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comparison dwt/dnd/DropTargetEffect.d @ 135:242e33c0e383

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Added dnd source, ByteArrayTransfer,Clipboard completed
author Frank Benoit <benoit@tionex.de>
date Wed, 13 Feb 2008 04:51:22 +0100
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children 36f5cb12e1a2
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134:fa7d7d66b9ed 135:242e33c0e383
1 /*******************************************************************************
2 * Copyright (c) 2007 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 dwt.dnd.DropTargetEffect;
14
15
16 import dwt.DWT;
17 import dwt.graphics.Point;
18 import dwt.graphics.Rectangle;
19 import dwt.widgets.Control;
20 import dwt.widgets.Item;
21 import dwt.widgets.Table;
22 import dwt.widgets.Tree;
23 import dwt.widgets.TreeItem;
24 import dwt.widgets.Widget;
25 import dwt.dnd.DropTargetAdapter;
26
27
28 /**
29 * This class provides a default drag under effect during a drag and drop.
30 * The current implementation does not provide any visual feedback.
31 *
32 * <p>The drop target effect has the same API as the
33 * <code>DropTargetAdapter</code> so that it can provide custom visual
34 * feedback when a <code>DropTargetEvent</code> occurs.
35 * </p>
36 *
37 * <p>Classes that wish to provide their own drag under effect
38 * can extend the <code>DropTargetEffect</code> and override any applicable methods
39 * in <code>DropTargetAdapter</code> to display their own drag under effect.</p>
40 *
41 * <p>The feedback value is either one of the FEEDBACK constants defined in
42 * class <code>DND</code> which is applicable to instances of this class,
43 * or it must be built by <em>bitwise OR</em>'ing together
44 * (that is, using the <code>int</code> "|" operator) two or more
45 * of those <code>DND</code> effect constants.
46 * </p>
47 * <p>
48 * <dl>
49 * <dt><b>Feedback:</b></dt>
50 * <dd>FEEDBACK_EXPAND, FEEDBACK_INSERT_AFTER, FEEDBACK_INSERT_BEFORE,
51 * FEEDBACK_NONE, FEEDBACK_SELECT, FEEDBACK_SCROLL</dd>
52 * </dl>
53 * </p>
54 *
55 * @see DropTargetAdapter
56 * @see DropTargetEvent
57 *
58 * @since 3.3
59 */
60 public class DropTargetEffect : DropTargetAdapter {
61 Control control;
62
63 /**
64 * Creates a new <code>DropTargetEffect</code> to handle the drag under effect on the specified
65 * <code>Control</code>.
66 *
67 * @param control the <code>Control</code> over which the user positions the cursor to drop the data
68 *
69 * @exception IllegalArgumentException <ul>
70 * <li>ERROR_NULL_ARGUMENT - if the control is null</li>
71 * </ul>
72 */
73 public this(Control control) {
74 if (control is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
75 this.control = control;
76 }
77
78 /**
79 * Returns the Control which is registered for this DropTargetEffect. This is the control over which the
80 * user positions the cursor to drop the data.
81 *
82 * @return the Control which is registered for this DropTargetEffect
83 */
84 public Control getControl() {
85 return control;
86 }
87
88 /**
89 * Returns the item at the given x-y coordinate in the receiver
90 * or null if no such item exists. The x-y coordinate is in the
91 * display relative coordinates.
92 *
93 * @param x the x coordinate used to locate the item
94 * @param y the y coordinate used to locate the item
95 * @return the item at the given x-y coordinate, or null if the coordinate is not in a selectable item
96 */
97 public Widget getItem(int x, int y) {
98 if ( auto table = cast(Table)control ) {
99 return getItem(table, x, y);
100 }
101 if ( auto tree = cast(Tree)control ) {
102 return getItem(tree, x, y);
103 }
104 return null;
105 }
106
107 Widget getItem(Table table, int x, int y) {
108 Point coordinates = new Point(x, y);
109 coordinates = table.toControl(coordinates);
110 Item item = table.getItem(coordinates);
111 if (item is null) {
112 Rectangle area = table.getClientArea();
113 if (area.contains(coordinates)) {
114 // Scan across the width of the table.
115 for (int x1 = area.x; x1 < area.x + area.width; x1++) {
116 Point pt = new Point(x1, coordinates.y);
117 item = table.getItem(pt);
118 if (item !is null) {
119 break;
120 }
121 }
122 }
123 }
124 return item;
125 }
126
127 Widget getItem(Tree tree, int x, int y) {
128 Point coordinates = new Point(x, y);
129 coordinates = tree.toControl(coordinates);
130 Item item = tree.getItem(coordinates);
131 if (item is null) {
132 Rectangle area = tree.getClientArea();
133 if (area.contains(coordinates)) {
134 // Scan across the width of the tree.
135 for (int x1 = area.x; x1 < area.x + area.width; x1++) {
136 Point pt = new Point(x1, coordinates.y);
137 item = tree.getItem(pt);
138 if (item !is null) {
139 break;
140 }
141 }
142 }
143 }
144 return item;
145 }
146
147 TreeItem nextItem(Tree tree, TreeItem item) {
148 if (item is null) return null;
149 if (item.getExpanded()) return item.getItem(0);
150 TreeItem childItem = item;
151 TreeItem parentItem = childItem.getParentItem();
152 int index = parentItem is null ? tree.indexOf(childItem) : parentItem.indexOf(childItem);
153 int count = parentItem is null ? tree.getItemCount() : parentItem.getItemCount();
154 while (true) {
155 if (index + 1 < count) return parentItem is null ? tree.getItem(index + 1) : parentItem.getItem(index + 1);
156 if (parentItem is null) return null;
157 childItem = parentItem;
158 parentItem = childItem.getParentItem();
159 index = parentItem is null ? tree.indexOf(childItem) : parentItem.indexOf(childItem);
160 count = parentItem is null ? tree.getItemCount() : parentItem.getItemCount();
161 }
162 }
163
164 TreeItem previousItem(Tree tree, TreeItem item) {
165 if (item is null) return null;
166 TreeItem childItem = item;
167 TreeItem parentItem = childItem.getParentItem();
168 int index = parentItem is null ? tree.indexOf(childItem) : parentItem.indexOf(childItem);
169 if (index is 0) return parentItem;
170 TreeItem nextItem = parentItem is null ? tree.getItem(index-1) : parentItem.getItem(index-1);
171 int count = nextItem.getItemCount();
172 while (count > 0 && nextItem.getExpanded()) {
173 nextItem = nextItem.getItem(count - 1);
174 count = nextItem.getItemCount();
175 }
176 return nextItem;
177 }
178 }