LayoutManager JLabel ändert GridBayLayout-Gewichtung

[benedikt.s]

Hallo Zusammen,

habe ein kleines Problem mit der Gewichtung eines GridBayLayouts, sobald dort JLabels eingefügt werden.
Das Einfügen des JLabels bewirkt, dass die Gewichtung der darüber liegenden Komponenten verschoben wird.

Zum Testen habe ich ein kleines Beispiel erstellt, dass das Problem minimiert darstellt:

JFrame->ContentPanel (GridBagLayout)
Darin 4 JPanels
->Position 0,0
->Position 0,1
->Position 1,0
->Position 1,1

Alle 4 Panels haben dieselbe Gewichtung:

weightx = 1;
weighty = 1;

und füllen den Platz komplett aus:

fill = GridBagConstraints.BOTH;

Damit die Größen erkennbar sind hat jedes Panel eine Border bekommen (1px Line).

Test1:
Startet man das Programm nun, so bekommt jedes Panel immer dieselbe Höhe und Breite zugewiesen.
Schön gleichmäßig wie es nach der Gewichtung von oben auch sein sollte.

Test2:
Nun füge Ich in Panel 4 (rechts unten) ein JLabel ein.

Startet man das Programm nun, so bekommt das Panel 4 eine etwas höhere Gewichtung in Breite und Höhe als die anderen Panels.
Die Gewichtung der Panels scheint hier nicht mehr vorrangig behandelt zu werden?

---

Kann man hier irgendwie verhindern, dass sich das JLabel auf das darüber liegende Layout auswirkt?

Danke für alle Ideen.

Folgend noch der Quelltext zum selber testen:

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.SystemColor;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

public class test extends JFrame {

	private static final long serialVersionUID = 1L;
	private JPanel jContentPane = null;
	private JPanel jPanel = null;
	private JPanel jPanel1 = null;
	private JPanel jPanel2 = null;
	private JPanel jPanel3 = null;
	private JLabel jLabel = null;
	/**
	 * This method initializes jPanel	
	 * 	
	 * @return javax.swing.JPanel	
	 */
	private JPanel getJPanel() {
		if (jPanel == null) {
			jPanel = new JPanel();
			jPanel.setLayout(new GridBagLayout());
			jPanel.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
		}
		return jPanel;
	}

	/**
	 * This method initializes jPanel1	
	 * 	
	 * @return javax.swing.JPanel	
	 */
	private JPanel getJPanel1() {
		if (jPanel1 == null) {
			jPanel1 = new JPanel();
			jPanel1.setLayout(new GridBagLayout());
			jPanel1.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
		}
		return jPanel1;
	}

	/**
	 * This method initializes jPanel2	
	 * 	
	 * @return javax.swing.JPanel	
	 */
	private JPanel getJPanel2() {
		if (jPanel2 == null) {
			jPanel2 = new JPanel();
			jPanel2.setLayout(new GridBagLayout());
			jPanel2.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
		}
		return jPanel2;
	}

	/**
	 * This method initializes jPanel3	
	 * 	
	 * @return javax.swing.JPanel	
	 */
	private JPanel getJPanel3() {
		if (jPanel3 == null) {
			GridBagConstraints gridBagConstraints4 = new GridBagConstraints();
			gridBagConstraints4.gridx = 0;
			gridBagConstraints4.anchor = GridBagConstraints.NORTHWEST;
			gridBagConstraints4.weighty = 0.0;
			gridBagConstraints4.weightx = 0.0;
			gridBagConstraints4.gridy = 0;
			jLabel = new JLabel();
			jLabel.setText("JLabel");			
			jPanel3 = new JPanel();
			jPanel3.setLayout(new GridBagLayout());
			jPanel3.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
			jPanel3.add(jLabel, gridBagConstraints4);
		}
		return jPanel3;
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				test thisClass = new test();
				thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				thisClass.setVisible(true);
			}
		});
	}

	/**
	 * This is the default constructor
	 */
	public test() {
		super();
		initialize();
	}

