About paintComponent
how can i make a panel paintComponent draw a background image only once? as i have other panel added to the background panel and i only want the component panel to redraw ... i cant seems to repaint only the component panel as i cant put them in separate paintComponent. any idea of how to go about?
thanks~
Create a BufferedImage and do the custom painting on the BufferedImage.
If your painting is relatively static then you could create an ImageIcon from the BufferedImage and add the icon to a label and add the label to the GUI. If you need to change the custom painting then you would need to recreate the icon and update the image.
If you painting is relatively dynamic, then you just change the paintComponent() method to draw the buffered image.
Similar Messages
-
Hello,
I am using swing to develop an user interface for a medium-complex program. Here is the code in the paintComponent method:
public void paintComponent (Graphics g) {
Graphics2D g2 = (Graphics2D)g;
super.paintComponents(g2);
if (frame.m == null)
System.out.println("Es null main");
else {
System.out.println("No es null main");
Vector clusters = frame.m.obtenerClusters();
Iterator it = clusters.iterator();
while (it.hasNext()) {
Cluster c = (Cluster)it.next();
Punto p = c.obtenerCoordinador();
Color color = c.obtenerColor();
Vector sen = c.obtenerSensores();
Iterator itS = sen.iterator();
while (itS.hasNext()) {
Sensor s = (Sensor)itS.next();
dibujarSensor(g2, s, color);
if (p != null) {
dibujarCoordinador(g2, p, color);
if (frame.isSelectedDibujarCirculo()) {
dibujarCirculoMinimo(g2, c.obtenerCoordinador(), c.obtenerRadio(), color);
NodoSink s = frame.m.obtenerSink();
if (s != null) {
dibujarSink(g2,s);
}Every time that this method is called (by me using repaint() or by the virtual machine), the program needs to "walk" over the hole Vector structure and paint again and again the same things, which is very inefficient.
There are some way to avoid it? I'm worry about it because the Vector structure is commonly very long.
Thanks!Create a BufferedImage and do the custom painting on the BufferedImage.
If your painting is relatively static then you could create an ImageIcon from the BufferedImage and add the icon to a label and add the label to the GUI. If you need to change the custom painting then you would need to recreate the icon and update the image.
If you painting is relatively dynamic, then you just change the paintComponent() method to draw the buffered image. -
Can I convert a variable of type double to a variable of type int? The reason for this is I am creating a program that will draw graphs of parabolas, cubics, etc. and the user will be able to change the values for stretches, translations, etc.
So my code for the drawing of a parabola at the moment is somewhat primitive, I just want the basic parabola drawn in. I've done a program that does exactly this using Turing (of all things...) but Java is proving to be more picky.
int count = 0;
int X = 0;
double tempY = 0;
int Y = 0;
while(count <= 600){
tempY = Math.pow(X - 300,2) + 200;
Y = tempY; //error here
if(Y >= 0 && Y <= 400){
g.fillOval(X, Y, 1, 1);
count++;
X++;
}Don't worry about paintComponent() and all that, it's there I'm just posting the necessary parts you guys need to see.
So the error I get is 'possible loss of precision' at the line indicated, and I know this, it's pretty obvious, but this is what I want/need to do as the fillOval will only accept ints for it's coordinates. I also tried forgetting about having the double value of tempY and doing the math to an int but then I get 'possible loss of precision' in the math line. If anyone can give me ideas/fixes to change a double into an int it would be much appreciated as this is what I really want to do, or if you can come up with alternative ways of doing what I need to do that would also be appreciated.
EDIT
In case you are wondering why I am adding and subtracting those values it's because my panel I'm drawing on is (600,400) and of course (0,0) is the top left corner rather than the center where it would be on a Cartesian plane, so I think I've made all the necassary adjustments so (0,0) is now in essentially the center of the panel. It's basically scanning across from the left to right and finding X^2 from '-300' to '300' but only drawing it in if the value for Y will appear in the panel. I know it's pretty fucked up and probably some really messy code, lol. I'm somewhat inexperienced and probably being a bit too adventurous.
Edited by: vortex on Jan 15, 2008 11:07 AM
Edited by: vortex on Jan 15, 2008 11:15 AMI haven't tried that, I will try that when I get to school. I think the issue could be that -300^2 may be too big to be an int? I was just thinking before I fell asleep about it last night and that could be it too...So naturally I'll just start from say, -100, or even -25 as that isn't exactly gonna fit on the graph so I'm just wasting processor power currently I suppose. Anyways I'm gonna try both of these out and get back to you guys.
Another issue I'm foreseeing is that one of the graphs is the root of x, so I'm going to be dealing with decimals, that's fine for double but when I turn that into an int (assuming I ever figure out how to, hoping your idea, possibly coupled with mine works) how can I round/drop the decimals?
