I am developing an app using Swing. While user interact with the app, help data may become available in a closed section of the screen, and I'd like to draw a small arrow pointing to that section when this happens.
To do this, I extended a JPanel and added it as the glasspane of the app jframe. The name of the custom glass pane class is AlertGlassPane.
The AlertGlassPane do this: waits until new help data is available. When this happens and the help section is closed, it finds the position of the help section on the screen and then draws an animated arrow at its side.
To draw the arrow I extended the method paintComponent of the glass pane.
To animate the arrow I created a small thread that loop every 100 ms, calling repaint on the glass pane.
The problem: Java ignores my drawing... if a trigger the start of the animation and stand still, nothing happens. No drawing is shown on the app.
I know that the loop is running and paintComponent is being called, but the custom paint is not taking effect.
But if I move the mouse over the region where the arrow should be rendered, it does! But just when the mouse is moving. If a stop move the mouse, the animation stops too, and the arrow freezes on the last position before the mouse stop (or leaves the area).
I tried a lot of things (as set the clip region of the drawing, for example), but nothing seems to work. The only thing that works was when I called by mistake repaint from inside the paintComponent.
At this moment I'm looking for a way to comunicate to the rendering system that a givem region of my glasspane needs to be repainted (repaint(x, y, w, h) didn't work...). Maybe moving the custom rendering to a JLabel and then adding this label to the glasspane? I don't like this approach...
I'll try to clean up the code before post a snippet here. Would it help?
Thanks in advance!
snnipet:
package br.com.r4j.test;
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.image.BufferedImage;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.text.JTextComponent;
/**
*
* #author
*/
public class TestGlassPaneAnimation extends JPanel
{
private static TestGlassPaneAnimation gvp = new TestGlassPaneAnimation();
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
JFrame f = new JFrame("Anitest in glass");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//f.setResizable(false);
f.setLayout(new GridLayout(5, 3));
f.add(new JLabel("First Name :"));
f.add(new JTextField(20));
f.add(new JLabel("Last Name :"));
f.add(new JTextField(20));
f.add(new JLabel("Phone Number :"));
f.add(new JTextField(20));
f.add(new JLabel("Email:"));
f.add(new JTextField(20));
f.add(new JLabel("Address :"));
f.add(new JTextField(20));
JButton btnStart = new JButton("Click me, please!");
f.add(btnStart);
btnStart.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
gvp.startAnimation();
}
});
f.setGlassPane(gvp);
f.pack();
f.setVisible(true);
gvp.setVisible(true);
}
});
}
private BufferedImage icon;
private boolean animate = false;
private long timeStart = 0;
private Thread thrLastActive = null;
public TestGlassPaneAnimation()
{
setLayout(null);//this is the exception to the rule case a layoutmanager might make setting Jlabel co-ords harder
setOpaque(false);
Icon icon1 = UIManager.getIcon("OptionPane.warningIcon");
int imgW = icon1.getIconWidth();
int imgH = icon1.getIconHeight();
this.icon = ImageUtilities.getBufferedImageOfIcon(icon1, imgW, imgH);
this.animate = false;
}
public void startAnimation()
{
this.animate = true;
this.timeStart = (new Date()).getTime();
if (this.thrLastActive != null)
this.thrLastActive.interrupt();
this.thrLastActive = new Thread(new Runnable()
{
public void run()
{
try
{
while (true)
{
// int x = 250, y = 250;
// int width = 60, height = 60;
Thread.currentThread().sleep(100);
// frmRoot.invalidate();
// repaint(x, y, width, height);
repaint(new Rectangle(x, y, width, height));
// repaint(new Rectangle(10, 10, 2000, 2000));
// repaint();
// paintComponent(getGraphics());
}
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
this.thrLastActive.start();
}
protected void paintComponent(Graphics g)
{
try
{
// enables anti-aliasing
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
java.awt.Composite composite = g2.getComposite();
System.err.println("b1: " + g.getClipBounds());
if (this.animate)
{
long timeSpent = (new Date()).getTime() - timeStart;
int x = 10, y = 150;
int width = 60, height = 60;
float maxAlpha = 0.8f;
x += (-100*Math.sin(5*2*Math.PI*timeSpent/10000)+50)/15;
System.err.println("painting::x: " + x + ", y: " + y + ", sin: " + (Math.sin(6*2*Math.PI*timeSpent/10000)));
// g.setClip(x-10, y-10, width, height);
System.err.println("b2: " + g.getClipBounds());
AlphaComposite alpha2 = AlphaComposite.SrcOver.derive(maxAlpha);
g2.setComposite(alpha2);
g2.drawImage(this.icon, x, y, null);
g2.setComposite(composite);
g2.setComposite(composite);
}
}
catch (Throwable e)
{
System.err.println("Errr!");
e.printStackTrace();
}
}
}
class ImageUtilities {
