So if I add a background picture, then I click the button lots of times, my program will be slower and slower. But if I don't add that background picture, it won't get slower. Can anyone tell me why? Thanks!
here is my JFrame class:
public class test extends JFrame implements ActionListener {
private Container contentPane;
public test() throws FileNotFoundException {
// set the position of the GUI related with screen size
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
double width = screenSize.getWidth();
double height = screenSize.getHeight();
this.setBounds((int) width / 4, (int) height / 4, (int) width / 2, (int) height / 2);
//set background
ImageIcon img = new ImageIcon("background.jpeg");
// get the container
contentPane = this.getContentPane();
//contentPane.setLayout(new GridLayout(3, 1));
/*
*background panel
*/
JPanel backgroundPanel = new JPanel(){
{
this.setOpaque(false);
}
public void paintComponent(Graphics g) {
img.setImage(img.getImage().getScaledInstance(this.getWidth(), this.getHeight(), Image.SCALE_AREA_AVERAGING));
g.drawImage(img.getImage(), 0, 0, this);
super.paintComponent(g);
}
};
contentPane.add(backgroundPanel);
backgroundPanel.setLayout(new GridLayout(3, 1));
/*
* second area
*/
JPanel secondPanel = new JPanel();
secondPanel.setOpaque(false);
// display button
makeButton(secondPanel, "Display", this);
backgroundPanel.add(secondPanel);
}
private void makeButton(JPanel p, String name, ActionListener target) {
JButton b = new JButton(name);
b.setFont(new Font(null, Font.PLAIN, 20));
// add it to the specified JPanel and button group and make the JPanel listen
p.add(b);
b.addActionListener(target);
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
String command = e.getActionCommand();
// Load button
// Display button
if (command.equals("Display")) {
// check is there any document has been loaded
// pop-up window
JOptionPane.showMessageDialog(null, "Please load a document first!", "Error",JOptionPane.PLAIN_MESSAGE);
}
// show states button
}
}
here is the main method:
public class DocumentViewer {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
JFrame frm = new test();
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.setVisible(true);
}
}
Here:
public void paintComponent(Graphics g) {
img.setImage(img.getImage().getScaledInstance(this.getWidth(), this.getHeight(), Image.SCALE_AREA_AVERAGING));
g.drawImage(img.getImage(), 0, 0, this);
super.paintComponent(g);
}
You're doing resource-hungry calculations within a painting method, a method that contributes greatly to user-perceived program responsiveness. Don't do this. Scale the image once, and store it in a variable, and then only draw the image within the paintComponent method.
If you need the image to resize with the GUI, then do the resizing within a ComponentListener, and again not within a painting method.
Related
I want to create a grid of squares in my Java Swing GUI. I need to toggle their state so I'm thinking a JToggleButton is appropriate for each of the squares.
The problem that I have is that I want to partially colour each toggle button according to given percentages. e.g. if 50% and 50% I want the left half of the button to be green and the right to be red. If 25%,25%,50% I'd need 3 colours. I also need to use the button Text field so hiding that isn't allowed in the solution.
Is it possible to do something like this with a JToggleButton? Is there a better element to use? Or how might I go about it?
I apologise for not posting my work so far but I can't find anything close to an example of this type of thing.
I want to end up with something like this where each square is a button.
You can construct a button with changeable 2-color background as required by overriding
paintComponent:
import java.awt.*;
import javax.swing.*;
public class TwoColorsButton extends JButton{
private final Color leftColor, rightColor;
private int percentOfLeftColor;
public TwoColorsButton(String text) {
this(text,Color.RED, Color.GREEN, 50);
}
public TwoColorsButton(String text, Color leftColor,Color rightColor, int percentOfLeftColor) {
super(text);
this.leftColor = leftColor;
this.rightColor = rightColor;
this.percentOfLeftColor = percentOfLeftColor;
//make button transparent
setOpaque(false);
setContentAreaFilled(false);
setBorderPainted(false);
}
#Override
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
int leftWidth = getWidth() * percentOfLeftColor/100;
g2.setColor(leftColor);
g2.fillRect(0, 0, leftWidth , getHeight());
g2.setColor(rightColor);
g2.fillRect(leftWidth, 0, getWidth() -leftWidth, getHeight());
g2.setPaint(Color.BLACK);
super.paintComponent(g2); //button is transparent so super paints text only
g2.dispose();
}
public void setPercentOfLeftColor(int percentOfLeftColor) {
this.percentOfLeftColor = percentOfLeftColor;
repaint();
}
public int getPercentOfLeftColor() {
return percentOfLeftColor;
}
public static void main(String[] args) {
//run button test
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
JPanel topPanel = new JPanel();
TwoColorsButton twoColorBtn = new TwoColorsButton("Some Text");
topPanel.add(twoColorBtn);
frame.add(topPanel, BorderLayout.PAGE_START);
JPanel bottomPanel = new JPanel();
JButton runTestBtn = new JButton("Run test");
runTestBtn.addActionListener(e->{
runTestBtn.setEnabled(false);
new Timer(1000, e1 ->{
int percent = twoColorBtn.getPercentOfLeftColor() +25;
percent = percent > 100 ? 0 : percent;
twoColorBtn.setPercentOfLeftColor(percent);
}).start();
});
bottomPanel.add(runTestBtn);
frame.add(bottomPanel, BorderLayout.PAGE_END);
frame.pack();
frame.setVisible(true);
}
}
The code can easily be modified to allow 3 colors, if needed.