	/**
	 * This method initializes this
	 * 
	 * @return void
	 */
	private void initialize() {
		this.setSize(493, 220);
		this.setContentPane(getJContentPane());
		this.setTitle("JFrame");
	}

	/**
	 * This method initializes jContentPane
	 * 
	 * @return javax.swing.JPanel
	 */
	private JPanel getJContentPane() {
		if (jContentPane == null) {
			GridBagConstraints gridBagConstraints3 = new GridBagConstraints();
			gridBagConstraints3.insets = new Insets(0, 0, 0, 0);
			gridBagConstraints3.gridy = 1;
			gridBagConstraints3.ipadx = 0;
			gridBagConstraints3.ipady = 0;
			gridBagConstraints3.weightx = 1.0;
			gridBagConstraints3.weighty = 1.0;
			gridBagConstraints3.fill = GridBagConstraints.BOTH;
			gridBagConstraints3.anchor = GridBagConstraints.NORTHWEST;
			gridBagConstraints3.gridx = 1;
			GridBagConstraints gridBagConstraints2 = new GridBagConstraints();
			gridBagConstraints2.insets = new Insets(0, 0, 0, 0);
			gridBagConstraints2.gridy = 1;
			gridBagConstraints2.ipadx = 0;
			gridBagConstraints2.ipady = 0;
			gridBagConstraints2.weightx = 1.0;
			gridBagConstraints2.weighty = 1.0;
			gridBagConstraints2.fill = GridBagConstraints.BOTH;
			gridBagConstraints2.anchor = GridBagConstraints.NORTHWEST;
			gridBagConstraints2.gridx = 0;
			GridBagConstraints gridBagConstraints1 = new GridBagConstraints();
			gridBagConstraints1.insets = new Insets(0, 0, 0, 0);
			gridBagConstraints1.gridy = 0;
			gridBagConstraints1.ipadx = 0;
			gridBagConstraints1.ipady = 0;
			gridBagConstraints1.weightx = 1.0;
			gridBagConstraints1.weighty = 1.0;
			gridBagConstraints1.fill = GridBagConstraints.BOTH;
			gridBagConstraints1.anchor = GridBagConstraints.NORTHWEST;
			gridBagConstraints1.gridx = 1;
			GridBagConstraints gridBagConstraints = new GridBagConstraints();
			gridBagConstraints.insets = new Insets(0, 0, 0, 0);
			gridBagConstraints.gridy = 0;
			gridBagConstraints.ipadx = 0;
			gridBagConstraints.ipady = 0;
			gridBagConstraints.weightx = 1.0;
			gridBagConstraints.weighty = 1.0;
			gridBagConstraints.fill = GridBagConstraints.BOTH;
			gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
			gridBagConstraints.gridx = 0;
			jContentPane = new JPanel();
			jContentPane.setLayout(new GridBagLayout());
			jContentPane.add(getJPanel(), gridBagConstraints);
			jContentPane.add(getJPanel1(), gridBagConstraints1);
			jContentPane.add(getJPanel2(), gridBagConstraints2);
			jContentPane.add(getJPanel3(), gridBagConstraints3);
		}
		return jContentPane;
	}

}  //  @jve:decl-index=0:visual-constraint="53,10"

 

[André Uhres]

public class test extends JFrame {
    private Dimension size = new Dimension(20,20);
...
            jPanel.setPreferredSize(size);
...
            jPanel1.setPreferredSize(size);
...
            jPanel2.setPreferredSize(size);
...
            jPanel3.setPreferredSize(size);

 

[benedikt.s]

Der Tipp von André hilft schon viel weiter.

Alle Panels haben nun dieselbe Breite, egal wie groß das Fenster ist.

---

Nun aber folgendes Problem:

Ist die Gesamtbreite des Hauptpanels nicht exakt durch die Anzahl der Panels teilbar, so bleibt logischerweise etwas Platz übrig.
Dieser freie Platz wird wohl nach belieben vorne und hinten im Hauptpanel verteilt.

Beim Verändern der Größe entsteht so ein unschöner "Sprungeffekt".

Vermutlich würde es schon wesentlich besser aussehen, wenn der freie Platz nur am Ende angefügt wird.
Optimal wäre es das letzte Panel die freien Pixel ausfüllen zu lassen.