public static BufferedImage resize(BufferedImage image, int width, int height) {
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TRANSLUCENT);
Graphics2D g2d = (Graphics2D) bi.createGraphics();
g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
g2d.drawImage(image, 0, 0, width, height, null);
g2d.dispose();
return bi;
}
public static BufferedImage getBufferedImageOfIcon(Icon icon, int imgW, int imgH) {
BufferedImage img = new BufferedImage(imgW, imgH, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = (Graphics2D) img.getGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
icon.paintIcon(null, g2d, 0, 0);
g2d.dispose();
return img;
}
}
Hmm not sure exactly whats going on with the snippet you gave but as it looks like it was taken from mine I wrote another example (I had to change a 1 or 2 lines of code in showWarningIcon(Component c) and refreshLocations() methods but nothing major:
If anything except david is typed and the button (click me, please) clicked it will show this:
import java.awt.Component;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class TestGlassPaneAnimation {
private static GlassValidationPane gvp = new GlassValidationPane();
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame f = new JFrame("Anitest in glass");
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
//f.setResizable(false);
f.setLayout(new GridBagLayout());
GridBagConstraints gc = new GridBagConstraints();
gc.fill = GridBagConstraints.HORIZONTAL;
gc.weightx = 1;
gc.weighty = 1;
gc.insets = new Insets(15, 15, 15, 15);//give some space so icon doesnt cover components when shown
gc.gridx = 0;
gc.gridy = 0;
f.add(new JLabel("First Name:"), gc);
final JTextField jtf = new JTextField(20);
gc.gridx = 1;
f.add(jtf, gc);
gc.gridx = 0;
gc.gridy = 1;
f.add(new JLabel("Surname:"), gc);
final JTextField jtf2 = new JTextField(20);
gc.gridx = 1;
f.add(jtf2, gc);
JButton btnStart = new JButton("Click me, please!");
gc.gridx = 2;
f.add(btnStart, gc);
btnStart.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (!jtf.getText().equalsIgnoreCase("david")) {
gvp.showWarningIcon(jtf);
}
}
});
f.addComponentListener(new ComponentAdapter() {//so wjen frame is resized icons follow
#Override
public void componentResized(ComponentEvent ce) {
super.componentResized(ce);
gvp.refreshLocations();
}
});
f.setGlassPane(gvp);
f.pack();
f.setVisible(true);
gvp.setVisible(true);
}
});
}
}
class GlassValidationPane extends JPanel {
private HashMap<Component, JLabel> warningLabels = new HashMap<>();
private ImageIcon warningIcon;
public GlassValidationPane() {
setLayout(null);//this is the exception to the rule case a layoutmanager might make setting Jlabel co-ords harder
setOpaque(false);
Icon icon = UIManager.getIcon("OptionPane.warningIcon");
int imgW = icon.getIconWidth();
int imgH = icon.getIconHeight();
BufferedImage img = ImageUtilities.getBufferedImageOfIcon(icon, imgW, imgH);
warningIcon = new ImageIcon(ImageUtilities.resize(img, 24, 24));
}
void showWarningIcon(Component c) {
if (warningLabels.containsKey(c)) {
return;
}
JLabel label = new JLabel();
label.setIcon(warningIcon);
//int x=c.getX();//this will make it insode the component
int x = c.getX() - warningIcon.getIconWidth();//this makes it appear outside/next to component if space
int y = c.getY();
label.setBounds(x, y, warningIcon.getIconWidth(), warningIcon.getIconHeight());
add(label);
revalidate();
repaint();
warningLabels.put(c, label);
}
public void removeWarningIcon(Component c) {
for (Map.Entry<Component, JLabel> entry : warningLabels.entrySet()) {
Component component = entry.getKey();
JLabel jLabel = entry.getValue();
if (component == c) {
remove(jLabel);
revalidate();
repaint();
break;
}
}
warningLabels.remove(c);
}
public void refreshLocations() {
for (Map.Entry<Component, JLabel> entry : warningLabels.entrySet()) {
Component c = entry.getKey();
JLabel label = entry.getValue();
//int x=c.getX();//this will make it insode the component
int x = c.getX() - label.getIcon().getIconWidth();//this makes it appear outside/next to component
int y = c.getY();
label.setBounds(x, y, label.getIcon().getIconWidth(), label.getIcon().getIconHeight());
revalidate();
repaint();
}
}
}
class ImageUtilities {
public static BufferedImage resize(BufferedImage image, int width, int height) {
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TRANSLUCENT);
Graphics2D g2d = (Graphics2D) bi.createGraphics();
g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
g2d.drawImage(image, 0, 0, width, height, null);
g2d.dispose();
return bi;
}
public static BufferedImage getBufferedImageOfIcon(Icon icon, int imgW, int imgH) {
BufferedImage img = new BufferedImage(imgW, imgH, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = (Graphics2D) img.getGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
icon.paintIcon(null, g2d, 0, 0);
g2d.dispose();
return img;
}
}
If you are looking for a more mature library have a look at JXLayer - Validation Overlays and Validation overlays using glass pane.
Also might want to have a read here which shows many ways of validating a textfields data (other than button press) like DocumentFilter and InputVerifier etc.
Related
After learning that dispose() should be called on Graphics/Graphics2D object after use, I went about changing my game to incorporate this.
When I added g2d.dispose() in overridden paintComponent(Graphics g) of JPanel, my components which I added (extensions of JLabel class) where not rendered I was able to still click on them etc but they would not be painted.
I tested with a normal JLabel and JButton with same effect (though JButton is rendered when mouse is over it).
So my question is why does this happen?
Here is an SSCCE to demonstrate:
after uncommenting call to dispose() in paintComponent of MainMenuPanel class:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Test {
public Test() {
try {
initComponents();
} catch (Exception ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test();
}
});
}
private void initComponents() throws Exception {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
MainMenuPanel mmp = new MainMenuPanel();
frame.add(mmp);
frame.pack();
frame.setVisible(true);
}
}
class MainMenuPanel extends JPanel {
//create labels for Main Menu
private PopUpJLabel versusesModeLabel;
private PopUpJLabel singlePlayerModeLabel;
private PopUpJLabel optionsLabel;
private PopUpJLabel helpLabel;
private PopUpJLabel aboutLabel;
//create variable to hold background
private Image background;
private Dimension preferredDimensions;
public static String gameType;
public static final String SINGLE_PLAYER = "Single Player", VERSUS_MODE = "VS Mode";
/**
* Default constructor to initialize double buffered JPanel with
* GridBagLayout
*/
public MainMenuPanel() {
super(new GridBagLayout(), true);
try {
initComponents();
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, "Could not load main menu background!", "Main Menu Error: 0x004", JOptionPane.ERROR_MESSAGE);
System.exit(4);
}
}
/*
* Create JPanel and its components
*/
private void initComponents() throws Exception {
//set prefered size of JPanel
preferredDimensions = new Dimension(800, 600);
background = scaleImage(800, 600, ImageIO.read(new URL("http://photos.appleinsider.com/12.08.30-Java.jpg")));
//create label instances
singlePlayerModeLabel = new PopUpJLabel("Single Player Mode");
singlePlayerModeLabel.setEnabled(false);
versusesModeLabel = new PopUpJLabel("Versus Mode");
optionsLabel = new PopUpJLabel("Options");
helpLabel = new PopUpJLabel("Help");
aboutLabel = new PopUpJLabel("About");
//create new constraints for gridbag
GridBagConstraints gc = new GridBagConstraints();
gc.fill = GridBagConstraints.HORIZONTAL;
gc.ipady = 50;//vertical spacing
//add newGameLabel to panel with constraints
gc.gridx = 0;
gc.gridy = 0;
add(singlePlayerModeLabel, gc);
gc.gridy = 1;
add(versusesModeLabel, gc);
//add optionsLabel to panel with constraints (x is the same)
gc.gridy = 2;
add(optionsLabel, gc);
//add helpLabel to panel with constraints (x is the same)
gc.gridy = 3;
add(helpLabel, gc);
//add aboutLabel to panel with constraints (x is the same)
gc.gridy = 4;
add(aboutLabel, gc);
}
public static BufferedImage scaleImage(int w, int h, BufferedImage img) throws Exception {
BufferedImage bi;
//bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
bi = new BufferedImage(w, h, img.getType());
Graphics2D g2d = (Graphics2D) bi.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
g2d.drawImage(img, 0, 0, w, h, null);
g2d.dispose();
return bi;
}
/*
* Will return the preffered size of JPanel
*/
#Override
public Dimension getPreferredSize() {
return preferredDimensions;
}
/*
* Will draw the background to JPanel with anti-aliasing on and quality rendering
*/
#Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
//convert graphics object to graphics2d object
Graphics2D g2d = (Graphics2D) grphcs;
//set anti-aliasing on and rendering etc
//GamePanel.applyRenderHints(g2d);
//draw the image as the background
g2d.drawImage(background, 0, 0, null);
//g2d.dispose();//if I uncomment this no LAbels will be shown
}
}
class PopUpJLabel extends JLabel {
public final static Font defaultFont = new Font("Arial", Font.PLAIN, 50);
public final static Font hoverFont = new Font("Arial", Font.BOLD, 70);
PopUpJLabel(String text) {
super(text);
setHorizontalAlignment(JLabel.CENTER);
setForeground(Color.ORANGE);
setFont(defaultFont);
//allow component to be focusable
setFocusable(true);
//add focus adapter to change fints when focus is gained or lost (used for transversing labels with keys)
addFocusListener(new FocusAdapter() {
#Override
public void focusGained(FocusEvent fe) {
super.focusGained(fe);
if (isEnabled()) {
setFont(getHoverFont());
}
}
#Override
public void focusLost(FocusEvent fe) {
super.focusLost(fe);
setFont(getDefaultFont());
}
});
addMouseListener(new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent me) {
super.mouseEntered(me);
if (isEnabled()) {
setFont(getHoverFont());
}
//call for focus mouse is over this component
requestFocusInWindow();
}
});
}
Font getDefaultFont() {
return defaultFont;
}
Font getHoverFont() {
return hoverFont;
}
}
The thing is that the Graphics context you are using in paintComponent is created and provided by the caller (the framework), which is also responsible for disposing of it.