(Test it online here)
(See a basic 3 colors toggle button here)
I'm developing a Java application that demands a customized button. I'm using Swing for the GUI and found myself limited to some tricky solutions.
Here's one I found (from this website). It's supposed to use a custom image for the button and make it round.
public class RoundButton extends JButton
{
private static final long serialVersionUID = 1L;
protected Shape shape, base;
public RoundButton()
{
this(null, null);
}
public RoundButton(Icon icon)
{
this(null, icon);
}
public RoundButton(String text)
{
this(text, null);
}
public RoundButton(Action a)
{
this();
setAction(a);
}
public RoundButton(String text, Icon icon)
{
setModel(new DefaultButtonModel());
init(text, icon);
if(icon==null) return;
setBorder(BorderFactory.createEmptyBorder(1,1,1,1));
setBackground(Color.BLACK);
setContentAreaFilled(false);
setFocusPainted(false);
//setVerticalAlignment(SwingConstants.TOP);
setAlignmentY(Component.TOP_ALIGNMENT);
init_shape();
}
protected void init_shape()
{
if(!getBounds().equals(base))
{
Dimension s = getPreferredSize();
base = getBounds();
shape = new Ellipse2D.Float(0, 0, s.width-1, s.height-1);
}
}
#Override
public Dimension getPreferredSize()
{
Icon icon = getIcon();
Insets i = getInsets();
int iw = Math.max(icon.getIconWidth(), icon.getIconHeight());
return new Dimension(iw+i.right+i.left, iw+i.top+i.bottom);
}
#Override
protected void paintBorder(Graphics g)
{
init_shape();
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(getBackground());
//g2.setStroke(new BasicStroke(1.0f));
g2.draw(shape);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_OFF);
}
#Override
public boolean contains(int x, int y)
{
init_shape();
return shape.contains(x, y);
//or return super.contains(x, y) && ((image.getRGB(x, y) >> 24) & 0xff) > 0;
}
}
Here's some test code I wrote:
public class BtnTest extends JFrame
{
private static final long serialVersionUID = 1L;
private RoundButton btn;
public BtnTest()
{
init_components();
}
private void init_components()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 400);
setBackground(Color.BLACK);
setResizable(false);
btn = new RoundButton(
new ImageIcon("/path/to/file.png"));
btn.setBounds(50, 50, 50, 50);
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e)
{
System.out.println("click");
}
});
add(btn);
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
BtnTest frame = new BtnTest();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
This is the result:
The problem is: the image's rendered away from the button location, so my ActionListener isn't triggered when I press the icon, but when the region inside the black circle (top left) is clicked. Can someone explain me why, and offer a solution?
PS: I'm in my first year of Java programming, so make it as simple as possible please.
PS2: JavaFX and other external solutions are out of question, this must be done pure Java.
The problem is: the image's rendered away from the button location,
What is happening is that you are adding the button to the frame without using a constraint. By default this means the component is added to BorderLayout.CENTER, which means the component will be sized to fill the entire frame.
Also, by default, when you paint an Icon in a JLabel, the Icon is centered in the spaced available to the label, so you see the Icon in the center of the frame. Try resizing the frame to see the Icon move.
However, you hard code the painting of the Border to be painted at the (0, 0) location of the label so it paints at the top/left.
The contains() method is also defined from the top/left of the component, so mouse detection only works from the top/left, not the center.
This means your button must always be painted at its "preferred size" in order for it to be painted properly and for the contains(...) method to work.
A simple way to demonstrate this is to use:
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout( new FlowLayout() );
The FlowLayout does respect the preferred size of the button, so the Icon and Border will be painted properly.
