/******************************************************************************* * Copyright (c) 2018 Red Hat 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: * Red Hat - initial API and implementation *******************************************************************************/ package org.eclipse.swt.tests.gtk.snippets; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.List; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Table; import org.eclipse.swt.widgets.TableItem; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class Bug305864_ListItemHeight { public static void main(String[] args) { testTree(); testList(); testTable(); } private static void testTree() { final Display display = new Display(); final Shell shell = new Shell(display); FillLayout layout = new FillLayout(SWT.VERTICAL); shell.setLayout(layout); final Tree tree = new Tree(shell, SWT.BORDER); for (int i=0; i<32; i++) { TreeItem iItem = new TreeItem (tree, 0); iItem.setText ("TreeItem (1) -" + (i+1)); for (int j=0; j<4; j++) { TreeItem jItem = new TreeItem (iItem, 0); jItem.setText ("TreeItem (2) -" + (j+1)); for (int k=0; k<4; k++) { TreeItem kItem = new TreeItem (jItem, 0); kItem.setText ("TreeItem (3) -" + (k+1)); for (int l=0; l<4; l++) { TreeItem lItem = new TreeItem (kItem, 0); lItem.setText ("TreeItem (4) -" + (l+1)); } } } } final Button button = new Button (shell, SWT.PUSH); button.setText("Visible Items []"); button.addListener(SWT.Selection, e -> { Rectangle rect = tree.getClientArea(); int itemHeight = tree.getItemHeight(); double visibleCount = ((double) rect.height) / itemHeight; button.setText("Visible Items [" + Math.round(visibleCount) + "]"); }); shell.setSize(200, 250); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) { display.sleep(); } } display.dispose(); } private static void testList() { final Display display = new Display(); final Shell shell = new Shell(display); FillLayout layout = new FillLayout(SWT.VERTICAL); shell.setLayout(layout); final List list = new List(shell, SWT.BORDER | SWT.SINGLE | SWT.V_SCROLL); list.setData("name", "list"); for (int i = 0; i < 100; i++) { list.add("Item " + (i + 1) + " is quite long"); } final Button button = new Button (shell, SWT.PUSH); button.setText("Visible Items []"); button.addListener(SWT.Selection, e -> { Rectangle rect = list.getClientArea(); int itemHeight = list.getItemHeight(); double visibleCount = ((double) rect.height) / itemHeight; button.setText("Visible Items [" + Math.round(visibleCount) + "]"); }); shell.setSize(200, 250); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) { display.sleep(); } } display.dispose(); } private static void testTable() { final Display display = new Display(); final Shell shell = new Shell(display); FillLayout layout = new FillLayout(SWT.VERTICAL); shell.setLayout(layout); final Table table = new Table(shell, SWT.NONE); for (int i = 0; i < 32; i++) { TableItem item = new TableItem(table, SWT.NONE); item.setText("Item " + (i + 1) + " is quite long"); } final Button button = new Button (shell, SWT.PUSH); button.setText("Visible Items []"); button.addListener(SWT.Selection, e -> { Rectangle rect = table.getClientArea(); int itemHeight = table.getItemHeight(); int headerHeight = table.getHeaderHeight(); double visibleCount = ((double) (rect.height - headerHeight)) / itemHeight; button.setText("Visible Items [" + Math.round(visibleCount) + "]"); }); shell.setSize(200, 250); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) { display.sleep(); } } display.dispose(); } }