I have a JScrollPane that fills a JPanel (which is the content pane for my JFrame). The JPanel performs custom drawing - however, it doesn't appear over top of the JScrollPane. Should I override something other than paintComponent?
Here is a demo:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.LayoutManager;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
public class Test {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
// Create the frame.
JFrame frame = new JFrame();
frame.setPreferredSize(new Dimension(1024, 768));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel custom = new CustomPanel(new BorderLayout());
// Add the scroll pane.
JScrollPane scroll = new JScrollPane();
scroll.setBorder(BorderFactory.createLineBorder(Color.blue));
custom.add(scroll, BorderLayout.CENTER);
// Display the frame.
frame.setContentPane(custom);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
#SuppressWarnings("serial")
class CustomPanel extends JPanel {
public CustomPanel(LayoutManager lm) {
super(lm);
}
#Override
public void paintComponent(Graphics g) {
g.setColor(Color.red);
g.drawRect(200, 200, 200, 200);
}
}
I'd like for the paint on the JPanel to go over top of the paint on
the JScrollPane
you can to paint to the
JViewport as you can to see here and here
use JLayer(Java7) based on JXlayer(Java6)
very similair (as todays JLayer) is painting to GlassPane, notice GlassPane to consume()(by default) MouseEvent in the case there is(are) added some JComponent(s), GlassPane can to covers whole RootPane or only part of available Rectangle, depends of used LayoutManager and Dimension returns from layed JComponent(s)
Just a simple problem. You are adding the scrollpane to the custompanel which is hiding what your are drawing. Instead, consider intializing your scrollpane with the cutsompanel as its content.
Example:
JScrollPane scrlPane = new JScrollPane(customPanel);
when you add a single component to a BorderLayout and specify BorderLayout.CENTER, the component will expand to completely fill its parent. If the component is opaque, you won't be able to see any custom painting you are doing in the parent.
The way that worked (as #mKorbel suggested) is to play with the JViewport:
scroll.setViewport(new CustomViewPort());
where CustomViewPort is a class extending JViewport that overrides the paintComponent method.
Related
This is the add(main) version
This is the add(scroll) version
Im trying to get a window full of lables and make it scrollable, this is my code for that purpose:
public class JobHistoryListScreen extends JFrame implements View
{
#Override
public void showScreen()
{
setSize(800, 800);
setLayout(new BorderLayout());
setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel main = new JPanel();
main.setSize(500,500);
JScrollPane scroll = new JScrollPane(main,JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scroll.setSize(500,500);
//Font
//Font david50 = new Font("David", Font.BOLD, 50);
for(int i=0; i<1000; i++)
{
JLabel empty = new JLabel("No jobs to display!");
empty.setBounds(0,i+250,400,100);
empty.setFont(david50);
main.add(empty);
}
add(main);
setVisible(true);
}
public static void main(String[] args) {
JobHistoryListScreen v = new JobHistoryListScreen();
v.showScreen();
}
}
For some reason the window gets filled with the labels but is not scrollable at all.
Learn about layout managers. Refer to Laying Out Components Within a Container. Default for JPanel is FlowLayout and because the JPanel is inside a JScrollPanel, the labels will not wrap. And since you set the horizontal scroll bar policy to NEVER, there is no horizontal scroll bar and hence you cannot scroll horizontally. Try using BoxLayout to display all the labels one under the other. Alternatively you could use a GridLayout with 0 (zero) rows and 1 (one) column. Refer to the tutorial for more details.
EDIT
Here is my modified version of your code. Explanatory notes appear after the code.
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.WindowConstants;
public class JobHistoryListScreen implements Runnable {
private JFrame frame;
#Override // java.lang.Runnable
public void run() {
showScreen();
}
public void showScreen() {
frame = new JFrame("Jobs");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel main = new JPanel(new GridLayout(0, 1));
JScrollPane scroll = new JScrollPane(main,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scroll.setPreferredSize(new Dimension(500, 500));
Font david50 = new Font("David", Font.BOLD, 50);
for(int i=0; i<1000; i++) {
JLabel empty = new JLabel("No jobs to display!");
empty.setFont(david50);
main.add(empty);
}
frame.add(scroll);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
JobHistoryListScreen v = new JobHistoryListScreen();
// Launch Event Dispatch Thread (EDT)
EventQueue.invokeLater(v);
}
}
I don't know what interface View is so I removed that part.
No need to extend class JFrame.
No need to explicitly call setSize() on JFrame. Better to call pack().
Default content pane for JFrame is JPanel and default layout manager for that JPanel is BorderLayout so no need to explicitly set.
No need to call setSize() on JPanel.
