Question

我想通过使用mouseDrag事件制作一个包含可移动图标的JLabel。它在使用默认布局时工作正常，但是当我通过指定null LayoutManager动画使用AbsoluteLayout时，动画非常糟糕。这是代码。

import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class Example 
{
    private static int pX, pY;

    public static void main(String[] args)
    {
        ImageIcon myIcon = new ImageIcon("C:\\Users\\User\\Desktop\\x.png");

        JFrame jf = new JFrame();
        jf.setLayout(null);
        jf.setSize(800, 800);

        JLabel label = new JLabel(myIcon);
        label.setSize(100, 100);

        label.addMouseListener(new MouseAdapter()
        {
            @Override
            public void mousePressed(MouseEvent arg0) {
                pX = arg0.getX();
                pY = arg0.getY();
            }
        });

        label.addMouseMotionListener(new MouseMotionAdapter() {
            @Override
            public void mouseDragged(MouseEvent arg0) {
                label.setLocation(label.getX() + arg0.getX() - pX, label.getY() + arg0.getY() - pY);
            }   
        });

        jf.add(label);
        jf.setVisible(true);
    }
}

编辑：添加了示例代码

Answer 1

我很久以前写过这个闪烁或说摇晃的方法，

唯一的问题是，直到JComponent MouseExited Listener被解雇的时间，您的组件才会闪烁，还有一个案例，当组件处于非常靠近的位置时，例如更少比10px。
闪烁主要是针对JLabel，但是当你连接一个JButton或JPanel类型的组件时，它会垂直或水平摇动它。
此外，您还只允许在水平轴或垂直轴上摇晃。

尝试以下源代码：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;

//Sometimes due to the Cursor contains the bounds of component 
//and don't leave the component so the MouseExited event not fired
//which leads to the component not flickering issue
public class FlickerExample {

    private static boolean flickerVertical = false;
    private static boolean mouseEntered = false;
    private static boolean isThreadBusy = false;
    private static ArrayList<String> 
        compAbsoluteFixedFlagHashAddresses = new ArrayList<String>();

    public static void main(String[] args) {

        JLabel openLabel = new JLabel("click button to open", SwingConstants.CENTER);
        openLabel.setForeground(Color.BLACK);
        openLabel.setFont(new Font("Dialog", Font.BOLD, 22));
        openLabel.setSize(80, 30);
        flickerComponent(openLabel, false, false);

        JButton openButton = new JButton("click me to open");
        openButton.setFocusPainted(false);
        openButton.setSize(80, 30);
        openButton.setFont(openLabel.getFont());
        flickerComponent(openButton, false, false);

        JFrame frame = new JFrame();
        frame.setTitle("Flicker JComponent");
        frame.getContentPane().setLayout(new BorderLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setBounds(500, 250, 300, 200);

        frame.getContentPane().add(openLabel, BorderLayout.PAGE_START);
        frame.getContentPane().add(openButton, BorderLayout.PAGE_END);

        frame.setVisible(true);

    }

    public static void moveComponent(final JComponent comp, final Point p) {
        SwingUtilities.invokeLater(new Runnable() {
          @Override
          public void run() {
            comp.setLocation(p);
          }
        });
    }

    public static void setVertical(boolean bool){
        flickerVertical = bool;
    }

    public static void flickerComponent(final JComponent comp){
        flickerComponent(comp, false, false);
    }

    public synchronized static void flickerComponent(final JComponent comp, boolean absoluteFixedFlag, boolean requiredFlag){

        if(absoluteFixedFlag){
            flickerVertical = requiredFlag;
            compAbsoluteFixedFlagHashAddresses.add(String.valueOf(comp.hashCode()) + ":" + String.valueOf(requiredFlag));
        }

        comp.addMouseListener(new MouseAdapter(){
            @Override
            public void mouseEntered(MouseEvent evt){
                //System.out.println("mouse entered for flickering...");
                if(!mouseEntered && !isThreadBusy){
                    isThreadBusy = true;
                    mouseEntered = true;
                    new Thread(new Runnable(){
                        public void run(){
                            try{
                                short min = 0, max = 0;
                                byte delay = 7;
                                Font tempFont = null;
                                final Point loc = comp.getLocation();

                                if(compAbsoluteFixedFlagHashAddresses.size()>0){
                                    Iterator<String> itr = compAbsoluteFixedFlagHashAddresses.iterator();
                                    String hc = String.valueOf(comp.hashCode());
                                    loop: 
                                    while(itr.hasNext()){
                                        String str = itr.next();
                                        if(str.indexOf(hc) != -1){
                                            flickerVertical = new Boolean(str.substring(str.indexOf(":")+1));
                                            break loop;
                                        }
                                    }
                                    itr = null;
                                }

                                if(comp instanceof JLabel){
                                    tempFont = ((JLabel)comp).getFont(); 
                                    ((JLabel)comp).setFont(new Font(tempFont.getFamily(), tempFont.getStyle(), tempFont.getSize()+5));
                                }

                                if(flickerVertical){
                                    min = (short) (loc.y - 4);
                                    max = (short) (loc.y + 4);

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setVerticalTextPosition(SwingConstants.BOTTOM);
                                    while(comp.getLocation().y != min){
                                        moveComponent(comp, new Point(loc.x, comp.getY()-2));
                                        Thread.sleep(delay);
                                    }

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setVerticalTextPosition(SwingConstants.TOP);
                                    delay = 3;
                                    while(comp.getLocation().y != max){
                                        moveComponent(comp, new Point(loc.x, comp.getY()+2));
                                        Thread.sleep(delay);
                                    }

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setVerticalTextPosition(SwingConstants.BOTTOM);
                                    delay = 5;
                                    while(comp.getLocation().y != loc.y){
                                        moveComponent(comp, new Point(loc.x, comp.getY()-2));
                                        Thread.sleep(delay);
                                    }

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setVerticalTextPosition(SwingConstants.CENTER);
                                }else{
                                    min = (short) (loc.x - 4);
                                    max = (short) (loc.x + 4);

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setHorizontalTextPosition(SwingConstants.RIGHT);
                                    while(comp.getLocation().x != min){
                                        moveComponent(comp, new Point(comp.getX()-2, loc.y));
                                        Thread.sleep(delay);
                                    }

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setHorizontalTextPosition(SwingConstants.LEFT);
                                    delay = 3;
                                    while(comp.getLocation().x != max){
                                        moveComponent(comp, new Point(comp.getX()+2, loc.y));
                                        Thread.sleep(delay);
                                    }

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setHorizontalTextPosition(SwingConstants.RIGHT);
                                    delay = 5;
                                    while(comp.getLocation().x != loc.x){
                                        moveComponent(comp, new Point(comp.getX()-2, loc.y));
                                        Thread.sleep(delay);
                                    }

                                    if(comp instanceof JLabel)
                                        ((JLabel)comp).setHorizontalTextPosition(SwingConstants.CENTER);
                                }

                                if(comp instanceof JLabel) 
                                    ((JLabel)comp).setFont(tempFont);

                                moveComponent(comp, loc);
                                flickerVertical = !flickerVertical;
                                isThreadBusy = false;
                            }catch(InterruptedException ie){
                                ie.printStackTrace();
                            }
                        }
                    }).start();
                }
            }

            @Override
            public void mouseExited(MouseEvent evt){
                if(!isThreadBusy)
                    if(mouseEntered)
                        mouseEntered = false;
            }

        });
    }

}

使用AbsoluteLayout移动JLabel时，Swing GUI动画闪烁

1 个答案: