Package org.eclipse.swt.dnd
Class ByteArrayTransfer
- java.lang.Object
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- org.eclipse.swt.dnd.Transfer
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- org.eclipse.swt.dnd.ByteArrayTransfer
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- Direct Known Subclasses:
FileTransfer,HTMLTransfer,ImageTransfer,RTFTransfer,TextTransfer,URLTransfer
public abstract class ByteArrayTransfer extends Transfer
The classByteArrayTransferprovides a platform specific mechanism for converting a javabyte[]to a platform specific representation of the byte array and vice versa.ByteArrayTransferis never used directly but is sub-classed by transfer agents that convert between data in a java format such as aStringand a platform specific byte array.If the data you are converting does not map to a
byte[], you should sub-classTransferdirectly and do your own mapping to a platform data type.The following snippet shows a subclass 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}; } }- Since:
- 1.3
- See Also:
Transfer
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Constructor Summary
Constructors Constructor Description ByteArrayTransfer()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description TransferData[]getSupportedTypes()Returns a list of the platform specific data types that can be converted using this transfer agent.booleanisSupportedType(TransferData transferData)Returns true if theTransferDatadata type can be converted using this transfer agent, or false otherwise (including if transferData isnull).voidjavaToNative(java.lang.Object object, TransferData transferData)This implementation ofjavaToNativeconverts a javabyte[]to a platform specific representation.java.lang.ObjectnativeToJava(TransferData transferData)This implementation ofnativeToJavaconverts a platform specific representation of a byte array to a javabyte[].-
Methods inherited from class org.eclipse.swt.dnd.Transfer
getTypeIds, getTypeNames, registerType, validate
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Method Detail
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getSupportedTypes
public TransferData[] getSupportedTypes()
Description copied from class:TransferReturns a list of the platform specific data types that can be converted using this transfer agent.Only the data type fields of the
TransferDataobjects are filled in.- Specified by:
getSupportedTypesin classTransfer- Returns:
- a list of the data types that can be converted using this transfer agent
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isSupportedType
public boolean isSupportedType(TransferData transferData)
Description copied from class:TransferReturns true if theTransferDatadata type can be converted using this transfer agent, or false otherwise (including if transferData isnull).- Specified by:
isSupportedTypein classTransfer- Parameters:
transferData- a platform specific description of a data type; only the data type fields of theTransferDataobject need to be filled in- Returns:
- true if the transferData data type can be converted using this transfer agent
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javaToNative
public void javaToNative(java.lang.Object object, TransferData transferData)This implementation ofjavaToNativeconverts a javabyte[]to a platform specific representation.- Specified by:
javaToNativein classTransfer- Parameters:
object- a javabyte[]containing the data to be convertedtransferData- an emptyTransferDataobject that will be filled in on return with the platform specific format of the data- See Also:
Transfer.nativeToJava(org.eclipse.swt.dnd.TransferData)
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nativeToJava
public java.lang.Object nativeToJava(TransferData transferData)
This implementation ofnativeToJavaconverts a platform specific representation of a byte array to a javabyte[].- Specified by:
nativeToJavain classTransfer- Parameters:
transferData- the platform specific representation of the data to be converted- Returns:
- a java
byte[]containing the converted data if the conversion was successful; otherwise null - See Also:
Transfer.javaToNative(java.lang.Object, org.eclipse.swt.dnd.TransferData)
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