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package sun.awt.dnd;

import java.awt.AWTEvent;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.EventQueue;
import java.awt.Image;
import java.awt.Point;

import java.awt.datatransfer.Transferable;

import java.awt.dnd.DnDConstants;
import java.awt.dnd.DragSourceContext;
import java.awt.dnd.DragSourceEvent;
import java.awt.dnd.DragSourceDropEvent;
import java.awt.dnd.DragSourceDragEvent;
import java.awt.dnd.DragGestureEvent;
import java.awt.dnd.InvalidDnDOperationException;

import java.awt.dnd.peer.DragSourceContextPeer;

import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;

import java.util.Map;
import java.util.SortedMap;

import sun.awt.SunToolkit;
import sun.awt.datatransfer.DataTransferer;
import java.awt.datatransfer.DataFlavor;


TBC

Since:JDK1.3.1
/** * <p> * TBC * </p> * * @since JDK1.3.1 * */
public abstract class SunDragSourceContextPeer implements DragSourceContextPeer { private DragGestureEvent trigger; private Component component; private Cursor cursor; private Image dragImage; private Point dragImageOffset; private long nativeCtxt; private DragSourceContext dragSourceContext; private int sourceActions; private static boolean dragDropInProgress = false; private static boolean discardingMouseEvents = false; /* * dispatch constants */ protected final static int DISPATCH_ENTER = 1; protected final static int DISPATCH_MOTION = 2; protected final static int DISPATCH_CHANGED = 3; protected final static int DISPATCH_EXIT = 4; protected final static int DISPATCH_FINISH = 5; protected final static int DISPATCH_MOUSE_MOVED = 6;
construct a new SunDragSourceContextPeer
/** * construct a new SunDragSourceContextPeer */
public SunDragSourceContextPeer(DragGestureEvent dge) { trigger = dge; if (trigger != null) { component = trigger.getComponent(); } else { component = null; } }
Synchro messages in AWT
/** * Synchro messages in AWT */
public void startSecondaryEventLoop(){} public void quitSecondaryEventLoop(){}
initiate a DnD operation ...
/** * initiate a DnD operation ... */
public void startDrag(DragSourceContext dsc, Cursor c, Image di, Point p) throws InvalidDnDOperationException { /* Fix for 4354044: don't initiate a drag if event sequence provided by * DragGestureRecognizer is empty */ if (getTrigger().getTriggerEvent() == null) { throw new InvalidDnDOperationException("DragGestureEvent has a null trigger"); } dragSourceContext = dsc; cursor = c; sourceActions = getDragSourceContext().getSourceActions(); dragImage = di; dragImageOffset = p; Transferable transferable = getDragSourceContext().getTransferable(); SortedMap<Long,DataFlavor> formatMap = DataTransferer.getInstance(). getFormatsForTransferable(transferable, DataTransferer.adaptFlavorMap (getTrigger().getDragSource().getFlavorMap())); long[] formats = DataTransferer.getInstance(). keysToLongArray(formatMap); startDrag(transferable, formats, formatMap); /* * Fix for 4613903. * Filter out all mouse events that are currently on the event queue. */ discardingMouseEvents = true; EventQueue.invokeLater(new Runnable() { public void run() { discardingMouseEvents = false; } }); } protected abstract void startDrag(Transferable trans, long[] formats, Map formatMap);
set cursor
/** * set cursor */
public void setCursor(Cursor c) throws InvalidDnDOperationException { synchronized (this) { if (cursor == null || !cursor.equals(c)) { cursor = c; // NOTE: native context can be null at this point. // setNativeCursor() should handle it properly. setNativeCursor(getNativeContext(), c, c != null ? c.getType() : 0); } } }
return cursor
/** * return cursor */
public Cursor getCursor() { return cursor; }
Returns the drag image. If there is no image to drag, the returned value is null
Returns:the reference to the drag image
/** * Returns the drag image. If there is no image to drag, * the returned value is {@code null} * * @return the reference to the drag image */
public Image getDragImage() { return dragImage; }
Returns an anchor offset for the image to drag.
