Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2015 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 * Mark Siegel <mark.siegel@businessobjects.com> - Fix for Bug 184533 * [Progress] ProgressIndicator uses hardcoded style for ProgressBar *******************************************************************************/ package org.eclipse.jface.dialogs; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.StackLayout; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.ProgressBar; /** * A control for showing progress feedback for a long running operation. This * control supports both determinate and indeterminate SWT progress bars. For * indeterminate progress, we don't have to know the total amount of work in * advance and no <code>worked</code> method needs to be called. */ public class ProgressIndicator extends Composite { private final static int PROGRESS_MAX = 1000; // value to use for max in // progress bar private boolean animated = true; private StackLayout layout; private ProgressBar determinateProgressBar; private ProgressBar indeterminateProgressBar; private double totalWork; private double sumWorked; /** * Create a ProgressIndicator as a child under the given parent. * * @param parent * The widgets parent */ public ProgressIndicator(Composite parent) { this(parent, SWT.NONE); } /** * Create a ProgressIndicator as a child under the given parent. * * @param parent * The widgets parent * @param style the SWT style constants for progress monitors created * by the receiver. * @since 3.4 */ public ProgressIndicator(Composite parent, int style) { super(parent, SWT.NULL); // Enforce horizontal only if vertical isn't set if ((style & SWT.VERTICAL) == 0) style |= SWT.HORIZONTAL; determinateProgressBar = new ProgressBar(this, style); indeterminateProgressBar = new ProgressBar(this, style | SWT.INDETERMINATE); layout = new StackLayout(); setLayout(layout); } /** * Initialize the progress bar to be animated. */ public void beginAnimatedTask() { done(); layout.topControl = indeterminateProgressBar; layout(); animated = true; } /** * Initialize the progress bar. * * @param max * The maximum value. */ public void beginTask(int max) { done(); this.totalWork = max; this.sumWorked = 0; determinateProgressBar.setMinimum(0); determinateProgressBar.setMaximum(PROGRESS_MAX); determinateProgressBar.setSelection(0); layout.topControl = determinateProgressBar; layout(); animated = false; } /** * Progress is done. */ public void done() { if (!animated) { determinateProgressBar.setMinimum(0); determinateProgressBar.setMaximum(0); determinateProgressBar.setSelection(0); } layout.topControl = null; layout(); } /** * Moves the progress indicator to the end. */ public void sendRemainingWork() { worked(totalWork - sumWorked); } /** * Moves the progress indicator by the given amount of work units * @param work the amount of work to increment by. */ public void worked(double work) { if (work == 0 || animated) { return; } sumWorked += work; if (sumWorked > totalWork) { sumWorked = totalWork; } if (sumWorked < 0) { sumWorked = 0; } int value = (int) (sumWorked / totalWork * PROGRESS_MAX); if (determinateProgressBar.getSelection() < value) { determinateProgressBar.setSelection(value); } } /** * Show the receiver as showing an error. * @since 3.4 */ public void showError() { determinateProgressBar.setState(SWT.ERROR); indeterminateProgressBar.setState(SWT.ERROR); } /** * Show the receiver as being paused. * @since 3.4 */ public void showPaused() { determinateProgressBar.setState(SWT.PAUSED); indeterminateProgressBar.setState(SWT.PAUSED); } /** * Reset the progress bar to it's normal style. * @since 3.4 */ public void showNormal() { determinateProgressBar.setState(SWT.NORMAL); indeterminateProgressBar.setState(SWT.NORMAL); } }