getHeight() giving two different valpues for the same JPanel

[peterhabe]

The getHeight() of projectileAnimationJPanel is giving two different values depending on when it is run. I need both of the values for the height to be the same.

Heres the main class:

package projectileProgram;

import javax.swing.*;
import java.awt.*;

public class ProjectileProgramFixedSize {
	//class objects
/////////////////////////////JPanel i need the height of////////////////////////////////
	ProjectileAnimationJPanel projectileAnimationJPanel = new ProjectileAnimationJPanel();

	ControlPanelJPanel controlPanelJPanel = new ControlPanelJPanel();
	TimeSpeedGraphJPanel timeSpeedGraphJPanel = new TimeSpeedGraphJPanel(controlPanelJPanel);
	HorizontalVelocityGraphJPanel horizontalVelocityGraphJPanel = new HorizontalVelocityGraphJPanel();
	VerticalVelocityGraphJPanel verticalVelocityGraphJPanel = new VerticalVelocityGraphJPanel();
	//variables
	JScrollPane timeSpeedGraphJScrollPane = new JScrollPane(timeSpeedGraphJPanel);
	JScrollPane horizontalVelocityGraphJScrollPane = new JScrollPane(horizontalVelocityGraphJPanel);
	JScrollPane verticalVelocityGraphJScrollPane = new JScrollPane(verticalVelocityGraphJPanel);
	
	//main method
	public static void main(String args[]){
		new ProjectileProgramFixedSize();
	}
	//constructor
	public ProjectileProgramFixedSize(){
		JFrame frame = new JFrame("Projectile Program");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		//setting frame
		frame.setSize(1920,1080);
		frame.setLayout(new GridBagLayout());
		
		//setting layout
		GridBagConstraints gc = new GridBagConstraints();
		gc.gridx = 0;
		gc.gridy = 0;
		gc.gridwidth = 1;
		gc.gridheight = 3;
		gc.weightx = 100;
		gc.weighty = 100;
		gc.insets = new Insets(5,5,5,5);
		gc.anchor = GridBagConstraints.CENTER;
		gc.fill = GridBagConstraints.BOTH;
		frame.add(projectileAnimationJPanel, gc);
		
		gc.gridx = 1;
		gc.gridy = 0;
		gc.gridwidth = 1;
		gc.gridheight = 1;
		gc.weightx = 50;
		gc.weighty = 50;
		gc.insets = new Insets(5,5,5,5);
		gc.anchor = GridBagConstraints.CENTER;
		gc.fill = GridBagConstraints.BOTH;
		frame.add(timeSpeedGraphJScrollPane, gc);
		
		gc.gridx = 1;
		gc.gridy = 1;
		gc.gridwidth = 1;
		gc.gridheight = 1;
		gc.insets = new Insets(5,5,5,5);
		gc.anchor = GridBagConstraints.CENTER;
		gc.fill = GridBagConstraints.BOTH;
		frame.add(horizontalVelocityGraphJScrollPane, gc);

		gc.gridx = 1;
		gc.gridy = 2;
		gc.gridwidth = 1;
		gc.gridheight = 1;
		gc.insets = new Insets(5,5,5,5);
		gc.anchor = GridBagConstraints.CENTER;
		gc.fill = GridBagConstraints.BOTH;
		frame.add(verticalVelocityGraphJScrollPane, gc);
		
		gc.gridx = 0;
		gc.gridy = 3;
		gc.gridwidth = 2;
		gc.gridheight = 1;
		gc.weighty = 5;
		gc.insets = new Insets(5,5,5,5);
		gc.anchor = GridBagConstraints.CENTER;
		gc.fill = GridBagConstraints.BOTH;
		frame.add(controlPanelJPanel, gc);
		
		frame.setResizable(false);
		frame.setVisible(true);
		
		settingVariablesForOtherClasses();
	}
	public void settingVariablesForOtherClasses(){
		//creating thread to set elevation
		Thread settingElevationThread = new Thread(new SettingElevationThread(controlPanelJPanel, projectileAnimationJPanel));
		settingElevationThread.start();
		
		//setting x and y positions in ProjectileAnimationJPanel class on first run
projectileAnimationJPanel.settingXAndYPosisions(projectileAnimationJPanel.getWidth()/20-projectileAnimationJPanel.getHeight()/40, projectileAnimationJPanel.getHeight()-controlPanelJPanel.getElevation()-projectileAnimationJPanel.getHeight()/8-projectileAnimationJPanel.getHeight()/20);
		
		//giving actionPerformed() in ControlPanelJPanel class the variables needed to start and run threads