Call setPreferredSize() rather than setSize() on JScrollPane.
Add the JScrollPane to the JFrame and not the JPanel.
No need to call setBounds() because GridLayout handles this.
Explicitly launch EDT (Event Dispatch Thread) by calling invokeLater().
Here is a screen capture of the running app. Note the vertical scroll bar.
I have a JFrame, and within it, a JLabel that is filled by an image of a Map. I want to have clickable square “Tiles” in a grid over the image of the map. To do this, I made a large grid of JButtons that I have added to the JLabel containing the Map. However, the Map cannot be seen, so I have made the JButtons completely transparent. However, when they are Transparent, I can’t see where one JButton ends, and where another one starts. I want to create a JButton that is totally transparent on the inside, but still has a visible border around it. I have tried setOpaque(false) and then setBorderPainted(true) but that makes them opaque again. I have tried everything I could find, but nothing happens. Any suggestions?
Once again, all I want is a Transparent JButton with Visible Borders
You should be able to replace border with you own...
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setBackground(Color.RED);
setLayout(new GridBagLayout());
JButton btn = new JButton("Hello");
btn.setOpaque(false);
btn.setContentAreaFilled(false);
btn.setBorderPainted(true);
btn.setBorder(new LineBorder(Color.BLUE));
add(btn);
}
}
}
You might need to use a CompoundBorder with a EmptyBorder on the inside to provide some padding (I tried using setMargins but it didn't seem to work)
If I paint directly on the frame, it shows up fine but the ship will not show up on top of the panel...
package MoonBlast;
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JFrame;
public class Frame extends JFrame{
PlaySpace p;
Ship s;
public Frame(String title){
this.setTitle(title);
this.setSize(800, 800);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
p = new PlaySpace();
s = new Ship();
p.add(s);
this.add(p, BorderLayout.CENTER);
this.setVisible(true);
}
}
package MoonBlast;
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JPanel;
public class PlaySpace extends JPanel {
public PlaySpace(){
super();
this.setPreferredSize(new Dimension(800, 800));
this.setBackground(Color.BLACK);
}
}
package MoonBlast;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Polygon;
import javax.swing.JComponent;
public class Ship extends JComponent{
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
Polygon p = new Polygon();
p.addPoint(350, 750);
p.addPoint(450, 750);
p.addPoint(400, 700);
g.setColor(Color.YELLOW);
g.fillPolygon(p);
}
}
The only class I left out was the 1 line viewer class. I have tried everything I could think of and a few more people have looked at it too. Thanks in advance.
You need to override the getPreferredSize() method of your Ship class to return the size of the component. Every Swing component is responsible for knowing its preferred size since it is the component that is doing the custom painting.
but the ship will not show up on top of the panel...
Your PlaySpace class using a FlowLayout by default which respects the preferred size of any component added to it. By default the preferred size of the Ship is (0, 0) so there is nothing to paint.
If I paint directly on the frame, it shows up fine
The default layout manager of the content pane of the frame is a BorderLayout. When you add a component to the CENTER of a BorderLayout, the layout ignores the preferred size of the component and just makes the component take up all the available space in the frame.
Read the section from the Swing tutorial on Layout Managers for more information and working examples of each layout manager.
I am trying to draw graphics that is bigger than the JFrame and use JScrollPane to scroll the entire graphics. I created a simple example with two lines. The scroll bars appear but the graphics do not show.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class Test extends JPanel{
public static void main(String... args) {
Test test = new Test();
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.add(test);
JScrollPane scrollPane = new JScrollPane(panel);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.setBounds(0, 0, 1350, 700);
JPanel contentPane = new JPanel(null);
contentPane.setPreferredSize(new Dimension(1400, 700));
contentPane.add(scrollPane);
frame.setContentPane(contentPane);
frame.pack();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(true);
}
#Override
protected void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D)g;
g2.drawLine(30,30,30,3000);
g2.drawLine(30, 400, 500, 3000);
}
}
Welcome to a wonderful example of why null layouts suck...
Avoid using null layouts, pixel perfect layouts are an illusion within modern ui design. There are too many factors which affect the individual size of components, none of which you can control. Swing was designed to work with layout managers at the core, discarding these will lead to no end of issues and problems that you will spend more and more time trying to rectify
Also see Why is it frowned upon to use a null layout in SWING? for more details...
The basic problem is, the JScrollPane, has a JViewport, which actually contains your component. The JViewport uses your components sizing hints to make determinations about how big it should be and the JScrollPane uses the decisions the JViewport makes to make determinations about whether it needs to display the scrollbars or not.
The JViewport is taking a look at your component and has decided, because you've not told it otherwise, that it should be 0x0 in size.
