My main issue is with the following piece of code when setting up a JFrame:
Why the panel doesn't show if I use the pack() and how to make it work?
Why the first requestFocusInWindow() doesn't work and what the principle to use it?
Why the default layout manager of JPanel doesn't work if I delete the setLayout()?
public class SoundGUI extends KeyAdapter{
public static void main(String[] args) {
SoundGUI sGUI = new SoundGUI();
sGUI.setUp();
}
public void setUp () {
JFrame frame = new JFrame ("Key test");
frame.setSize (1000, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible (true);
Panel p = new Panel ();
p.setLayout(new BorderLayout());//why this sentence is necessary FlowLayout doesn't fill the container but rather lets components size to their preferredSizes.
p.addKeyListener (this);
p.requestFocusInWindow();//it's useless here
//requestFocus only works on focusable components that are displayed.
MyDrawPanel dp = new MyDrawPanel();
dp.setBackground(Color.darkGray);
JLabel test = new JLabel("a trial");
JButton t = new JButton("b");
dp.add(t);
dp.add (test);
p.add (dp);
frame.getContentPane().add(p);
p.requestFocusInWindow();
//frame.pack();//why it doesn't work
//frame.setVisible(true);
}
class MyDrawPanel extends JPanel {
public void paintComponent (Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.white);
for (int i = 0; i < 1000; i += 42) {
g2.fill3DRect(i,100 ,20 ,80 ,true);
}
g2.setColor(Color.black);
for (int i = 21; i < 1000; i += 42) {
g2.fill3DRect(i,100 ,20 ,80 ,true);
}
}
}
}
Suggestions:
Call setVisible(true) after calling pack(). Makes sense, doesn't it?
The BorderLayout will tell the MyDrawPanel to fill the p container, since the component is being added in a default way (meaning BorderLayout.CENTER), and that's how BorderLayout works.
FlowLayout doesn't fill the container but rather lets components size to their preferredSizes.
Don't mix Swing with AWT components. i.e., don't use Panels, but rather use JPanels.
requestFocus only works on focusable components that are displayed.
Better to use Key Bindings than KeyListeners.
Better to avoid setting the sizes of anything if possible.
Based on your new code, your problem is due to you're calling setSize(). Most layout managers don't respect this but rather the preferred size. If your drawing JPanel needs to be so big, then make it so. For example try:
class MyDrawPanel extends JPanel {
private static final int PREF_W = 1000;
private static final int PREF_H = 300;
public void paintComponent(Graphics g) {
super.paintComponent(g); //!! ******** don't forget this!!! *********
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.white);
for (int i = 0; i < 1000; i += 42) {
g2.fill3DRect(i, 100, 20, 80, true);
}
g2.setColor(Color.black);
for (int i = 21; i < 1000; i += 42) {
g2.fill3DRect(i, 100, 20, 80, true);
}
}
// the getPReferredSize will make this JPanel preferentially be this size
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
}
Also note that request focus does work if the component is focusable:
JPanel p = new JPanel(); //!! This should be a JPanel, not a Panel
p.setFocusable(true); //!! This is needed
p.setLayout(new BorderLayout());
p.addKeyListener(this);
p.requestFocusInWindow();
But also note that KeyListeners should be avoided. Use Key Bindings instead.
Related
So I have made a chess game where Inside the JFrame there is a boardPanel (chessboard) and a sidePanel (contains buttons like flipBoardButton).
The whole JFrame has a Dimension of 900x640 and the boardPanel therefore is 640x640.
public class BoardPanel extends JPanel{
private static final long serialVersionUID = 1L;
public BoardPanel() {
this.setSize(640, 640);
this.setLocation(0, 0);
}
#Override
public void paint(Graphics g){
boolean white = true;
for(int y = 0; y < 8; y++){
for(int x = 0; x < 8; x++){
if(white){
g.setColor(new Color(235, 235, 235));
}
else{
g.setColor(new Color(166, 123, 90));
}
g.fillRect(x*80, y*80, 80, 80);
white = !white;
}
white = !white;
}
for(Piece p : BoardHandler.piecesOnBoard)
{
Image image;
image = p.getImage();
g.drawImage(image, p.getX(), p.getY(), this);
}
}
}
My SidePanel should be on the right (at x=641 y=0) and have a width of 900-640=260 and a height of 640...
public class SidePanel extends JPanel{
public SidePanel()
{
this.setSize(260,640);
this.setLocation(641, 0);
}
#Override
public void paint(Graphics g) {
g.setColor(new Color(50,50,50));
g.fillRect(this.getX(), this.getY(), this.getWidth(), this.getHeight());
}
}
This is how I implemented both the panels (usual stuff):
JFrame frame = new JFrame("Chess");
BoardPanel boardPanel = new BoardPanel();
SidePanel sidePanel = new SidePanel();
frame.add(boardPanel);
frame.add(sidePanel);
frame.setVisible(true);
And I thought everything is working because this is what I got:
BUT: when I go into SidePanel calss and change the setSize to 100x100 or when I set the Location to 700,0 , I get the SAME result !
However, when I change Location / Size in the BoardPanel class, it works perfectly fine ?! (the chessboard then gets rearranged/resized)
How is this possible when I used the "same" code for both classes !?
The whole JFrame has a Dimension of 900x640 and the boardPanel therefore is 640x640.
The frame and boardPanel can't possibly have the same height because the frame has a border and a titlebar. Don't attempt to set the size/location of components. That is the job of layout managers.
Many issues:
Swing components are responsible for determining their own size. So when you do custom painting you need to implement the getPreferredSize() method so the layout manager can do its job.
