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 *******************************************************************************/ package org.eclipse.jface.action; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.core.runtime.IProgressMonitorWithBlocking; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.NullProgressMonitor; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; /** * A status line manager is a contribution manager which realizes itself and its items * in a status line control. * <p> * This class may be instantiated; it may also be subclassed if a more * sophisticated layout is required. * </p> */ public class StatusLineManager extends ContributionManager implements IStatusLineManager { /** * Identifier of group marker used to position contributions at the beginning * of the status line. * * @since 3.0 */ public static final String BEGIN_GROUP = "BEGIN_GROUP"; //$NON-NLS-1$ /** * Identifier of group marker used to position contributions in the middle * of the status line. * * @since 3.0 */ public static final String MIDDLE_GROUP = "MIDDLE_GROUP"; //$NON-NLS-1$ /** * Identifier of group marker used to position contributions at the end * of the status line. * * @since 3.0 */ public static final String END_GROUP = "END_GROUP"; //$NON-NLS-1$ /** * The status line control; <code>null</code> before * creation and after disposal. */ private Composite statusLine = null; /** * Creates a new status line manager. * Use the <code>createControl</code> method to create the * status line control. */ public StatusLineManager() { add(new GroupMarker(BEGIN_GROUP)); add(new GroupMarker(MIDDLE_GROUP)); add(new GroupMarker(END_GROUP)); } /** * Creates and returns this manager's status line control. * Does not create a new control if one already exists. * <p> * Note: Since 3.0 the return type is <code>Control</code>. Before 3.0, the return type was * the package-private class <code>StatusLine</code>. * </p> * * @param parent the parent control * @return the status line control */ public Control createControl(Composite parent) { return createControl(parent, SWT.NONE); } /** * Creates and returns this manager's status line control. * Does not create a new control if one already exists. * * @param parent the parent control * @param style the style for the control * @return the status line control * @since 3.0 */ public Control createControl(Composite parent, int style) { if (!statusLineExist() && parent != null) { statusLine = new StatusLine(parent, style); update(false); } return statusLine; } /** * Disposes of this status line manager and frees all allocated SWT resources. * Notifies all contribution items of the dispose. Note that this method does * not clean up references between this status line manager and its associated * contribution items. Use <code>removeAll</code> for that purpose. */ public void dispose() { if (statusLineExist()) { statusLine.dispose(); } statusLine = null; IContributionItem items[] = getItems(); for (int i = 0; i < items.length; i++) { items[i].dispose(); } } /** * Returns the control used by this StatusLineManager. * * @return the control used by this manager */ public Control getControl() { return statusLine; } /** * Returns the progress monitor delegate. Override this method * to provide your own object used to handle progress. * * @return the IProgressMonitor delegate * @since 3.0 */ protected IProgressMonitor getProgressMonitorDelegate() { return (IProgressMonitor) getControl(); } @Override public IProgressMonitor getProgressMonitor() { final IProgressMonitor progressDelegate = statusLineExist() ? getProgressMonitorDelegate() : new NullProgressMonitor(); return new IProgressMonitorWithBlocking() { @Override public void beginTask(String name, int totalWork) { progressDelegate.beginTask(name, totalWork); } @Override public void done() { progressDelegate.done(); } @Override public void internalWorked(double work) { progressDelegate.internalWorked(work); } @Override public boolean isCanceled() { return progressDelegate.isCanceled(); } @Override public void setCanceled(boolean value) { //Don't bother updating for disposed status if (statusLineExist()) { progressDelegate.setCanceled(value); } } @Override public void setTaskName(String name) { progressDelegate.setTaskName(name); } @Override public void subTask(String name) { progressDelegate.subTask(name); } @Override public void worked(int work) { progressDelegate.worked(work); } @Override public void clearBlocked() { //Do nothing here as we let the modal context handle it } @Override public void setBlocked(IStatus reason) { // Do nothing here as we let the modal context handle it } }; } @Override public boolean isCancelEnabled() { return statusLineExist() && ((StatusLine) statusLine).isCancelEnabled(); } @Override public void setCancelEnabled(boolean enabled) { if (statusLineExist()) { ((StatusLine) statusLine).setCancelEnabled(enabled); } } @Override public void setErrorMessage(String message) { if (statusLineExist()) { ((StatusLine) statusLine).setErrorMessage(message); } } @Override public void setErrorMessage(Image image, String message) { if (statusLineExist()) { ((StatusLine) statusLine).setErrorMessage(image, message); } } @Override public void setMessage(String message) { if (statusLineExist()) { ((StatusLine) statusLine).setMessage(message); } } @Override public void setMessage(Image image, String message) { if (statusLineExist()) { ((StatusLine) statusLine).setMessage(image, message); } } /** * Returns whether the status line control is created * and not disposed. * * @return <code>true</code> if the control is created * and not disposed, <code>false</code> otherwise */ private boolean statusLineExist() { return statusLine != null && !statusLine.isDisposed(); } @Override public void update(boolean force) { //boolean DEBUG= false; if (isDirty() || force) { if (statusLineExist()) { statusLine.setRedraw(false); // NOTE: the update algorithm is non-incremental. // An incremental algorithm requires that SWT items can be created in the middle of the list // but the ContributionItem.fill(Composite) method used here does not take an index, so this // is not possible. Control ws[] = statusLine.getChildren(); for (int i = 0; i < ws.length; i++) { Control w = ws[i]; Object data = w.getData(); if (data instanceof IContributionItem) { w.dispose(); } } int oldChildCount = statusLine.getChildren().length; IContributionItem[] items = getItems(); for (int i = 0; i < items.length; ++i) { IContributionItem ci = items[i]; if (ci.isVisible()) { ci.fill(statusLine); // associate controls with contribution item Control[] newChildren = statusLine.getChildren(); for (int j = oldChildCount; j < newChildren.length; j++) { newChildren[j].setData(ci); } oldChildCount = newChildren.length; } } setDirty(false); statusLine.layout(); statusLine.setRedraw(true); } } } }