Name: sdC67446 Date: 03/13/98


The specification for
java.awt.dnd.DragSource.createDragSourceContext(DragSourceContextPeer,
Component,int actions,Cursor,Image,Point,Transferable,DragSourceListener)
does not specify behavior for argument actions when
it is invalid. The current behavior is to throw IllegalArgumentException for
DnDConstants.ACTION_NONE and ignore other invalid values.
More acceptable behavior for all invalid actions here is to throw
IllegalArgumentException unless otherwise specified.

Here is what doc says:
--------------------------------------------------
protected DragSourceContext createDragSourceContext(
              java.awt.dnd.peer.DragSourceContextPeer dscp,
              Component c,
              int actions,
              Cursor dragCursor,
              Image dragImage,
              Point imageOffset,
              Transferable t,
              DragSourceListener dsl)

      Create the DragSourceContext to handle this Drag. To incorporate a new
      DragSourceContext subclass, subclass DragSource and override this method.
      Parameters:
            dscp - The DragSourceContextPeer for this operation
            c - The Component the drag started in
            actions - The drag "verbs" appropriate
            dragCursor - The initial cursor
            dragImage - The image to drag or null
            imageOffset - The offset of the image origin from the hotspot
                          of the cursor at
            the instant of the trigger
            transferable - The subject data of the operation
            dsl - The DragSourceListener

Here is the test demonstrating the bug
-----------------Test.java------------------------
import java.awt.*;
import java.awt.image.*;
import java.awt.dnd.*;
import java.awt.dnd.peer.*;
import java.awt.datatransfer.*;

public class Test extends DragSource {

    public DragSourceContext createDragSourceContext(
        DragSourceContextPeer dscp, Component component,
        int act, Cursor cursors, Image image, Point point,
        Transferable transferable, DragSourceListener dsl) {

        return super.createDragSourceContext(dscp, component, act,
            cursors, image, point, transferable, dsl);
    }

    // valid actions
    static int actions[] = {
        DnDConstants.ACTION_NONE,
        DnDConstants.ACTION_COPY,
        DnDConstants.ACTION_MOVE,
        DnDConstants.ACTION_COPY_OR_MOVE,
        DnDConstants.ACTION_LINK,
        DnDConstants.ACTION_REFERENCE
    };

    static DragSourceContextPeer dscp = new DragSourceContextPeer() {
        public void startDrag(DragSourceContext ds, AWTEvent trigger, Cursor cursor, int actions) {}
        public Component getComponent() { return null; }
        public void cancelDrag() {}
        public Cursor getCursor() { return null; }
        public void setCursor(Cursor c) {}
        public AWTEvent getTrigger() {return null;}
    };

    static Component component = new Button();

    static Cursor cursor = DragSource.DefaultCopyDrop;

    static Image image = new Image() {
        public int getWidth(ImageObserver observer) {return 0;}
        public int getHeight(ImageObserver observer){return 0;}
        public ImageProducer getSource() {return null;}
        public Graphics getGraphics() {return null;}
        public void flush() {}
        public Object getProperty(String name, ImageObserver observer) {
            return null;
        }
    };

    static Point point = new Point(0,0);

    static Transferable transferable = new Transferable() {
        public Object getTransferData(DataFlavor df) {
            return null;
        }
        public DataFlavor[] getTransferDataFlavors() {
            return null;
        }
        public boolean isDataFlavorSupported(DataFlavor df) {
            return false;
        }
    };

    static DragSourceListener dsl = new DragSourceListener() {
        public void dragEnter(DragSourceDragEvent dsde) {}
        public void dragOver(DragSourceDragEvent dsde) {}
        public void dropActionChanged(DragSourceDragEvent dsde) {}
        public void dragExit(DragSourceEvent dsde) {}
        public void dragDropEnd(DragSourceDropEvent dsde) {}
    };

    public static void main(String[] args) {
        Test test = new Test();
        int act = 666;

        // make sure act is unsupported
        for (int i=0;i<actions.length;i++) {
            if (act == actions[i]) {
                System.out.println("oops!");
                return;
            }
        }

        try {
            DragSourceContext dsc =
                test.createDragSourceContext(dscp,
                                             component,
                                             act,
                                             cursor,
                                             image,
                                             point,
                                             transferable,
                                             dsl);
        } catch (Exception e) {
            System.out.println(e);
        }
        System.out.println("unexpected passage.");
    }
}
---------Output from the test---------------------
unexpected passage.
--------------------------------------------------

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