org.eclipse.swt.custom.ScrolledCompositeLayout source code

1 /*******************************************************************************
2  * Copyright (c) 2000, 2006 IBM Corporation and others.
3  * All rights reserved. This program and the accompanying materials
4  * are made available under the terms of the Eclipse Public License v1.0
5  * which accompanies this distribution, and is available at
6  * http://www.eclipse.org/legal/epl-v10.html
7  *
8  * Contributors:
9  *     IBM Corporation - initial API and implementation
10  * Port to the D programming language:
11  *     Frank Benoit <benoit@tionex.de>
12  *******************************************************************************/
13 module org.eclipse.swt.custom.ScrolledCompositeLayout;
14 
15 import java.lang.all;
16 
17 import org.eclipse.swt.SWT;
18 import org.eclipse.swt.graphics.Point;
19 import org.eclipse.swt.graphics.Rectangle;
20 import org.eclipse.swt.widgets.Composite;
21 import org.eclipse.swt.widgets.Control;
22 import org.eclipse.swt.widgets.Layout;
23 import org.eclipse.swt.widgets.ScrollBar;
24 import org.eclipse.swt.custom.ScrolledComposite;
25 
26 
27 /**
28  * This class provides the layout for ScrolledComposite
29  *
30  * @see ScrolledComposite
31  */
32 class ScrolledCompositeLayout : Layout {
33 
34     bool inLayout = false;
35     static const int DEFAULT_WIDTH  = 64;
36     static const int DEFAULT_HEIGHT = 64;
37 
38 protected override Point computeSize(Composite composite, int wHint, int hHint, bool flushCache) {
39     ScrolledComposite sc = cast(ScrolledComposite)composite;
40     Point size = new Point(DEFAULT_WIDTH, DEFAULT_HEIGHT);
41     if (sc.content !is null) {
42         Point preferredSize = sc.content.computeSize(wHint, hHint, flushCache);
43         Point currentSize = sc.content.getSize();
44         size.x = sc.getExpandHorizontal() ? preferredSize.x : currentSize.x;
45         size.y = sc.getExpandVertical() ? preferredSize.y : currentSize.y;
46     }
47     size.x = Math.max(size.x, sc.minWidth);
48     size.y = Math.max(size.y, sc.minHeight);
49     if (wHint !is SWT.DEFAULT) size.x = wHint;
50     if (hHint !is SWT.DEFAULT) size.y = hHint;
51     return size;
52 }
53 
54 protected override bool flushCache(Control control) {
55     return true;
56 }
57 
58 protected override void layout(Composite composite, bool flushCache) {
59     if (inLayout) return;
60     ScrolledComposite sc = cast(ScrolledComposite)composite;
61     if (sc.content is null) return;
62     ScrollBar hBar = sc.getHorizontalBar();
63     ScrollBar vBar = sc.getVerticalBar();
64     if (hBar !is null) {
65         if (hBar.getSize().y >= sc.getSize().y) {
66             return;
67         }
68     }
69     if (vBar !is null) {
70         if (vBar.getSize().x >= sc.getSize().x) {
71             return;
72         }
73     }
74     inLayout = true;
75     Rectangle contentRect = sc.content.getBounds();
76     if (!sc.alwaysShowScroll) {
77         bool hVisible = sc.needHScroll(contentRect, false);
78         bool vVisible = sc.needVScroll(contentRect, hVisible);
79         if (!hVisible && vVisible) hVisible = sc.needHScroll(contentRect, vVisible);
80         if (hBar !is null) hBar.setVisible(hVisible);
81         if (vBar !is null) vBar.setVisible(vVisible);
82     }
83     Rectangle hostRect = sc.getClientArea();
84     if (sc.expandHorizontal) {
85         contentRect.width = Math.max(sc.minWidth, hostRect.width);
86     }
87     if (sc.expandVertical) {
88         contentRect.height = Math.max(sc.minHeight, hostRect.height);
89     }
90 
91     if (hBar !is null) {
92         hBar.setMaximum (contentRect.width);
93         hBar.setThumb (Math.min (contentRect.width, hostRect.width));
94         int hPage = contentRect.width - hostRect.width;
95         int hSelection = hBar.getSelection ();
96         if (hSelection >= hPage) {
97             if (hPage <= 0) {
98                 hSelection = 0;
99                 hBar.setSelection(0);
100             }
101             contentRect.x = -hSelection;
102         }
103     }
104 
105     if (vBar !is null) {
106         vBar.setMaximum (contentRect.height);
107         vBar.setThumb (Math.min (contentRect.height, hostRect.height));
108         int vPage = contentRect.height - hostRect.height;
109         int vSelection = vBar.getSelection ();
110         if (vSelection >= vPage) {
111             if (vPage <= 0) {
112                 vSelection = 0;
113                 vBar.setSelection(0);
114             }
115             contentRect.y = -vSelection;
116         }
117     }
118 
119     sc.content.setBounds (contentRect);
120     inLayout = false;
121 }
122 }