You only need to dispose of Graphics when you actually create it yourself (for example by calling Component.getGraphics()). In your case, you're not creating it, you're just casting it, so do not call dispose in this case.
Because .dispose() releases your resources. Yes, everything.
After learning that dispose() should be called on Graphics/Graphics2D object after use, I went about changing my game to incorporate this.
When I added g2d.dispose() in overridden paintComponent(Graphics g) of JPanel, my components which I added (extensions of JLabel class) where not rendered I was able to still click on them etc but they would not be painted.
I tested with a normal JLabel and JButton with same effect (though JButton is rendered when mouse is over it).
So my question is why does this happen?
Here is an SSCCE to demonstrate:
after uncommenting call to dispose() in paintComponent of MainMenuPanel class:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Test {
public Test() {
try {
initComponents();
} catch (Exception ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test();
}
});
}
private void initComponents() throws Exception {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
MainMenuPanel mmp = new MainMenuPanel();
frame.add(mmp);
frame.pack();
frame.setVisible(true);
}
}
class MainMenuPanel extends JPanel {
//create labels for Main Menu
private PopUpJLabel versusesModeLabel;
private PopUpJLabel singlePlayerModeLabel;
private PopUpJLabel optionsLabel;
private PopUpJLabel helpLabel;
private PopUpJLabel aboutLabel;
//create variable to hold background
private Image background;
private Dimension preferredDimensions;
public static String gameType;
public static final String SINGLE_PLAYER = "Single Player", VERSUS_MODE = "VS Mode";
/**
* Default constructor to initialize double buffered JPanel with
* GridBagLayout
*/
public MainMenuPanel() {
super(new GridBagLayout(), true);
try {
initComponents();
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, "Could not load main menu background!", "Main Menu Error: 0x004", JOptionPane.ERROR_MESSAGE);
System.exit(4);
}
}
/*
* Create JPanel and its components
*/
private void initComponents() throws Exception {
//set prefered size of JPanel
preferredDimensions = new Dimension(800, 600);
background = scaleImage(800, 600, ImageIO.read(new URL("http://photos.appleinsider.com/12.08.30-Java.jpg")));
//create label instances
singlePlayerModeLabel = new PopUpJLabel("Single Player Mode");
singlePlayerModeLabel.setEnabled(false);
versusesModeLabel = new PopUpJLabel("Versus Mode");
optionsLabel = new PopUpJLabel("Options");
helpLabel = new PopUpJLabel("Help");
aboutLabel = new PopUpJLabel("About");
//create new constraints for gridbag
GridBagConstraints gc = new GridBagConstraints();
gc.fill = GridBagConstraints.HORIZONTAL;
gc.ipady = 50;//vertical spacing
//add newGameLabel to panel with constraints
gc.gridx = 0;
gc.gridy = 0;
add(singlePlayerModeLabel, gc);
gc.gridy = 1;
add(versusesModeLabel, gc);
//add optionsLabel to panel with constraints (x is the same)
gc.gridy = 2;
add(optionsLabel, gc);
//add helpLabel to panel with constraints (x is the same)
gc.gridy = 3;
add(helpLabel, gc);
//add aboutLabel to panel with constraints (x is the same)
gc.gridy = 4;
add(aboutLabel, gc);
}
public static BufferedImage scaleImage(int w, int h, BufferedImage img) throws Exception {
BufferedImage bi;
//bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
bi = new BufferedImage(w, h, img.getType());
Graphics2D g2d = (Graphics2D) bi.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
g2d.drawImage(img, 0, 0, w, h, null);
g2d.dispose();
return bi;
}
/*
* Will return the preffered size of JPanel
*/
#Override
public Dimension getPreferredSize() {
return preferredDimensions;
}
/*
* Will draw the background to JPanel with anti-aliasing on and quality rendering
*/
#Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
//convert graphics object to graphics2d object
Graphics2D g2d = (Graphics2D) grphcs;
//set anti-aliasing on and rendering etc
//GamePanel.applyRenderHints(g2d);
//draw the image as the background
g2d.drawImage(background, 0, 0, null);
//g2d.dispose();//if I uncomment this no LAbels will be shown
}
}
class PopUpJLabel extends JLabel {
public final static Font defaultFont = new Font("Arial", Font.PLAIN, 50);
public final static Font hoverFont = new Font("Arial", Font.BOLD, 70);
PopUpJLabel(String text) {
super(text);
setHorizontalAlignment(JLabel.CENTER);
setForeground(Color.ORANGE);
setFont(defaultFont);
//allow component to be focusable
setFocusable(true);
//add focus adapter to change fints when focus is gained or lost (used for transversing labels with keys)
addFocusListener(new FocusAdapter() {
#Override
public void focusGained(FocusEvent fe) {
super.focusGained(fe);
if (isEnabled()) {
setFont(getHoverFont());
}
}
#Override
public void focusLost(FocusEvent fe) {
super.focusLost(fe);
setFont(getDefaultFont());
}
});
addMouseListener(new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent me) {
super.mouseEntered(me);
if (isEnabled()) {
setFont(getHoverFont());
}
//call for focus mouse is over this component
requestFocusInWindow();
}
});
}
Font getDefaultFont() {
return defaultFont;
}
Font getHoverFont() {
return hoverFont;
}
}
The thing is that the Graphics context you are using in paintComponent is created and provided by the caller (the framework), which is also responsible for disposing of it.
