bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ToolTipSupport.java

/*******************************************************************************
 * Copyright (c) 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
 *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 *     Fredy Dobler <fredy@dobler.net> - bug 159600
 ******************************************************************************/

package org.eclipse.jface.viewers;

import java.util.Timer;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;

/**
 * The TooltipSupport is the class that provides tooltips for
 * ColumnViewers.
 * @since 3.3
 * <strong>EXPERIMENTAL</strong> This class or interface has been added as
 * part of a work in progress. This API may change at any given time. Please 
 * do not use this API without consulting with the Platform/UI team.
 *
 */
class ToolTipSupport {
	private ColumnViewer viewer;
	private Listener listener = new MouseListener();
	private static final int DEFAULT_SHIFT_X = 10;
	private static final int DEFAULT_SHIFT_Y = 0;
	
	ToolTipSupport(ColumnViewer viewer) {
		this.viewer = viewer;
	}
	
	/**
	 * activate tooltip support for this viewer
	 */
	public void activate() {
		deactivate();
		viewer.getControl().addListener(SWT.Dispose, listener);
		viewer.getControl().addListener(SWT.MouseHover, listener);
		viewer.getControl().addListener(SWT.MouseMove, listener);
		viewer.getControl().addListener(SWT.MouseExit, listener);
		viewer.getControl().addListener(SWT.MouseDown, listener);
	}
	
	/**
	 * deactivate tooltip support for this viewer
	 */
	public void deactivate() {
		viewer.getControl().removeListener(SWT.Dispose, listener);
		viewer.getControl().removeListener(SWT.MouseHover, listener);
		viewer.getControl().removeListener(SWT.MouseMove, listener);
		viewer.getControl().removeListener(SWT.MouseExit, listener);
		viewer.getControl().removeListener(SWT.MouseDown, listener);
	}
	
	private class MouseListener implements Listener {
		private Shell tip;
		private TooltipHideListener hideListener = new TooltipHideListener();
		private Timer timer = new Timer(true);
		
		/* (non-Javadoc)
		 * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event)
		 */
		public void handleEvent(Event event) {
			switch (event.type) {
			case SWT.Dispose:
				if( timer != null ) {
					timer.cancel();
				}
			case SWT.KeyDown:
			case SWT.MouseMove:
			case SWT.MouseDown:
				disposeTooltip(tip);
				break;
			case SWT.MouseHover:
                if (!(event.widget instanceof Control))
                  break;
                // map receiver-relative coordinates to display-relative coordinates
                ViewerRow row = viewer.getRowPart(((Control) event.widget).toDisplay(
                    event.x, event.y));
                viewer.getControl().setToolTipText(""); //$NON-NLS-1$

                if (row != null)
                {
                  // use receiver-relative coordinates
                  popupTooltip(row, new Point(event.x, event.y));
                }
                break;
			}
		}
		
		/**
		 * Popup a tooltip for the row at Point p.
		 * @param row
		 * @param p
		 */
		private void popupTooltip(ViewerRow row, Point p) {
			Object element = row.getItem().getData();
			disposeTooltip(tip);

			ViewerColumn viewPart = viewer.getViewerColumn(row.getColumnIndex(p));
			
			if( viewPart == null ) {
				return;
			}
			
			CellLabelProvider labelProvider = viewPart.getLabelProvider();
			
			String text = labelProvider.getToolTipText(element);
			
			if( text != null ) {
				
				if( labelProvider.useNativeToolTip(element) ) {
					viewer.getControl().setToolTipText(text);
					return;
				}
				
				tip = new Shell(viewer.getControl().getShell(), SWT.ON_TOP | SWT.TOOL);
				tip.setLayout(new FillLayout());
				CLabel label = new CLabel(tip, labelProvider.getToolTipStyle(element));
				label.setText(text);
				label.addListener(SWT.MouseExit, hideListener);
				label.addListener(SWT.MouseDown, hideListener);
				
				Image img =  labelProvider.getToolTipImage(element);
				
				if( img != null) {
					label.setImage(img);
				}
				
				Color color = labelProvider.getToolTipForegroundColor(element);
				if( color == null ) {
					color = viewer.getControl().getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND);
				}
				label.setForeground(color);
				
				color = labelProvider.getToolTipBackgroundColor(element);
				if( color == null ) {
					color = viewer.getControl().getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND);
				}
				label.setBackground(color);
				
				Font font = labelProvider.getToolTipFont(element);
				
				if( font != null ) {
					label.setFont(font);
				}
				
				Point pt = viewer.getControl().toDisplay(p);
				Point shift = labelProvider.getToolTipShift(element);
				
				if( shift == null ) {
					pt.x += DEFAULT_SHIFT_X;
					pt.y += DEFAULT_SHIFT_Y;
				} else {
					pt.x += shift.x;
					pt.y += shift.y;
				}
				
				tip.pack();
				tip.setLocation(pt);
				tip.setVisible(true);
			}
		}
		
		/**
		 * Dispose the tooltip.
		 * @param tip
		 */
		private void disposeTooltip(Shell tip) {
			if (tip != null && !tip.isDisposed()) {
				tip.dispose();
			}

			tip = null;
		}
	}
	
	/**
	 * TooltipHideListener is a listener for tooltip removal.
	 * @since 3.3
	 *
	 */
	private class TooltipHideListener implements Listener {
		/* (non-Javadoc)
		 * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event)
		 */
		public void handleEvent(Event event) {
			CLabel label = (CLabel) event.widget;
			Shell shell = label.getShell();
			switch (event.type) {
			case SWT.MouseDown:
				viewer.setSelection(new StructuredSelection());
				// fall through
			case SWT.MouseExit:
				viewer.getControl().setFocus();
				shell.dispose();
				break;
			}
		}
	}
}