使用 AffineTransform 缩放图形 [英] Scaling graphics with AffineTransform
本文介绍了使用 AffineTransform 缩放图形的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在用 Swing 制作一个 GUI，它使用 AffineTransform 来缩放绘制在 JInternalFrame 上的 Graphics2D 对象.问题是它在当前状态下有问题，我不知道为什么.
I am making a GUI with Swing that uses an AffineTransform to scale Graphics2D objects painted on a JInternalFrame. The problem is that it is buggy in the current state and I can't figure out why.
为什么我的代码不能正确缩放?为什么图形在调整大小时跳"到面板顶部?
Why isn't my code scaling properly? Why do the graphics "jump" to the top of the panel on a resize?
这是我的自包含示例:
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.util.*;
public class MainPanel extends JFrame implements ActionListener{
private static final double version = 1.0;
private JDesktopPane desktop;
public static RFInternalFrame frame;
private java.util.List<Point> POINT_LIST = Arrays.asList(
//Top Row
new Point(50, 30),
new Point(70, 30),
new Point(90, 30),
new Point(110, 30),
new Point(130, 30),
new Point(150, 30),
new Point(170, 30),
new Point(190, 30),
new Point(210, 30),
new Point(230, 30),
//Circle of Radios
new Point(140, 60),
new Point(120, 80),
new Point(100, 100),
new Point(100, 120),
new Point(120, 140),
new Point(140, 160),
new Point(160, 140),
new Point(180, 120),
new Point(180, 100),
new Point(160, 80));
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
private static void createAndShowGui() {
JFrame frame = new MainPanel();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setLocationByPlatform(false);
frame.setVisible(true);
}
public MainPanel() {
super("MainPanel " + version);
//Make the big window be indented 50 pixels from each edge
//of the screen.
int inset = 50;
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
setBounds(inset, inset,
screenSize.width - inset * 7,
screenSize.height - inset * 4);
//Set up the GUI.
desktop = new JDesktopPane(); //a specialized layered pane
desktop.setBackground(Color.DARK_GRAY);
createRFFrame(); //create first RFFrame
createScenarioFrame(); //create ScenarioFrame
setContentPane(desktop);
setJMenuBar(createMenuBar());
//Make dragging a little faster but perhaps uglier.
desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
}
protected JMenuBar createMenuBar() {
JMenuBar menuBar = new JMenuBar();
//Set up the lone menu.
JMenu menu = new JMenu("File");
menu.setMnemonic(KeyEvent.VK_D);
menuBar.add(menu);
//Set up the first menu item.
JMenuItem menuItem = new JMenuItem("Add Panel");
menuItem.setMnemonic(KeyEvent.VK_N);
menuItem.setAccelerator(KeyStroke.getKeyStroke(
KeyEvent.VK_N, ActionEvent.ALT_MASK));
menuItem.setActionCommand("new");
menuItem.addActionListener(this);
menu.add(menuItem);
//Set up the second menu item.
menuItem = new JMenuItem("Quit");
menuItem.setMnemonic(KeyEvent.VK_Q);
menuItem.setAccelerator(KeyStroke.getKeyStroke(
KeyEvent.VK_Q, ActionEvent.ALT_MASK));
menuItem.setActionCommand("quit");
menuItem.addActionListener(this);
menu.add(menuItem);
return menuBar;
}
//React to menu selections.
public void actionPerformed(ActionEvent e) {
if ("new".equals(e.getActionCommand())) { //new
createRFFrame();
} else {
//quit
quit();
}
}
/*
* ActivateAllAction activates all radios on the panel, essentially changes the color
* of each ellipse from INACTIVE to ACTIVE
*/
private class ActivateAllAction extends AbstractAction {
public ActivateAllAction(String name) {
super(name);
int mnemonic = (int) name.charAt(1);
putValue(MNEMONIC_KEY, mnemonic);
}
/*
* This will find the selected tab and extract the DrawEllipses instance from it
* Then for the actionPerformed it will call activateAll() from DrawEllipses
*/
@Override
public void actionPerformed(ActionEvent e) {
Component comp = desktop.getSelectedFrame();
if (comp instanceof DrawEllipses){
DrawEllipses desktop = (DrawEllipses) comp;
desktop.activateAll();
}
}
}
/*
* DeactivateAllAction deactivates all radios on the panel, essentially changes the color
* of each ellipse from ACTIVE to INACTIVE
*/
private class DeactivateAllAction extends AbstractAction {
public DeactivateAllAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
/*
* This will find the selected tab and extract the DrawPanel2 instance from it
* Then for the actionPerformed it will call activateAll() from DrawEllipses
*/
@Override
public void actionPerformed(ActionEvent e) {
Component comp = desktop.getSelectedFrame();
if (comp instanceof DrawEllipses){
DrawEllipses desktop = (DrawEllipses) comp;
desktop.deactivateAll();
}
}
}
/*
* Define a JPanel that will hold the activate and deactivate all JButtons
*/
protected JPanel btnPanel() {
JPanel btnPanel = new JPanel();
btnPanel.setBorder(BorderFactory.createLoweredSoftBevelBorder());
//Set the layout of the frame to a grid bag layout
btnPanel.setLayout(new GridBagLayout());
//Creates constraints variable to hold values to be applied to each aspect of the layout
GridBagConstraints c = new GridBagConstraints();
//Column 1
c.gridx = 0;
btnPanel.add(new JButton(new ActivateAllAction("Activate All")));
//Column 2
c.gridx = 1;
btnPanel.add(new JButton(new DeactivateAllAction("Deactivate All")));
return btnPanel;
}
//not used currently
protected JPanel drawPanel() {
JPanel drawPanel = new JPanel();
drawPanel.setBorder(BorderFactory.createLoweredSoftBevelBorder());
DrawEllipses drawEllipses = new DrawEllipses(POINT_LIST);
drawPanel.add(drawEllipses);
return drawPanel;
}
//Create a new internal frame.