Other options (instead of changing the layout of the frame) are to use a "wrapper" panel for the button. For example:
//add(btn);
JPanel wrapper = new JPanel(); // default to FlowLayout
wrapper.add( btn );
add( wrapper );
Now when you add the panel to the frame, the panel will grow in size, but the button will still be painted at its preferred size.
btn.setBounds(50, 50, 50, 50);
Also, not you should NOT be using this method. It is the job of the layout manager to set the size/location of the component. The above statement is effectively ignored.
I have a very simple java swing application, I have a canvas class extended from JPanel
public class Canvas extends JPanel
{
private void doDrawing(Graphics g)
{
Graphics2D g2d = (Graphics2D) g;
g2d.drawString("Java 2D", 50, 50);
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
doDrawing(g);
}
}
And then I have my main class
public class SwingCounter extends JFrame {
private JTextField tfCount; // Use Swing's JTextField instead of AWT's TextField
private int count = 0;
public SwingCounter () {
Container cp = getContentPane();
cp.setLayout(new FlowLayout());
cp.add(new JLabel("Counter"));
tfCount = new JTextField("0", 10);
tfCount.setEditable(false);
cp.add(tfCount);
JButton btnCount = new JButton("Count");
cp.add(btnCount);
Canvas canvas = new Canvas();
canvas.setSize(150, 150);
cp.add(canvas);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Exit program if close-window button clicked
setTitle("Swing Counter"); // "this" JFrame sets title
setSize(300, 100); // "this" JFrame sets initial size
setVisible(true); // "this" JFrame shows
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new SwingCounter(); // Let the constructor do the job
}
});
}
}
It is basically code from a tutorial, apart from the JPanel. Everything shows fine, the JPanel/Canvas doesn't. What is missing?
You are adding your Canvas class to a panel which uses a FlowLayout. The FlowLayout respects the preferred size of all components. Your component has a preferred size of (0, 0) so there is nothing to paint.
You need to override the getPreferredSize() method of your Canvas class to return an appropriate Dimension for your panel.
Read the section from the Swing tutorial on Custom Painting for more information and a working example that does implement the getPreferredSize() method.
Also, don't call your class Canvas, since that is already an AWT component and is confusing. Use a more descriptive name.
I have MDI project. I add the customer JPanel in the JInternalFrame. My customer JPanel has a public method to change some component background color. When the button on the JFrame is clicked, I want it to change the label or text on my customer JPanel for all InternalFrame. How can I call the method? Thanks in advance
The following code is the action for the button on JFrame
private void categoryAction(ActionEvent e){
try{
JButton b=(JButton)e.getSource();
Color c=b.getBackground();
JInternalFrame[] allframes = desktop.getAllFrames();
int count = allframes.length;
for (int i=0; i<allframes.length-1; i++){
//call the method on the PDFJPanel
}
}
catch(Exception err){
Utility.DisplayErrorMsg(err.toString());
}
The following code is add the internal frame into the desktop
private void AddNote(File file){
JInternalFrame internalFrame = new JInternalFrame("PDFAnnotation"
+ file.getName(), true, true, true, true);
internalFrame.setBounds(0, 0, 600, 100);
desktop.add(internalFrame);
PDFJPanel p=new PDFJPanel(file);
internalFrame.add(p, BorderLayout.CENTER);
internalFrame.setVisible(true);
try {
internalFrame.setSelected(true);
}
catch (java.beans.PropertyVetoException e) {}
this.add(desktop, BorderLayout.CENTER);
//resize the internal frame as full screen
Dimension size = desktop.getSize();
int w = size.width ;
int h = size.height ;
int x=0;
int y=0;
desktop.getDesktopManager().resizeFrame(internalFrame, x, y, w, h);
}
There is the method on my customer JPanel
Public void setDefaultColor(Color c){
//change the label and textbox color
}
You can utilize JDesktopPane.getSelectedFrame that returns currently active frame. You can retrieve PDFJPanel from the layout manager, ie using BorderLayout.getLayoutComponent(). Or easier and cleaner, you can extend JInternalFrame, ie:
class PDFFrame extends JInternalFrame {
private PDFJPanel panel;
public PDFFrame(File file) {
panel = new PDFJPanel(file);
add(panel, BorderLayout.CENTER);
}
public void setDefaultColor(Color c){
panel.setDefaultColor();
}
}
Then, access it:
JDesktopPane desktop = ...;
PDFFrame frame = (PDFFrame) desktop.getSelectedFrame();
frame.setDefaultColor(Color.BLUE);
Here is my code: I took out some stuff that I felt wasn't necessary. I might've took out some brackets too, but I'm just trying to show the content I have.
