Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2010 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 * Code Orchestra Limited - added image support *******************************************************************************/ package codeOrchestra.lcs.status; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.action.ContributionItem; import org.eclipse.jface.action.IContributionManager; import org.eclipse.jface.action.LegacyActionTools; import org.eclipse.jface.action.StatusLineLayoutData; import org.eclipse.jface.util.Util; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.CLabel; import org.eclipse.swt.events.MouseListener; 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.widgets.Composite; import org.eclipse.swt.widgets.Label; /** * A contribution item to be used with status line managers. * <p> * This class may be instantiated; it is not intended to be subclassed. * </p> * * @since 3.4 */ public class StatusLineContributionItemEx extends ContributionItem { private final static int DEFAULT_CHAR_WIDTH = 40; /** * A constant indicating that the contribution should compute its actual size * depending on the text. It will grab all space necessary to display the * whole text. * * @since 3.6 */ public final static int CALC_TRUE_WIDTH = -1; private int charWidth; private CLabel label; /** * The composite into which this contribution item has been placed. This will * be <code>null</code> if this instance has not yet been initialized. */ private Composite statusLine = null; private String text = Util.ZERO_LENGTH_STRING; private int widthHint = -1; private int heightHint = -1; private Image image; private MouseListener mouseListener; /** * Creates a status line contribution item with the given id. * * @param id * the contribution item's id, or <code>null</code> if it is to have * no id */ public StatusLineContributionItemEx(String id) { this(id, DEFAULT_CHAR_WIDTH); } /** * Creates a status line contribution item with the given id that displays the * given number of characters. * * @param id * the contribution item's id, or <code>null</code> if it is to have * no id * @param charWidth * the number of characters to display. If the value is * CALC_TRUE_WIDTH then the contribution will compute the preferred * size exactly. Otherwise the size will be based on the average * character size * 'charWidth' */ public StatusLineContributionItemEx(String id, int charWidth) { super(id); this.charWidth = charWidth; setVisible(false); // no text to start with } public void setMouseListener(MouseListener mouseListener) { this.mouseListener = mouseListener; } public CLabel getLabel() { return label; } public void fill(Composite parent) { statusLine = parent; Label sep = new Label(parent, SWT.SEPARATOR); label = new CLabel(statusLine, SWT.SHADOW_NONE); label.setText(text); label.setImage(image); if (mouseListener != null) { label.addMouseListener(mouseListener); } if (charWidth == CALC_TRUE_WIDTH) { // compute the size of the label to get the width hint for the // contribution Point preferredSize = label.computeSize(SWT.DEFAULT, SWT.DEFAULT); widthHint = preferredSize.x; heightHint = preferredSize.y; } else if (widthHint < 0) { // Compute the size base on 'charWidth' average char widths GC gc = new GC(statusLine); gc.setFont(statusLine.getFont()); FontMetrics fm = gc.getFontMetrics(); widthHint = fm.getAverageCharWidth() * charWidth; heightHint = fm.getHeight(); gc.dispose(); } StatusLineLayoutData data = new StatusLineLayoutData(); data.widthHint = widthHint; label.setLayoutData(data); data = new StatusLineLayoutData(); data.heightHint = heightHint; sep.setLayoutData(data); } /** * An accessor for the current location of this status line contribution item * -- relative to the display. * * @return The current location of this status line; <code>null</code> if not * yet initialized. */ public Point getDisplayLocation() { if ((label != null) && (statusLine != null)) { return statusLine.toDisplay(label.getLocation()); } return null; } /** * Retrieves the text that is being displayed in the status line. * * @return the text that is currently being displayed */ public String getText() { return text; } public Image getImage() { return image; } public void setImage(Image image) { this.image = image; if (label != null && !label.isDisposed()) { label.setImage(image); IContributionManager contributionManager = getParent(); if (contributionManager != null) { contributionManager.update(true); } } } /** * Sets the text to be displayed in the status line. * * @param text * the text to be displayed, must not be <code>null</code> */ public void setText(String text) { Assert.isNotNull(text); this.text = LegacyActionTools.escapeMnemonics(text); if (label != null && !label.isDisposed()) { label.setText(this.text); } if (this.text.length() == 0) { if (isVisible()) { setVisible(false); IContributionManager contributionManager = getParent(); if (contributionManager != null) { contributionManager.update(true); } } } else { // Always update if using 'CALC_TRUE_WIDTH' if (!isVisible() || charWidth == CALC_TRUE_WIDTH) { setVisible(true); IContributionManager contributionManager = getParent(); if (contributionManager != null) { contributionManager.update(true); } } } } }