Returns:a Point object that corresponds to coordinates of an anchor offset of the image relative to the upper left corner of the image. The point (0,0) returns by default.
/** * Returns an anchor offset for the image to drag. * * @return a {@code Point} object that corresponds * to coordinates of an anchor offset of the image * relative to the upper left corner of the image. * The point {@code (0,0)} returns by default. */
public Point getDragImageOffset() { if (dragImageOffset == null) { return new Point(0,0); } return new Point(dragImageOffset); }
downcall into native code
/** * downcall into native code */
protected abstract void setNativeCursor(long nativeCtxt, Cursor c, int cType); protected synchronized void setTrigger(DragGestureEvent dge) { trigger = dge; if (trigger != null) { component = trigger.getComponent(); } else { component = null; } } protected DragGestureEvent getTrigger() { return trigger; } protected Component getComponent() { return component; } protected synchronized void setNativeContext(long ctxt) { nativeCtxt = ctxt; } protected synchronized long getNativeContext() { return nativeCtxt; } protected DragSourceContext getDragSourceContext() { return dragSourceContext; }
Notify the peer that the transferables' DataFlavors have changed. No longer useful as the transferables are determined at the time of the drag.
/** * Notify the peer that the transferables' DataFlavors have changed. * * No longer useful as the transferables are determined at the time * of the drag. */
public void transferablesFlavorsChanged() { } protected final void postDragSourceDragEvent(final int targetAction, final int modifiers, final int x, final int y, final int dispatchType) { final int dropAction = SunDragSourceContextPeer.convertModifiersToDropAction(modifiers, sourceActions); DragSourceDragEvent event = new DragSourceDragEvent(getDragSourceContext(), dropAction, targetAction & sourceActions, modifiers, x, y); EventDispatcher dispatcher = new EventDispatcher(dispatchType, event); SunToolkit.invokeLaterOnAppContext( SunToolkit.targetToAppContext(getComponent()), dispatcher); startSecondaryEventLoop(); }
upcall from native code
/** * upcall from native code */
protected void dragEnter(final int targetActions, final int modifiers, final int x, final int y) { postDragSourceDragEvent(targetActions, modifiers, x, y, DISPATCH_ENTER); }
upcall from native code
/** * upcall from native code */
private void dragMotion(final int targetActions, final int modifiers, final int x, final int y) { postDragSourceDragEvent(targetActions, modifiers, x, y, DISPATCH_MOTION); }
upcall from native code
/** * upcall from native code */
private void operationChanged(final int targetActions, final int modifiers, final int x, final int y) { postDragSourceDragEvent(targetActions, modifiers, x, y, DISPATCH_CHANGED); }
upcall from native code
/** * upcall from native code */
protected final void dragExit(final int x, final int y) { DragSourceEvent event = new DragSourceEvent(getDragSourceContext(), x, y); EventDispatcher dispatcher = new EventDispatcher(DISPATCH_EXIT, event); SunToolkit.invokeLaterOnAppContext( SunToolkit.targetToAppContext(getComponent()), dispatcher); startSecondaryEventLoop(); }
upcall from native code
/** * upcall from native code */
private void dragMouseMoved(final int targetActions, final int modifiers, final int x, final int y) { postDragSourceDragEvent(targetActions, modifiers, x, y, DISPATCH_MOUSE_MOVED); }
upcall from native code via implemented class (do)
/** * upcall from native code via implemented class (do) */
protected final void dragDropFinished(final boolean success, final int operations, final int x, final int y) { DragSourceEvent event = new DragSourceDropEvent(getDragSourceContext(), operations & sourceActions, success, x, y); EventDispatcher dispatcher = new EventDispatcher(DISPATCH_FINISH, event); SunToolkit.invokeLaterOnAppContext( SunToolkit.targetToAppContext(getComponent()), dispatcher); startSecondaryEventLoop(); setNativeContext(0); dragImage = null; dragImageOffset = null; } public static void setDragDropInProgress(boolean b) throws InvalidDnDOperationException { synchronized (SunDragSourceContextPeer.class) { if (dragDropInProgress == b) { throw new InvalidDnDOperationException(getExceptionMessage(b)); } dragDropInProgress = b; } }
