问题
I'm using a Swing Timer to execute animations in my program. In many instances, there are several different calls made to the animate() method at once, with a separate Timer created for each. I know that, because of the way Swing timers are designed, these all get executed together - all my animations occur at the same time. However, there are some instances where I need to wait for one animation to complete to execute another.
Is there a way to make Swing timers execute sequentially - one after the other, rather than all at once? Or is there an alternative mechanism to the Swing timer that might better match my use case?
EDIT: I'm afraid I oversimplified my use case a bit. @peeskillet's suggestion would work perfectly if I knew at each "scene transition" what animations would need to be executed, or if the same sequence of animations occurred each time. Unfortunately that's not the case -- each transition requires a different set of animations, with different sets of components moving onto, off of and around on the panel.
What I want is to execute the animations of items off the screen first, and then (after that completes) animate the components on the screen. It's not a problem to distinguish between these "types" of animations at runtime - they're initiated from different methods, and thus its easy to imagine adding them to two different "queues" - a queue of outgoing items and a queue of incoming items. Having done so, I could then implement the basic strategy of calling a
That said - that all only makes sense to me intuitively, heuristically - I haven't figured out how to implement it in practice. What would those "queues" actually be, and what class would hold and later execute them?? Presumably one that implements Runnable, creating a second thread that can execute the animations with tighter control on how they proceed? Or does the event-dispatch thread give me the ample control here, if only I fully grasped how to use it? In which case - please help me do that.
(PS I realize that I've changed the question significantly here, essentially turning it into a new question, and that @peetskillet answered it as previously worded perfectly well, so I accepted that answer and posted a new question here.
回答1:
"Is there a way to make Swing timers execute sequentially - one after the other, rather than all at once? "
Just use a `boolean of some sort, telling when the first timer when it should stop and when the second timer should start. Something like
Timer timer1 = new Timer(delay, null); <---- initialize
Timer timer2 = new Timer(delay, null);
boolean something = false;
public Constructor() {
timer1 = new Timer(delay, new Action Listener(){
public void actionPerformed(ActionEvent e) {
if (something) { ------
timer2.start(); |
timer1.stop(); |---- some code should lead to
} esle { | `something` being true. Maybe
animateFirstSomething(); | another if statement inside the
} | else. Like if x equals y
} ------ something = true, else,
}); animateFirstSomething()
timer1.start();
timer2 = new Timer(delay, new ActionListener(){
public void actionPerformed(ActionEvent e) {
animationSecondSomething();
}
});
}
Here's simple example
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class TestTwoTimers extends JPanel {
int rectOneX = 0;
int rectTwoX = 0;
Timer timer1 = new Timer(100, null);
Timer timer2 = new Timer(100, null);
boolean rectOneGo = true;
public TestTwoTimers() {
timer1 = new Timer(100, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (rectOneGo) {
if (rectOneX >= 225) {
timer2.start();
timer1.stop();
} else {
rectOneX += 10;
repaint();
}
}
}
});
timer2 = new Timer(100, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (rectTwoX < 225) {
rectTwoX += 10;
repaint();
} else {
timer2.stop();
}
}
});
final JButton button = new JButton("Start First Timer");
button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
timer1.start();
}
});
setLayout(new BorderLayout());
add(button, BorderLayout.PAGE_END);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(rectOneX, 50, 75, 75);
g.setColor(Color.BLUE);
g.fillRect(rectTwoX, 150, 75, 75);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run() {
JFrame frame = new JFrame("Double Timers");
frame.add(new TestTwoTimers());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
来源：https://stackoverflow.com/questions/21298002/sequential-swing-timer-execution