1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
/*******************************************************************************
* Copyright (c) 2000, 2016 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
*******************************************************************************/
package org.eclipse.swt.snippets;
/*
* Tree snippet: Text that spans multiple columns
*
* 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 Snippet240 {
public static void main(String [] args) {
final Display display = new Display();
Shell shell = new Shell (display);
shell.setText("Text spans two columns in a TreeItem");
shell.setLayout (new FillLayout());
final Tree tree = new Tree(shell, SWT.MULTI | SWT.FULL_SELECTION);
tree.setHeaderVisible(true);
int columnCount = 4;
for (int i=0; i<columnCount; i++) {
TreeColumn column = new TreeColumn(tree, SWT.NONE);
column.setText("Column " + i);
}
int itemCount = 8;
for (int i = 0; i < itemCount; i++) {
TreeItem item = new TreeItem(tree, SWT.NONE);
item.setText(0, "item "+i+" a");
item.setText(3, "item "+i+" d");
for (int j = 0; j < 3; j++) {
TreeItem subItem = new TreeItem(item, SWT.NONE);
subItem.setText(0, "subItem "+i+"-"+j+" a");
subItem.setText(3, "subItem "+i+"-"+j+" d");
}
}
/*
* NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
* Therefore, it is critical for performance that these methods be
* as efficient as possible.
*/
final String string = "text that spans two columns";
GC gc = new GC(tree);
final Point extent = gc.stringExtent(string);
gc.dispose();
final Color red = display.getSystemColor(SWT.COLOR_RED);
Listener paintListener = event -> {
switch(event.type) {
case SWT.MeasureItem: {
if (event.index == 1 || event.index == 2) {
event.width = extent.x/2;
event.height = Math.max(event.height, extent.y + 2);
}
break;
}
case SWT.PaintItem: {
if (event.index == 1 || event.index == 2) {
int offset = 0;
if (event.index == 2) {
TreeColumn column1 = tree.getColumn(1);
offset = column1.getWidth();
}
event.gc.setForeground(red);
int y = event.y + (event.height - extent.y)/2;
event.gc.drawString(string, event.x - offset, y, true);
}
break;
}
}
};
tree.addListener(SWT.MeasureItem, paintListener);
tree.addListener(SWT.PaintItem, paintListener);
for (int i = 0; i < columnCount; i++) {
tree.getColumn(i).pack();
}
shell.pack();
shell.open();
while(!shell.isDisposed()) {
if(!display.readAndDispatch()) display.sleep();
}
display.dispose();
}
}
|