Edited by: vortex on Jan 16, 2008 8:10 AM -
I was to come here and "search" for examples on this but i havnt found any so im jsut going to post it:
How do i set an image to be the background of a JPanel? setBackground(image); doesnt work... i was toal something about paintComponent() but i tried it with that too and it didnt work... anyhelp would be greatly appreciatedIve tried many of the things that search suggested but none of them pertained enough to what i am doing for it to work. Here is my code:package gameFunctions;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class loginScreen extends JFrame implements ActionListener
JTextField USERNAME, Username, PASSWORD, Password; // yeah i know, bad practice but there is some logic to the names relative to capitalization
String username, password;
JButton LOGIN;
Dimension res = Toolkit.getDefaultToolkit().getScreenSize();
ImageIcon background = new ImageIcon("C:\\FileTesting\\testImage.jpg");;
JPanel pane;
public static void main(String[] args)
loginScreen frame = new loginScreen();
frame.setVisible(true);
public loginScreen()
Container c = getContentPane();
setSize(400, 300);
setLocation((int)res.getWidth()/2-getWidth()/2, (int)res.getHeight()/2-getHeight()/2);
setResizable(false);
setLayout(null);
pane = new JPanel();
pane.setSize(getWidth(), getHeight());
pane.setLayout(null);
c.add(pane);
USERNAME = new JTextField("Username:");
USERNAME.setSize(68,25);
USERNAME.setLocation(getWidth()/2-USERNAME.getWidth()/2-80, getHeight()/2-USERNAME.getHeight()/2-50);
USERNAME.setEditable(false);
pane.add(USERNAME);
PASSWORD = new JTextField("Password:");
PASSWORD.setSize(68,25);
PASSWORD.setLocation(USERNAME.getX(), USERNAME.getY()+30);
PASSWORD.setEditable(false);
pane.add(PASSWORD);
Username = new JTextField();
Username.setSize(150,25);
Username.setLocation(USERNAME.getX()+USERNAME.getWidth()+5, USERNAME.getY());
Username.setEditable(true);
pane.add(Username);
Password = new JTextField();
Password.setSize(150,25);
Password.setLocation(Username.getX(), Username.getY()+30);
Password.setEditable(false); // because im not working with PW's yet
pane.add(Password);
LOGIN = new JButton("LOGIN");
LOGIN.setSize(80,30);
LOGIN.setLocation(getWidth()/2-LOGIN.getWidth()/2, PASSWORD.getY()+30);
pane.add(LOGIN);
setDefaultCloseOperation(EXIT_ON_CLOSE);
public void actionPerformed(ActionEvent event)
}i want "pane" to be the image of "background" imageIcon is the only thing that works like this because i dont know how to use straight up "Image". everything works if i set the ImageIcon "background" to be the background of JButton "LOGIN"
any help would be greatly appreciated -
Bmp file as a background for a window, or panel?
I've been trying to find info on setting the background of containers with images instead of colors. Is this possible? Can anyone tell me where I can find info on this subject?
On the subtopic paintComponent() versus paint():
1. Denis is wrong about the ordering of paint()'s calls, it is:
a. paintComponent()
b. paintBorder()
c. paintChildren()
try having a child that spills over the border to test this, or take a peek at the source code.
2. Someone asked if, when the code is fairly simple, there is any advantage to overriding paint versus paintComponent? This is a question about OOP, generally speaking. Your first concern should always be correctness, not efficiency. You override a method when its current implementation is wrong for the currect class: what's wrong about paint()? Nothing! What's wrong about paintComponent()? It's missing some drawString() calls ==> override paintComponent. If you override paint() as the poster is considering, their component will never be able to draw its border. They may not have a border todat, but how about tommorrow?
Also, looking at the source code for JComponent's paint() I see it has some code involving printing and checking for clipping: are you sure you want to toss out that framework code?
Conclusion: override when you want to change behavior, not because its seem convenient.
By the way, one of my pet peeves is code that overrides JFrame: in 99 cases out of 100 this is unnecessary: what method is being overridden -- none!
Off the soapbox,
Nax -
About draw GIF in "paintComponent(Graphics)" Method ???
I extends a new class A from JPanel and overwrite the method of "paintComponent(Graphics)", the code is like below:
public void paintComponent(Graphics g)
super.paintComponent(g);
// imgObj is a GIF file.
g.drawImage(imgObj, 100, 100, this);
}it's OK, the GIF can be show like a movie.
but if the code in an other class B, and invoke in A.paintComponent method, it can not show like a movie, it only show a static frame. Code like below:
public void paintComponent(Graphics g)
super.paintComponent(g);
bClassObj.drawGIF(g);
public class B
public void drawGIF(Graphics g)
g.drawImage(imgObj, 100, 100, this);
} WHY !!!!???I try it OK...
the last parameter of method drawImage() in B must be point to instance of A. -
Problem with paintComponent, and CPU usage
Hi,
I had the weirdest problem when one of my JDialogs would open. Inside the JDialog, I have a JPanel, with this paintComponent method:
public void paintComponent(Graphics g) {
super.paintComponent(g);
Color old = g.getColor();
g.setColor(Color.BLACK);
g.drawString("TEXT", 150, 15);
g.setColor(old);
parent.repaint();
now when this method is called, the CPU usage would be at about 99%. If i took out the line:
parent.repaint();
the CPU usage would drop to normal. parent is just a reference to the Jdialog that this panel lies in.
Anyone have any ideas on why this occurs?
Thanks!1) I never got a stack overflow, and i have had this in my code for quite sometime...If you called paint() or paintComponent(), I'm betting that you would see a stack overflow. The way I understand it, since you are calling repaint(), all you are doing is notifying the repaint manager that the component needs to be repainted at the next available time, not calling a paint method directly. good article on how painting is done : http://java.sun.com/products/jfc/tsc/articles/painting/index.html#mgr
2) If this is the case, and the two keep asking eachother to paint over and over, .....
see above answer -
Question about distance of a point to a segment
The following code uses Line2D.ptSegDist in order to find the closest distance of each point from (0, 0), (0, 1)... to (100, 100). If the distance returned from the method is r (0), then the 1x1 rectangle being drawn is white, but the line drawn in the loops is dotted and not like the one drawn by the Graphics.drawLine method. The line is drawn correctly when r's value is changed to 0.5, but I do not believe that that is the proper way to handle the value returned, because if the line is diagonal (0, 0, 10, 10), then r can remain as 0. My goal is to test to see if a point is contained on a given line. I can achieve this by using the Bresenham line algorithm, but I was wondering if it's possible to do it using the Line2D.ptSegDist method, and if so, how could I go about doing this?
