java/11 : java.desktop/java/awt/dnd/DragSourceDragEvent.java

DragSourceDragEvent
https://openjdk.java.net/
GPLv2 + Classpath Exception
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package java.awt.dnd;

import java.awt.event.InputEvent;

The DragSourceDragEvent is delivered from the DragSourceContextPeer, via the DragSourceContext, to the DragSourceListener registered with that DragSourceContext and with its associated DragSource.  The DragSourceDragEvent reports the target drop action
and the user drop action that reflect the current state of
the drag operation.

Target drop action is one of DnDConstants that represents the drop action selected by the current drop target if this drop action is supported by the drag source or DnDConstants.ACTION_NONE if this drop action is not supported by the drag source. 

User drop action 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:
  Ctrl + Shift -> ACTION_LINK
  Ctrl         -> ACTION_COPY
  Shift        -> ACTION_MOVE

If the user selects a drop action, the user drop action is one of DnDConstants that represents the selected drop action if this drop action is supported by the drag source or DnDConstants.ACTION_NONE if this drop action is not supported by the drag source.  If the user doesn't select a drop action, the set of DnDConstants that represents the set of drop actions supported by the drag source is searched for DnDConstants.ACTION_MOVE, then for DnDConstants.ACTION_COPY, then for DnDConstants.ACTION_LINK and the user drop action is the
first constant found. If no constant is found the user drop action is DnDConstants.ACTION_NONE. 
Since: 1.2/**
 * The {@code DragSourceDragEvent} is
 * delivered from the {@code DragSourceContextPeer},
 * via the {@code DragSourceContext}, to the {@code DragSourceListener}
 * registered with that {@code DragSourceContext} and with its associated
 * {@code DragSource}.
 * <p>
 * The {@code DragSourceDragEvent} reports the <i>target drop action</i>
 * and the <i>user drop action</i> that reflect the current state of
 * the drag operation.
 * <p>
 * <i>Target drop action</i> is one of {@code DnDConstants} that represents
 * the drop action selected by the current drop target 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>
 * <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 -&gt; ACTION_LINK
 *   Ctrl         -&gt; ACTION_COPY
 *   Shift        -&gt; 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 DragSourceDragEvent extends DragSourceEvent {

    private static final long serialVersionUID = 481346297933902471L;

    Constructs a DragSourceDragEvent. This class is typically instantiated by the DragSourceContextPeer rather than directly by client code. The coordinates for this DragSourceDragEvent are not specified, so getLocation will return null for this event.  The arguments dropAction and action should be one of DnDConstants that represents a single action. The argument modifiers should be either a bitwise mask of old java.awt.event.InputEvent.*_MASK constants or a bitwise mask of extended java.awt.event.InputEvent.*_DOWN_MASK constants. This constructor does not throw any exception for invalid dropAction, action and modifiers. 
Params: dsc – the DragSourceContext that is to manage notifications for this event.
dropAction – the user drop action.
action – the target drop action.
modifiers – the modifier keys down during event (shift, ctrl,
       alt, meta)
       Either extended _DOWN_MASK or old _MASK modifiers
       should be used, but both models should not be mixed
       in one event. Use of the extended modifiers is
       preferred.
Throws: IllegalArgumentException – if dsc is null.
See Also: InputEvent
DragSourceEvent.getLocation/**
     * Constructs a {@code DragSourceDragEvent}.
     * This class is typically
     * instantiated by the {@code DragSourceContextPeer}
     * rather than directly
     * by client code.
     * The coordinates for this {@code DragSourceDragEvent}
     * are not specified, so {@code getLocation} will return
     * {@code null} for this event.
     * <p>
     * The arguments {@code dropAction} and {@code action} should
     * be one of {@code DnDConstants} that represents a single action.
     * The argument {@code modifiers} should be either a bitwise mask
     * of old {@code java.awt.event.InputEvent.*_MASK} constants or a
     * bitwise mask of extended {@code java.awt.event.InputEvent.*_DOWN_MASK}
     * constants.
     * This constructor does not throw any exception for invalid {@code dropAction},
     * {@code action} and {@code modifiers}.
     *
     * @param dsc the {@code DragSourceContext} that is to manage
     *            notifications for this event.
     * @param dropAction the user drop action.
     * @param action the target drop action.
     * @param modifiers the modifier keys down during event (shift, ctrl,
     *        alt, meta)
     *        Either extended _DOWN_MASK or old _MASK modifiers
     *        should be used, but both models should not be mixed
     *        in one event. Use of the extended modifiers is
     *        preferred.
     *
     * @throws IllegalArgumentException if {@code dsc} is {@code null}.
     *
     * @see java.awt.event.InputEvent
     * @see DragSourceEvent#getLocation
     */

