SubModuleToolTip.java

/*******************************************************************************
 * Copyright (c) 2007, 2014 compeople AG 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:
 *    compeople AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.riena.ui.swt.facades.internal;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

import org.eclipse.riena.ui.swt.lnf.LnfKeyConstants;
import org.eclipse.riena.ui.swt.lnf.rienadefault.RienaDefaultLnf;

/**
 * ToolTip for the tree items in the tree of the sub-modules. ToolTip is only
 * displayed if the text of the tree item was clipped or the navigation node of
 * the sub-module has a tool tip.
 */
public class SubModuleToolTip extends AbstractNavigationToolTip {

	private final Tree tree;
	private final ILabelProvider labelProvider;

	/**
	 * Creates new instance which add TooltipSupport to the tree. ToolTip is
	 * only displayed if the text of the tree item was clipped.
	 * 
	 * @param parent
	 *            the tree on whose action the tooltip is shown
	 * @param labelProvider
	 *            an {@link ILabelProvider} instance; never null. It has to
	 *            return the text for the tooltip, presumably based on the
	 *            corresponding sub-module navigation node.
	 */
	public SubModuleToolTip(final Tree parent, final ILabelProvider labelProvider) {
		super(parent);
		this.tree = parent;
		Assert.isNotNull(labelProvider);
		this.labelProvider = labelProvider;
		setShift(new Point(0, 0));
	}

	@Override
	public Point getLocation(final Point tipSize, final Event event) {
		Point location = super.getLocation(tipSize, event);
		final TreeItem item = getTreeItem(event);
		if (item != null) {
			location = tree.toDisplay(item.getBounds().x, item.getBounds().y);
		}

		return location;
	}

	// protected methods
	////////////////////

	@Override
	protected boolean shouldCreateToolTip(final Event event) {
		boolean should = super.shouldCreateToolTip(event);

		if (should) {
			final String text = getItemText(event);
			final String longText = getItemLongText(event);
			should = !text.equals(longText);
		}

		return should;
	}

	@Override
	protected String getToolTipText(final Event event) {
		return getItemLongText(event);
	}

	@Override
	protected Integer getLnfDelay(final RienaDefaultLnf lnf) {
		return lnf.getIntegerSetting(LnfKeyConstants.SUB_MODULE_ITEM_TOOLTIP_POPUP_DELAY);
	}

	@Override
	protected Font getLnfFont(final RienaDefaultLnf lnf) {
		return lnf.getFont(LnfKeyConstants.SUB_MODULE_ITEM_TOOLTIP_FONT);
	}

	@Override
	protected Color getLnfBackground(final RienaDefaultLnf lnf) {
		return lnf.getColor(LnfKeyConstants.SUB_MODULE_ITEM_TOOLTIP_BACKGROUND);
	}

	@Override
	protected Color getLnfForeground(final RienaDefaultLnf lnf) {
		return lnf.getColor(LnfKeyConstants.SUB_MODULE_ITEM_TOOLTIP_FOREGROUND);
	}

	// helping methods
	//////////////////

	/**
	 * Returns original (not clipped) text of the item at the given point (
	 * <code>event.x</code> and <code>event.x</code>) or null if no such item
	 * exists.
	 * 
	 * @param event
	 *            event with the x- and y-position of the mouse pointer
	 * @return original (not clipped) item text
	 */
	private String getItemLongText(final Event event) {
		String result = ""; //$NON-NLS-1$
		final TreeItem item = getTreeItem(event);
		if (item != null) {
			final Object element = item.getData();
			result = labelProvider.getText(element);
		}
		return result;
	}

	/**
	 * Returns text of the item at the given point (<code>event.x</code> and
	 * <code>event.x</code>) or null if no such item exists.
	 * 
	 * @param event
	 *            event with the x- and y-position of the mouse pointer
	 * @return item text
	 */
	private String getItemText(final Event event) {
		String text = ""; //$NON-NLS-1$
		final TreeItem item = getTreeItem(event);
		if (item != null) {
			text = item.getText();
		}
		return text;
	}

	/**
	 * Returns the item at the given point (<code>event.x</code> and
	 * <code>event.x</code>) or null if no such item exists.
	 * 
	 * @param event
	 *            event with the x- and y-position of the mouse pointer
	 * @return the item at the given point, or null if the point is not in a
	 *         selectable item
	 */
	private TreeItem getTreeItem(final Event event) {
		final Point point = new Point(event.x, event.y);
		return tree.getItem(point);
	}

}