放大使用鼠标和图形 [英] zoom using mouse and graphics
问题描述
我在JComponent的一些曲线等。与图形G（未2D）。
I draw in my JComponent some curves, etc .. with Graphics G ( not 2D ).
现在我想用我的鼠标的滚轮来放大和缩小。
Now I want to use the scroll wheel of my mouse to zoom in and out.
所有的曲目？
我听到谈论BuferredImage？
I heard talk about a BuferredImage ?
推荐答案
有你需要考虑的几个因素...
There are a few considerations you need to take into account...
最终的结果将取决于你想要达到的目标。如果您绘制使用Graphics2D API曲线，它可能是简单的只是每个组件渲染时间尺度的坐标。您需要确保在任何规模的变化会反映在组件本身的preferred大小。
The end result will depend on what you want to achieve. If you are drawing curves using the Graphics2D API, it might be simpler to simply scale the coordinates each time the component is rendered. You will need to make sure that any changes in the scale are reflected in the preferred size of the component itself.
您也可以使默认输出到的BufferedImage 键，只需简单地使用的AffineTransform 来更改比例将用于呈现的结果，例如
You could also render the "default" output to a BufferedImage and simply use an AffineTransform to change the scaling the is used to render the result, for example.
这简单的使用的BufferedImage 并从磁盘加载一张图片，但基本概念是相同的。
This simple uses a BufferedImage and loads a picture from disk, but the basic concept is the same.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseWheelEvent;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ZoomPane {
public static void main(String[] args) {
new ZoomPane();
}
public ZoomPane() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(new TestPane()));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage img;
private float scale = 1;
public TestPane() {
try {
img = ImageIO.read(new File("/path/to/image"));
} catch (IOException ex) {
ex.printStackTrace();
}
addMouseWheelListener(new MouseAdapter() {
@Override
public void mouseWheelMoved(MouseWheelEvent e) {
double delta = 0.05f * e.getPreciseWheelRotation();
scale += delta;
revalidate();
repaint();
}
});
}
@Override
public Dimension getPreferredSize() {
Dimension size = new Dimension(200, 200);
if (img != null) {
size.width = Math.round(img.getWidth() * scale);
size.height = Math.round(img.getHeight() * scale);
}
return size;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
Graphics2D g2d = (Graphics2D) g.create();
AffineTransform at = new AffineTransform();
at.scale(scale, scale);
g2d.drawImage(img, at, this);
g2d.dispose();
}
}
}
}
您还可以通过扩展直接在的paintComponent 方法图形上下文。
You could also scale the Graphics context passed to your paintComponent method directly.
这里最重要的是要记住将的AffineTransform 您已经完成后，否则会被传递到其他组件，当他们被渲染，这将不会产生预期的输出...
The important thing here is to remember to reset the AffineTransform after you have completed, otherwise it will be passed to other components when they are rendered, which won't generate the expected output...
本实例主要创建，我们可以操纵和不影响原处分的图形上下文的副本，使它更易于惹
This example basically creates a copy of the Graphics context which we can manipulate and dispose of without effecting the original, making it simpler to mess with
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseWheelEvent;
import java.awt.geom.AffineTransform;
import java.awt.geom.GeneralPath;
import java.awt.geom.Path2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ZoomPane {
public static void main(String[] args) {
new ZoomPane();
}
public ZoomPane() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(new TestPane()));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private float scale = 1;
public TestPane() {
addMouseWheelListener(new MouseAdapter() {
@Override
public void mouseWheelMoved(MouseWheelEvent e) {
double delta = 0.05f * e.getPreciseWheelRotation();
scale += delta;
revalidate();
repaint();
}
});
}
@Override
public Dimension getPreferredSize() {
Dimension size = new Dimension(200, 200);
size.width = Math.round(size.width * scale);
size.height = Math.round(size.height * scale);
return size;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
AffineTransform at = new AffineTransform();
at.scale(scale, scale);
g2d.setTransform(at);
g2d.setColor(Color.RED);
// This is for demonstration purposes only
// I prefer to use getWidth and getHeight
int width = 200;
int height = 200;
Path2D.Float path = new Path2D.Float();
int seg = width / 3;
path.moveTo(0, height / 2);
path.curveTo(0, 0, seg, 0, seg, height / 2);
path.curveTo(
seg, height,
seg * 2, height,
seg * 2, height / 2);
path.curveTo(
seg * 2, 0,
seg * 3, 0,
seg * 3, height / 2);
g2d.draw(path);
g2d.dispose();
}
}
}
看看转化形状，文本和图像的更多细节
这篇关于放大使用鼠标和图形的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