You only need to dispose of Graphics when you actually create it yourself (for example by calling Component.getGraphics()). In your case, you're not creating it, you're just casting it, so do not call dispose in this case.
Because .dispose() releases your resources. Yes, everything.
I borrowed the class below to make a selection area tool for a project. But it has a issue when I try to make a selection when the content is not aligned at top-left, it get my mouse coordinates related to the ScrollPane, but draws over the image - See this SS for better understanding:
sscce:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
/** Getting a Rectangle of interest on the screen.
Requires the MotivatedEndUser API - sold separately. */
public class ScreenCaptureRectangle {
Rectangle captureRect;
ScreenCaptureRectangle(final BufferedImage screen) {
final BufferedImage screenCopy = new BufferedImage(screen.getWidth(), screen.getHeight(), screen.getType());
final JLabel screenLabel = new JLabel(new ImageIcon(screenCopy));
JScrollPane screenScroll = new JScrollPane(screenLabel);
screenScroll.setPreferredSize(new Dimension((int)(screen.getWidth()*2), (int)(screen.getHeight()*2)));
JPanel panel = new JPanel(new BorderLayout());
panel.add(screenScroll, BorderLayout.CENTER);
final JLabel selectionLabel = new JLabel("Drag a rectangle in the screen shot!");
panel.add(selectionLabel, BorderLayout.SOUTH);
repaint(screen, screenCopy);
screenLabel.repaint();
screenLabel.addMouseMotionListener(new MouseMotionAdapter() {
Point start = new Point();
#Override
public void mouseMoved(MouseEvent me) {
start = me.getPoint();
repaint(screen, screenCopy);
selectionLabel.setText("Start Point: " + start);
screenLabel.repaint();
}
#Override
public void mouseDragged(MouseEvent me) {
Point end = me.getPoint();
captureRect = new Rectangle(start, new Dimension(end.x-start.x, end.y-start.y));
repaint(screen, screenCopy);
screenLabel.repaint();
selectionLabel.setText("Rectangle: " + captureRect);
}
});
JOptionPane.showMessageDialog(null, panel);
System.out.println("Rectangle of interest: " + captureRect);
}
public void repaint(BufferedImage orig, BufferedImage copy) {
Graphics2D g = copy.createGraphics();
g.drawImage(orig,0,0, null);
if (captureRect!=null) {
g.setColor(Color.RED);
g.draw(captureRect);
g.setColor(new Color(255,255,255,150));
g.fill(captureRect);
}
g.dispose();
}
public static void main(String[] args) throws Exception {
Robot robot = new Robot();
final Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
final BufferedImage screen = robot.createScreenCapture(new Rectangle(300,0,300,300));
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ScreenCaptureRectangle(screen);
}
});
}
}
I think you have problems because you are attempting to center the image in the panel.
The easiest solution is to make sure the image is painted from the top/left of the panel:
final JLabel screenLabel = new JLabel(new ImageIcon(screenCopy));
screenLabel.setHorizontalAlignment(JLabel.LEFT);
screenLabel.setVerticalAlignment(JLabel.TOP);
Basically, what's happening, is you are drawing directly to the image surface (which is held by the JLabel), so while, you drag at 2x2x36x36 on the screen, this then draws on the rectangle RELATIVE to the image itself
So even though the image is centered within the context of the JLabel, you are still rendering to the local context of the image (0x0), hence the disconnection between the two.