What happens is, when I run the program, the background image paints (it's a PNG in resources), and only ONE button appears (my PLAY button), which is the first button - it's auto-selected.
I actually have four buttons but I've only included PLAY and INSTRUCTIONS in my code. The other three don't show up unless I mouse over them. I know it's probably something weird with the paint method, but I don't know how to fix it.
If I select a different button and minimize the window then open it again, that selected button is the only one that appears. I have to mouse over to get the other buttons to appear.
I've added super.paint() to the paint method too and I get all my buttons but the background is grey.
I think the problem is super.paint() paints all my buttons, and g.drawImage(bg, 0, 0, null) only paints my background and I can't do one without painting over the other.
Sorry if this was a mess. I'm new at Java and I have trouble articulating what I'm trying to say.
public class MainMenu extends JFrame {
private JPanel contentPane;
/**
* Launch the application.
*/
//variables
public static Image bg;
public static void main(String[] args) {
MainMenu mainFrame = new MainMenu();
mainFrame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
mainFrame.setResizable(false);
mainFrame.setLocationRelativeTo(null);
mainFrame.setTitle ("Zumby");
mainFrame.setLayout(null);
// Loads the background image and stores in bg object.
try {
bg = ImageIO.read(new File("zumby.png"));
} catch (IOException e) {
}
mainFrame.setVisible(true);
}
/**
* Overrides the paint method.
* MONDAY
*/
public void paint(Graphics g)
{
// Draws the img to the BackgroundPanel.
System.out.println("paint");
g.drawImage(bg, 0, 0, null);
}
/**
*/
public MainMenu() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 800, 500);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setOpaque(false);
setContentPane(contentPane);
contentPane.setLayout(null);
//create buttons
JButton btnPlay = new JButton("PLAY");
btnPlay.setBackground(Color.BLACK);
btnPlay.setForeground(Color.WHITE);
btnPlay.setFont(font);
btnPlay.setBorder(border);
btnPlay.setFocusPainted(false);
//if "Play" is clicked
btnPlay.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent click) {
setVisible(false);
new GamePlay(); //opens up GamePlay window
}
});
btnPlay.setBounds(600, 64, 141, 61);
contentPane.add(btnPlay);
JButton btnInstructions = new JButton("INSTRUCTIONS");
btnInstructions.setBounds(600, 160, 141, 61);
btnInstructions.setBackground(Color.BLACK);
btnInstructions.setFocusPainted(false);
// btnInstructions.setEnabled(true);
contentPane.add(btnInstructions);
repaint();
pack();
setVisible(true);
}
}
Swing uses a "layering" concept for it's painting...
paint calls paintComponent, paintBorder and paintChildren. By overriding paint and failing to call super.paint, you've prevented the component from painting it's various layers.
In Swing, it is preferred to use paintComponent to provide custom painting, which allows you to paint underneath any other components that might be added to the component.
public class TestPaint01 {
public static void main(String[] args) {
new TestPaint01();
}
public TestPaint01() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private Image backgroundImage;
public TestPane() {
try {
BufferedImage background = ImageIO.read(new File("/path/to/image.jpg"));
//backgroundImage = background.getScaledInstance(-1, background.getHeight() / 4, Image.SCALE_SMOOTH);
backgroundImage = background;
} catch (IOException ex) {
ex.printStackTrace();
}
setLayout(new GridBagLayout());
add(new JButton("Hello"));
}
#Override
public Dimension getPreferredSize() {
return backgroundImage == null ? super.getPreferredSize() : new Dimension(backgroundImage.getWidth(this), backgroundImage.getHeight(this));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int x = (getWidth() - backgroundImage.getWidth(this)) / 2;
int y = (getHeight() - backgroundImage.getHeight(this)) / 2;
g.drawImage(backgroundImage, x, y, this);
}
}
}
You might find A Closer look at the Paint Mechanism and Painting in AWT and Swing informative.
I think it's because you're overriding the paint method. It's better to override repaint, then call super.repaint(); Like this:
public void repaint(Graphics g)
{
super.repaint(g);
// Draws the img to the BackgroundPanel.
System.out.println("paint");
g.drawImage(bg, 0, 0, null);
}
Then the components get redrawn as well.
But if all you want to do is show an image as the background see here.
You're overriding paint() but don't call super.paint(). So the normal painting of the components done by the JFrame's paint() method implementation is not executed.
Since you are using Swing and JFrame the painting mechanism used to override paintComponent not paint that is usually used with applets or AWT.