    public DragSourceDragEvent(DragSourceContext dsc, int dropAction,
                               int action, int modifiers) {
        super(dsc);

        targetActions    = action;
        gestureModifiers = modifiers;
        this.dropAction  = dropAction;
        if ((modifiers & ~(JDK_1_3_MODIFIERS | JDK_1_4_MODIFIERS)) != 0) {
            invalidModifiers = true;
        } else if ((getGestureModifiers() != 0) && (getGestureModifiersEx() == 0)) {
            setNewModifiers();
        } else if ((getGestureModifiers() == 0) && (getGestureModifiersEx() != 0)) {
            setOldModifiers();
        } else {
            invalidModifiers = true;
        }
    }

    Constructs a DragSourceDragEvent given the specified DragSourceContext, user drop action, target drop action, modifiers and coordinates.  The arguments dropAction and action should be one of DnDConstants that represents a single action. The argument modifiers should be either a bitwise mask of old java.awt.event.InputEvent.*_MASK constants or a bitwise mask of extended java.awt.event.InputEvent.*_DOWN_MASK constants. This constructor does not throw any exception for invalid dropAction, action and modifiers. 
Params: dsc – the DragSourceContext associated with this event.
dropAction – the user drop action.
action – the target drop action.
modifiers – the modifier keys down during event (shift, ctrl,
       alt, meta)
       Either extended _DOWN_MASK or old _MASK modifiers
       should be used, but both models should not be mixed
       in one event. Use of the extended modifiers is
       preferred.
x –   the horizontal coordinate for the cursor location
y –   the vertical coordinate for the cursor location
Throws: IllegalArgumentException – if dsc is null.
See Also: InputEvent
Since: 1.4/**
     * Constructs a {@code DragSourceDragEvent} given the specified
     * {@code DragSourceContext}, user drop action, target drop action,
     * modifiers and coordinates.
     * <p>
     * The arguments {@code dropAction} and {@code action} should
     * be one of {@code DnDConstants} that represents a single action.
     * The argument {@code modifiers} should be either a bitwise mask
     * of old {@code java.awt.event.InputEvent.*_MASK} constants or a
     * bitwise mask of extended {@code java.awt.event.InputEvent.*_DOWN_MASK}
     * constants.
     * This constructor does not throw any exception for invalid {@code dropAction},
     * {@code action} and {@code modifiers}.
     *
     * @param dsc the {@code DragSourceContext} associated with this
     *        event.
     * @param dropAction the user drop action.
     * @param action the target drop action.
     * @param modifiers the modifier keys down during event (shift, ctrl,
     *        alt, meta)
     *        Either extended _DOWN_MASK or old _MASK modifiers
     *        should be used, but both models should not be mixed
     *        in one event. Use of the extended modifiers is
     *        preferred.
     * @param x   the horizontal coordinate for the cursor location
     * @param y   the vertical coordinate for the cursor location
     *
     * @throws IllegalArgumentException if {@code dsc} is {@code null}.
     *
     * @see java.awt.event.InputEvent
     * @since 1.4
     */
    public DragSourceDragEvent(DragSourceContext dsc, int dropAction,
                               int action, int modifiers, int x, int y) {
        super(dsc, x, y);

