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* accompanied this code).
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package java.awt.dnd;
import java.awt.Point;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.util.List;
/**
* The {@code DropTargetDragEvent} is delivered to a
* {@code DropTargetListener} via its
* dragEnter() and dragOver() methods.
* <p>
* The {@code DropTargetDragEvent} reports the <i>source drop actions</i>
* and the <i>user drop action</i> that reflect the current state of
* the drag operation.
* <p>
* <i>Source drop actions</i> is a bitwise mask of {@code DnDConstants}
* that represents the set of drop actions supported by the drag source for
* this drag operation.
* <p>
* <i>User drop action</i> depends on the drop actions supported by the drag
* source and the drop action selected by the user. The user can select a drop
* action by pressing modifier keys during the drag operation:
* <pre>
* Ctrl + Shift -> ACTION_LINK
* Ctrl -> ACTION_COPY
* Shift -> ACTION_MOVE
* </pre>
* If the user selects a drop action, the <i>user drop action</i> is one of
* {@code DnDConstants} that represents the selected drop action if this
* drop action is supported by the drag source or
* {@code DnDConstants.ACTION_NONE} if this drop action is not supported
* by the drag source.
* <p>
* If the user doesn't select a drop action, the set of
* {@code DnDConstants} that represents the set of drop actions supported
* by the drag source is searched for {@code DnDConstants.ACTION_MOVE},
* then for {@code DnDConstants.ACTION_COPY}, then for
* {@code DnDConstants.ACTION_LINK} and the <i>user drop action</i> is the
* first constant found. If no constant is found the <i>user drop action</i>
* is {@code DnDConstants.ACTION_NONE}.
*
* @since 1.2
*/
public class DropTargetDragEvent extends DropTargetEvent {
private static final long serialVersionUID = -8422265619058953682L;
/**
* Construct a {@code DropTargetDragEvent} given the
* {@code DropTargetContext} for this operation,
* the location of the "Drag" {@code Cursor}'s hotspot
* in the {@code Component}'s coordinates, the
* user drop action, and the source drop actions.
*
* @param dtc The DropTargetContext for this operation
* @param cursorLocn The location of the "Drag" Cursor's
* hotspot in Component coordinates
* @param dropAction The user drop action
* @param srcActions The source drop actions
*
* @throws NullPointerException if cursorLocn is null
* @throws IllegalArgumentException if dropAction is not one of
* {@code DnDConstants}.
* @throws IllegalArgumentException if srcActions is not
* a bitwise mask of {@code DnDConstants}.
* @throws IllegalArgumentException if dtc is {@code null}.
*/
public DropTargetDragEvent(DropTargetContext dtc, Point cursorLocn, int dropAction, int srcActions) {
super(dtc);
if (cursorLocn == null) throw new NullPointerException("cursorLocn");
if (dropAction != DnDConstants.ACTION_NONE &&
dropAction != DnDConstants.ACTION_COPY &&
dropAction != DnDConstants.ACTION_MOVE &&
dropAction != DnDConstants.ACTION_LINK
) throw new IllegalArgumentException("dropAction" + dropAction);
if ((srcActions & ~(DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_LINK)) != 0) throw new IllegalArgumentException("srcActions");
location = cursorLocn;
actions = srcActions;
this.dropAction = dropAction;
}
/**
* This method returns a {@code Point}
* indicating the {@code Cursor}'s current
* location within the {@code Component'}s
* coordinates.
*
* @return the current cursor location in
* {@code Component}'s coords.
*/
public Point getLocation() {
return location;
}
/**
* This method returns the current {@code DataFlavor}s from the
* {@code DropTargetContext}.
*
* @return current DataFlavors from the DropTargetContext
*/
public DataFlavor[] getCurrentDataFlavors() {
return getDropTargetContext().getCurrentDataFlavors();
}
/**
* This method returns the current {@code DataFlavor}s
* as a {@code java.util.List}
*
* @return a {@code java.util.List} of the Current {@code DataFlavor}s
*/
public List<DataFlavor> getCurrentDataFlavorsAsList() {
return getDropTargetContext().getCurrentDataFlavorsAsList();
}
/**
* This method returns a {@code boolean} indicating
* if the specified {@code DataFlavor} is supported.
*
* @param df the {@code DataFlavor} to test
*
* @return if a particular DataFlavor is supported
*/
public boolean isDataFlavorSupported(DataFlavor df) {
return getDropTargetContext().isDataFlavorSupported(df);
}
/**
* This method returns the source drop actions.
*
* @return the source drop actions
*/
public int getSourceActions() { return actions; }
/**
* This method returns the user drop action.
*
* @return the user drop action
*/
public int getDropAction() { return dropAction; }
/**
* This method returns the Transferable object that represents
* the data associated with the current drag operation.
*
* @return the Transferable associated with the drag operation
* @throws InvalidDnDOperationException if the data associated with the drag
* operation is not available
*
* @since 1.5
*/
public Transferable getTransferable() {
return getDropTargetContext().getTransferable();
}
/**
* Accepts the drag.
*
* This method should be called from a
* {@code DropTargetListeners dragEnter},
* {@code dragOver}, and {@code dropActionChanged}
* methods if the implementation wishes to accept an operation
* from the srcActions other than the one selected by
* the user as represented by the {@code dropAction}.
*
* @param dragOperation the operation accepted by the target
*/
public void acceptDrag(int dragOperation) {
getDropTargetContext().acceptDrag(dragOperation);
}
/**
* Rejects the drag as a result of examining either the
* {@code dropAction} or the available {@code DataFlavor}
* types.
*/
public void rejectDrag() {
getDropTargetContext().rejectDrag();
}
/*
* fields
*/
/**
* The location of the drag cursor's hotspot in Component coordinates.
*
* @serial
*/
private Point location;
/**
* The source drop actions.
*
* @serial
*/
private int actions;
/**
* The user drop action.
*
* @serial
*/
private int dropAction;
}