Можете ли вы найти, кто инициировал вызов repaint ()? - PullRequest
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Можете ли вы найти, кто инициировал вызов repaint ()?

0 голосов
/ 21 июня 2019

Используя следующий код в качестве примера.
Если вы щелкнете по углу JFrame и измените его размер, Java выполнит вызов repaint (), который, в свою очередь, вызовет paintComponent () внутри этого объекта.
Если вы нажмете кнопку, она также вызовет paintComponent (), сделав явный вызов repaint (). 

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class WhoCalledPaint extends JPanel {

  static WhoCalledPaint panel;

  public void paintComponent(Graphics g) 
  {
    Thread.dumpStack();
    System.out.println("Inside paintComponet()");
    g.setColor(Color.orange);
    g.fillRect(0, 0, getWidth(), getHeight());
    g.setColor(Color.red);
    g.fillOval(getWidth()/4, getHeight()/4, 
        getWidth()/2, getHeight()/2);
  }

  public static void main(String args[]) {
    JFrame frame = new JFrame("OvalPaint");
    JButton jb = new JButton("Repaint");
    jb.addActionListener(new ActionListener()
    {
        @Override
        public void actionPerformed(ActionEvent e)
        {
            panel.repaint();
        }
    });

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    panel = new WhoCalledPaint ();

    panel.add(jb);
    frame.add(panel);

    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}


При изменении размера JFrame стек выглядит так: 

Inside paintComponet()
at java.lang.Thread.dumpStack(Thread.java:1336)
at WhoCalledPaint.paintComponent(WhoCalledPaint.java:13)
at javax.swing.JComponent.paint(JComponent.java:1056)
at javax.swing.JComponent.paintChildren(JComponent.java:889)
at javax.swing.JComponent.paint(JComponent.java:1065)
at javax.swing.JComponent.paintChildren(JComponent.java:889)
at javax.swing.JComponent.paint(JComponent.java:1065)
at javax.swing.JLayeredPane.paint(JLayeredPane.java:586)
at javax.swing.JComponent.paintChildren(JComponent.java:889)
at javax.swing.JComponent.paintToOffscreen(JComponent.java:5217)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579)
at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502)
at javax.swing.RepaintManager.paint(RepaintManager.java:1272)
at javax.swing.JComponent.paint(JComponent.java:1042)
at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:39)
at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:79)
at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:116)
at java.awt.Container.paint(Container.java:1978)
at java.awt.Window.paint(Window.java:3906)
at javax.swing.RepaintManager$4.run(RepaintManager.java:842)
at javax.swing.RepaintManager$4.run(RepaintManager.java:814)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789)
at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738)
at javax.swing.RepaintManager.access$1200(RepaintManager.java:64)
at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)


При нажатии кнопки стек выглядит следующим образом: 

java.lang.Exception: Stack trace
at java.lang.Thread.dumpStack(Thread.java:1336)
at WhoCalledPaint.paintComponent(WhoCalledPaint.java:13)
at javax.swing.JComponent.paint(JComponent.java:1056)
at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579)
at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502)
at javax.swing.RepaintManager.paint(RepaintManager.java:1272)
at javax.swing.JComponent._paintImmediately(JComponent.java:5158)
at javax.swing.JComponent.paintImmediately(JComponent.java:4969)
at javax.swing.RepaintManager$4.run(RepaintManager.java:831)
at javax.swing.RepaintManager$4.run(RepaintManager.java:814)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789)
at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738)
at javax.swing.RepaintManager.access$1200(RepaintManager.java:64)
at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)


Можно ли различить, вызван ли paintComponent () из Java или из явного вызова repaint () из другой процедуры в коде?

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