dialog.java

jfa2ce 源码帮助开发人员更好的理解运用

/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.dialogs;

import java.util.Arrays;
import java.util.HashMap;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.Policy;
import org.eclipse.jface.window.IShellProvider;
import org.eclipse.jface.window.SameShellProvider;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FormData;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Shell;

/**
 * A dialog is a specialized window used for narrow-focused communication with
 * the user.
 * <p>
 * Dialogs are usually modal. Consequently, it is generally bad practice to open
 * a dialog without a parent. A modal dialog without a parent is not prevented
 * from disappearing behind the application's other windows, making it very
 * confusing for the user.
 * </p>
 * <p>
 * If there is more than one modal dialog is open the second one should be
 * parented off of the shell of the first one otherwise it is possible that the
 * OS will give focus to the first dialog potentially blocking the UI.
 * </p>
 */
public abstract class Dialog extends Window {
	/**
	 * Image registry key for error image (value
	 * <code>"dialog_error_image"</code>).
	 * 
	 * @deprecated use
	 *             org.eclipse.swt.widgets.Display.getSystemImage(SWT.ICON_ERROR)
	 */
	public static final String DLG_IMG_ERROR = "dialog_error_image"; //$NON-NLS-1$

	/**
	 * Image registry key for info image (value <code>"dialog_info_image"</code>).
	 * 
	 * @deprecated use
	 *             org.eclipse.swt.widgets.Display.getSystemImage(SWT.ICON_INFORMATION)
	 */
	public static final String DLG_IMG_INFO = "dialog_info_imageg"; //$NON-NLS-1$

	/**
	 * Image registry key for question image (value
	 * <code>"dialog_question_image"</code>).
	 * 
	 * @deprecated org.eclipse.swt.widgets.Display.getSystemImage(SWT.ICON_QUESTION)
	 */
	public static final String DLG_IMG_QUESTION = "dialog_question_image"; //$NON-NLS-1$

	/**
	 * Image registry key for warning image (value
	 * <code>"dialog_warning_image"</code>).
	 * 
	 * @deprecated use
	 *             org.eclipse.swt.widgets.Display.getSystemImage(SWT.ICON_WARNING)
	 */
	public static final String DLG_IMG_WARNING = "dialog_warning_image"; //$NON-NLS-1$

	/**
	 * Image registry key for info message image (value
	 * <code>"dialog_messasge_info_image"</code>).
	 * 
	 * @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_INFO = "dialog_messasge_info_image"; //$NON-NLS-1$

	/**
	 * Image registry key for info message image (value
	 * <code>"dialog_messasge_warning_image"</code>).
	 * 
	 * @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_WARNING = "dialog_messasge_warning_image"; //$NON-NLS-1$

	/**
	 * Image registry key for info message image (value
	 * <code>"dialog_message_error_image"</code>).
	 * 
	 * @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_ERROR = "dialog_message_error_image"; //$NON-NLS-1$

	/**
	 * Image registry key for help image (value
	 * <code>"dialog_help_image"</code>).
	 * 
	 * @since 3.2
	 */
	public static final String DLG_IMG_HELP = "dialog_help_image"; //$NON-NLS-1$

	/**
	 * The ellipsis is the string that is used to represent shortened text.
	 * 
	 * @since 3.0
	 */
	public static final String ELLIPSIS = "..."; //$NON-NLS-1$

	/**
	 * The dialog settings key name for stored dialog x location.
	 * 
	 * @since 3.2
	 */
	private static final String DIALOG_ORIGIN_X = "DIALOG_X_ORIGIN"; //$NON-NLS-1$

	/**
	 * The dialog settings key name for stored dialog y location.
	 * 
	 * @since 3.2
	 */
	private static final String DIALOG_ORIGIN_Y = "DIALOG_Y_ORIGIN"; //$NON-NLS-1$

	/**
	 * The dialog settings key name for stored dialog width.
	 * 
	 * @since 3.2
	 */
	private static final String DIALOG_WIDTH = "DIALOG_WIDTH"; //$NON-NLS-1$

	/**
	 * The dialog settings key name for stored dialog height.
	 * 
	 * @since 3.2
	 */
	private static final String DIALOG_HEIGHT = "DIALOG_HEIGHT"; //$NON-NLS-1$
	
	/**
	 * The dialog settings key name for the font used when the dialog
	 * height and width was stored.
	 *
	 *@since 3.2
	 */
	private static final String DIALOG_FONT_DATA = "DIALOG_FONT_NAME"; //$NON-NLS-1$
	
	/**
	 * A value that can be used for stored dialog width or height that
	 * indicates that the default bounds should be used.
	 * 
	 * @since 3.2
	 */
	public static final int DIALOG_DEFAULT_BOUNDS = -1;