Ich habe das Testprogramm von oben mal erweitert um das Problem zu veranschaulichen.
Dem ContentPanel habe ich eine Farbe gegeben, so seht ihr genau wo der frei Platz auftritt.

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.SystemColor;
 
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.ComponentOrientation;
 
public class test extends JFrame {
 
    private static final long serialVersionUID = 1L;
    private JPanel jContentPane = null;
    private JPanel jPanel = null;
    private JPanel jPanel1 = null;
    private JPanel jPanel2 = null;
    private JPanel jPanel3 = null;
    private JLabel jLabel = null;
	private JPanel jPanel4 = null;
	private JPanel jPanel5 = null;
    /**
     * This method initializes jPanel   
     *  
     * @return javax.swing.JPanel   
     */
    private JPanel getJPanel() {
        if (jPanel == null) {
            jPanel = new JPanel();
            jPanel.setLayout(new GridBagLayout());
            jPanel.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
        }
        return jPanel;
    }
 
    /**
     * This method initializes jPanel1  
     *  
     * @return javax.swing.JPanel   
     */
    private JPanel getJPanel1() {
        if (jPanel1 == null) {
            jPanel1 = new JPanel();
            jPanel1.setLayout(new GridBagLayout());
            jPanel1.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
        }
        return jPanel1;
    }
 
    /**
     * This method initializes jPanel2  
     *  
     * @return javax.swing.JPanel   
     */
    private JPanel getJPanel2() {
        if (jPanel2 == null) {
            jPanel2 = new JPanel();
            jPanel2.setLayout(new GridBagLayout());
            jPanel2.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
        }
        return jPanel2;
    }
 
    /**
     * This method initializes jPanel3  
     *  
     * @return javax.swing.JPanel   
     */
    private JPanel getJPanel3() {
        if (jPanel3 == null) {
            GridBagConstraints gridBagConstraints4 = new GridBagConstraints();
            gridBagConstraints4.gridx = 0;
            gridBagConstraints4.anchor = GridBagConstraints.NORTHWEST;
            gridBagConstraints4.weighty = 0.0;
            gridBagConstraints4.weightx = 0.0;
            gridBagConstraints4.gridy = 0;
            jLabel = new JLabel();
            jLabel.setText("JLabel");           
            jPanel3 = new JPanel();
            jPanel3.setLayout(new GridBagLayout());
            jPanel3.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
            jPanel3.add(jLabel, gridBagConstraints4);
        }
        return jPanel3;
    }
 
    /**
	 * This method initializes jPanel4	
	 * 	
	 * @return javax.swing.JPanel	
	 */
	private JPanel getJPanel4() {
		if (jPanel4 == null) {
			jPanel4 = new JPanel();
			jPanel4.setLayout(new GridBagLayout());
			jPanel4.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
		}
		return jPanel4;
	}

	/**
	 * This method initializes jPanel5	
	 * 	
	 * @return javax.swing.JPanel	
	 */
	private JPanel getJPanel5() {
		if (jPanel5 == null) {
			jPanel5 = new JPanel();
			jPanel5.setLayout(new GridBagLayout());
			jPanel5.setBorder(BorderFactory.createLineBorder(SystemColor.activeCaption, 1));
		}
		return jPanel5;
	}

	/**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                test thisClass = new test();
                thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                thisClass.setVisible(true);
            }
        });
    }
 
    /**
     * This is the default constructor
     */
    public test() {
        super();
        initialize();
    }
 
    /**
     * This method initializes this
     * 
     * @return void
     */
    private void initialize() {
        this.setSize(752, 220);
        this.setContentPane(getJContentPane());
        this.setTitle("JFrame");
    }
 