import java.awt.Color;
import java.awt.Graphics;
import java.awt.geom.Line2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class PtSegDistTest extends JPanel {
private final double x1 = 9;
private final double y1 = 22;
private final double x2 = 19;
private final double y2 = 92;
private final double r = 0.0;
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i = 0; i < 100; i++) {
for (int j = 0; j < 100; j++) {
g.setColor(Line2D.ptSegDist(x1, y1, x2, y2, i, j) <= r
? Color.WHITE : Color.BLACK);
g.fillRect(i, j, 1, 1);
g.setColor(Color.WHITE);
g.drawLine((int) x1 + 10, (int) y1, (int) x2 + 10, (int) y2);
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new PtSegDistTest());
f.setSize(250, 250);
f.setVisible(true);
}Thank you for your help.Thank you for helping me to understand. I was hoping that I could use the method in order to test to see if a point was on the line by using the distance method. The Bresenham line algorithm works fine, but do you know of any other way (just out of curiosity) that doesn't involve going through each individual point on the line that would achieve similar results?
What I'm trying to do is take two arbitrary points with a distance of 15, and see if any other arbitrary points fall between that line. I've found that the margin for "pixels sufficiently close to the line" is 0.5 (as noted above), but when I use this margin, some different points appear and are missing in comparison to the Bresenham line algorithm
Edited by: batj on May 16, 2010 6:23 AM -
Confused about painting in Java2D
HI, I'm trying to get a simple app - note I don't want to do this in an Applet - that displays some text on screen and then exits when a key is pressed. I don't know how to get it to paint if I just call paint() from the class constructor it complains about the parameter.
paint(java.awt.Graphics) cannot be applied to ()
If I try to call paint from the calling class I get the same problem.
Do I need a JPanel and if so, what for? Where should I use paint() and not paintComponent() or vice versa and what's the difference? I've seen pieces of code which draw without a JPanel or JFrame but I don't know how those work. Here's what I've got so far:
public class Controller
public CallingClass
Intro intro = new Intro();
public static void main(String[] args)
Controller callingClass = new CallingClass;
import java.awt.*;
import java.awt.Color;
public class Intro
public Intro()
paint();
public void paint(Graphics g)
setBackgrond(Color.black);
g.setColor(Color.green);
g.drawString("Blah",512,20);
g.drawString("Blah",20,60);
g.drawString("Blah",20,80);
g.drawString("Blah",20,120);
g.drawString("Blah",20,140);
g.drawString("Blah",20,160);
g.drawString("Blah",20,180);
g.drawString("Press F to start or q to quit",20,200);
public void keyDown(Event e, int key)
switch(key)
case 'F':
//MainClass mainClass = new MainClass(); //ignore this
break;
case 'Q':
System.exit(0);
break;
}I know I sound like a noob but I'm having trouble finding this sort of information.I just used the keyDown()
method so I wouldn't have to override the methods for
the KeyListener interface.Well you should still use a KeyListener.
I followed BinaryDigit's
advice, but I'm still confused, do I need both a
JFrame and JPanel to draw to the screen?You should have your Intro class extend JPanel (and override paintComponent(), not paint()). You should then use that JPanel as the content pane in a JFrame. And remember to call repaint(), not paint() or paintComponent(). -
SwingUtilities.paintComponent - problems with painting childs of components
Maybe this question was mention already but i cant find any answer...
Thats what could be found in API about method paintComponent in SwingUtilities:
Paints a component c on an arbitrary graphics g in the specified rectangle, specifying the rectangle's upper left corner and size. The component is reparented to a private container (whose parent becomes p) which prevents c.validate() and c.repaint() calls from propagating up the tree. The intermediate container has no other effect.
The component should either descend from JComponent or be another kind of lightweight component. A lightweight component is one whose "lightweight" property (returned by the Component isLightweight method) is true. If the Component is not lightweight, bad things map happen: crashes, exceptions, painting problems...
So this method perfectly works for simple Java components like JButton / JCheckbox e.t.c.
But there are problems with painting JScrollBar / JScrollPane (only background of this component appears).
I tried to understand why this happens and i think the answer is that it has child components that does not draw at all using SwingUtilities.paintComponent()
(JScrollBar got at least 2 childs - 2 buttons on its both sides for scroll)
Only parent component appears on graphics - and thats why i see only gray background of scrollbar
So is there any way to draw something like panel with a few components on it if i have some Graphics2D to paint on and component itself?
Simple example with JScrollPane:
JScrollPane pane = new JScrollPane(new JLabel("TEST"));
pane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
pane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
SwingUtilities.paintComponent(g2d, pane, new JPanel(), 0, 0, 200, 200);Edited by: mgarin on Aug 11, 2008 7:48 AMWell the thing you advised could work... but this wont be effective, because i call repaint of the area, where Components painted, very often..
So it will lag like hell when i make 10-20 repaints in a second... (for e.g. when i drag anything i need mass repainting of the area)
Isnt there any more optimal way to do painting of the sub-components?
As i understand when any component (even complicated with childs) paints in swing - its paint method calls its child components paint() to show them... can this thing be reproduced to paint such components as JScrollPane? -
Overriding paintComponent but not everything is showing. Should be easy
The outdent objects are bying drawed and last.
