alignabletab.java

很好的学习swt的 sample 很好的学习swt的 sample

package org.eclipse.swt.examples.controlexample;

/*
 * (c) Copyright IBM Corp. 2000, 2002.
 * This file is made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 */

import org.eclipse.swt.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.events.*;

/**
 * <code>AlignableTab</code> is the abstract
 * superclass of example controls that can be
 * aligned.
 */
abstract class AlignableTab extends Tab {

	/* Allignment Controls */
	Button leftButton, rightButton, centerButton;

	/* Alignment Group */
	Group allignmentGroup;

	/**
	 * Creates the Tab within a given instance of ControlExample.
	 */
	AlignableTab(ControlExample instance) {
		super(instance);
	}

	/**
	 * Creates the "Control" group. 
	 */
	void createControlGroup () {
		super.createControlGroup ();
		
		/* Create the group */
		allignmentGroup = new Group (controlGroup, SWT.NULL);
		allignmentGroup.setLayout (new GridLayout ());
		allignmentGroup.setLayoutData (new GridData(GridData.HORIZONTAL_ALIGN_FILL |
			GridData.VERTICAL_ALIGN_FILL));
		allignmentGroup.setText (ControlExample.getResourceString("Alignment"));
	
		/* Create the controls */
		leftButton = new Button (allignmentGroup, SWT.RADIO);
		leftButton.setText (ControlExample.getResourceString("Left"));
		centerButton = new Button (allignmentGroup, SWT.RADIO);
		centerButton.setText(ControlExample.getResourceString("Center"));
		rightButton = new Button (allignmentGroup, SWT.RADIO);
		rightButton.setText (ControlExample.getResourceString("Right"));
	
		/* Add the listeners */
		SelectionListener selectionListener = new SelectionAdapter () {
			public void widgetSelected(SelectionEvent event) {
				if (!((Button) event.widget).getSelection ()) return;
				setExampleWidgetAlignment ();
			};
		};
		leftButton.addSelectionListener (selectionListener);
		centerButton.addSelectionListener (selectionListener);
		rightButton.addSelectionListener (selectionListener);
	}
	
	/**
	 * Sets the alignment of the "Example" widgets.
	 */
	abstract void setExampleWidgetAlignment ();
	
	/**
	 * Sets the state of the "Example" widgets.
	 */
	void setExampleWidgetState () {
		super.setExampleWidgetState ();
		Control [] controls = getExampleWidgets ();
		if (controls.length != 0) {
			leftButton.setSelection ((controls [0].getStyle () & SWT.LEFT) != 0);
			centerButton.setSelection ((controls [0].getStyle () & SWT.CENTER) != 0);
			rightButton.setSelection ((controls [0].getStyle () & SWT.RIGHT) != 0);
		}
	}
}