Thread: JFrame

EDIT: Sent the project to a friend, who compiled it and says it appears fine on his display, this had led me to believe that it's either my OS, GPU or Monitor, either way I guess this means it is independent of my code. Please check over if you will and insure I have done everything correctly, in case the error can be resolved this way! Thanks

Ok, so I took a first try at making a simple window using a JFrame, ready to be drawn on with images. My CanvasHolder class extends Canvas, and is the component I'm using with a BufferStrategy of 2 to draw to the screen. For the moment, I am not drawing anything other than a clearRect to clear the screen of the previous data (when some will be present).

As this code stands, -sometimes- it works (3/5 times), and I get a red background as I should (I'm using red for the sake of ease of knowing that what I'm writing is working). The other 2/5 times I just get a white screen that when clicked outside of closes.

Also, the times where it does work, the boundary seems to start a certain amount of pixels to the right, giving me a black band across the left which is not accessible by the mouse. This occurs no matter what resolution I set it to perform at.

Like I said, this is my first attempt at something in Java using a JFrame, I might have blatently done something very wrong or that is very bad practice, any advice on the following code would be great.

Thanks guys.

Main Class:

package mainPackage;
 
import java.awt.DisplayMode;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
 
import javax.swing.JFrame;
 
import canvasPackage.CanvasHolder;
 
public class MainMethod 
{
	//fields to hold screen resolution
	private static int xResolution;
	private static int yResolution;
 
	//JFrame variable to hold JFrame that holds the canvas
	private static JFrame jFrame;
 
 
	//main
	public static void main(String[] args) 
	{
		//apply wanted resolution
		setXResolution(800);
		setYResolution(600);
 
		//see 'initialiseGraphics()' below
		jFrame = initialiseGraphics(xResolution, yResolution, 32, true);
 
		//creates an instance of the canvas holder, applying a dimension of the given resolution
		CanvasHolder canvas = new CanvasHolder(xResolution, yResolution);
 
		//apply canvas and set characteristics
		jFrame.add(canvas);
		jFrame.setVisible(true);
		jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
		//modified method which creates bufferstrategy of required amount
		canvas.addNotify(2);
 
		//main 'loop', see CanvasHolder class
		canvas.mainRenderer(xResolution, yResolution);
 
 
	}
 
	public static JFrame initialiseGraphics(int xResolution, int yResolution, int bitDepth, boolean isFullscreen)
	{
		//detect graphics environment and deduce graphics config
		GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();
		GraphicsDevice device = environment.getDefaultScreenDevice();
		GraphicsConfiguration config = device.getDefaultConfiguration();
 
		//create new JFrame with necessary config
		JFrame jFrame = new JFrame(config);
 
		//if fullscreen is specified, check it is supported and change resolution to given values
		if ( isFullscreen == true )
		{
			if ( device.isFullScreenSupported() ) 
			{ 
				device.setFullScreenWindow(jFrame);
 
				if ( device.isDisplayChangeSupported() )
				{
					device.setDisplayMode( new DisplayMode( xResolution, yResolution, bitDepth, DisplayMode.REFRESH_RATE_UNKNOWN ) );
				}
				else
				{
					System.err.println("Change display mode not supported");
				}
			}
			else
			{
				System.err.println("Full screen not supported");
			}
		}
 
		return jFrame;
 
	}
 
 
 
	public static int getXResolution()
	{
		return xResolution;
	}
 
	public static void setXResolution(int x)
	{
		xResolution = x;
	}
 
	public static int getYResolution()
	{
		return yResolution;
	}
 
	public static void setYResolution(int y)
	{
		yResolution = y;
	}
 
 
}

CanvasHolder class:

package canvasPackage;
 
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
 
public class CanvasHolder extends Canvas
{	
	//holds bufferstrategy
	BufferStrategy bufStrat;
 
	//constructor initiates canvas with given resolution and has focus. Background colour set here
	public CanvasHolder(int xRes, int yRes)
	{
		setBackground(Color.red);
		this.setPreferredSize(new Dimension(xRes, yRes));
		setFocusable(true);
		requestFocus();
 
	}
 
	//custom addNotify() to create buffer strategy
	public void addNotify(int buffer)
	{
		super.addNotify();
		this.createBufferStrategy(buffer);
		this.bufStrat = this.getBufferStrategy();
	}
 
	public void mainRenderer(int xRes, int yRes)
	{
		//create graphics object to 'represent' current off-screen image
		Graphics g = bufStrat.getDrawGraphics();
 
		//wipe last iteration's pixels from screen ready for re-drawing
		g.setColor(Color.red);
		g.clearRect(0, 0, xRes, yRes);
 
		/*
		 * Image drawing goes here
		 */
 
		//switch off-screen and on-screen images and release unneeded graphics representation
		bufStrat.show();
		g.dispose();
 
		//apply a sleep time to control tickrate
		try 
		{
			Thread.sleep(19);
		} 
		catch (InterruptedException e) 
		{
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
 
	//draw image method goes here
	public void drawImage(Graphics g, BufferedImage bufImage, int xLocation, int yLocation)
	{
 
	}
}

It full screens, then I seem to be getting a red flicker for about a second, then it stops at white, clicking does nothing for me, it just waits for me to hit alt+f4. An explanation of the black band could be from your monitor not being adjusted correctly for the 800x600 resolution. I know when i change resolution on my lcd, i have to hit the auto button for it to fill the screen.

Moved to - AWT / Java Swing