	/**
	 * Constants that can be used for specifying the strategy for persisting
	 * dialog bounds.  These constants represent bit masks that can be used
	 * together.
	 *
	 *@since 3.2
	 */
	
	/**
	 * Persist the last location of the dialog.
	 * @since 3.2
	 */
	public static final int DIALOG_PERSISTLOCATION = 0x0001;
	/**
	 * Persist the last known size of the dialog.
	 * @since 3.2
	 */
	public static final int DIALOG_PERSISTSIZE = 0x0002;
	

	/**
	 * NOTE: Dialog does not the following images in the registry DLG_IMG_ERROR
	 * DLG_IMG_INFO DLG_IMG_QUESTION DLG_IMG_WARNING
	 * 
	 * They are now coming directly from SWT see ImageRegistry. For backwards
	 * compatibility they are still supported, however new code should use SWT
	 * for these.
	 * 
	 * @see Display#getSystemIcon(int ID)
	 */
	static {
		ImageRegistry reg = JFaceResources.getImageRegistry();
		reg.put(DLG_IMG_MESSAGE_INFO, ImageDescriptor.createFromFile(
				Dialog.class, "images/message_info.gif")); //$NON-NLS-1$
		reg.put(DLG_IMG_MESSAGE_WARNING, ImageDescriptor.createFromFile(
				Dialog.class, "images/message_warning.gif")); //$NON-NLS-1$
		reg.put(DLG_IMG_MESSAGE_ERROR, ImageDescriptor.createFromFile(
				Dialog.class, "images/message_error.gif")); //$NON-NLS-1$
	}

	/**
	 * The dialog area; <code>null</code> until dialog is layed out.
	 */
	protected Control dialogArea;

	/**
	 * The button bar; <code>null</code> until dialog is layed out.
	 */
	public Control buttonBar;
	
	/**
	 * A mouse listener that can be used to restore the default size
	 * of a dialog.  
	 * 
	 * @since 3.2
	 */
	private MouseListener restoreSizeMouseListener = new MouseAdapter() {
		public void mouseDoubleClick(MouseEvent event) {
			restoreDialogToComputedSize();
		}
	};

	/**
	 * Collection of buttons created by the <code>createButton</code> method.
	 */
	private HashMap buttons = new HashMap();

	/**
	 * Font metrics to use for determining pixel sizes.
	 */
	private FontMetrics fontMetrics;
	
	/**
	 * Point used for storing initial computed size of the dialog so
	 * that it may be restored.
	 */
	private Point computedSize;

	/**
	 * Number of horizontal dialog units per character, value <code>4</code>.
	 */
	private static final int HORIZONTAL_DIALOG_UNIT_PER_CHAR = 4;

	/**
	 * Number of vertical dialog units per character, value <code>8</code>.
	 */
	private static final int VERTICAL_DIALOG_UNITS_PER_CHAR = 8;

	/**
	 * Returns the number of pixels corresponding to the height of the given
	 * number of characters.
	 * <p>
	 * The required <code>FontMetrics</code> parameter may be created in the
	 * following way: <code>
	 * 	GC gc = new GC(control);
	 *	gc.setFont(control.getFont());
	 *	fontMetrics = gc.getFontMetrics();
	 *	gc.dispose();
	 * </code>
	 * </p>
	 * 
	 * @param fontMetrics
	 *            used in performing the conversion
	 * @param chars
	 *            the number of characters
	 * @return the number of pixels
	 * @since 2.0
	 */
	public static int convertHeightInCharsToPixels(FontMetrics fontMetrics,
			int chars) {
		return fontMetrics.getHeight() * chars;
	}

	/**
	 * Returns the number of pixels corresponding to the given number of
	 * horizontal dialog units.
	 * <p>
	 * The required <code>FontMetrics</code> parameter may be created in the
	 * following way: <code>
	 * 	GC gc = new GC(control);
	 *	gc.setFont(control.getFont());
	 *	fontMetrics = gc.getFontMetrics();
	 *	gc.dispose();
	 * </code>
	 * </p>
	 * 
	 * @param fontMetrics
	 *            used in performing the conversion
	 * @param dlus
	 *            the number of horizontal dialog units
	 * @return the number of pixels
	 * @since 2.0
	 */
	public static int convertHorizontalDLUsToPixels(FontMetrics fontMetrics,
			int dlus) {
		// round to the nearest pixel
		return (fontMetrics.getAverageCharWidth() * dlus + HORIZONTAL_DIALOG_UNIT_PER_CHAR / 2)
				/ HORIZONTAL_DIALOG_UNIT_PER_CHAR;
	}