protected void createRFFrame() {
RFInternalFrame iframe = new RFInternalFrame();
iframe.setLayout(new BorderLayout());
DrawEllipses drawEllipses = new DrawEllipses(POINT_LIST);
iframe.add(drawEllipses);
iframe.add(btnPanel(), BorderLayout.SOUTH);
iframe.setVisible(true);
desktop.add(iframe);
try {
iframe.setSelected(true);
} catch (java.beans.PropertyVetoException e) {}
}
protected void createScenarioFrame() {
ScenarioInternalFrame frame = new ScenarioInternalFrame();
frame.setLayout(new BorderLayout());
frame.setVisible(true);
desktop.add(frame);
try {
frame.setSelected(true);
} catch (java.beans.PropertyVetoException e) {}
}
//Quit the application.
protected void quit() {
System.exit(0);
}
}
@SuppressWarnings("serial")
class DrawEllipses extends JPanel {
private double translateX; //
private double translateY; //
protected static double scale; //
private static final int OVAL_WIDTH = 15;
private static final Color INACTIVE_COLOR = Color.RED;
private static final Color ACTIVE_COLOR = Color.green;
private java.util.List<Point> points; //
private java.util.List<Ellipse2D> ellipses = new ArrayList<>();
private Map<Ellipse2D, Color> ellipseColorMap = new HashMap<>();
public DrawEllipses(java.util.List<Point> points) {
this.points = points; //
translateX = 0; //
translateY = 0; //
scale = 1; //
setOpaque(true); //
setDoubleBuffered(true); //
for (Point p : points) {
int x = p.x - OVAL_WIDTH / 2;
int y = p.y - OVAL_WIDTH / 2;
int w = OVAL_WIDTH;
int h = OVAL_WIDTH;
Ellipse2D ellipse = new Ellipse2D.Double(x, y, w, h);
ellipses.add(ellipse);
ellipseColorMap.put(ellipse, INACTIVE_COLOR);
}
MyMouseAdapter mListener = new MyMouseAdapter();
addMouseListener(mListener);
addMouseMotionListener(mListener);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
AffineTransform tx = new AffineTransform(); //
tx.translate(translateX, translateY); //
tx.scale(scale, scale); //
Graphics2D g2 = (Graphics2D) g;
g2.setTransform(tx);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (Ellipse2D ellipse : ellipses) {
g2.setColor(ellipseColorMap.get(ellipse));
g2.fill(ellipse);
}
}
private class MyMouseAdapter extends MouseAdapter {
@Override
public void mousePressed(MouseEvent e) {
for (Ellipse2D ellipse : ellipses) {
if (ellipse.contains(e.getPoint())) {
Color c = ellipseColorMap.get(ellipse);
c = (c == INACTIVE_COLOR) ? ACTIVE_COLOR : INACTIVE_COLOR;
ellipseColorMap.put(ellipse, c);
}
}
repaint();
}
}
//Used for button click action to change all ellipses to ACTIVE_COLOR
public void activateAll(){
for (Ellipse2D ellipse : ellipses){
ellipseColorMap.put(ellipse, ACTIVE_COLOR);
}
repaint();
}
//Used for button click action to change all ellipses to INACTIVE_COLOR
public void deactivateAll(){
for (Ellipse2D ellipse : ellipses){
ellipseColorMap.put(ellipse, INACTIVE_COLOR);
}
repaint();
}
}
class RFInternalFrame extends JInternalFrame implements ComponentListener {
protected static double scale = 1; //
static int openFrameCount = 0;
static final int xOffset = 300, yOffset = 0;
public RFInternalFrame() {
super("RF Panel #" + (++openFrameCount),
true, //resizable
true, //closable
true, //maximizable
true);//iconifiable
setSize(300, 300);
setMinimumSize(new Dimension(300, 300));
addComponentListener(this);
if (openFrameCount == 1) {
setLocation(0,0);
}
else if (openFrameCount <= 4) {
//Set the window's location.