The others are drown but you can only see them if you move the window arround (when hy needs to repaint constantly)
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g); //JPanel magic
this.setSize(200,200);
Graphics2D brush = (Graphics2D) g;
brush.setBackground(Color.PINK);
brush.drawOval(150, 150, 50, 150); //visable
brush.drawOval(150, 150, 50, -150);
brush.drawLine(15, 15, 100, 5); //visable
brush.setColor(Color.CYAN);
brush.fillOval(100,100,50,50); //visable
brush.drawOval(300, 300, 100, 150);
brush.setColor(Color.BLUE);
brush.fillOval(300, 300, 100,150);
brush.drawOval(250, 250, 50, 150);
Alle help welcome stuck for a while now.
Its just includeed in a pannel and the panel in the frameI was unable to open your "evil" vi.
It seems that you already know this, but just in case...
To customize the apperance of your vi at run-time, in the front panel right-click in the vi icon at the upper-right corner and select "VI Setup..." from the pop-up menu.
Select "Windows Options" from the menu. Clear the checkmark for those attributes you don't want (Show scroll bars, Show menu bar, etc.)
Also, I posted an answer about dialog boxes that include an example. It may help you:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=50650000000800000008190000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0
Best regards;
EJV
www.vartortech.com -
Hello,
I'm working with some JScrollBars, but I want to give them a more unique look, because it's for use in a game. But I'm not sure how to repaint them. should I override the paintComponent method, and how will I know all the dimensions of al the parts of the scrollbar? Does anyone have any ideas about this ?
thanks in advance,
RabonHi,
It would be better if you subclassed the UI class (BasicScrollBarUI) and wrote your own paintTrack() and paintThumb() methods. If you want them to be different sizes from the standard values, override getTrackBounds() and getThumbBounds() as well.
Hope that helped,
Ian -
Custom JPanel moves inside JFrame when Jpanel.paintComponent(...) is called
I have a custom JPanel (CompassCalculatorPanel) that is created, setup and placed within a custom JFrame (CompassCalcFrame). Calling the JFrame constructor sets this all up and makes the Frame show up. All is good with placement and drawing initially. Then when a user changes the spinner value (change the compass heading) it is supposed to redraw the arrow within the panel. It does this just fine, but on the repaint, and subsequent paints, the Panel ends up being placed in the upper left corner of the frame, rather than at the place I positioned it. I've tried saving the upper left corner placement coordinates and calling setBounds(...) before and after the paintComponent(...) method is called. This has no effect, the panel still resides at 0, 0.
boldAny help that keeps the panel in place would be appreciated!*bold*
I am opening a new CompassCalcFrame with the following code from another GUI application like this (but this works from an example program perspective):
import com.vikingvirtual.flightsim.CompassCalcFrame;
* @author madViking
public class Main
public static void main(String[] args)
CompassCalcFrame CCF = new CompassCalcFrame();
}The CompassCalcFrame.java code:
package com.vikingvirtual.flightsim;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Insets;
import java.awt.Point;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JSeparator;
import javax.swing.JSpinner;
import javax.swing.JTextField;
* @author madViking
public class CompassCalcFrame extends JFrame
private CompassCalculatorPanel ccPanel;
private JButton closeButton;
private JLabel frameTitle;
private JSeparator frameSeparator1;
private JSpinner hdgSpinner;
private JTextField neField;
private JTextField eField;
private JTextField seField;
private JTextField sField;
private JTextField swField;
private JTextField wField;
private JTextField nwField;
private Point ccPanelPoint;
public CompassCalcFrame()
super ("Compass Heading Calculator");
initComponents();
this.setVisible(true);
calculateAndDraw();
private void initComponents()
this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
this.setLayout(null);
this.setBackground(Color.BLACK);
this.setForeground(Color.BLACK);
Container ccPane = this.getContentPane();
Dimension panelDim = ccPane.getSize();
Font buttonFont = new Font("Tahoma", 0, 12);
Font compassFont = new Font("Digital-7", 0, 24);
Font titleFont = new Font("Lucida Sans", 1, 14);
frameTitle = new JLabel();
frameTitle.setText("Compass Heading Calculator");
frameTitle.setFont(titleFont);
frameTitle.setForeground(Color.WHITE);
closeButton = new JButton();
closeButton.setText("Close");
closeButton.setToolTipText("Click to close view");
closeButton.setFont(buttonFont);
closeButton.addActionListener(new java.awt.event.ActionListener() {public void actionPerformed(java.awt.event.ActionEvent evt)
{closeButtonActionPerformed(evt);}});
hdgSpinner = new JSpinner();
hdgSpinner.setFont(compassFont);
hdgSpinner.setModel(new javax.swing.SpinnerNumberModel(0, 0, 359, 1));
hdgSpinner.setToolTipText("Enter heading to see angles change");