    /**
     * This method initializes jContentPane
     * 
     * @return javax.swing.JPanel
     */
    private JPanel getJContentPane() {
        if (jContentPane == null) {
            GridBagConstraints gridBagConstraints21 = new GridBagConstraints();
            gridBagConstraints21.gridx = 5;
            gridBagConstraints21.weightx = 1.0;
            gridBagConstraints21.weighty = 1.0;
            gridBagConstraints21.fill = GridBagConstraints.BOTH;
            gridBagConstraints21.ipadx = 0;
            gridBagConstraints21.gridy = 0;
            GridBagConstraints gridBagConstraints11 = new GridBagConstraints();
            gridBagConstraints11.gridx = 4;
            gridBagConstraints11.weightx = 1.0;
            gridBagConstraints11.weighty = 1.0;
            gridBagConstraints11.fill = GridBagConstraints.BOTH;
            gridBagConstraints11.ipadx = 0;
            gridBagConstraints11.gridy = 0;
            GridBagConstraints gridBagConstraints3 = new GridBagConstraints();
            gridBagConstraints3.insets = new Insets(0, 0, 0, 0);
            gridBagConstraints3.gridy = 0;
            gridBagConstraints3.ipadx = 0;
            gridBagConstraints3.ipady = 0;
            gridBagConstraints3.weightx = 1.0;
            gridBagConstraints3.weighty = 1.0;
            gridBagConstraints3.fill = GridBagConstraints.BOTH;
            gridBagConstraints3.anchor = GridBagConstraints.NORTHWEST;
            gridBagConstraints3.gridx = 3;
            GridBagConstraints gridBagConstraints2 = new GridBagConstraints();
            gridBagConstraints2.insets = new Insets(0, 0, 0, 0);
            gridBagConstraints2.gridy = 0;
            gridBagConstraints2.ipadx = 0;
            gridBagConstraints2.ipady = 0;
            gridBagConstraints2.weightx = 1.0;
            gridBagConstraints2.weighty = 1.0;
            gridBagConstraints2.fill = GridBagConstraints.BOTH;
            gridBagConstraints2.anchor = GridBagConstraints.NORTHWEST;
            gridBagConstraints2.gridx = 2;
            GridBagConstraints gridBagConstraints1 = new GridBagConstraints();
            gridBagConstraints1.insets = new Insets(0, 0, 0, 0);
            gridBagConstraints1.gridy = 0;
            gridBagConstraints1.ipadx = 0;
            gridBagConstraints1.ipady = 0;
            gridBagConstraints1.weightx = 1.0;
            gridBagConstraints1.weighty = 1.0;
            gridBagConstraints1.fill = GridBagConstraints.BOTH;
            gridBagConstraints1.anchor = GridBagConstraints.NORTHWEST;
            gridBagConstraints1.gridx = 1;
            GridBagConstraints gridBagConstraints = new GridBagConstraints();
            gridBagConstraints.insets = new Insets(0, 0, 0, 0);
            gridBagConstraints.gridy = 0;
            gridBagConstraints.ipadx = 0;
            gridBagConstraints.ipady = 0;
            gridBagConstraints.weightx = 1.0;
            gridBagConstraints.weighty = 1.0;
            gridBagConstraints.fill = GridBagConstraints.BOTH;
            gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
            gridBagConstraints.gridx = 0;
            jContentPane = new JPanel();
            jContentPane.setLayout(new GridBagLayout());
            jContentPane.setBackground(Color.BLACK);
            jContentPane.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
            jContentPane.add(getJPanel(), gridBagConstraints);
            jContentPane.add(getJPanel1(), gridBagConstraints1);
            jContentPane.add(getJPanel2(), gridBagConstraints2);
            jContentPane.add(getJPanel3(), gridBagConstraints3);
            jContentPane.add(getJPanel4(), gridBagConstraints11);
            jContentPane.add(getJPanel5(), gridBagConstraints21);
            getJPanel().setPreferredSize(new Dimension(0,0));
            getJPanel1().setPreferredSize(new Dimension(0,0));
            getJPanel2().setPreferredSize(new Dimension(0,0));
            getJPanel3().setPreferredSize(new Dimension(0,0));
            getJPanel4().setPreferredSize(new Dimension(0,0));
            getJPanel5().setPreferredSize(new Dimension(0,0));
        }
        return jContentPane;
    }
 
}  //  @jve:decl-index=0:visual-constraint="53,10"

Grüße Benedikt