Mercurial > projects > dwt-mac
view dwt/internal/Callback.d @ 13:f565d3a95c0a
Ported dwt.internal
author | Jacob Carlborg <doob@me.com> <jacob.carlborg@gmail.com> |
---|---|
date | Fri, 22 Aug 2008 16:46:34 +0200 |
parents | a329f9c3d66d |
children | 2952d5604c0a |
line wrap: on
line source
/******************************************************************************* * Copyright (c) 2000, 2007 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: * Jacob Carlborg <jacob.carlborg@gmail.com> *******************************************************************************/ module dwt.internal.Callback; import dwt.dwthelper.utils; import dwt.internal.C; import c = dwt.internal.c.callback; /** * Instances of this class represent entry points into Java * which can be invoked from operating system level callback * routines. * <p> * IMPORTANT: A callback is only valid when invoked on the * thread which created it. The results are undefined (and * typically bad) when a callback is passed out to the * operating system (or other code) in such a way that the * callback is called from a different thread. */ public class Callback { Object object; String method, signature; int argCount; int /*long*/ address, errorResult; boolean isStatic, isArrayBased; static final String PTR_SIGNATURE = C.PTR_SIZEOF == 4 ? "I" : "J"; //$NON-NLS-1$ //$NON-NLS-2$ static final String SIGNATURE_0 = getSignature(0); static final String SIGNATURE_1 = getSignature(1); static final String SIGNATURE_2 = getSignature(2); static final String SIGNATURE_3 = getSignature(3); static final String SIGNATURE_4 = getSignature(4); static final String SIGNATURE_N = "(["+PTR_SIGNATURE+")"+PTR_SIGNATURE; //$NON-NLS-1$ //$NON-NLS-2$ /** * Constructs a new instance of this class given an object * to send the message to, a string naming the method to * invoke and an argument count. Note that, if the object * is an instance of <code>Class</code> it is assumed that * the method is a static method on that class. * * @param object the object to send the message to * @param method the name of the method to invoke * @param argCount the number of arguments that the method takes */ public this (Object object, String method, int argCount) { this (object, method, argCount, false); } /** * Constructs a new instance of this class given an object * to send the message to, a string naming the method to * invoke, an argument count and a flag indicating whether * or not the arguments will be passed in an array. Note * that, if the object is an instance of <code>Class</code> * it is assumed that the method is a static method on that * class. * * @param object the object to send the message to * @param method the name of the method to invoke * @param argCount the number of arguments that the method takes * @param isArrayBased <code>true</code> if the arguments should be passed in an array and false otherwise */ public this (Object object, String method, int argCount, boolean isArrayBased) { this (object, method, argCount, isArrayBased, 0); } /** * Constructs a new instance of this class given an object * to send the message to, a string naming the method to * invoke, an argument count, a flag indicating whether * or not the arguments will be passed in an array and a value * to return when an exception happens. Note that, if * the object is an instance of <code>Class</code> * it is assumed that the method is a static method on that * class. * * @param object the object to send the message to * @param method the name of the method to invoke * @param argCount the number of arguments that the method takes * @param isArrayBased <code>true</code> if the arguments should be passed in an array and false otherwise * @param errorResult the return value if the java code throws an exception */ public this (Object object, String method, int argCount, boolean isArrayBased, int /*long*/ errorResult) { /* Set the callback fields */ this.object = object; this.method = method; this.argCount = argCount; this.isStatic = cast(ClassInfo) object; this.isArrayBased = isArrayBased; this.errorResult = errorResult; /* Inline the common cases */ if (isArrayBased) { signature = SIGNATURE_N; } else { switch (argCount) { case 0: signature = SIGNATURE_0; break; //$NON-NLS-1$ case 1: signature = SIGNATURE_1; break; //$NON-NLS-1$ case 2: signature = SIGNATURE_2; break; //$NON-NLS-1$ case 3: signature = SIGNATURE_3; break; //$NON-NLS-1$ case 4: signature = SIGNATURE_4; break; //$NON-NLS-1$ default: signature = getSignature(argCount); } } /* Bind the address */ address = bind (this, object, method, signature, argCount, isStatic, isArrayBased, errorResult); } /** * Allocates the native level resources associated with the * callback. This method is only invoked from within the * constructor for the argument. * * @param callback the callback to bind * @param object the callback's object * @param method the callback's method * @param signature the callback's method signature * @param argCount the callback's method argument count * @param isStatic whether the callback's method is static * @param isArrayBased whether the callback's method is array based * @param errorResult the callback's error result */ static synchronized int /*long*/ bind (Callback callback, Object object, String method, String signature, int argCount, boolean isStatic, boolean isArrayBased, int /*long*/ errorResult) { return c.bind(callback, object, method, signature, argCount, isStatic, isArrayBased, errorResult); } /** * Releases the native level resources associated with the callback, * and removes all references between the callback and * other objects. This helps to prevent (bad) application code * from accidentally holding onto extraneous garbage. */ public void dispose () { if (object is null) return; unbind (this); object = method = signature = null; address = 0; } /** * Returns the address of a block of machine code which will * invoke the callback represented by the receiver. * * @return the callback address */ public int /*long*/ getAddress () { return address; } /** * Returns the SWT platform name. * * @return the platform name of the currently running SWT */ public static String getPlatform (); /** * Returns the number of times the system has been recursively entered * through a callback. * <p> * Note: This should not be called by application code. * </p> * * @return the entry count * * @since 2.1 */ public static int getEntryCount () { return c.getEntryCount; } static String getSignature(int argCount) { String signature = "("; //$NON-NLS-1$ for (int i = 0; i < argCount; i++) signature = PTR_SIGNATURE; signature += ")" ~ PTR_SIGNATURE; //$NON-NLS-1$ return signature; } /** * Indicates whether or not callbacks which are triggered at the * native level should cause the messages described by the matching * <code>Callback</code> objects to be invoked. This method is used * to safely shut down SWT when it is run within environments * which can generate spurious events. * <p> * Note: This should not be called by application code. * </p> * * @param enable true if callbacks should be invoked */ public static final synchronized void setEnabled (boolean enable) { return c.setEnabled(enable); } /** * Returns whether or not callbacks which are triggered at the * native level should cause the messages described by the matching * <code>Callback</code> objects to be invoked. This method is used * to safely shut down SWT when it is run within environments * which can generate spurious events. * <p> * Note: This should not be called by application code. * </p> * * @return true if callbacks should not be invoked */ public static final synchronized boolean getEnabled () { return c.getEnabled; } /** * This might be called directly from native code in environments * which can generate spurious events. Check before removing it. * * @deprecated * * @param ignore true if callbacks should not be invoked */ static final void ignoreCallbacks (boolean ignore) { setEnabled (!ignore); } /** * Immediately wipes out all native level state associated * with <em>all</em> callbacks. * <p> * <b>WARNING:</b> This operation is <em>extremely</em> dangerous, * and should never be performed by application code. * </p> */ public static final synchronized void reset (); /** * Releases the native level resources associated with the callback. * * @see #dispose */ static final synchronized void unbind (Callback callback) { c.unbind(callback); } }