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

/**
 * <code>Tab</code> is the abstract superclass of every page
 * in the example's tab folder.  Each page in the tab folder
 * describes a control.
 *
 * A Tab itself is not a control but instead provides a
 * hierarchy with which to share code that is common to
 * every page in the folder.
 *
 * A typical page in a Tab contains a two column composite.
 * The left column contains the "Example" group.  The right
 * column contains "Control" group.  The "Control" group
 * contains controls that allow the user to interact with
 * the example control.  The "Control" group typically
 * contains a "Style", "Display" and "Size" group.  Subclasses
 * can override these defaults to augment a group or stop
 * a group from being created.
 */
abstract class Tab {	
	/* Common control buttons */
	Button borderButton, enabledButton, visibleButton;
	Button preferredButton, tooSmallButton, smallButton, largeButton, fillButton;

	/* Common groups and composites */
	Composite tabFolderPage;
	Group exampleGroup, controlGroup, displayGroup, sizeGroup, styleGroup, colorGroup;

	/* Controlling instance */
	final ControlExample instance;

	/* Sizing constants for the "Size" group */
	static final int TOO_SMALL_SIZE	= 10;
	static final int SMALL_SIZE		= 50;
	static final int LARGE_SIZE		= 100;

	/* Common controls for the "Colors" group */
	Button backgroundButton, foregroundButton, fontButton;
	Color backgroundColor, foregroundColor;
	Font font;	

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

	/**
	 * Creates the "Control" group.  The "Control" group
	 * is typically the right hand column in the tab.
	 */
	void createControlGroup () {
	
		/*
		 * Create the "Control" group.  This is the group on the
		 * left half of each example tab.  It consists of the
		 * style group, the display group and the size group.
		 */	
		controlGroup = new Group (tabFolderPage, SWT.NONE);
		GridLayout gridLayout= new GridLayout ();
		controlGroup.setLayout (gridLayout);
		gridLayout.numColumns = 2;
		gridLayout.makeColumnsEqualWidth = true;
		controlGroup.setLayoutData (new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
		controlGroup.setText (ControlExample.getResourceString("Parameters"));
	
		/* Create individual groups inside the "Control" group */
		createStyleGroup ();
		createDisplayGroup ();
		createSizeGroup ();
		createColorGroup ();
	
		/*
		 * For each Button child in the style group, add a selection
		 * listener that will recreate the example controls.  If the
		 * style group button is a RADIO button, ensure that the radio
		 * button is selected before recreating the example controls.
		 * When the user selects a RADIO button, the current RADIO
		 * button in the group is deselected and the new RADIO button
		 * is selected automatically.  The listeners are notified for
		 * both these operations but typically only do work when a RADIO
		 * button is selected.
		 */
		SelectionListener selectionListener = new SelectionAdapter () {
			public void widgetSelected (SelectionEvent event) {
				if ((event.widget.getStyle () & SWT.RADIO) != 0) {
					if (!((Button) event.widget).getSelection ()) return;
				}
				recreateExampleWidgets ();
			};
		};
		Control [] children = styleGroup.getChildren ();
		for (int i=0; i<children.length; i++) {
			if (children [i] instanceof Button) {
				Button button = (Button) children [i];
				button.addSelectionListener (selectionListener);
			}
		}
	}
	
	/**
	 * Creates the "Control" widget children.
	 * Subclasses override this method to augment
	 * the standard controls created in the "Style",
	 * "Display" and "Size" groups.
	 */
	void createControlWidgets () {
	}
	
	/**
	 * Creates the "Color" group. This is typically
	 * a child of the "Control" group. Subclasses override
	 * this method to customize and set system colors.
	 */
	void createColorGroup () {
		/* Create the group */
		colorGroup = new Group(controlGroup, SWT.NULL);
		colorGroup.setLayout (new GridLayout (2, false));
		colorGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
		colorGroup.setText (ControlExample.getResourceString ("Colors"));
		new Label (colorGroup, SWT.NONE).setText (ControlExample.getResourceString ("Foreground_Color"));
		foregroundButton = new Button (colorGroup, SWT.PUSH);
		new Label (colorGroup, SWT.NONE).setText (ControlExample.getResourceString ("Background_Color"));
		backgroundButton = new Button (colorGroup, SWT.PUSH);
		fontButton = new Button (colorGroup, SWT.PUSH);
		fontButton.setText(ControlExample.getResourceString("Font"));
		
