bundles/org.eclipse.jface/src/org/eclipse/jface/action/StatusLineManager.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are 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
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.action;

import java.util.HashMap;

import org.eclipse.core.runtime.IProgressMonitor;
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 {

	/**
	 * The status line control; <code>null</code> before
	 * creation and after disposal.
	 */
	private StatusLine statusLine = null;
/**
 * Creates a new status line manager.
 * Use the <code>createControl</code> method to create the 
 * status line control.
 */
public StatusLineManager() {
}
/**
 * Creates and returns this manager's status line control. 
 * Does not create a new control if one already exists.
 *
 * @param parent the parent control
 * @return the status line control
 */
public StatusLine createControl(Composite parent) {
	if (!statusLineExist() && parent != null) {
		statusLine= new StatusLine(parent);
		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();
	}
}
/**
 * Internal -- returns the StatusLine control.
 * <p>
 * This method is not intended to be used outside of the JFace framework.
 * </p>
 */
public Control getControl() {
	return statusLine;
}
/*
 * (non-Javadoc)
 * Method declared on IStatusLineManager
 */
public IProgressMonitor getProgressMonitor() {
	return statusLine;
}
/* (non-Javadoc)
 * Method declared on IStatueLineManager
 */
public boolean isCancelEnabled() {
	return statusLineExist() && statusLine.isCancelEnabled();
}
/* (non-Javadoc)
 * Method declared on IStatueLineManager
 */
public void setCancelEnabled(boolean enabled) {
	if (statusLineExist())
		statusLine.setCancelEnabled(enabled);
}
/* (non-Javadoc)
 * Method declared on IStatusLineManager.
 */
public void setErrorMessage(String message) {
	if (statusLineExist())
		statusLine.setErrorMessage(message);
}
/* (non-Javadoc)
 * Method declared on IStatusLineManager.
 */
public void setErrorMessage(Image image, String message) {
	if (statusLineExist())
		statusLine.setErrorMessage(image, message);
}
/* (non-Javadoc)
 * Method declared on IStatusLineManager.
 */
public void setMessage(String message) {
	if (statusLineExist())
		statusLine.setMessage(message);
}
/* (non-Javadoc)
 * Method declared on IStatusLineManager.
 */
public void setMessage(Image image, String message) {
	if (statusLineExist())
		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(); 
}
/* (non-Javadoc)
 * Method declared on IContributionManager.
 */
public void update(boolean force) {
	
	//boolean DEBUG= false;
	
	if (isDirty() || force) {
		
		if (statusLineExist()) {
			statusLine.setRedraw(false);
	
//			if (DEBUG) System.out.println("update:");
			if (false) {	// non-incremental update
				Control ws[]= statusLine.getChildren();
				for (int i= 0; i < ws.length; i++) {
					Control w= ws[i];
					Object data= w.getData();
					if (data instanceof IContributionItem) {
//						if (DEBUG) System.out.println("  disposing item: " + data);
						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);
//						if (DEBUG) System.out.println("  added item: " + ci);
						// associate controls with contribution item
						Control[] newChildren = statusLine.getChildren();
						for (int j = oldChildCount; j < newChildren.length; j++) {
							newChildren[j].setData(ci);
						}
						oldChildCount = newChildren.length;							
					}
				}
				
			} else {	// incremental update
				// copy all active items into set
				IContributionItem[] items= getItems();
				HashMap ht= new HashMap(items.length*2);
				for (int i = 0; i < items.length; ++i) {
					IContributionItem ci= items[i];
					if (ci.isVisible())
						ht.put(ci, ci);
				}
				// remove obsolete (removed or non active)
				Control ws[]= statusLine.getChildren();
				for (int i= 0; i < ws.length; i++) {
					Object data= ws[i].getData();
					if (data instanceof IContributionItem) {
						IContributionItem item= (IContributionItem) data;
						if (ht.get(item) == null) {	// not found
						//	if (DEBUG) System.out.println("  disposing item: " + data);
							ws[i].dispose();
						}
					}
				}
				// add new
				IContributionItem src, dest;
				ws= statusLine.getChildren();
				
				// scrIx is used to skip over the standard status line widgets
				// (label, stop button and progress bar). There is thus a dependency
				// between this code and the creation and layout of the standard widgets
				// in the StatusLine constructor and in StatusLineLayout.layout
				
				int srcIx= 3;
				int destIx= 0;
				int oldChildCount = ws.length;
				Control previousControl = ws[srcIx - 1];
				
				for (int i = 0; i < items.length; ++i) {
					src= (IContributionItem) items[i];
					
					// if not active skip this one
					if (!src.isVisible())
						continue;	// we don't bounce the destIx!
						
					// get corresponding item in SWT widget
					if (srcIx < ws.length)
						dest= (IContributionItem) ws[srcIx].getData();
					else
						dest= null;
						
					if (dest != null && src.equals(dest)) {	// no change
						//if (DEBUG) System.out.println("  no change: ");
						previousControl = ws[srcIx];
						srcIx++;
					} else {
						// src is a new one: insert it at next position
						src.fill(statusLine);
					//	if (DEBUG) System.out.println("  added at " + destIx + ": ");
						// associate controls with contribution item
						Control[] newChildren = statusLine.getChildren();
						for (int j = oldChildCount; j < newChildren.length; j++) {
							newChildren[j].setData(src);
							// To keep the Control order the same as the contribution item
							// otherwise, if a contribution item in the middle becomes visible
							// the control will appear at the end.
							newChildren[j].moveBelow(previousControl);
							previousControl = newChildren[j];
						}
						oldChildCount = newChildren.length;
					}
					destIx++;
				}
				
				// remove any old status line items not accounted for
				for (; srcIx < ws.length; srcIx++) {
					ws[srcIx].dispose();
				}
			}
			setDirty(false);
			
			statusLine.layout();
			statusLine.setRedraw(true);
		}
	}
}
}