setLocation(xOffset * (openFrameCount - 1), yOffset * (openFrameCount - 1));
}
else if (openFrameCount == 5) {
setLocation(xOffset - 300, yOffset + 300);
}
else if (openFrameCount == 6) {
setLocation(xOffset + 600, yOffset + 300);
}
}
@Override
public void componentResized(ComponentEvent e) {
String str = "";
if (getWidth() < 300) {
str = "0." + getWidth();
} else {
str = "1." + (getWidth() - 300);
System.out.println(getWidth() - 300);
}
double dou = Double.parseDouble(str);
MainPanel.frame.scale = dou;
repaint();
}
@Override
public void componentMoved(ComponentEvent componentEvent) {
}
@Override
public void componentShown(ComponentEvent componentEvent) {
}
@Override
public void componentHidden(ComponentEvent componentEvent) {
}
}
class ScenarioInternalFrame extends JInternalFrame {
static int openFrameCount = 0;
static final int xOffset = 300, yOffset = 300;
public ScenarioInternalFrame() {
super("Test Scenario" + (++openFrameCount),
true, //resizable
true, //closable
true, //maximizable
true);//iconifiable
//...Create the GUI and put it in the window...
//...Then set the window size or call pack...
setSize(600, 300);
//Set the window's location.
setLocation(xOffset, yOffset);
}
}
推荐答案
据我所知，Graphics 对象已经包含一个转换，该转换执行转换以考虑内部框架的标题栏的高度.当您替换转换时，您会丢失此转换，因此您的代码将绘制在标题栏下方的框架顶部.
As I understand it, the Graphics object already contains a transform that does a translate to account for the height of the title bar of the internal frame. When you replace the transform you lose this translation so your code is painted at the top of the frame under the title bar.
- 不要更改传递给paintComponent() 方法的Graphics 对象的属性.而是创建一个您可以自定义的 Graphics2D 对象.
- 创建新转换时，您需要先应用现有转换，然后再添加新转换.
基本结构类似于:
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g.create();
AffineTransform tx = new AffineTransform(); //
tx.concatenate( g2.getTransform() );
tx.scale(...);
g2.setTransform(tx);
// do custom painting
g2.dispose(); // release Graphics resources
这将有助于绘画.您还有几个问题(我无法解决):
This will just help the painting. You still have several problems (which I can't solve):
您的比例值永远不会更新.您应该将 ComponentListener 添加到 DrawEllipse 面板.您可能希望在您调用的面板中创建一个
setScale()方法，以便在调整面板大小时设置比例.
Your scale value is never getting updated. You should be adding the ComponentListener to the DrawEllipse panel. You might want to create a
setScale()method in the panel that you invoked to set the scale when the panel is resized.
一旦你绘制了缩放的圆圈，你的 MouseListener 将无法工作.所有圆圈的位置都会有所不同，因为它们已被缩放.您可以在循环访问圆圈列表时缩放每个圆圈.
Once you do paint the circles scaled, you MouseListener won't work. The location of all the circles will be different because they have been scaled. You might be able to scale each circle as you iterate through the list of circles.
此外，当您有问题时，请发布一个适当的 SSCCE 来演示该问题.您有一个关于在面板上使用变换的简单问题.因此，创建一个带有面板的框架并在面板上绘制几个圆圈以测试概念.
Also, when you have a question post a proper SSCCE that demonstrates the problem. You have a simple question about using a transform on a panel. So create a frame with a panel and paint a couple of circles on the panel to test the concept.
所有其他代码都与问题无关.菜单项无关紧要，第二个内部框架无关紧要.MouseListener 单击代码无关紧要.我们没有时间通读 100 行代码来理解问题.
All the other code is irrelevant to the problem. The menu items are irrelevant, the second internal frame is irrelevant. The MouseListener clicking code is irrelevant. We don't have time to read through 100's of lines of code to understand the question.
我改变了代码的顺序.必须在将转换设置为 Graphics 对象之前调用 tx.scale(...) 方法.
I changed the order of the code. The tx.scale(...) method must be invoked before setting the transform to the Graphics object.
这篇关于使用 AffineTransform 缩放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！
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