hdgSpinner.addChangeListener(new javax.swing.event.ChangeListener() {public void stateChanged(javax.swing.event.ChangeEvent evt)
{hdgSpinnerStateChanged(evt);}});
neField = new JTextField();
neField.setBackground(Color.BLACK);
neField.setEditable(false);
neField.setFont(compassFont);
neField.setForeground(Color.WHITE);
neField.setHorizontalAlignment(JTextField.CENTER);
neField.setBorder(null);
eField = new JTextField();
eField.setBackground(Color.BLACK);
eField.setEditable(false);
eField.setFont(compassFont);
eField.setForeground(Color.WHITE);
eField.setHorizontalAlignment(JTextField.CENTER);
eField.setBorder(null);
seField = new JTextField();
seField.setBackground(Color.BLACK);
seField.setEditable(false);
seField.setFont(compassFont);
seField.setForeground(Color.WHITE);
seField.setHorizontalAlignment(JTextField.CENTER);
seField.setBorder(null);
sField = new JTextField();
sField.setBackground(Color.BLACK);
sField.setEditable(false);
sField.setFont(compassFont);
sField.setForeground(Color.WHITE);
sField.setHorizontalAlignment(JTextField.CENTER);
sField.setBorder(null);
swField = new JTextField();
swField.setBackground(Color.BLACK);
swField.setEditable(false);
swField.setFont(compassFont);
swField.setForeground(Color.WHITE);
swField.setHorizontalAlignment(JTextField.CENTER);
swField.setBorder(null);
wField = new JTextField();
wField.setBackground(Color.BLACK);
wField.setEditable(false);
wField.setFont(compassFont);
wField.setForeground(Color.WHITE);
wField.setHorizontalAlignment(JTextField.CENTER);
wField.setBorder(null);
nwField = new JTextField();
nwField.setBackground(Color.BLACK);
nwField.setEditable(false);
nwField.setFont(compassFont);
nwField.setForeground(Color.WHITE);
nwField.setHorizontalAlignment(JTextField.CENTER);
nwField.setBorder(null);
frameSeparator1 = new JSeparator();
frameSeparator1.setForeground(Color.WHITE);
frameSeparator1.setBackground(Color.BLACK);
ccPanel = new CompassCalculatorPanel();
// Add components to pane
ccPane.add(frameTitle);
ccPane.add(closeButton);
ccPane.add(frameSeparator1);
ccPane.add(nwField);
ccPane.add(hdgSpinner);
ccPane.add(neField);
ccPane.add(wField);
ccPane.add(ccPanel);
ccPane.add(eField);
ccPane.add(swField);
ccPane.add(sField);
ccPane.add(seField);
// Begin Component Layout
Insets paneInsets = ccPane.getInsets();
Point P1 = new Point(0, 0);
Point P2 = new Point(0, 0);
Point P3 = new Point(0, 0);
Dimension size = frameTitle.getPreferredSize();
frameTitle.setBounds((5 + paneInsets.left), (5 + paneInsets.top), size.width, size.height);
P1.setLocation((5 + paneInsets.left), (5 + paneInsets.top + size.height + 5));
P2.setLocation((P1.x + size.width + 5), (paneInsets.top + 5));
size = closeButton.getPreferredSize();
closeButton.setBounds(P2.x, P2.y, size.width, size.height);
frameSeparator1.setBounds(P1.x, P1.y, (panelDim.width - paneInsets.left - paneInsets.right), 10);
P1.setLocation(P1.x, (P1.y + 10 + 5));
P2.setLocation((P1.x + 50 + 75), P1.y);
P3.setLocation((P1.x + 50 + 75 + 60 + 75), P1.y);
nwField.setBounds(P1.x, P1.y, 50, 26);
hdgSpinner.setBounds(P2.x, P2.y, 60, 26);
neField.setBounds(P3.x, P3.y, 50, 26);
P2.setLocation((P1.x + 50 + 5), (P1.y + 26 + 5));
P1.setLocation(P1.x, (P1.y + 26 + 5 + 87));
P3.setLocation((P1.x + 50 + 5 + 200 + 5), P1.y);
wField.setBounds(P1.x, P1.y, 50, 26);
ccPanel.setBounds(P2.x, P2.y, 200, 200);
ccPanelPoint = new Point(P2.x, P2.y);
eField.setBounds(P3.x, P3.y, 50, 26);
P1.setLocation(P1.x, (P1.y + 26 + 87 + 5));
P2.setLocation((P1.x + 50 + 80), P1.y);
P3.setLocation((P1.x + 50 + 80 + 50 + 80), P1.y);
swField.setBounds(P1.x, P1.y, 50, 26);
sField.setBounds(P2.x, P2.y, 50, 26);
seField.setBounds(P3.x, P3.y, 50, 26);
// End with Frame sizing
Dimension frameDim = new Dimension((paneInsets.left + 5 + 50 + 5 + 200 + 5 + 50 + 5 + paneInsets.right + 10), (P1.y + 26 + 5 + paneInsets.bottom + 40));
this.setPreferredSize(frameDim);
this.setSize(frameDim);
//this.setSize((paneInsets.left + 5 + 50 + 5 + 200 + 5 + 50 + 5 + paneInsets.right), (P1.y + 26 + 5 + paneInsets.bottom));
private void closeButtonActionPerformed(java.awt.event.ActionEvent evt)
this.dispose();
private void hdgSpinnerStateChanged(javax.swing.event.ChangeEvent evt)
calculateAndDraw();
private void calculateAndDraw()
int angle = (Integer)hdgSpinner.getValue();
int[] headings = new int[7];
int addAngle = 45;
for (int i = 0; i < 7; i++)
headings[i] = angle + addAngle;
if (headings[i] >= 360)
headings[i] -= 360;
addAngle += 45;
neField.setText(String.valueOf(headings[0]));
eField.setText(String.valueOf(headings[1]));
seField.setText(String.valueOf(headings[2]));
sField.setText(String.valueOf(headings[3]));
swField.setText(String.valueOf(headings[4]));
wField.setText(String.valueOf(headings[5]));
nwField.setText(String.valueOf(headings[6]));
ccPanel.paintComponent(this.getGraphics(), angle);
ccPanel.setBounds(ccPanelPoint.x, ccPanelPoint.y, 200, 200);
//ccPanel.repaint(this.getGraphics(), angle);
}The CompassCalculatorPanel.java code:
* To change this template, choose Tools | Templates
* and open the template in the editor.
