Demonstrates how to fix common alignment problems : FlowLayout « Swing « Java Tutorial






Demonstrates how to fix common alignment problems
/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */


import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;

import javax.swing.AbstractButton;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.border.LineBorder;
import javax.swing.border.TitledBorder;

public class BoxAlignmentDemo extends JPanel {
  public BoxAlignmentDemo() {
    super(new BorderLayout());
    JTabbedPane tabbedPane = new JTabbedPane();

    JPanel buttonRow = new JPanel();
    // Use default FlowLayout.
    buttonRow.add(createButtonRow(false));
    buttonRow.add(createButtonRow(true));
    tabbedPane.addTab("Altering alignments", buttonRow);

    JPanel labelAndComponent = new JPanel();
    // Use default FlowLayout.
    labelAndComponent.add(createLabelAndComponent(false));
    labelAndComponent.add(createLabelAndComponent(true));
    tabbedPane.addTab("X alignment mismatch", labelAndComponent);

    JPanel buttonAndComponent = new JPanel();
    // Use default FlowLayout.
    buttonAndComponent.add(createYAlignmentExample(false));
    buttonAndComponent.add(createYAlignmentExample(true));
    tabbedPane.addTab("Y alignment mismatch", buttonAndComponent);

    // Add tabbedPane to this panel.
    add(tabbedPane, BorderLayout.CENTER);
  }

  protected JPanel createButtonRow(boolean changeAlignment) {
    JButton button1 = new JButton("A JButton", createImageIcon("images/middle.gif"));
    button1.setVerticalTextPosition(AbstractButton.BOTTOM);
    button1.setHorizontalTextPosition(AbstractButton.CENTER);

    JButton button2 = new JButton("Another JButton", createImageIcon("images/geek-cght.gif"));
    button2.setVerticalTextPosition(AbstractButton.BOTTOM);
    button2.setHorizontalTextPosition(AbstractButton.CENTER);

    String title;
    if (changeAlignment) {
      title = "Desired";
      button1.setAlignmentY(BOTTOM_ALIGNMENT);
      button2.setAlignmentY(BOTTOM_ALIGNMENT);
    } else {
      title = "Default";
    }

    JPanel pane = new JPanel();
    pane.setBorder(BorderFactory.createTitledBorder(title));
    pane.setLayout(new BoxLayout(pane, BoxLayout.X_AXIS));
    pane.add(button1);
    pane.add(button2);
    return pane;
  }

  protected JPanel createLabelAndComponent(boolean doItRight) {
    JPanel pane = new JPanel();

    JComponent component = new JPanel();
    Dimension size = new Dimension(150, 100);
    component.setMaximumSize(size);
    component.setPreferredSize(size);
    component.setMinimumSize(size);
    TitledBorder border = new TitledBorder(new LineBorder(Color.black), "A JPanel",
        TitledBorder.CENTER, TitledBorder.BELOW_TOP);
    border.setTitleColor(Color.black);
    component.setBorder(border);

    JLabel label = new JLabel("This is a JLabel");
    String title;
    if (doItRight) {
      title = "Matched";
      label.setAlignmentX(CENTER_ALIGNMENT);
    } else {
      title = "Mismatched";
    }

    pane.setBorder(BorderFactory.createTitledBorder(title));
    pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS));
    pane.add(label);
    pane.add(component);
    return pane;
  }

  protected JPanel createYAlignmentExample(boolean doItRight) {
    JPanel pane = new JPanel();
    String title;

    JComponent component1 = new JPanel();
    Dimension size = new Dimension(100, 50);
    component1.setMaximumSize(size);
    component1.setPreferredSize(size);
    component1.setMinimumSize(size);
    TitledBorder border = new TitledBorder(new LineBorder(Color.black), "A JPanel",
        TitledBorder.CENTER, TitledBorder.BELOW_TOP);
    border.setTitleColor(Color.black);
    component1.setBorder(border);

    JComponent component2 = new JPanel();
    size = new Dimension(100, 50);
    component2.setMaximumSize(size);
    component2.setPreferredSize(size);
    component2.setMinimumSize(size);
    border = new TitledBorder(new LineBorder(Color.black), "A JPanel", TitledBorder.CENTER,
        TitledBorder.BELOW_TOP);
    border.setTitleColor(Color.black);
    component2.setBorder(border);

    if (doItRight) {
      title = "Matched";
    } else {
      component1.setAlignmentY(TOP_ALIGNMENT);
      title = "Mismatched";
    }

    pane.setBorder(BorderFactory.createTitledBorder(title));
    pane.setLayout(new BoxLayout(pane, BoxLayout.X_AXIS));
    pane.add(component1);
    pane.add(component2);
    return pane;
  }

  /** Returns an ImageIcon, or null if the path was invalid. */
  protected static ImageIcon createImageIcon(String path) {
    java.net.URL imgURL = BoxAlignmentDemo.class.getResource(path);
    if (imgURL != null) {
      return new ImageIcon(imgURL);
    } else {
      System.err.println("Couldn't find file: " + path);
      return null;
    }
  }

  /**
   * Create the GUI and show it. For thread safety, this method should be
   * invoked from the event-dispatching thread.
   */
  private static void createAndShowGUI() {
    // Create and set up the window.
    JFrame frame = new JFrame("BoxAlignmentDemo");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // Create and set up the content pane.
    BoxAlignmentDemo newContentPane = new BoxAlignmentDemo();
    newContentPane.setOpaque(true); // content panes must be opaque
    frame.setContentPane(newContentPane);

    // Display the window.
    frame.pack();
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    // Schedule a job for the event-dispatching thread:
    // creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    });
  }
}








14.89.FlowLayout
14.89.1.Laying Out Components in a Flow (Left-to-Right, Top-to-Bottom)
14.89.2.Three constructors available for the FlowLayout manager.
14.89.3.Layout manager
14.89.4.FlowLayout: the default layout manager for a JPanel.
14.89.5.FlowLayout BehaviorFlowLayout Behavior
14.89.6.Using FlowLayoutUsing FlowLayout
14.89.7.Changing the GapChanging the Gap
14.89.8.Setting the gaps between components and rows explicitly by calling the setHgap()Setting the gaps between components and rows explicitly by calling the setHgap()
14.89.9.Demonstrates how to fix common alignment problemsDemonstrates how to fix common alignment problems
14.89.10.Use FlowLayout to hold checkBox, Label and TextField