            }
        }
    }

    /**
     * Helper method used by GetLayoutInfo to distribute extra space
     * based on weight distribution.
     *
     * @param sizes   Sizes of rows/columns.
     * @param weights Weights of rows/columns.
     * @param range   Dimension of container.
     */
    private void calcCellSizes (int[] sizes, double[] weights, int range)
    {
      int totalSize = sumIntArray (sizes);
      double totalWeight = sumDoubleArray (weights);

      int diff = range - totalSize;

      if (diff == 0)
        return;

      for (int i = 0; i < sizes.length; i++)
        {
          int newsize = (int) (sizes[i] + (((double) diff) * weights [i] / totalWeight ));

          if (newsize > 0)
            sizes[i] = newsize;
        }
    }

    private void dumpLayoutInfo (GridBagLayoutInfo info)
    {
	System.out.println ("GridBagLayoutInfo:");
	System.out.println ("cols: " + info.cols + ", rows: " + info.rows);
	System.out.print ("colWidths: ");
	dumpArray(info.colWidths);
	System.out.print ("rowHeights: ");
	dumpArray(info.rowHeights);
	System.out.print ("colWeights: ");
	dumpArray(info.colWeights);
	System.out.print ("rowWeights: ");
	dumpArray(info.rowWeights);
    }

    private void dumpArray(int[] array)
    {
	String sep = "";
	for(int i = 0; i < array.length; i++)
	{
	    System.out.print(sep);
	    System.out.print(array[i]);
	    sep = ", ";
	}
	System.out.println();
    }

    private void dumpArray(double[] array)
    {
	String sep = "";
	for(int i = 0; i < array.length; i++)
	{
	    System.out.print(sep);
	    System.out.print(array[i]);
	    sep = ", ";
	}
	System.out.println();
    }
  
    /**
     * @since 1.4
     */
    protected void arrangeGrid (Container parent)
    {
      ArrangeGrid (parent);
    }

    /**
     * @since 1.4
     */
    protected GridBagLayoutInfo getLayoutInfo (Container parent, int sizeflag)
    {
      return GetLayoutInfo (parent, sizeflag);
    }

    /**
     * @since 1.4
     */
    protected void adjustForGravity (GridBagConstraints gbc, Rectangle rect)
    {
      AdjustForGravity (gbc, rect);
    }
}