package com.vikingvirtual.flightsim;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Stroke;
* @author madViking
public class CompassCalculatorPanel extends javax.swing.JPanel
private int xCent;
private int yCent;
public CompassCalculatorPanel()
super();
@Override
public void paintComponent(Graphics g)
paintComponent(g, 0);
public void repaint(Graphics g, int angle)
paintComponent(g, angle);
public void paintComponent(Graphics g, int angle)
super.paintComponent(g);
Dimension panelDim = this.getSize();
xCent = (panelDim.width / 2);
yCent = (panelDim.height / 2);
float[] dashArray = {8.0f};
Graphics2D g2D = (Graphics2D)g;
g2D.setColor(new Color(53, 153, 0));
g2D.fillRect(0, 0, panelDim.width, panelDim.height);
BasicStroke hdgLine = new BasicStroke(3.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
BasicStroke northLine = new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL, 10.0f, dashArray, 0.0f);
Stroke stdStroke = g2D.getStroke();
// Setup Heading Arrow Points
Point hdgBottom = new Point(xCent, panelDim.height - 15);
Point hdgTop = new Point(xCent, 15);
Point ltHdgArr = new Point(xCent - 10, 20);
Point rtHdgArr = new Point(xCent + 10, 20);
// Setup North Arrow Points
Point nthBottom = new Point(xCent, panelDim.height - 15);
Point nthTop = new Point(xCent, 15);
Point ltNthArr = new Point(xCent - 8, 20);
Point rtNthArr = new Point(xCent + 8, 20);
// Rotate North Arrow Points
nthBottom = rotatePoint(nthBottom, (0 - angle), true);
nthTop = rotatePoint(nthTop, (0 - angle), true);
ltNthArr = rotatePoint(ltNthArr, (0 - angle), true);
rtNthArr = rotatePoint(rtNthArr, (0 - angle), true);
// Draw Heading Line
g2D.setColor(Color.RED);
g2D.setStroke(hdgLine);
g2D.drawLine(hdgBottom.x, hdgBottom.y, hdgTop.x, hdgTop.y);
g2D.drawLine(ltHdgArr.x, ltHdgArr.y, hdgTop.x, hdgTop.y);
g2D.drawLine(rtHdgArr.x, rtHdgArr.y, hdgTop.x, hdgTop.y);
g2D.setStroke(stdStroke);
// Draw North Line
g2D.setColor(Color.WHITE);
g2D.setStroke(northLine);
g2D.drawLine(nthBottom.x, nthBottom.y, nthTop.x, nthTop.y);
g2D.drawLine(ltNthArr.x, ltNthArr.y, nthTop.x, nthTop.y);
g2D.drawLine(rtNthArr.x, rtNthArr.y, nthTop.x, nthTop.y);
g2D.setStroke(stdStroke);
// Draw circles
g2D.setColor(Color.BLUE);
g2D.setStroke(hdgLine);
g2D.drawOval(5, 5, (panelDim.width - 10), (panelDim.height - 10));
g2D.setStroke(stdStroke);
g2D.fillOval((xCent - 2), (yCent - 2), 5, 5);
g2D.setStroke(stdStroke);
private Point rotatePoint(Point p, int angle, boolean centerRelative)
double ix, iy;
double hyp = 0.0;
double degrees = 0.0;
if (centerRelative == true)
ix = (double)(p.x - xCent);
iy = (double)((p.y - yCent)*-1);
else
ix = (double)p.x;
iy = (double)p.y;
if (ix == 0)
ix = 1;
hyp = Math.sqrt((Math.pow(ix, 2)) + (Math.pow(iy, 2)));
if ((ix >= 0) && (iy >= 0))
degrees = Math.toDegrees(Math.atan(ix/iy));
else if((ix >= 0) && (iy < 0))
degrees = Math.abs(Math.toDegrees(Math.atan(iy/ix)));
degrees = degrees + 90.0;
else if ((ix < 0) && (iy < 0))
degrees = Math.toDegrees(Math.atan(ix/iy));
degrees = degrees + 180.0;
else if ((ix < 0) && (iy >= 0))
degrees = Math.abs(Math.toDegrees(Math.atan(iy/ix)));
degrees = degrees + 270.0;
degrees = degrees + angle;
if (degrees >= 360)
degrees = degrees - 360;
if (degrees < 0)
degrees = degrees + 360;
double interX = Math.sin(Math.toRadians(degrees));
double interY = Math.cos(Math.toRadians(degrees));
interX = interX * hyp;
interY = ((interY * hyp) * -1);
if (centerRelative == true)
p.x = xCent + (int)Math.floor(interX);
p.y = yCent + (int)Math.floor(interY);
else
p.x = (int)Math.floor(interX);
p.y = (int)Math.floor(interY);
return p;
}In response to the first couple of comments made about using Absolute positioning (layout null), I took a look at the page on doing layouts, which happens to be the link you sent. I read about each, and decided that a GridBag layout would be best. So I created a new class called CompassCalcGridBagFrame and set it all up using the same components, but with a Grid Bag layout. I encounter the exact same problem.
Just FYI: I originally created this frame using the NetBeans (6.9.1) Frame form builder. By default that uses the Free Design setting, which creates group layouts for both vertical and horizontal spacing. This is where the problem first came to be. I next used the builder to create an absolute positioning frame, which had the same issue. That is when I started building my frames using code only - no NetBeans GUIs. This is where the absolute layout from scratch code started. Same effect. And now, I've created a Grid Bag layout from code, and same effect. There has to be something I'm missing overall, as this effects all of my different layout designs.
The one thing from gimbal2's previous comment is, should I be using this custom panel within another panel? I am currently adding all of the components (and in Grid Bag, the GridBag layout) to the frame pane itself. Is that OK, or should I use a generic JPanel, and have the components all within that?