Depending on what it is you want to achieve, you change the way the painting works and take more direct control, for example...
import java.awt.AWTException;
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.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DrawimgExample {
public static void main(String[] args) {
try {
Robot robot = new Robot();
final Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
final BufferedImage screen = robot.createScreenCapture(new Rectangle(300, 0, 300, 300));
new DrawimgExample(screen);
} catch (AWTException exp) {
exp.printStackTrace();
}
}
public DrawimgExample(final BufferedImage screen) {
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 DrawingPane(screen));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class DrawingPane extends JPanel {
private BufferedImage img;
private Rectangle drawRect;
public DrawingPane(BufferedImage img) {
this.img = img;
MouseAdapter mouseHandler = new MouseAdapter() {
private Point startPoint;
#Override
public void mousePressed(MouseEvent e) {
startPoint = e.getPoint();
}
#Override
public void mouseDragged(MouseEvent e) {
Point endPoint = e.getPoint();
int startX = Math.min(startPoint.x, endPoint.x);
int startY = Math.min(startPoint.y, endPoint.y);
int width = Math.max(startPoint.x, endPoint.x) - startX;
int height = Math.max(startPoint.y, endPoint.y) - startY;
drawRect = new Rectangle(
startX,
startY,
width,
height
);
repaint();
}
};
addMouseListener(mouseHandler);
addMouseMotionListener(mouseHandler);
}
#Override
public Dimension getPreferredSize() {
return img == null ? new Dimension(200, 200) : new Dimension(img.getWidth(), img.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - img.getWidth()) / 2;
int y = (getHeight() - img.getHeight()) / 2;
g2d.drawImage(img, x, y, this);
if (drawRect != null) {
g2d.setColor(Color.RED);
g2d.draw(drawRect);
g2d.setColor(new Color(255, 255, 255, 150));
g2d.fill(drawRect);
}
g2d.dispose();
}
}
}
Having said that, where possible, you should avoid painting images directly, as JLabel already does a good job, but sometimes, if it doesn't meet your needs, you might need to take more direct control
I am having problem in creating an transparent rectangle over blurred background. I am trying to do this task on glasspane. Here is my code snippet.
void createBlur() {
alpha = 1.0f;
JRootPane root = SwingUtilities.getRootPane(jf);
blurBuffer = GraphicsUtilities.createCompatibleImage(jf.getWidth(), jf.getHeight());
Graphics2D g2d = blurBuffer.createGraphics();
root.paint(g2d);
g2d.dispose();
backBuffer = blurBuffer;
blurBuffer = GraphicsUtilities.createThumbnailFast(blurBuffer, jf.getWidth() / 2);
blurBuffer = new GaussianBlurFilter(5).filter(blurBuffer, null);
}
where, backBuffer and blurBuffer are objects of BufferedImage & jf = JFrame, alpha is used for opacity.
The above method create an Blurred Effect very well.
Here is the code which creates an transparent rectangle over Panel
protected void paintComponent(Graphics g) {
int x = 34;
int y = 34;
int w = getWidth() - 68;
int h = getHeight() - 68;
int arc = 30;
//Graphics2D g2 = currentGraphics.createGraphics();
//g2.drawImage(currentGraphics, 0, 0, null);
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(new Color(0, 0, 0, 220));
g2.fillRoundRect(x, y, w, h, arc, arc);
g2.setStroke(new BasicStroke(1f));
g2.setColor(Color.WHITE);
g2.drawRoundRect(x, y, w, h, arc, arc);
g2.dispose();
}
Now where I stuck is how do I paint the blurred effect and transparent rectangle at the same time.
I didn't posted whole code over here, if anyone wish to see the code here the link.
And here is an desired image of sample output. Thanks in advance.
I'm trying to make heads and tails of your code...
You fail to call super.paintComponent...this could lead you into a same serious issues if you're not careful. General rule of thumb, just call it ;)
Be careful when modifiying the state of a Graphics context, for example...
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
Will affect ALL components painted after this one and could cause some interesting graphical glitches you weren't expecting...
jf.getGlassPane().setVisible(false);
glassPanel = new GlassPanel();
jf.getGlassPane().setVisible(true);
Seems pointless, as the component set using jf.setGlassPane(glassPanel); will still be the component that is made visible when you call jf.getGlassPane().setVisible(true);. This also means that the GlassPane component is never used...
Checking isVisible in paintComponent is pointless, as Swing is clever enough to know not to paint invisible components...
Now, having said all that...
If you wanted to paint on top of the BlurPanel you would either...paint content after the blurBuffer is drawn, so you are drawing ontop of it OR add another component onto the BlurPanel pane which contains the drawing logic you want to apply...
This is a basic example of that concept. This adds another panel onto the glass pane which paints the custom frame of the panel as I want.