Filters out all mouse events that were on the java event queue when startDrag was called.
/** * Filters out all mouse events that were on the java event queue when * startDrag was called. */
public static boolean checkEvent(AWTEvent event) { if (discardingMouseEvents && event instanceof MouseEvent) { MouseEvent mouseEvent = (MouseEvent)event; if (!(mouseEvent instanceof SunDropTargetEvent)) { return false; } } return true; } public static void checkDragDropInProgress() throws InvalidDnDOperationException { if (dragDropInProgress) { throw new InvalidDnDOperationException(getExceptionMessage(true)); } } private static String getExceptionMessage(boolean b) { return b ? "Drag and drop in progress" : "No drag in progress"; } public static int convertModifiersToDropAction(final int modifiers, final int supportedActions) { int dropAction = DnDConstants.ACTION_NONE; /* * Fix for 4285634. * Calculate the drop action to match Motif DnD behavior. * If the user selects an operation (by pressing a modifier key), * return the selected operation or ACTION_NONE if the selected * operation is not supported by the drag source. * If the user doesn't select an operation search the set of operations * supported by the drag source for ACTION_MOVE, then for * ACTION_COPY, then for ACTION_LINK and return the first operation * found. */ switch (modifiers & (InputEvent.SHIFT_DOWN_MASK | InputEvent.CTRL_DOWN_MASK)) { case InputEvent.SHIFT_DOWN_MASK | InputEvent.CTRL_DOWN_MASK: dropAction = DnDConstants.ACTION_LINK; break; case InputEvent.CTRL_DOWN_MASK: dropAction = DnDConstants.ACTION_COPY; break; case InputEvent.SHIFT_DOWN_MASK: dropAction = DnDConstants.ACTION_MOVE; break; default: if ((supportedActions & DnDConstants.ACTION_MOVE) != 0) { dropAction = DnDConstants.ACTION_MOVE; } else if ((supportedActions & DnDConstants.ACTION_COPY) != 0) { dropAction = DnDConstants.ACTION_COPY; } else if ((supportedActions & DnDConstants.ACTION_LINK) != 0) { dropAction = DnDConstants.ACTION_LINK; } } return dropAction & supportedActions; } private void cleanup() { trigger = null; component = null; cursor = null; dragSourceContext = null; SunDropTargetContextPeer.setCurrentJVMLocalSourceTransferable(null); SunDragSourceContextPeer.setDragDropInProgress(false); } private class EventDispatcher implements Runnable { private final int dispatchType; private final DragSourceEvent event; EventDispatcher(int dispatchType, DragSourceEvent event) { switch (dispatchType) { case DISPATCH_ENTER: case DISPATCH_MOTION: case DISPATCH_CHANGED: case DISPATCH_MOUSE_MOVED: if (!(event instanceof DragSourceDragEvent)) { throw new IllegalArgumentException("Event: " + event); } break; case DISPATCH_EXIT: break; case DISPATCH_FINISH: if (!(event instanceof DragSourceDropEvent)) { throw new IllegalArgumentException("Event: " + event); } break; default: throw new IllegalArgumentException("Dispatch type: " + dispatchType); } this.dispatchType = dispatchType; this.event = event; } public void run() { DragSourceContext dragSourceContext = SunDragSourceContextPeer.this.getDragSourceContext(); try { switch (dispatchType) { case DISPATCH_ENTER: dragSourceContext.dragEnter((DragSourceDragEvent)event); break; case DISPATCH_MOTION: dragSourceContext.dragOver((DragSourceDragEvent)event); break; case DISPATCH_CHANGED: dragSourceContext.dropActionChanged((DragSourceDragEvent)event); break; case DISPATCH_EXIT: dragSourceContext.dragExit(event); break; case DISPATCH_MOUSE_MOVED: dragSourceContext.dragMouseMoved((DragSourceDragEvent)event); break; case DISPATCH_FINISH: try { dragSourceContext.dragDropEnd((DragSourceDropEvent)event); } finally { SunDragSourceContextPeer.this.cleanup(); } break; default: throw new IllegalStateException("Dispatch type: " + dispatchType); } } finally { SunDragSourceContextPeer.this.quitSecondaryEventLoop(); } } } }