Java tutorial
/******************************************************************************* * Copyright (c) 2007, 2017 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 * - fix for bug 183850, 182652, 182800, 215069 *******************************************************************************/ package org.eclipse.jface.viewers; import org.eclipse.core.runtime.Assert; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; /** * A concrete implementation of {@link FocusCellHighlighter} using by setting * the control into owner draw mode and highlighting the currently selected * cell. To make the use this class you should create the control with the * {@link SWT#FULL_SELECTION} bit set * * This class can be subclassed to configure how the coloring of the selected * cell. * * @since 3.3 * */ public class FocusCellOwnerDrawHighlighter extends FocusCellHighlighter { private boolean removeNonFocusedSelectionInformation; /** * Create a new instance which can be passed to a * {@link TreeViewerFocusCellManager} * * @param viewer * the viewer */ public FocusCellOwnerDrawHighlighter(ColumnViewer viewer) { this(viewer, true); } /** * Create a new instance which can be passed to a * {@link TreeViewerFocusCellManager} * * @param viewer * the viewer * @param removeNonFocusedSelectionInformation * <code>true</code> if only the currently focused cell should be * indicated as selected. <code>false</code> to indicate both the * full selection and the currently focused cell. * @since 3.14 */ public FocusCellOwnerDrawHighlighter(ColumnViewer viewer, boolean removeNonFocusedSelectionInformation) { super(viewer); this.removeNonFocusedSelectionInformation = removeNonFocusedSelectionInformation; hookListener(viewer); } private void markFocusedCell(Event event, ViewerCell cell) { Color background = (cell.getControl().isFocusControl()) ? getSelectedCellBackgroundColor(cell) : getSelectedCellBackgroundColorNoFocus(cell); Color foreground = (cell.getControl().isFocusControl()) ? getSelectedCellForegroundColor(cell) : getSelectedCellForegroundColorNoFocus(cell); if (foreground != null || background != null || onlyTextHighlighting(cell)) { GC gc = event.gc; if (background == null) { background = cell.getItem().getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION); } if (foreground == null) { foreground = cell.getItem().getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION_TEXT); } gc.setBackground(background); gc.setForeground(foreground); if (onlyTextHighlighting(cell)) { Rectangle area = event.getBounds(); Rectangle rect = cell.getTextBounds(); if (rect != null) { area.x = rect.x; } gc.fillRectangle(area); } else { gc.fillRectangle(event.getBounds()); } event.detail &= ~SWT.SELECTED; } } private void removeSelectionInformation(Event event, ViewerCell cell) { GC gc = event.gc; gc.setBackground(cell.getViewerRow().getBackground(cell.getColumnIndex())); gc.setForeground(cell.getViewerRow().getForeground(cell.getColumnIndex())); gc.fillRectangle(cell.getBounds()); event.detail &= ~SWT.SELECTED; } private void hookListener(final ColumnViewer viewer) { Listener listener = event -> { if ((event.detail & SWT.SELECTED) > 0) { ViewerCell focusCell = getFocusCell(); ViewerRow row = viewer.getViewerRowFromItem(event.item); Assert.isNotNull(row, "Internal structure invalid. Item without associated row is not possible."); //$NON-NLS-1$ ViewerCell cell = row.getCell(event.index); if (focusCell == null || !cell.equals(focusCell)) { if (removeNonFocusedSelectionInformation) { removeSelectionInformation(event, cell); } } else { markFocusedCell(event, cell); } } }; viewer.getControl().addListener(SWT.EraseItem, listener); } /** * The color to use when rendering the background of the selected cell when * the control has the input focus * * @param cell * the cell which is colored * @return the color or <code>null</code> to use the default */ protected Color getSelectedCellBackgroundColor(ViewerCell cell) { return removeNonFocusedSelectionInformation ? null : cell.getItem().getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION); } /** * The color to use when rendering the foreground (=text) of the selected * cell when the control has the input focus * * @param cell * the cell which is colored * @return the color or <code>null</code> to use the default */ protected Color getSelectedCellForegroundColor(ViewerCell cell) { return null; } /** * The color to use when rendering the foreground (=text) of the selected * cell when the control has <b>no</b> input focus * * @param cell * the cell which is colored * @return the color or <code>null</code> to use the same used when * control has focus * @since 3.4 */ protected Color getSelectedCellForegroundColorNoFocus(ViewerCell cell) { return null; } /** * The color to use when rendering the background of the selected cell when * the control has <b>no</b> input focus * * @param cell * the cell which is colored * @return the color or <code>null</code> to use the same used when * control has focus * @since 3.4 */ protected Color getSelectedCellBackgroundColorNoFocus(ViewerCell cell) { return null; } /** * Controls whether the whole cell or only the text-area is highlighted * * @param cell * the cell which is highlighted * @return <code>true</code> if only the text area should be highlighted * @since 3.4 */ protected boolean onlyTextHighlighting(ViewerCell cell) { return false; } @Override protected void focusCellChanged(ViewerCell newCell, ViewerCell oldCell) { super.focusCellChanged(newCell, oldCell); // Redraw new area if (newCell != null) { Rectangle rect = newCell.getBounds(); int x = newCell.getColumnIndex() == 0 ? 0 : rect.x; int width = newCell.getColumnIndex() == 0 ? rect.x + rect.width : rect.width; // 1 is a fix for Linux-GTK newCell.getControl().redraw(x, rect.y - 1, width, rect.height + 1, true); } if (oldCell != null) { Rectangle rect = oldCell.getBounds(); int x = oldCell.getColumnIndex() == 0 ? 0 : rect.x; int width = oldCell.getColumnIndex() == 0 ? rect.x + rect.width : rect.width; // 1 is a fix for Linux-GTK oldCell.getControl().redraw(x, rect.y - 1, width, rect.height + 1, true); } } }