This example uses personal library code and is intended as an example of the concept alone, not a completely runnable example.
import core.ui.GlowEffectFactory;
import core.ui.GraphicsUtilities;
import core.util.ByteFormatter;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.text.DateFormat;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRootPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
public class TransparentTest {
public static void main(String[] args) {
new TransparentTest();
}
public TransparentTest() {
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 TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage background;
private BlurredGlassPane blurredGlassPane;
private InfoPane infoPane;
public TestPane() {
try {
background = ImageIO.read(new File("get your own image"));
} catch (IOException ex) {
ex.printStackTrace();
}
blurredGlassPane = new BlurredGlassPane();
blurredGlassPane.setLayout(new GridBagLayout());
infoPane = new InfoPane();
infoPane.setFile(new File("get your own image"));
blurredGlassPane.add(infoPane);
JButton click = new JButton("Click");
click.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Window win = SwingUtilities.getWindowAncestor(TestPane.this);
if (win instanceof JFrame) {
JFrame frame = (JFrame) win;
frame.setGlassPane(blurredGlassPane);
blurredGlassPane.setVisible(true);
}
}
});
setLayout(new GridBagLayout());
add(click);
}
#Override
public Dimension getPreferredSize() {
return background == null ? new Dimension(200, 200) : new Dimension(background.getWidth(), background.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (background != null) {
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - background.getWidth()) / 2;
int y = (getHeight() - background.getHeight()) / 2;
g2d.drawImage(background, x, y, this);
g2d.dispose();
}
}
}
public static class InfoPane extends JPanel {
protected static final int RADIUS = 20;
protected static final int FRAME = 4;
protected static final int INSET = RADIUS + FRAME;
protected static final DateFormat DATE_FORMAT = DateFormat.getDateTimeInstance();
private JLabel name;
private JLabel path;
private JLabel length;
private JLabel lastModified;
private JLabel canExecute;
private JLabel canRead;
private JLabel canWrite;
private JLabel isDirectory;
private JLabel isHidden;
public InfoPane() {
setBorder(new EmptyBorder(INSET, INSET, INSET, INSET));
setOpaque(false);
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1;
gbc.anchor = GridBagConstraints.WEST;
gbc.gridwidth = GridBagConstraints.REMAINDER;
name = createLabel(Font.BOLD, 48);
add(name, gbc);
gbc.gridy++;
path = createLabel();
add(path, gbc);
gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 2;
gbc.anchor = GridBagConstraints.WEST;
length = createLabel();
lastModified = createLabel();
add(createLabel("Size: "), gbc);
gbc.gridx++;
gbc.insets = new Insets(0, 0, 0, 10);
add(length, gbc);
gbc.insets = new Insets(0, 0, 0, 0);
gbc.gridx++;
add(createLabel("Last Modified: "), gbc);
gbc.gridx++;
add(lastModified, gbc);
}
public JLabel createLabel(String text) {
JLabel label = new JLabel(text);
label.setForeground(Color.WHITE);
return label;
}
public JLabel createLabel() {
return createLabel("");
}
public JLabel createLabel(int style, float size) {
JLabel label = createLabel();
label.setFont(label.getFont().deriveFont(style, size));
return label;
}
public void setFile(File file) {
name.setText(file.getName());
try {
path.setText(file.getParentFile().getCanonicalPath());
} catch (IOException ex) {
ex.printStackTrace();
}
length.setText(ByteFormatter.format(file.length()));
lastModified.setText(DATE_FORMAT.format(new Date(file.lastModified())));
file.canExecute();
file.canRead();
file.canWrite();
file.isDirectory();
file.isHidden();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
GraphicsUtilities.applyQualityRenderingHints(g2d);
int width = getWidth() - 1;
int height = getHeight() - 1;
int buffer = FRAME / 2;
RoundRectangle2D base = new RoundRectangle2D.Double(buffer, buffer, width - FRAME, height - FRAME, RADIUS, RADIUS);
g2d.setColor(new Color(0, 0, 0, 128));
g2d.fill(base);
g2d.setColor(Color.WHITE);
g2d.setStroke(new BasicStroke(FRAME, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
g2d.draw(base);
g2d.dispose();
}
}
public class BlurredGlassPane extends JPanel {
private BufferedImage background;
#Override
public void setVisible(boolean visible) {
if (visible) {
Container parent = SwingUtilities.getAncestorOfClass(JRootPane.class, this);
if (parent != null) {
JRootPane rootPane = (JRootPane) parent;
BufferedImage img = new BufferedImage(rootPane.getWidth(), rootPane.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
rootPane.printAll(g2d);
g2d.dispose();
background = GlowEffectFactory.generateBlur(img, 40);
}
}
super.setVisible(visible);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(background, 0, 0, this);
}
}
}
I need to resize the font of multiple JLabel based on the scaling factor used to resize the container. To do this, I am setting the font of each JLabel to null so that they take the font of the container. It works, but it also produces strange results.
To be specific, the text seems to "lag" behind the container and sometimes it gets even truncated. I would like to avoid this behavior. Any idea how?