You can prove this by adding a LineBorder to your component, setBorder(new LineBorder(Color.RED));, you won't see it either (or if you do, it will be a little red square)
Start by overriding the getPrefferedSize method of the Test panel and return some appropriate size
Next, call super.paintComponent before you perform any custom painting, otherwise you'll end up with some awesome, but annoying, paint artifacts...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test extends JPanel {
public static void main(String... args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
Test test = new Test();
JFrame frame = new JFrame();
JScrollPane scrollPane = new JScrollPane(test);
frame.add(scrollPane);
frame.pack();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(true);
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(3000, 3000);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.drawLine(30, 30, 30, 3000);
g2.drawLine(30, 400, 500, 3000);
}
}
You'll probably want to take a look at the Scrollable interface next, so you can control the default size of the JViewport, so it won't try and fill the entire screen.
Take a look at Implementing a Scrolling-Savvy Client for more details
The problem comes from the lines
JPanel panel = new JPanel();
panel.add(test);
JScrollPane scrollPane = new JScrollPane(panel);
You are adding test to panel which uses FlowLayout by default. This layout does not strech the components in it, so test on which you draw has dimensions 0x0 and what you see in the scroll pane is the empty panel.
To fix this you can set panel to use BorderLayout which stretches the center component:
JPanel panel = new JPanel(new BorderLayout());
panel.add(test);
JScrollPane scrollPane = new JScrollPane(panel);
or add test directly to the scroll pane:
JScrollPane scrollPane = new JScrollPane(test);
Additionally:
Always call super.paintComponent(g) as the first line when overriding paintComponent.
Don't use null layouts (and consequently don't set bounds on components).
When you use setPreferredSize remember that if the dimensions are too large they will "flow off" the screen.
it's my first post so I hope it'll not be too cringeworthy. So I am trying to create a hex-based strategy game, not quite there yet but anyways.
To achieve a hex-based game I would like to create a field made of hexes which the user should be able to click, and receive the coordinates of that pixel. At the moment I can produce either a field of hexes or a mouselistener/mouseadapter but not both. The last one executed replaces the other on the screen.
If the pane.add(New HexMap()); is switched with pane.add(new MouseListener()); the listener works but the line is not printed
I've looked around for quite some time but the posts that I've encountered had either dealt with changing the background color which the mouselistener can do, because background is independent of the mousesensorhttp://docs.oracle.com/javase/tutorial/uiswing/events/mouselistener.html? The other examples I've come by have been too advanced for me, because they're using multiple panes, and I have not been able to comprehend themhttp://docs.oracle.com/javase/tutorial/uiswing/components/layeredpane.html.
So what I'm looking for is a way to add a mouselistener over a single pane, displaying the hexes. Would this be possible?
E.G adding the hexMap after the mouselistener would not overwrite the mouselistener but rather act as an addition
A single line has been created acting as a placeholder for the hexes.
The code:
import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.util.*;
import java.util.List;
import javax.swing.*;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
public class GraphicsSetup extends JPanel{
public static final int FRAME_WIDTH = 600;
public static final int FRAME_HEIGHT= 400;
private static JFrame frame;
public static void main(String[] args){
GraphicsSetup draw = new GraphicsSetup();
}
public GraphicsSetup(){
HexMap hexMap = new HexMap();
JPanel panel = new JPanel();
frame = new JFrame("HexExample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(FRAME_WIDTH,FRAME_HEIGHT);
Container pane = frame.getContentPane();
pane.setBackground(new Color(20, 100, 30));
pane.add(new MouseListener());
pane.add(new HexMap());
frame.setVisible(true);
}
public class HexMap extends JComponent{
public void paint(Graphics g){
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.blue);
g2d.drawLine(0,0, FRAME_WIDTH, FRAME_HEIGHT);
}
}
class MouseListener extends JComponent{
public MouseListener(){
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent me) {
System.out.println("Mouse Event" + me);
}
});
}
}
}
Yours Sincerely
I'm not entirely sure what you're after, but try adding your components to your panel object. Such as:
panel.add(new MouseListener());
panel.add(new HexMap());
And then add this to the content pane of your frame:
pane.add(panel);
If you're wondering how to arrange your interface differently, read about layout managers here:
http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html
Edit
Try the following:
Set the layout manager to use a BorderLayout:
JPanel panel = new JPanel(new BorderLayout());
Add your components to the panel and set their location:
panel.add(new MouseListener(), BorderLayout.NORTH);
panel.add(new HexMap(), BorderLayout.CENTER);
Add the panel to the frame content pane:
pane.add(panel);
This will work but the size of the MouseListener panel is quite small...you'll need to figure that out next...