xylayout.java

the programme is written with java,not my composition by download from the net.

package com.chat.util;

import java.awt.*;
import java.util.*;
//import com.borland.jbcl.util.*;

public class XYLayout implements LayoutManager2, java.io.Serializable
{
  private static final long serialVersionUID = 200L;

  int width;           // <= 0 means use the container's preferred size
  int height;          // <= 0 means use the container's preferred size

  public XYLayout() {}

  public XYLayout(int width, int height) {
    this.width  = width;
    this.height = height;
  }

  public int getWidth() { return width; }
  public void setWidth(int width) { this.width = width; }

  public int getHeight() { return height; }
  public void setHeight(int height) { this.height = height; }

  public String toString() {
    return "XYLayout" + "[width=" + width + ",height=" + height + "]";  
  }

  // LayoutManager interface

  public void addLayoutComponent(String name, Component component) {
    //System.err.println("XYLayout.addLayoutComponent(" + name + "," + component + ")");
  }

  public void removeLayoutComponent(Component component) {
    //System.err.println("XYLayout.removeLayoutComponent(" + component + ")");
    info.remove(component);
  }

  public Dimension preferredLayoutSize(Container target) {
    return getLayoutSize(target, true);
  }

  public Dimension minimumLayoutSize(Container target) {
    return getLayoutSize(target, false);
  }

  public void layoutContainer(Container target) {
    Insets insets = target.getInsets();
    int count = target.getComponentCount();
    //System.err.println("XYLayout.layoutContainer(" + target + ") insets=" + insets + " count=" + count);
    for (int i = 0 ; i < count; i++) {
      Component component = target.getComponent(i);
      if (component.isVisible()) {
        Rectangle r = getComponentBounds(component, true);
        component.setBounds(insets.left + r.x, insets.top + r.y, r.width, r.height);
      }
    }
  }

  // LayoutManager2 interface

  public void addLayoutComponent(Component component, Object constraints) {
    //System.err.println("XYLayout.addLayoutComponent(" + component + "," + constraints + ")");
    if (constraints instanceof XYConstraints)
      info.put(component, constraints);
  }

  public Dimension maximumLayoutSize(Container target) {
    return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
  }

  public float getLayoutAlignmentX(Container target) {
    return 0.5f;
  }

  public float getLayoutAlignmentY(Container target) {
    return 0.5f;
  }

  public void invalidateLayout(Container target) {}

  // internal

  Hashtable<Component, Object> info = new Hashtable<Component, Object>(); // leave this as non-transient
  static final XYConstraints defaultConstraints = new XYConstraints();

  Rectangle getComponentBounds(Component component, boolean doPreferred) {
    XYConstraints constraints = (XYConstraints)info.get(component);
    //System.err.println("XYLayout.getComponentBounds(" + component + "," + doPreferred + ") constraints=" + constraints + " width=" + width + " height=" + height);
    if (constraints == null)
      constraints = defaultConstraints;
    Rectangle r = new Rectangle(constraints.x, constraints.y, constraints.width, constraints.height);
    if (r.width <= 0 || r.height <= 0) {
      Dimension d = doPreferred ? component.getPreferredSize() : component.getMinimumSize();
      if (r.width <= 0)
        r.width = d.width;
      if (r.height <= 0)
        r.height = d.height;
    }
    return r;
  }

  Dimension getLayoutSize(Container target, boolean doPreferred) {
    Dimension dim = new Dimension(0, 0);

    //System.err.println("XYLayout.getLayoutSize(" + target + "," + doPreferred + ") width=" + width + " height=" + height);
    if (width <= 0 || height <= 0) {
      int count = target.getComponentCount();
      for (int i = 0; i < count; i++) {
        Component component = target.getComponent(i);
        if (component.isVisible()) {
          Rectangle r = getComponentBounds(component, doPreferred);
          //System.err.println(" bounds for " + component + " is " + r);
          dim.width  = Math.max(dim.width , r.x + r.width);
          dim.height = Math.max(dim.height, r.y + r.height);
        }
      }
    }
    if (width > 0)
      dim.width = width;
    if (height > 0)
      dim.height = height;
    Insets insets = target.getInsets();
    dim.width += insets.left + insets.right;
    dim.height += insets.top + insets.bottom;
    //System.err.println("  preferred container size is " + dim);
    return dim;
  }
}