Example code simulating the behavior:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.geom.AffineTransform;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class TextResize implements Runnable {
public static void main(String[] args) {
TextResize example = new TextResize();
SwingUtilities.invokeLater(example);
}
public void run() {
JFrame frame = new JFrame("JLabel Text Resize");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setPreferredSize(new Dimension(800, 400));
Container container = frame.getContentPane();
container.setLayout(new BorderLayout());
final JPanel labelContainer = new JPanel(new GridBagLayout());
labelContainer.setBorder(BorderFactory.createLineBorder(Color.black));
//initial font
final Font textFont = new Font("Lucida Console", Font.PLAIN, 10).deriveFont(AffineTransform.getScaleInstance(1, 1));
labelContainer.setFont(textFont);
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
c.insets = new Insets(0, 10, 0, 10);
c.weightx = 1;
for (int i = 0; i < 5; i++) {
JLabel f = new JLabel("Text here with possibly looooooooong words");
f.setBorder(BorderFactory.createLineBorder(Color.green));
f.setFont(null);//take the font from parent
c.gridy = i;
labelContainer.add(f, c);
}
JSlider slider = new JSlider(0,50000,10000);
slider.addChangeListener(new ChangeListener() {
double containerWidth = labelContainer.getPreferredSize().getWidth();
double containerHeight = labelContainer.getPreferredSize().getHeight();
#Override
public void stateChanged(ChangeEvent ev) {
JSlider source = (JSlider) ev.getSource();
double scale = (double) (source.getValue() / 10000d);
//scaling the container
labelContainer.setSize((int) (containerWidth * scale), (int) (containerHeight * scale));
//adjusting the font: why does it 'lag' ? why the truncation at times?
Font newFont = textFont.deriveFont(AffineTransform.getScaleInstance(scale, scale));
labelContainer.setFont(newFont);
//print (font.getSize() does not change?)
System.out.println(scale + " " + newFont.getTransform() + newFont.getSize2D());
}
});
container.add(slider, BorderLayout.NORTH);
JPanel test = new JPanel();
test.setLayout(null);
labelContainer.setBounds(5, 5, labelContainer.getPreferredSize().width, labelContainer.getPreferredSize().height);
test.add(labelContainer);
container.add(test, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
}
Picture:
http://i.stack.imgur.com/tZLOO.png
Thanks,
-s
You can use any of the following methods:
by #trashgod
by #StanislavL
by #coobird
I sort of solved the problem adding:
#Override
protected void paintComponent(Graphics g) {
final Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
g2d.setRenderingHint(java.awt.RenderingHints.KEY_TEXT_ANTIALIASING, java.awt.RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
super.paintComponent(g2d);
}
Thanks anyway.
If performance speed is an issue, then you might find the following information about the 3 methods pointed to by MKorbel above useful.
Coobird's code has some limitations if used on a multi-call basis (eg in a sizeChanged Listener or a LayoutManager)
Trashgod's method is between 2 and 4 times slower than Stanislav's (but it also is designed to fill the area BOTH directions as the OP asked in that question, so not unexpected.)
The code below improves on Stanislav's rectangle method (by starting from the current font size each time rather than reverting back to MIN_FONT_SIZE each time) and thus runs between 20 and 50 times faster than that code, especially when the window/font is large.
It also addresses a limitation in that code which only effectively works for labels located at 0,0 (as in the sample given there). The code below works for multiple labels on a panel and at any location.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
// Improved version of http://java-sl.com/tip_adapt_label_font_size.html
public class FontResizingLabel extends JLabel {
public static final int MIN_FONT_SIZE=3;
public static final int MAX_FONT_SIZE=240;
Graphics g;
int currFontSize = 0;
public FontResizingLabel(String text) {
super(text);
currFontSize = this.getFont().getSize();
init();
}
protected void init() {
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
adaptLabelFont(FontResizingLabel.this);
}
});
}
protected void adaptLabelFont(JLabel l) {
if (g==null) {
return;
}
currFontSize = this.getFont().getSize();
Rectangle r = l.getBounds();
r.x = 0;
r.y = 0;
int fontSize = Math.max(MIN_FONT_SIZE, currFontSize);
Font f = l.getFont();
Rectangle r1 = new Rectangle(getTextSize(l, l.getFont()));
while (!r.contains(r1)) {
fontSize --;
if (fontSize <= MIN_FONT_SIZE)
break;
r1 = new Rectangle(getTextSize(l, f.deriveFont(f.getStyle(), fontSize)));
}
Rectangle r2 = new Rectangle();
while (fontSize < MAX_FONT_SIZE) {
r2.setSize(getTextSize(l, f.deriveFont(f.getStyle(),fontSize+1)));
if (!r.contains(r2)) {
break;
}
fontSize++;
}
setFont(f.deriveFont(f.getStyle(),fontSize));
repaint();
}
private Dimension getTextSize(JLabel l, Font f) {
Dimension size = new Dimension();
//g.setFont(f); // superfluous.
FontMetrics fm = g.getFontMetrics(f);
size.width = fm.stringWidth(l.getText());
size.height = fm.getHeight();
return size;
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
this.g=g;
}
public static void main(String[] args) throws Exception {
FontResizingLabel label=new FontResizingLabel("Some text");
JFrame frame=new JFrame("Resize label font");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(label);
frame.setSize(300,300);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}