		Shell shell = backgroundButton.getShell ();
		final ColorDialog backgroundDialog = new ColorDialog (shell);
		final ColorDialog foregroundDialog = new ColorDialog (shell);
		final FontDialog fontDialog = new FontDialog (shell);

		/* Create images to display current colors */
		int imageSize = 12;
		Display display = shell.getDisplay ();
		final Image backgroundImage = new Image (display, imageSize, imageSize);	
		final Image foregroundImage = new Image (display, imageSize, imageSize);

		/* Add listeners to set the colors and font */
		backgroundButton.setImage(backgroundImage);
		backgroundButton.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent event) {
				RGB rgb = backgroundDialog.open();
				if (rgb == null) return;
				Color oldColor = backgroundColor;
				backgroundColor = new Color (backgroundButton.getDisplay(), rgb);
				setExampleWidgetBackground ();
				if (oldColor != null) oldColor.dispose ();
			}
		});
		foregroundButton.setImage(foregroundImage);
		foregroundButton.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent event) {
				RGB rgb = foregroundDialog.open();
				if (rgb == null) return;
				Color oldColor = foregroundColor;
				foregroundColor = new Color (foregroundButton.getDisplay(), rgb);
				setExampleWidgetForeground ();
				if (oldColor != null) oldColor.dispose ();
			}
		});
		fontButton.addSelectionListener(new SelectionAdapter () {
			public void widgetSelected (SelectionEvent e) {
				FontData fontData = fontDialog.open ();
				if (fontData == null) return;
				Font oldFont = font;
				font = new Font (fontButton.getDisplay(), fontData);
				setExampleWidgetFont ();
				setExampleWidgetSize ();
				if (oldFont != null) oldFont.dispose ();
			}
		});
		backgroundButton.addDisposeListener(new DisposeListener() {
			public void widgetDisposed(DisposeEvent event) {
				if (backgroundImage != null) backgroundImage.dispose();
				if (foregroundImage != null) foregroundImage.dispose();
				if (backgroundColor != null) backgroundColor.dispose();
				if (foregroundColor != null) foregroundColor.dispose();
				if (font != null) font.dispose();
				backgroundColor = null;
				foregroundColor = null;
				font = null;				
			}
		});
	}
	
	/**
	 * Creates the "Display" group.  This is typically
	 * a child of the "Control" group.
	 */
	void createDisplayGroup () {
		/* Create the group */
		displayGroup = new Group (controlGroup, SWT.NONE);
		displayGroup.setLayout (new GridLayout ());
		displayGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
		displayGroup.setText (ControlExample.getResourceString("State"));
	
		/* Create the controls */
		enabledButton = new Button(displayGroup, SWT.CHECK);
		enabledButton.setText(ControlExample.getResourceString("Enabled"));
		visibleButton = new Button(displayGroup, SWT.CHECK);
		visibleButton.setText(ControlExample.getResourceString("Visible"));
	
		/* Add the listeners */
		enabledButton.addSelectionListener (new SelectionAdapter () {
			public void widgetSelected (SelectionEvent event) {
				setExampleWidgetEnabled ();
			}
		});
		visibleButton.addSelectionListener (new SelectionAdapter () {
			public void widgetSelected (SelectionEvent event) {
				setExampleWidgetVisibility ();
			}
		});
	
		/* Set the default state */
		enabledButton.setSelection(true);
		visibleButton.setSelection(true);
	}
	
	/**
	 * Creates the "Example" group.  The "Example" group
	 * is typically the left hand column in the tab.
	 */
	void createExampleGroup () {	
		exampleGroup = new Group (tabFolderPage, SWT.NONE);
		GridLayout gridLayout = new GridLayout ();
		exampleGroup.setLayout (gridLayout);
		exampleGroup.setLayoutData (new GridData (GridData.FILL_BOTH));
	}
	
	/**
	 * Creates the "Example" widget children of the "Example" group.
	 * Subclasses override this method to create the particular
	 * example control.
	 */
	void createExampleWidgets () {
		/* Do nothing */
	}
	
	/**
	 * Creates the "Size" group.  The "Size" group contains
	 * controls that allow the user to change the size of
	 * the example widgets.
	 */
	void createSizeGroup () {