	/**
	 * Returns the number of pixels corresponding to the given number of
	 * vertical dialog units.
	 * <p>
	 * The required <code>FontMetrics</code> parameter may be created in the
	 * following way: <code>
	 * 	GC gc = new GC(control);
	 *	gc.setFont(control.getFont());
	 *	fontMetrics = gc.getFontMetrics();
	 *	gc.dispose();
	 * </code>
	 * </p>
	 * 
	 * @param fontMetrics
	 *            used in performing the conversion
	 * @param dlus
	 *            the number of vertical dialog units
	 * @return the number of pixels
	 * @since 2.0
	 */
	public static int convertVerticalDLUsToPixels(FontMetrics fontMetrics,
			int dlus) {
		// round to the nearest pixel
		return (fontMetrics.getHeight() * dlus + VERTICAL_DIALOG_UNITS_PER_CHAR / 2)
				/ VERTICAL_DIALOG_UNITS_PER_CHAR;
	}

	/**
	 * Returns the number of pixels corresponding to the width of the given
	 * number of characters.
	 * <p>
	 * The required <code>FontMetrics</code> parameter may be created in the
	 * following way: <code>
	 * 	GC gc = new GC(control);
	 *	gc.setFont(control.getFont());
	 *	fontMetrics = gc.getFontMetrics();
	 *	gc.dispose();
	 * </code>
	 * </p>
	 * 
	 * @param fontMetrics
	 *            used in performing the conversion
	 * @param chars
	 *            the number of characters
	 * @return the number of pixels
	 * @since 2.0
	 */
	public static int convertWidthInCharsToPixels(FontMetrics fontMetrics,
			int chars) {
		return fontMetrics.getAverageCharWidth() * chars;
	}

	/**
	 * Shortens the given text <code>textValue</code> so that its width in
	 * pixels does not exceed the width of the given control. Overrides
	 * characters in the center of the original string with an ellipsis ("...")
	 * if necessary. If a <code>null</code> value is given, <code>null</code>
	 * is returned.
	 * 
	 * @param textValue
	 *            the original string or <code>null</code>
	 * @param control
	 *            the control the string will be displayed on
	 * @return the string to display, or <code>null</code> if null was passed
	 *         in
	 * 
	 * @since 3.0
	 */
	public static String shortenText(String textValue, Control control) {
		if (textValue == null) {
			return null;
		}
		GC gc = new GC(control);
		int maxWidth = control.getBounds().width - 5;
		if (gc.textExtent(textValue).x < maxWidth) {
			gc.dispose();
			return textValue;
		}
		int length = textValue.length();
		int pivot = length / 2;
		int start = pivot;
		int end = pivot + 1;
		while (start >= 0 && end < length) {
			String s1 = textValue.substring(0, start);
			String s2 = textValue.substring(end, length);
			String s = s1 + ELLIPSIS + s2;
			int l = gc.textExtent(s).x;
			if (l < maxWidth) {
				gc.dispose();
				return s;
			}
			start--;
			end++;
		}
		gc.dispose();
		return textValue;
	}

	/**
	 * Create a default instance of the blocked handler which does not do
	 * anything.
	 */
	public static IDialogBlockedHandler blockedHandler = new IDialogBlockedHandler() {
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.jface.dialogs.IDialogBlockedHandler#clearBlocked()
		 */
		public void clearBlocked() {
			// No default behaviour
		}

		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.jface.dialogs.IDialogBlockedHandler#showBlocked(org.eclipse.core.runtime.IProgressMonitor,
		 *      org.eclipse.core.runtime.IStatus, java.lang.String)
		 */
		public void showBlocked(IProgressMonitor blocking,
				IStatus blockingStatus, String blockedName) {
			// No default behaviour
		}

		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.jface.dialogs.IDialogBlockedHandler#showBlocked(org.eclipse.swt.widgets.Shell,
		 *      org.eclipse.core.runtime.IProgressMonitor,
		 *      org.eclipse.core.runtime.IStatus, java.lang.String)
		 */
		public void showBlocked(Shell parentShell, IProgressMonitor blocking,
				IStatus blockingStatus, String blockedName) {
			// No default behaviour
		}
	};

	/**
	 * Creates a dialog instance. Note that the window will have no visual
	 * representation (no widgets) until it is told to open. By default,
	 * <code>open</code> blocks for dialogs.
	 * 
	 * @param parentShell
	 *            the parent shell, or <code>null</code> to create a top-level
	 *            shell
	 */
	protected Dialog(Shell parentShell) {
		this(new SameShellProvider(parentShell));
		if (parentShell == null && Policy.DEBUG_DIALOG_NO_PARENT) {
			Policy.getLog().log(
					new Status(IStatus.INFO, Policy.JFACE, IStatus.INFO, this
							.getClass()
							+ " created with no shell",//$NON-NLS-1$
							new Exception()));
		}
	}

	/**
	 * Creates a dialog with the given parent.