Here is the code for the newest frame class (CompassCalcGridBagFrame):
package com.vikingvirtual.flightsim;
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.Point;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JSeparator;
import javax.swing.JSpinner;
import javax.swing.JTextField;
* @author madViking
public class CompassCalcGridBagFrame extends JFrame
private CompassCalculatorPanel ccPanel;
private JButton closeButton;
private JLabel frameTitle;
private JSeparator frameSeparator1;
private JSpinner hdgSpinner;
private JTextField neField;
private JTextField eField;
private JTextField seField;
private JTextField sField;
private JTextField swField;
private JTextField wField;
private JTextField nwField;
private Point ccPanelPoint;
public CompassCalcGridBagFrame()
super ("Compass Heading Calculator");
initComponents();
this.pack();
this.setVisible(true);
calculateAndDraw();
private void initComponents()
this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
Container ccPane = this.getContentPane();
ccPane.setLayout(new GridBagLayout());
ccPane.setBackground(Color.BLACK);
ccPane.setForeground(Color.BLACK);
Font buttonFont = new Font("Tahoma", 1, 12);
Font compassFont = new Font("Digital-7", 0, 24);
Font titleFont = new Font("Lucida Sans", 1, 14);
frameTitle = new JLabel();
frameTitle.setText("Compass Heading Calculator");
frameTitle.setFont(titleFont);
frameTitle.setHorizontalAlignment(JLabel.CENTER);
frameTitle.setPreferredSize(new Dimension(220, 25));
frameTitle.setForeground(Color.BLACK);
closeButton = new JButton();
closeButton.setText("Close");
closeButton.setToolTipText("Click to close view");
closeButton.setFont(buttonFont);
closeButton.setPreferredSize(new Dimension(75, 25));
closeButton.addActionListener(new java.awt.event.ActionListener() {public void actionPerformed(java.awt.event.ActionEvent evt)
{closeButtonActionPerformed(evt);}});
hdgSpinner = new JSpinner();
hdgSpinner.setFont(compassFont);
hdgSpinner.setModel(new javax.swing.SpinnerNumberModel(0, -1, 360, 1));
hdgSpinner.setToolTipText("Enter heading to see angles change");
hdgSpinner.setPreferredSize(new Dimension(50, 26));
hdgSpinner.addChangeListener(new javax.swing.event.ChangeListener() {public void stateChanged(javax.swing.event.ChangeEvent evt)
{hdgSpinnerStateChanged(evt);}});
neField = new JTextField();
neField.setBackground(Color.BLACK);
neField.setEditable(false);
neField.setFont(compassFont);
neField.setForeground(Color.WHITE);
neField.setHorizontalAlignment(JTextField.CENTER);
neField.setPreferredSize(new Dimension(50, 26));
neField.setBorder(null);
eField = new JTextField();
eField.setBackground(Color.BLACK);
eField.setEditable(false);
eField.setFont(compassFont);
eField.setForeground(Color.WHITE);
eField.setHorizontalAlignment(JTextField.CENTER);
eField.setPreferredSize(new Dimension(50, 26));
eField.setBorder(null);
seField = new JTextField();
seField.setBackground(Color.BLACK);
seField.setEditable(false);
seField.setFont(compassFont);
seField.setForeground(Color.WHITE);
seField.setHorizontalAlignment(JTextField.CENTER);
seField.setPreferredSize(new Dimension(50, 26));
seField.setBorder(null);
sField = new JTextField();
sField.setBackground(Color.BLACK);
sField.setEditable(false);
sField.setFont(compassFont);
sField.setForeground(Color.WHITE);
sField.setHorizontalAlignment(JTextField.CENTER);
sField.setPreferredSize(new Dimension(50, 26));
sField.setBorder(null);
swField = new JTextField();
swField.setBackground(Color.BLACK);
swField.setEditable(false);
swField.setFont(compassFont);
swField.setForeground(Color.WHITE);
swField.setHorizontalAlignment(JTextField.CENTER);
swField.setPreferredSize(new Dimension(50, 26));
swField.setBorder(null);
wField = new JTextField();
wField.setBackground(Color.BLACK);
wField.setEditable(false);
wField.setFont(compassFont);
wField.setForeground(Color.WHITE);
wField.setHorizontalAlignment(JTextField.CENTER);
wField.setPreferredSize(new Dimension(50, 26));
wField.setBorder(null);
nwField = new JTextField();
nwField.setBackground(Color.BLACK);
nwField.setEditable(false);
nwField.setFont(compassFont);
nwField.setForeground(Color.WHITE);
nwField.setHorizontalAlignment(JTextField.CENTER);
nwField.setPreferredSize(new Dimension(50, 26));
nwField.setBorder(null);
frameSeparator1 = new JSeparator();
frameSeparator1.setForeground(Color.WHITE);
frameSeparator1.setBackground(Color.BLACK);
frameSeparator1.setPreferredSize(new Dimension(320, 10));
ccPanel = new CompassCalculatorPanel();
ccPanel.setPreferredSize(new Dimension(250, 250));
GridBagConstraints gbc = new GridBagConstraints();
// Begin Component Layout
gbc.insets = new Insets(0, 0, 0, 0);
gbc.fill = GridBagConstraints.NONE;
gbc.gridx = 0;
gbc.gridy = 0;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.FIRST_LINE_START;
ccPane.add(nwField, gbc);
gbc.gridx = 1;
gbc.gridy = 0;
gbc.gridwidth = 2;
gbc.gridheight = 1;
gbc.weightx = 0.4;
gbc.weighty = 0.4;
gbc.anchor = GridBagConstraints.PAGE_START;
ccPane.add(hdgSpinner, gbc);
gbc.gridx = 3;
