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package sun.awt.X11;

import java.io.IOException;

import java.util.HashMap;

import sun.util.logging.PlatformLogger;

An abstract class for drop protocols on X11 systems. Contains protocol-independent drop target code.
Since:1.5
/** * An abstract class for drop protocols on X11 systems. * Contains protocol-independent drop target code. * * @since 1.5 */
abstract class XDropTargetProtocol { private static final PlatformLogger logger = PlatformLogger.getLogger("sun.awt.X11.xembed.xdnd.XDropTargetProtocol"); private final XDropTargetProtocolListener listener; public static final int EMBEDDER_ALREADY_REGISTERED = 0; public static final int UNKNOWN_MESSAGE = 0; public static final int ENTER_MESSAGE = 1; public static final int MOTION_MESSAGE = 2; public static final int LEAVE_MESSAGE = 3; public static final int DROP_MESSAGE = 4; protected XDropTargetProtocol(XDropTargetProtocolListener listener) { if (listener == null) { throw new NullPointerException("Null XDropTargetProtocolListener"); } this.listener = listener; } protected final XDropTargetProtocolListener getProtocolListener() { return listener; }
Returns the protocol name. The protocol name cannot be null.
/** * Returns the protocol name. The protocol name cannot be null. */
public abstract String getProtocolName(); /* The caller must hold AWT_LOCK. */ public abstract void registerDropTarget(long window); /* The caller must hold AWT_LOCK. */ public abstract void unregisterDropTarget(long window); /* The caller must hold AWT_LOCK. */ public abstract void registerEmbedderDropSite(long window); /* The caller must hold AWT_LOCK. */ public abstract void unregisterEmbedderDropSite(long window); /* The caller must hold AWT_LOCK. */ public abstract void registerEmbeddedDropSite(long embedded); /* The caller must hold AWT_LOCK. */ public final void unregisterEmbeddedDropSite(long embedded) { removeEmbedderRegistryEntry(embedded); } /* The caller must hold AWT_LOCK. */ public abstract boolean isProtocolSupported(long window); public abstract int getMessageType(XClientMessageEvent xclient); /* The caller must hold AWT_LOCK. */ public final boolean processClientMessage(XClientMessageEvent xclient) { int type = getMessageType(xclient); boolean processed = processClientMessageImpl(xclient); postProcessClientMessage(xclient, processed, type); return processed; } /* The caller must hold AWT_LOCK. */ protected abstract boolean processClientMessageImpl(XClientMessageEvent xclient); /* * Forwards a drag notification to the embedding toplevel modifying the event * to match the protocol version supported by the toplevel. * The caller must hold AWT_LOCK. * Returns True if the event is sent, False otherwise. */ protected final boolean forwardClientMessageToToplevel(long toplevel, XClientMessageEvent xclient) { EmbedderRegistryEntry entry = getEmbedderRegistryEntry(toplevel); if (logger.isLoggable(PlatformLogger.Level.FINEST)) { logger.finest(" entry={0}", entry); } // Window not registered as an embedder for this protocol. if (entry == null) { return false; } if (logger.isLoggable(PlatformLogger.Level.FINEST)) { logger.finest(" entry.isOverriden()={0}", entry.isOverriden()); } // Window didn't have an associated drop site, so there is no need // to forward the message. if (!entry.isOverriden()) { return false; } adjustEventForForwarding(xclient, entry); long proxy = entry.getProxy(); if (logger.isLoggable(PlatformLogger.Level.FINEST)) { logger.finest(" proxy={0} toplevel={1}", proxy, toplevel); } if (proxy == 0) { proxy = toplevel; } xclient.set_window(toplevel); XToolkit.awtLock(); try { XlibWrapper.XSendEvent(XToolkit.getDisplay(), proxy, false, XConstants.NoEventMask, xclient.pData); } finally { XToolkit.awtUnlock(); } return true; } /* True iff the previous notification was MotionEvent and it was forwarded to the browser. */ private boolean motionPassedAlong = false; protected abstract void sendEnterMessageToToplevel(long toplevel, XClientMessageEvent xclient); protected abstract void sendLeaveMessageToToplevel(long toplevel, XClientMessageEvent xclient); private void postProcessClientMessage(XClientMessageEvent xclient, boolean processed, int type) { long toplevel = xclient.get_window(); if (getEmbedderRegistryEntry(toplevel) != null) { /* * This code forwards drag notifications to the browser according to the * following rules: * - the messages that we failed to process are always forwarded to the * browser; * - MotionEvents and DropEvents are forwarded if and only if the drag * is not over a plugin window; * - XDnD: EnterEvents and LeaveEvents are never forwarded, instead, we * send synthesized EnterEvents or LeaveEvents when the drag * respectively exits or enters plugin windows; * - Motif DnD: EnterEvents and LeaveEvents are always forwarded. * Synthetic EnterEvents and LeaveEvents are needed, because the XDnD drop * site implemented Netscape 6.2 has a nice feature: when it receives * the first XdndPosition it continuously sends XdndStatus messages to * the source (every 100ms) until the drag terminates or leaves the drop * site. When the mouse is dragged over plugin window embedded in the * browser frame, these XdndStatus messages are mixed with the XdndStatus * messages sent from the plugin. * For Motif DnD, synthetic events cause Motif warnings being displayed, * so these events are always forwarded. However, Motif DnD drop site in * Netscape 6.2 is implemented in the same way, so there could be similar * problems if the drag source choose Motif DnD for communication. */ if (!processed) { forwardClientMessageToToplevel(toplevel, xclient); } else { boolean motifProtocol = xclient.get_message_type() == MotifDnDConstants.XA_MOTIF_DRAG_AND_DROP_MESSAGE.getAtom(); switch (type) { case XDropTargetProtocol.MOTION_MESSAGE: if (!isDragOverComponent()) { if (!motionPassedAlong && !motifProtocol) { sendEnterMessageToToplevel(toplevel, xclient); } forwardClientMessageToToplevel(toplevel, xclient); motionPassedAlong = true; } else { if (motionPassedAlong && !motifProtocol) { sendLeaveMessageToToplevel(toplevel, xclient); } motionPassedAlong = false; } break; case XDropTargetProtocol.DROP_MESSAGE: if (!isDragOverComponent()) { forwardClientMessageToToplevel(toplevel, xclient); } motionPassedAlong = false; break; case XDropTargetProtocol.ENTER_MESSAGE: case XDropTargetProtocol.LEAVE_MESSAGE: if (motifProtocol) { forwardClientMessageToToplevel(toplevel, xclient); } motionPassedAlong = false; break; } } } } public abstract boolean sendResponse(long ctxt, int eventID, int action); /* * Retrieves the data from the drag source in the specified format. * * @param ctxt a pointer to the XClientMessageEvent structure for this * protocol's drop message. * @param format the format in which the data should be retrieved. * * @throws IllegalArgumentException if ctxt doesn't point to the * XClientMessageEvent structure for this protocol's drop message. * @throws IOException if data retrieval failed. */ public abstract Object getData(long ctxt, long format) throws IllegalArgumentException, IOException; public abstract boolean sendDropDone(long ctxt, boolean success, int dropAction); public abstract long getSourceWindow(); public abstract void cleanup(); public abstract boolean isDragOverComponent(); public void adjustEventForForwarding(XClientMessageEvent xclient, EmbedderRegistryEntry entry) {} public abstract boolean forwardEventToEmbedded(long embedded, long ctxt, int eventID); /* * Returns true if the XEmbed protocol prescribes that an XEmbed server must * support this DnD protocol for drop sites associated with XEmbed clients. */ public abstract boolean isXEmbedSupported(); protected static final class EmbedderRegistryEntry { private final boolean overriden; private final int version; private final long proxy; EmbedderRegistryEntry(boolean overriden, int version, long proxy) { this.overriden = overriden; this.version = version; this.proxy = proxy; } public boolean isOverriden() { return overriden; } public int getVersion() { return version; } public long getProxy() { return proxy; } } /* Access to HashMap is synchronized on this XDropTargetProtocol instance. */ private final HashMap embedderRegistry = new HashMap(); protected final void putEmbedderRegistryEntry(long embedder, boolean overriden, int version, long proxy) { synchronized (this) { embedderRegistry.put(Long.valueOf(embedder), new EmbedderRegistryEntry(overriden, version, proxy)); } } protected final EmbedderRegistryEntry getEmbedderRegistryEntry(long embedder) { synchronized (this) { return (EmbedderRegistryEntry)embedderRegistry.get(Long.valueOf(embedder)); } } protected final void removeEmbedderRegistryEntry(long embedder) { synchronized (this) { embedderRegistry.remove(Long.valueOf(embedder)); } } }