For the boardPanel is would be something like:
#Override
public Dimension getPreferredSize()
{
return new Dimension(640, 640);
}
By default a JFrame uses a BorderLayout. You do NOT specify a constraint when you add your components to the frame, so be default each component is added to the CENTER. However, only the last component is managed by the BorderLayout so it will set the size/location of the sidePanel, which is why your attempt to do so is ignored.
Because the BorderLayout ignores the chessBoard your attempt to set the size/location appears to work.
However you should not attempt to set the size/location. Let the layout manager do its job.
Instead your code should be:
frame.add(boardPanel, BorderLayout.CENTER);
frame.add(sidePanel, BorderLayout.LINE_START);
Custom painting is done by overriding the paintComponent(...) method, not paint() and you always invoke super.paintComponent(...) first to make sure the background of the panel is cleared.
Custom painting is relative to the component, not relative to its location in the frame.
The following code in your sidePanel class is wrong:
g.fillRect(this.getX(), this.getY(), this.getWidth(), this.getHeight());
The getX()/getY() is wrong. If you really need to do custom painting then you should just use (0, 0).
However, there is no need to even use custom painting.
In the constructor of your class you just use:
setBackground( new Color(...) );
and the background will be painted automatically.
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)
when I run this code PaintComponent is never called because the "painted" message is never printed and I do not know why? can anyone help?
public class DisplayManager extends JPanel {
public static final int WIDTH = 700, HEIGHT = 900;
public Bottle bottle1 = new Bottle("res/bottleimage.png");
public Slider slider1 = new Slider();
public void initDisplay()
{
JFrame frame = new JFrame();
JPanel panel = new JPanel();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(WIDTH, HEIGHT));
frame.add(panel);
frame.setVisible(true);
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
bottle1.imageIcon.paintIcon(this, g, 50, 50);
System.out.println("painted");
}
}
There are a couple of problems with the basic code:
as already mentioned you need to add an instance of your DisplayManager class to a frame or panel.
When you do custom painting you need to override the getPreferredSize() method of the component to return your desired size. Currently the preferred size of your component is (0, 0).
The suggestion to add the DisplayManager to the frame only works because the default layout manager is a BorderLayout and by default is added to the CENTER of the layout which means it get all the available space in the frame.
However if you use:
frame.add(this, BorderLayout.PAGE_START);
you won't see the component size it has a size of (0, 0);
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 a poker game where I designed a nice pretty GUI that displays the cards and players. I did it all extending JPanel inside paint() with a lot of g2d.drawImage's and g2d.drawString()'s, with definite x and y locations.
My problem now is that I need to have a couple interactive buttons underneath it.. but whenever I try to add a JButton, it appears top and center. I've used setLocation(x, y) and setLayout(null) and everything I've seen in other replies, but none of them seem to match my need (Or at least I don't have a very well understanding of where to put it)
This is how my code is set up:
pokerserver.java
public class pokerserver extends JFrame {
public pokerserver() {
add(new drawing());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(720, 640);
setLocationRelativeTo(null);
setTitle("Poker HANGOUTS");
setResizable(false);
setVisible(true);
}
public static void main(String args[]) {
new pokerserver();
}
And then in drawing.class
public drawing() {
setFocusable(true);
setBackground(new Color(39,91,46));
setDoubleBuffered(true);
gameCards = new cards();
gameCards.shuffle();
for (int i = 0; i < 10; i++)
seats[i] = -1;
HQ = new HeadQuarters(this);
HQ.start();
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D)g;
//All my UI code
}
My last attempt was trying to add
JButton button = new JButton("TEST");
add(button);
button.setLocation(10, 500);
at the end of public drawing(). I Keep seeing things on layout management, but it's not helping me -- mainly because I'm not sure how to implement it
Here's a screenshot to help visualize what I'm talking about->
http://i.imgur.com/ttvif.png
Trying to get the button underneath. Unless there's a way to add an ActionListener to a drawImage()?
For your main panel use a BorderLayout.
Then to the "CENTER" you can add your game panel with all your custom painting.
Then create a panel and add the buttons to it. Now you can add this panel to the NORTH of the main panel.
In other words you are not restricted to using a single panel.
Also, custom painting should be done in the paintComponent() method of your panel, NOT the paint() method.
I'm not really sure what you are after, but here are two interpretations.
I suspect you want the 1st one 'Buttons over custom painting', but as a user I'd prefer the 2nd, with 'Buttons below custom painting'.
import java.awt.image.*;
import java.awt.*;
import javax.swing.*;
class PaintPanel extends JPanel {
BufferedImage bg;
PaintPanel(LayoutManager2 layout) {
super(layout);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (bg==null) {
bg = new BufferedImage(500,500,BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = bg.createGraphics();
GradientPaint gp = new GradientPaint(
0,0,Color.RED,500,500,Color.BLUE);
g2.setPaint(gp);
g2.fillRect(0,0,500,500);
g2.dispose();
}
g.drawImage(bg,0,0,getWidth(),getHeight(),this);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JPanel buttons = new JPanel(
new FlowLayout(FlowLayout.CENTER));
buttons.setOpaque(false);
buttons.add(new JButton("Start"));
buttons.add(new JButton("Stop"));
PaintPanel pp = new PaintPanel(new BorderLayout());
pp.setPreferredSize(new Dimension(200,100));
pp.add(buttons, BorderLayout.SOUTH);
JOptionPane.showMessageDialog(null,pp);
JPanel gui = new JPanel(new BorderLayout());
gui.setBackground(Color.ORANGE);
gui.add(pp, BorderLayout.CENTER);
gui.add(buttons, BorderLayout.SOUTH);
JOptionPane.showMessageDialog(null,gui);
}
});
}
}