        targetActions    = action;
        gestureModifiers = modifiers;
        this.dropAction  = dropAction;
        if ((modifiers & ~(JDK_1_3_MODIFIERS | JDK_1_4_MODIFIERS)) != 0) {
            invalidModifiers = true;
        } else if ((getGestureModifiers() != 0) && (getGestureModifiersEx() == 0)) {
            setNewModifiers();
        } else if ((getGestureModifiers() == 0) && (getGestureModifiersEx() != 0)) {
            setOldModifiers();
        } else {
            invalidModifiers = true;
        }
    }

    This method returns the target drop action.
Returns: the target drop action./**
     * This method returns the target drop action.
     *
     * @return the target drop action.
     */
    public int getTargetActions() {
        return targetActions;
    }


    private static final int JDK_1_3_MODIFIERS = InputEvent.SHIFT_DOWN_MASK - 1;
    private static final int JDK_1_4_MODIFIERS =
            ((InputEvent.ALT_GRAPH_DOWN_MASK << 1) - 1) & ~JDK_1_3_MODIFIERS;

    This method returns an int representing the current state of the input device modifiers associated with the user's gesture. Typically these would be mouse buttons or keyboard modifiers.  If the modifiers passed to the constructor are invalid, this method returns them unchanged. 
Returns: the current state of the input device modifiers/**
     * This method returns an {@code int} representing
     * the current state of the input device modifiers
     * associated with the user's gesture. Typically these
     * would be mouse buttons or keyboard modifiers.
     * <P>
     * If the {@code modifiers} passed to the constructor
     * are invalid, this method returns them unchanged.
     *
     * @return the current state of the input device modifiers
     */

    public int getGestureModifiers() {
        return invalidModifiers ? gestureModifiers : gestureModifiers & JDK_1_3_MODIFIERS;
    }

    This method returns an int representing the current state of the input device extended modifiers associated with the user's gesture. See InputEvent.getModifiersEx  If the modifiers passed to the constructor are invalid, this method returns them unchanged. 
Returns: the current state of the input device extended modifiers
Since: 1.4/**
     * This method returns an {@code int} representing
     * the current state of the input device extended modifiers
     * associated with the user's gesture.
     * See {@link InputEvent#getModifiersEx}
     * <P>
     * If the {@code modifiers} passed to the constructor
     * are invalid, this method returns them unchanged.
     *
     * @return the current state of the input device extended modifiers
     * @since 1.4
     */

    public int getGestureModifiersEx() {
        return invalidModifiers ? gestureModifiers : gestureModifiers & JDK_1_4_MODIFIERS;
    }

    This method returns the user drop action.
Returns: the user drop action./**
     * This method returns the user drop action.
     *
     * @return the user drop action.
     */
    public int getUserAction() { return dropAction; }

    This method returns the logical intersection of
the target drop action and the set of drop actions supported by
the drag source.
Returns: the logical intersection of the target drop action and
        the set of drop actions supported by the drag source./**
     * This method returns the logical intersection of
     * the target drop action and the set of drop actions supported by
     * the drag source.
     *
     * @return the logical intersection of the target drop action and
     *         the set of drop actions supported by the drag source.
     */
    public int getDropAction() {
        return targetActions & getDragSourceContext().getSourceActions();
    }

    /*
     * fields
     */

    The target drop action.
@serial /**
     * The target drop action.
     *
     * @serial
     */
    private int     targetActions    = DnDConstants.ACTION_NONE;

    The user drop action.
@serial /**
     * The user drop action.
     *
     * @serial
     */
    private int     dropAction       = DnDConstants.ACTION_NONE;

    The state of the input device modifiers associated with the user
gesture.
@serial /**
     * The state of the input device modifiers associated with the user
     * gesture.
     *
     * @serial
     */
    private int     gestureModifiers = 0;

