org.eclipse.swt.dnd
Class ByteArrayTransfer
java.lang.Object
|
+--org.eclipse.swt.dnd.Transfer
|
+--org.eclipse.swt.dnd.ByteArrayTransfer
- Direct Known Subclasses:
- EditorInputTransfer, FileTransfer, LocalSelectionTransfer, MarkerTransfer, PluginTransfer, ResourceTransfer, RTFTransfer, TextTransfer
- public abstract class ByteArrayTransfer
- extends Transfer
The class ByteArrayTransfer
provides a platform specific
mechanism for converting a java byte[]
to a platform
specific representation of the byte array and vice versa. See
Transfer
for additional information.
ByteArrayTransfer
is never used directly but is sub-classed
by transfer agents that convert between data in a java format such as a
String
and a platform specific byte array.
If the data you are converting does not map to a
byte[]
, you should sub-class Transfer
directly
and do your own mapping to a platform data type.
The following snippet shows a sublcass of ByteArrayTransfer that transfers
data defined by the class MyType
.
public class MyType {
public String fileName;
public long fileLength;
public long lastModified;
}
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};
}
}
Method Summary |
TransferData[] |
getSupportedTypes()
Returns a list of the platform specific data types that can be converted using
this transfer agent. |
boolean |
isSupportedType(TransferData transferData)
Returns true if the TransferData data type can be converted
using this transfer agent. |
protected void |
javaToNative(Object object,
TransferData transferData)
This implementation of javaToNative converts a java
byte[] to a platform specific representation. |
protected Object |
nativeToJava(TransferData transferData)
This implementation of nativeToJava converts a platform specific
representation of a byte array to a java byte[] . |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
ByteArrayTransfer
public ByteArrayTransfer()
getSupportedTypes
public TransferData[] getSupportedTypes()
- Description copied from class:
Transfer
- Returns a list of the platform specific data types that can be converted using
this transfer agent.
Only the data type fields of the TransferData
objects are filled
in.
- Overrides:
getSupportedTypes
in class Transfer
- Following copied from class:
org.eclipse.swt.dnd.Transfer
- Returns:
- a list of the data types that can be converted using this transfer agent
isSupportedType
public boolean isSupportedType(TransferData transferData)
- Description copied from class:
Transfer
- Returns true if the
TransferData
data type can be converted
using this transfer agent.
- Overrides:
isSupportedType
in class Transfer
- Following copied from class:
org.eclipse.swt.dnd.Transfer
- Parameters:
transferData
- a platform specific description of a data type; only the data
type fields of the TransferData
object need to be filled in- Returns:
- true if the transferData data type can be converted using this transfer
agent
javaToNative
protected void javaToNative(Object object,
TransferData transferData)
- This implementation of
javaToNative
converts a java
byte[]
to a platform specific representation. For additional
information see Transfer#javaToNative
.
- Overrides:
javaToNative
in class Transfer
- Parameters:
object
- a java byte[]
containing the data to be convertedtransferData
- an empty TransferData
object; this
object will be filled in on return with the platform specific format of the data- See Also:
Transfer.javaToNative(java.lang.Object, org.eclipse.swt.dnd.TransferData)
nativeToJava
protected Object nativeToJava(TransferData transferData)
- This implementation of
nativeToJava
converts a platform specific
representation of a byte array to a java byte[]
.
For additional information see Transfer#nativeToJava
.
- Overrides:
nativeToJava
in class Transfer
- Parameters:
transferData
- the platform specific representation of the data to be
been converted- Returns:
- a java
byte[]
containing the converted data if the
conversion was successful; otherwise null - See Also:
Transfer.nativeToJava(org.eclipse.swt.dnd.TransferData)
Copyright (c) IBM Corp. and others 2000, 2003. All Rights Reserved.