/////////////////////////where the hight of the JPanel is needed////////////////////
		controlPanelJPanel.settingValues(projectileAnimationJPanel, timeSpeedGraphJPanel, horizontalVelocityGraphJPanel, verticalVelocityGraphJPanel, controlPanelJPanel, projectileAnimationJPanel.returnWidth(), projectileAnimationJPanel.returnHeight(), projectileAnimationJPanel.getSizeOfMeter());
		
		//starting repaint thread
		Thread repaintThread = new Thread(new RepaintThread(projectileAnimationJPanel, timeSpeedGraphJPanel, horizontalVelocityGraphJPanel, verticalVelocityGraphJPanel));
		repaintThread.start();
	}
}

And heres the JPanel which i need the height of:

package projectileProgram;

import javax.swing.*;
import java.awt.*;

public class ProjectileAnimationJPanel extends JPanel{
	//variables
	float elevationDP, meter;
	int elevation, previousElevation, xPosition, yPosition;
	int i = 0;
	boolean run = false;
	//paint method
	public void paintComponent(Graphics g){
		Graphics2D g2 = (Graphics2D)g;
		super.paintComponent(g2);
		this.setBackground(Color.BLUE);
		
		//adding antialiasing
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		
		//drawing elevation
		g2.setColor(Color.GREEN);
		g2.fillRect(0, getHeight()-elevation-(this.getHeight()/8),this.getWidth()/20 , elevation+1);
		
		//drawing ground
		g2.setColor(Color.GREEN);
		g2.fillRect(0, 7*getHeight()/8, getWidth(), getHeight()/8+1);
		
		//drawing ball
		g2.setColor(Color.RED);
		g2.fillOval(xPosition, yPosition, getHeight()/20, getHeight()/20);
				
		//drawing black lines
		g2.setColor(Color.BLACK);
		//drawing on ground
		g2.drawLine(getWidth()/20, 7*getHeight()/8, getWidth(), 7*getHeight()/8);
		//drawing line on top of elevation
		g2.drawLine(0, 7*getHeight()/8-elevation, getWidth()/20, 7*getHeight()/8-elevation);
		//drawing line at side of elevation
		g2.drawLine(getWidth()/20, 7*getHeight()/8-elevation, getWidth()/20, 7*getHeight()/8);

/////////////////value for getHeight() is 875//////////////
System.out.println(getHeight());
	}
	public void setElevation(float e){
		elevationDP = (getWidth()*(e/50))/8;
		elevation = Math.round(elevationDP);
		
		//testing for change in elevation
		if(previousElevation != elevation){
			//setting height ball to new elevation
			settingXAndYStartingPosition();
			
			//setting previousElevation to new elevation
			previousElevation = elevation;
		}
	}
	public float getSizeOfMeter(){
		meter = Float.parseFloat(String.valueOf((getWidth())));
		return meter/400;
	}
	public float getElevation(){
		return elevation;
	}
	public void settingXAndYPosisions(double x, double y){
		xPosition = Math.round(Float.parseFloat(String.valueOf(x)));
		yPosition = Math.round(Float.parseFloat(String.valueOf(y)));
	}
	public void settingXAndYStartingPosition(){
		xPosition = getWidth()/20-getHeight()/40;
		yPosition = 7*getHeight()/8-elevation-getHeight()/20;
	}
	public int returnWidth(){
		return getWidth();
	}

////////////////method returning height of Jpanel to main class////////////////
	public int returnHeight(){

/////////////// value of getHeight() is 872///////////////////
		System.out.println(getHeight());
		return getHeight();
	}
}

[Norm]

Can you make a small program that compiles and demonstrates the problem.
Your posted code doesn't compile because of missing classes.

When does the value change relative to other GUI events? Events like setVisible, setResizable, adding of the component to a container

Does it change more than once? What causes the change?

[peterhabe]

I've found a solution. The part of the program that needs the dimensions of the JPanel now gets the dimensions when it needs it instead of using the values the methods above get on first run. I think the change in dimensions is because there are three panels next to the panel above, which are drawn on after this one and one pixel is added to each of them for what ever reason.

[mkj]

hi,
i have seen that you are working on projectile motion. i ma interested in modeling physical problem and i wish to know what does your projectile animation program do
thanks in advance

[DarrylBurke]

Don't post to long dead threads. This one's 1½ years old, and the member you're addressing hasn't posted here for almost 5 months.

When you have a question, start your own thread -- they're free.

Closing this thread.

db

edit You might like to give more importance to replying to responses in a thread that you started: converting double to pixel coordinates