    Indicates whether the gestureModifiers are invalid. 
@serial /**
     * Indicates whether the {@code gestureModifiers} are invalid.
     *
     * @serial
     */
    private boolean invalidModifiers;

    Sets new modifiers by the old ones.
The mouse modifiers have higher priority than overlaying key
modifiers.
/**
     * Sets new modifiers by the old ones.
     * The mouse modifiers have higher priority than overlaying key
     * modifiers.
     */
    @SuppressWarnings("deprecation")
    private void setNewModifiers() {
        if ((gestureModifiers & InputEvent.BUTTON1_MASK) != 0) {
            gestureModifiers |= InputEvent.BUTTON1_DOWN_MASK;
        }
        if ((gestureModifiers & InputEvent.BUTTON2_MASK) != 0) {
            gestureModifiers |= InputEvent.BUTTON2_DOWN_MASK;
        }
        if ((gestureModifiers & InputEvent.BUTTON3_MASK) != 0) {
            gestureModifiers |= InputEvent.BUTTON3_DOWN_MASK;
        }
        if ((gestureModifiers & InputEvent.SHIFT_MASK) != 0) {
            gestureModifiers |= InputEvent.SHIFT_DOWN_MASK;
        }
        if ((gestureModifiers & InputEvent.CTRL_MASK) != 0) {
            gestureModifiers |= InputEvent.CTRL_DOWN_MASK;
        }
        if ((gestureModifiers & InputEvent.ALT_GRAPH_MASK) != 0) {
            gestureModifiers |= InputEvent.ALT_GRAPH_DOWN_MASK;
        }
    }

    Sets old modifiers by the new ones.
/**
     * Sets old modifiers by the new ones.
     */
    @SuppressWarnings("deprecation")
    private void setOldModifiers() {
        if ((gestureModifiers & InputEvent.BUTTON1_DOWN_MASK) != 0) {
            gestureModifiers |= InputEvent.BUTTON1_MASK;
        }
        if ((gestureModifiers & InputEvent.BUTTON2_DOWN_MASK) != 0) {
            gestureModifiers |= InputEvent.BUTTON2_MASK;
        }
        if ((gestureModifiers & InputEvent.BUTTON3_DOWN_MASK) != 0) {
            gestureModifiers |= InputEvent.BUTTON3_MASK;
        }
        if ((gestureModifiers & InputEvent.SHIFT_DOWN_MASK) != 0) {
            gestureModifiers |= InputEvent.SHIFT_MASK;
        }
        if ((gestureModifiers & InputEvent.CTRL_DOWN_MASK) != 0) {
            gestureModifiers |= InputEvent.CTRL_MASK;
        }
        if ((gestureModifiers & InputEvent.ALT_GRAPH_DOWN_MASK) != 0) {
            gestureModifiers |= InputEvent.ALT_GRAPH_MASK;
        }
    }
}
Params:	dsc – the `DragSourceContext` that is to manage notifications for this event. dropAction – the user drop action. action – the target drop action. modifiers – the modifier keys down during event (shift, ctrl, alt, meta) Either extended _DOWN_MASK or old _MASK modifiers should be used, but both models should not be mixed in one event. Use of the extended modifiers is preferred.
Throws:	IllegalArgumentException – if `dsc` is `null`.
See Also:	InputEvent DragSourceEvent.getLocation
Params:	dsc – the `DragSourceContext` associated with this event. dropAction – the user drop action. action – the target drop action. modifiers – the modifier keys down during event (shift, ctrl, alt, meta) Either extended _DOWN_MASK or old _MASK modifiers should be used, but both models should not be mixed in one event. Use of the extended modifiers is preferred. x – the horizontal coordinate for the cursor location y – the vertical coordinate for the cursor location
Throws:	IllegalArgumentException – if `dsc` is `null`.
See Also:	InputEvent
Since:	1.4
Returns:	the current state of the input device extended modifiers
Since:	1.4
/

java/ 11/ java.desktop/java/awt/dnd/DragSourceDragEvent.java
