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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
/*******************************************************************************
* Copyright (c) 2000, 2008 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.dnd;
import org.eclipse.swt.internal.ole.win32.*;
import org.eclipse.swt.internal.win32.*;
/**
* The class <code>ByteArrayTransfer</code> provides a platform specific
* mechanism for converting a java <code>byte[]</code> to a platform
* specific representation of the byte array and vice versa.
*
* <p><code>ByteArrayTransfer</code> is never used directly but is sub-classed
* by transfer agents that convert between data in a java format such as a
* <code>String</code> and a platform specific byte array.
*
* <p>If the data you are converting <b>does not</b> map to a
* <code>byte[]</code>, you should sub-class <code>Transfer</code> directly
* and do your own mapping to a platform data type.</p>
*
* <p>The following snippet shows a subclass of ByteArrayTransfer that transfers
* data defined by the class <code>MyType</code>.</p>
*
* <pre><code>
* public class MyType {
* public String fileName;
* public long fileLength;
* public long lastModified;
* }
* </code></pre>
*
* <pre><code>
* public class MyTypeTransfer extends ByteArrayTransfer {
*
* private static final String MYTYPENAME = "my_type_name";
* private static final int MYTYPEID = registerType(MYTYPENAME);
* private static MyTypeTransfer _instance = new MyTypeTransfer();
*
* private MyTypeTransfer() {}
*
* public static MyTypeTransfer getInstance () {
* return _instance;
* }
* public void javaToNative (Object object, TransferData transferData) {
* if (object == null || !(object instanceof MyType[])) return;
*
* if (isSupportedType(transferData)) {
* MyType[] myTypes = (MyType[]) object;
* try {
* // write data to a byte array and then ask super to convert to pMedium
* ByteArrayOutputStream out = new ByteArrayOutputStream();
* DataOutputStream writeOut = new DataOutputStream(out);
* for (int i = 0, length = myTypes.length; i < length; i++){
* byte[] buffer = myTypes[i].fileName.getBytes();
* writeOut.writeInt(buffer.length);
* writeOut.write(buffer);
* writeOut.writeLong(myTypes[i].fileLength);
* writeOut.writeLong(myTypes[i].lastModified);
* }
* byte[] buffer = out.toByteArray();
* writeOut.close();
*
* super.javaToNative(buffer, transferData);
*
* } catch (IOException e) {
* }
* }
* }
* public Object nativeToJava(TransferData transferData){
*
* if (isSupportedType(transferData)) {
*
* byte[] buffer = (byte[])super.nativeToJava(transferData);
* if (buffer == null) return null;
*
* MyType[] myData = new MyType[0];
* try {
* ByteArrayInputStream in = new ByteArrayInputStream(buffer);
* DataInputStream readIn = new DataInputStream(in);
* while(readIn.available() > 20) {
* MyType datum = new MyType();
* int size = readIn.readInt();
* byte[] name = new byte[size];
* readIn.read(name);
* datum.fileName = new String(name);
* datum.fileLength = readIn.readLong();
* datum.lastModified = readIn.readLong();
* MyType[] newMyData = new MyType[myData.length + 1];
* System.arraycopy(myData, 0, newMyData, 0, myData.length);
* newMyData[myData.length] = datum;
* myData = newMyData;
* }
* readIn.close();
* } catch (IOException ex) {
* return null;
* }
* return myData;
* }
*
* return null;
* }
* protected String[] getTypeNames(){
* return new String[]{MYTYPENAME};
* }
* protected int[] getTypeIds(){
* return new int[] {MYTYPEID};
* }
* }
* </code></pre>
*
* @see Transfer
*/
public abstract class ByteArrayTransfer extends Transfer {
public TransferData[] getSupportedTypes() {
int[] types = getTypeIds();
TransferData[] data = new TransferData[types.length];
for (int i = 0; i < types.length; i++) {
data[i] = new TransferData();
data[i].type = types[i];
data[i].formatetc = new FORMATETC();
data[i].formatetc.cfFormat = types[i];
data[i].formatetc.dwAspect = COM.DVASPECT_CONTENT;
data[i].formatetc.lindex = -1;
data[i].formatetc.tymed = COM.TYMED_HGLOBAL;
}
return data;
}
public boolean isSupportedType(TransferData transferData){
if (transferData == null) return false;
int[] types = getTypeIds();
for (int i = 0; i < types.length; i++) {
FORMATETC format = transferData.formatetc;
if (format.cfFormat == types[i] &&
(format.dwAspect & COM.DVASPECT_CONTENT) == COM.DVASPECT_CONTENT &&
(format.tymed & COM.TYMED_HGLOBAL) == COM.TYMED_HGLOBAL )
return true;
}
return false;
}
/**
* This implementation of <code>javaToNative</code> converts a java
* <code>byte[]</code> to a platform specific representation.
*
* @param object a java <code>byte[]</code> containing the data to be converted
* @param transferData an empty <code>TransferData</code> object that will
* be filled in on return with the platform specific format of the data
*
* @see Transfer#nativeToJava
*/
protected void javaToNative (Object object, TransferData transferData) {
if (!checkByteArray(object) || !isSupportedType(transferData)) {
DND.error(DND.ERROR_INVALID_DATA);
}
// Allocate the memory because the caller (DropTarget) has not handed it in
// The caller of this method must release the data when it is done with it.
byte[] data = (byte[])object;
int size = data.length;
int /*long*/ newPtr = OS.GlobalAlloc(OS.GMEM_FIXED | OS.GMEM_ZEROINIT, size);
OS.MoveMemory(newPtr, data, size);
transferData.stgmedium = new STGMEDIUM();
transferData.stgmedium.tymed = COM.TYMED_HGLOBAL;
transferData.stgmedium.unionField = newPtr;
transferData.stgmedium.pUnkForRelease = 0;
transferData.result = COM.S_OK;
}
/**
* This implementation of <code>nativeToJava</code> converts a platform specific
* representation of a byte array to a java <code>byte[]</code>.
*
* @param transferData the platform specific representation of the data to be converted
* @return a java <code>byte[]</code> containing the converted data if the conversion was
* successful; otherwise null
*
* @see Transfer#javaToNative
*/
protected Object nativeToJava(TransferData transferData) {
if (!isSupportedType(transferData) || transferData.pIDataObject == 0) return null;
IDataObject data = new IDataObject(transferData.pIDataObject);
data.AddRef();
FORMATETC formatetc = transferData.formatetc;
STGMEDIUM stgmedium = new STGMEDIUM();
stgmedium.tymed = COM.TYMED_HGLOBAL;
transferData.result = getData(data, formatetc, stgmedium);
data.Release();
if (transferData.result != COM.S_OK) return null;
int /*long*/ hMem = stgmedium.unionField;
int size = OS.GlobalSize(hMem);
byte[] buffer = new byte[size];
int /*long*/ ptr = OS.GlobalLock(hMem);
OS.MoveMemory(buffer, ptr, size);
OS.GlobalUnlock(hMem);
OS.GlobalFree(hMem);
return buffer;
}
boolean checkByteArray(Object object) {
return (object != null && object instanceof byte[] && ((byte[])object).length > 0);
}
}
|