gbc.gridy = 0;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.FIRST_LINE_END;
ccPane.add(neField, gbc);
gbc.gridx = 0;
gbc.gridy = 1;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.LINE_START;
ccPane.add(wField, gbc);
gbc.gridx = 1;
gbc.gridy = 1;
gbc.gridwidth = 2;
gbc.gridheight = 1;
gbc.weightx = 1.0;
gbc.weighty = 1.0;
gbc.anchor = GridBagConstraints.CENTER;
ccPane.add(ccPanel, gbc);
gbc.gridx = 3;
gbc.gridy = 1;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.LINE_END;
ccPane.add(eField, gbc);
gbc.gridx = 0;
gbc.gridy = 2;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.LAST_LINE_START;
ccPane.add(swField, gbc);
gbc.gridx = 1;
gbc.gridy = 2;
gbc.gridwidth = 2;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.PAGE_END;
ccPane.add(sField, gbc);
gbc.gridx = 3;
gbc.gridy = 2;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.weightx = 0.5;
gbc.weighty = 0.5;
gbc.anchor = GridBagConstraints.LAST_LINE_END;
ccPane.add(seField, gbc);
gbc.gridx = 0;
gbc.gridy = 3;
gbc.gridwidth = 4;
gbc.gridheight = 1;
gbc.insets = new Insets(10, 5, 10, 5);
gbc.weightx = 0.6;
gbc.weighty = 0.6;
gbc.anchor = GridBagConstraints.CENTER;
ccPane.add(frameSeparator1, gbc);
gbc.gridx = 1;
gbc.gridy = 4;
gbc.gridwidth = 2;
gbc.gridheight = 1;
gbc.anchor = GridBagConstraints.PAGE_START;
ccPane.add(closeButton, gbc);
private void closeButtonActionPerformed(java.awt.event.ActionEvent evt)
this.dispose();
private void hdgSpinnerStateChanged(javax.swing.event.ChangeEvent evt)
calculateAndDraw();
private void calculateAndDraw()
int angle = (Integer)hdgSpinner.getValue();
if (angle == -1)
angle = 359;
if (angle == 360)
angle = 0;
int[] headings = new int[7];
int addAngle = 45;
for (int i = 0; i < 7; i++)
headings[i] = angle + addAngle;
if (headings[i] >= 360)
headings[i] -= 360;
addAngle += 45;
hdgSpinner.setValue(Integer.valueOf(angle));
neField.setText(String.valueOf(headings[0]));
eField.setText(String.valueOf(headings[1]));
seField.setText(String.valueOf(headings[2]));
sField.setText(String.valueOf(headings[3]));
swField.setText(String.valueOf(headings[4]));
wField.setText(String.valueOf(headings[5]));
nwField.setText(String.valueOf(headings[6]));
ccPanel.paintComponent(this.getGraphics(), angle);
} -
A question about Graphics repaint
hi all. I met a question about Graphics repaint
I create mypane class extends JPane .
Now I write a function to keep drawing a char at Screen when i resize my applet.
the function code :
bDrawChrToScr(Graphics2D bgr, char Chr,int iX,int iY,int iX1,int iY1)
bgr.setColor(Color.black);
bgr.fillRect(iX,iY,iX1,iY);
bgr.setColor(Color.red);
bgr.drawString(String.valueOf(Chr),iWidth,iHeight);
bgr=thispane.getGraphics();
and i call this function in paintcomponent .Now when i resize my applet ,i find it not work as my hope.
the screen flash two. First it draw this char but sencond it erase it.Why? ThanksThe super.paintComponent(g) method causes the default painting to occur - overriding you bDrawChrToScr() method. Therefore, change paintComponent() method to:
super.paintComponent(g);
bDrawChrToScr(...); -
Hi, there!
I'm trying to make a simple program using swing.
It's frame(window) contains serveral layers such as background layer, text layer, image layer, etc...
I wrote the layer class that inherites JPanel.
And I created two layer objects that draw their image.
The problem is that the layer's order is changed when whenever I executes.
Somtimes the first layer's image drawed at top, and somtimes the second layer's image drawed at top.
Help me.
What problem is it?
import java.awt.*;
import javax.swing.*;
public class Layer extends JPanel {
Image img;
Layer(Image img) {
this.img = img;
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, this);
import java.awt.*;
import javax.swing.*;
public class LayerManager {
public static void main(String[] args) {
JFrame mainFrame = new JFrame();
mainFrame.setSize(700, 500);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container contentPane = mainFrame.getContentPane();
contentPane.setLayout(null);
Layer layer1 = new Layer(Toolkit.getDefaultToolkit().getImage("res/image1.jpg"));
layer1.setBounds(50, 50, 200, 200);
contentPane.add(layer1, 0);
Layer layer2 = new Layer(Toolkit.getDefaultToolkit().getImage("res/image2.jpg"));
layer2.setBounds(100, 100, 200, 200);
contentPane.add(layer2, 0);
mainFrame.setVisible(true);
}Don't forget to use the Code Formatting Tags so the posted code retains its original formatting. That is done by selecting the code and then clicking on the "Code" button above the question input area.
You can't just place two components on top of one another.
If all you are trying to do is draw a background-image, then you can search the forum for different suggestions. I usually suggest using a custom [Background Panel|http://www.camick.com/java/blog.html?name=background-panel].
If you really want to know about layering panels then read the Swing tutorial on [How to Use Layered Panes|http://java.sun.com/docs/books/tutorial/uiswing/TOC.html].
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