Java tutorial
/******************************************************************************* * Copyright (c) 2006, 2015 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation * Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation * bugfix in: 195137, 198089 * Fredy Dobler <fredy@dobler.net> - bug 159600 * Brock Janiczak <brockj@tpg.com.au> - bug 182443 *******************************************************************************/ package org.eclipse.jface.viewers; import org.eclipse.jface.util.Policy; import org.eclipse.jface.window.DefaultToolTip; import org.eclipse.jface.window.ToolTip; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Event; /** * The ColumnViewerTooltipSupport is the class that provides tool tips for * ColumnViewers. * * @since 3.3 * */ public class ColumnViewerToolTipSupport extends DefaultToolTip { private ColumnViewer viewer; private static final String VIEWER_CELL_KEY = Policy.JFACE + "_VIEWER_CELL_KEY"; //$NON-NLS-1$ private static final int DEFAULT_SHIFT_X = 10; private static final int DEFAULT_SHIFT_Y = 0; /** * Enable ToolTip support for the viewer by creating an instance from this * class. To get all necessary informations this support class consults the * {@link CellLabelProvider}. * * @param viewer * the viewer the support is attached to * @param style * style passed to control tool tip behavior * * @param manualActivation * <code>true</code> if the activation is done manually using * {@link #show(Point)} */ protected ColumnViewerToolTipSupport(ColumnViewer viewer, int style, boolean manualActivation) { super(viewer.getControl(), style, manualActivation); this.viewer = viewer; } /** * Enable ToolTip support for the viewer by creating an instance from this * class. To get all necessary informations this support class consults the * {@link CellLabelProvider}. * * @param viewer * the viewer the support is attached to */ public static void enableFor(ColumnViewer viewer) { new ColumnViewerToolTipSupport(viewer, ToolTip.NO_RECREATE, false); } /** * Enable ToolTip support for the viewer by creating an instance from this * class. To get all necessary informations this support class consults the * {@link CellLabelProvider}. * * @param viewer * the viewer the support is attached to * @param style * style passed to control tool tip behavior * * @see ToolTip#RECREATE * @see ToolTip#NO_RECREATE */ public static void enableFor(ColumnViewer viewer, int style) { new ColumnViewerToolTipSupport(viewer, style, false); } @Override protected Object getToolTipArea(Event event) { return viewer.getCell(new Point(event.x, event.y)); } /** * Instead of overwriting this method subclasses should overwrite * {@link #createViewerToolTipContentArea(Event, ViewerCell, Composite)} */ @Override protected Composite createToolTipContentArea(Event event, Composite parent) { ViewerCell cell = (ViewerCell) getData(VIEWER_CELL_KEY); setData(VIEWER_CELL_KEY, null); return createViewerToolTipContentArea(event, cell, parent); } /** * Creates the content area of the tool tip giving access to the cell the * tip is shown for. Subclasses can overload this method to implement their * own tool tip design. * * <p> * This method is called from * {@link #createToolTipContentArea(Event, Composite)} and by default calls * the {@link DefaultToolTip#createToolTipContentArea(Event, Composite)}. * </p> * * @param event * the event that which * @param cell * the cell the tool tip is shown for * @param parent * the parent of the control to create * @return the control to be displayed in the tool tip area * @since 3.4 */ protected Composite createViewerToolTipContentArea(Event event, ViewerCell cell, Composite parent) { return super.createToolTipContentArea(event, parent); } @Override protected boolean shouldCreateToolTip(Event event) { if (!super.shouldCreateToolTip(event)) { return false; } boolean rv = false; ViewerRow row = viewer.getViewerRow(new Point(event.x, event.y)); viewer.getControl().setToolTipText(""); //$NON-NLS-1$ Point point = new Point(event.x, event.y); if (row != null) { Object element = row.getItem().getData(); ViewerCell cell = row.getCell(point); if (cell == null) { return false; } ViewerColumn viewPart = viewer.getViewerColumn(cell.getColumnIndex()); if (viewPart == null) { return false; } CellLabelProvider labelProvider = viewPart.getLabelProvider(); boolean useNative = labelProvider.useNativeToolTip(element); String text = labelProvider.getToolTipText(element); Image img = null; if (!useNative) { img = labelProvider.getToolTipImage(element); } if (useNative || (text == null && img == null)) { viewer.getControl().setToolTipText(text); rv = false; } else { setPopupDelay(labelProvider.getToolTipDisplayDelayTime(element)); setHideDelay(labelProvider.getToolTipTimeDisplayed(element)); Point shift = labelProvider.getToolTipShift(element); if (shift == null) { setShift(new Point(DEFAULT_SHIFT_X, DEFAULT_SHIFT_Y)); } else { setShift(new Point(shift.x, shift.y)); } setData(VIEWER_CELL_KEY, cell); setText(text); setImage(img); setStyle(labelProvider.getToolTipStyle(element)); setForegroundColor(labelProvider.getToolTipForegroundColor(element)); setBackgroundColor(labelProvider.getToolTipBackgroundColor(element)); setFont(labelProvider.getToolTipFont(element)); // Check if at least one of the values is set rv = getText(event) != null || getImage(event) != null; } } return rv; } @Override protected void afterHideToolTip(Event event) { super.afterHideToolTip(event); // Clear the restored value else this could be a source of a leak setData(VIEWER_CELL_KEY, null); if (event != null && event.widget != viewer.getControl()) { viewer.getControl().setFocus(); } } }