>From: ###@###.### (Doug Stein)
 
Category: AWT

Priority: Low (Low/Medium/High/Critical)

JDK version: JDK-1_0-win32-x86.exe

Platforms: Windows 95 [Version 4.00.950]
Windows NT version 3.51

Synopsis
--------

Frame's "validate" method is called spuriously on Windows.


Description
-----------

This bug occurs on Windows95 and WindowsNT.

When the top level frame is resized, "validate" is called many more times
than necessary. The number of times appears to be related to the number
of children contained by the frame.


Test Case
---------

- Compile and run validate.java:

javac validate.java
java validate

- Resize the window

  The "validate" method on the frame is called 13 times. One call to
  validate would suffice.

  
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import java.awt.*;

class BorderPanel extends Panel {
  private static final int borderWidth = 10;

  public Dimension minimumSize() {
    Dimension d;

    if (countComponents() > 0) {
      Component comp = getComponent(0);
      d = comp.minimumSize();
    }
    else {
      d = new Dimension(0, 0);
    }

    d.width += 2*borderWidth;
    d.height += 2*borderWidth;

    return d;
  }

  public Dimension preferredSize() {
    return minimumSize();
  }

  public void layout() {
    Dimension d = size();
    Component components[] = getComponents();

    for (int i=0; i<components.length; i++) {
      if (i==0) {
components[i].reshape(borderWidth, borderWidth,
d.width - 2*borderWidth,
d.height - 2*borderWidth);
      }
      else {
components[i].reshape(-1, -1, 0, 0);
      }
    }
  }

  public void paint(Graphics g) {
    Dimension d = size();
    g.drawRect(0, 0, d.width-1, d.height-1);
    g.drawRect(1, 1, d.width-3, d.height-3);
  }
}

public class validate extends Frame {
  private int validateCount;

  public static void main(String argv[]) {
    new validate();
  }

  public validate() {
    Button button = new Button("Button");
    Panel p = new BorderPanel();
    createNestedPanels(button, p, 10);
    add("Center", p);

    show();
    resize(preferredSize());
    validate();
  }

  public void createNestedPanels(Component c, Panel parent, int num) {
    if (num == 0)
      parent.add(c);
    else {
      Panel bp = new BorderPanel();
      parent.add(bp);
      createNestedPanels(c, bp, num-1);
    }
  }

  public void validate() {
    super.validate();
    System.out.println("validate " + validateCount++);
  }
}