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/*******************************************************************************
* Copyright (c) 2000, 2016 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
*******************************************************************************/
package org.eclipse.swt.snippets;
/*
* Table example snippet: Show a Table with images of various sizes
*
* For more info on custom-drawing TableItem and TreeItem content see
* http://www.eclipse.org/articles/article.php?file=Article-CustomDrawingTableAndTreeItems/index.html
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
*
* @since 3.2
*/
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
public class Snippet349 {
public static void main(String [] args) {
final int COLUMN_COUNT = 3;
final int TEXT_MARGIN = 3;
final String KEY_WIDTHS = "widths";
final String KEY_IMAGES = "images";
Display display = new Display();
Image[] images = new Image[4];
images[0] = createImage(display, 16, 16);
images[1] = createImage(display, 32, 16);
images[2] = createImage(display, 48, 16);
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
Table table = new Table(shell, SWT.NONE);
for (int i = 0; i < COLUMN_COUNT; i++) {
new TableColumn(table, SWT.NONE);
}
for (int i = 0; i < 8; i++) {
TableItem item = new TableItem(table, SWT.NONE);
Image[] itemImages = new Image[COLUMN_COUNT];
item.setData(KEY_IMAGES, itemImages);
for (int j = 0; j < COLUMN_COUNT; j++) {
item.setText(j, "item " + i + " col " + j);
itemImages[j] = images[(i * COLUMN_COUNT + j) % images.length];
}
}
/*
* NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
* Therefore, it is critical for performance that these methods be
* as efficient as possible.
*/
final int itemHeight = table.getItemHeight();
GC gc = new GC(table);
FontMetrics metrics = gc.getFontMetrics();
final int fontHeight = metrics.getHeight();
gc.dispose();
Listener paintListener = event -> {
switch (event.type) {
case SWT.MeasureItem: {
int column1 = event.index;
TableItem item1 = (TableItem)event.item;
Image[] images1 = (Image[])item1.getData(KEY_IMAGES);
Image image1 = images1[column1];
if (image1 == null) {
/* don't change the native-calculated event.width */
break;
}
int[] cachedWidths = (int[])item1.getData(KEY_WIDTHS);
if (cachedWidths == null) {
cachedWidths = new int[COLUMN_COUNT];
item1.setData(KEY_WIDTHS, cachedWidths);
}
if (cachedWidths[column1] == 0) {
int width = image1.getBounds().width + 2 * TEXT_MARGIN;
GC gc1 = new GC(item1.getParent());
width += gc1.stringExtent(item1.getText()).x;
gc1.dispose();
cachedWidths[column1] = width;
}
event.width = cachedWidths[column1];
break;
}
case SWT.EraseItem: {
int column2 = event.index;
TableItem item2 = (TableItem)event.item;
Image[] images2 = (Image[])item2.getData(KEY_IMAGES);
Image image2 = images2[column2];
if (image2 == null) {
break;
}
/* disable the native drawing of this item */
event.detail &= ~SWT.FOREGROUND;
break;
}
case SWT.PaintItem: {
int column3 = event.index;
TableItem item3 = (TableItem)event.item;
Image[] images3 = (Image[])item3.getData(KEY_IMAGES);
Image image3 = images3[column3];
if (image3 == null) {
/* this item is drawn natively, don't touch it*/
break;
}
int x = event.x;
event.gc.drawImage(image3, x, event.y + (itemHeight - image3.getBounds().height) / 2);
x += image3.getBounds().width + TEXT_MARGIN;
event.gc.drawString(item3.getText(column3), x, event.y + (itemHeight - fontHeight) / 2);
break;
}
}
};
table.addListener(SWT.MeasureItem, paintListener);
table.addListener(SWT.EraseItem, paintListener);
table.addListener(SWT.PaintItem, paintListener);
for (int i = 0; i < COLUMN_COUNT; i++) {
table.getColumn(i).pack();
}
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) display.sleep();
}
for (int i = 0; i < images.length; i++) {
if (images[i] != null) {
images[i].dispose();
}
}
display.dispose();
}
static Image createImage(Display display, int width, int height) {
Image result = new Image(display, width, height);
GC gc = new GC(result);
for (int x = -height; x < width; x += 4) {
gc.drawLine(x, 0, x + height, height);
}
gc.dispose();
return result;
}
}
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