Mercurial > projects > dwt-linux
view dwt/dnd/ByteArrayTransfer.d @ 150:f2e04420fd6c
reworked overrides and superclass aliases
author | Frank Benoit <benoit@tionex.de> |
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date | Thu, 31 Jan 2008 19:04:56 +0100 |
parents | 0f12f6bb9739 |
children | 17f8449522fd |
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/******************************************************************************* * Copyright (c) 2000, 2006 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 * Port to the D programming language: * Frank Benoit <benoit@tionex.de> *******************************************************************************/ module dwt.dnd.ByteArrayTransfer; import dwt.internal.gtk.OS; import dwt.dnd.Transfer; import dwt.dnd.TransferData; import dwt.dnd.DND; import dwt.dwthelper.utils; /** * 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. See * <code>Transfer</code> for additional information. * * <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 is 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 is 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> */ public abstract class ByteArrayTransfer : Transfer { public override 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 = cast(void*)types[i]; } return data; } public override bool isSupportedType(TransferData transferData){ if (transferData is null) return false; int[] types = getTypeIds(); for (int i = 0; i < types.length; i++) { if (transferData.type is cast(void*)types[i]) return true; } return false; } /** * This implementation of <code>javaToNative</code> converts a java * <code>byte[]</code> to a platform specific representation. For additional * information see <code>Transfer#javaToNative</code>. * * @see Transfer#javaToNative * * @param object a java <code>byte[]</code> containing the data to be converted * @param transferData an empty <code>TransferData</code> object; this * object will be filled in on return with the platform specific format of the data */ protected void javaToNative (Object object, TransferData transferData) { transferData.result = 0; if (!checkByteArray(object) || !isSupportedType(transferData)) { DND.error(DND.ERROR_INVALID_DATA); } byte[] buffer = (cast(ArrayWrapperByte)object).array; if (buffer.length is 0) return; byte* pValue = cast(byte*)OS.g_malloc(buffer.length); if (pValue is null) return; pValue[ 0 .. buffer.length ] = buffer; transferData.length = buffer.length; transferData.format = 8; transferData.pValue = cast(char*)pValue; transferData.result = 1; } /** * This implementation of <code>nativeToJava</code> converts a platform specific * representation of a byte array to a java <code>byte[]</code>. * For additional information see <code>Transfer#nativeToJava</code>. * * @see Transfer#nativeToJava * * @param transferData the platform specific representation of the data to be * been converted * @return a java <code>byte[]</code> containing the converted data if the * conversion was successful; otherwise null */ protected Object nativeToJava(TransferData transferData) { if ( !isSupportedType(transferData) || transferData.pValue is null) return null; int size = transferData.format * transferData.length / 8; if (size is 0) return null; byte* ptr = cast(byte*)transferData.pValue; return new ArrayWrapperByte( ptr[ 0 .. size ].dup ); } bool checkByteArray(Object object) { if( object is null ) return false; ArrayWrapperByte arr = cast(ArrayWrapperByte)object; if( arr is null ) return false; return arr.array.length > 0; } }