/*
* @(#)DragSourceDragEvent.java 1.29 03/12/19
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.awt.dnd;
import java.awt.event.InputEvent;
/**
* The <code>DragSourceDragEvent</code> is
* delivered from the <code>DragSourceContextPeer</code>,
* via the <code>DragSourceContext</code>, to the <code>DragSourceListener</code>
* registered with that <code>DragSourceContext</code> and with its associated
* <code>DragSource</code>.
* <p>
* The <code>DragSourceDragEvent</code> 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</code> 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</code> 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 -> 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</code> that represents the selected drop action if this
* drop action is supported by the drag source or
* <code>DnDConstants.ACTION_NONE</code> 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</code> that represents the set of drop actions supported
* by the drag source is searched for <code>DnDConstants.ACTION_MOVE</code>,
* then for <code>DnDConstants.ACTION_COPY</code>, then for
* <code>DnDConstants.ACTION_LINK</code> 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</code>.
*
* @version 1.29, 12/19/03
* @since 1.2
*
*/
public class DragSourceDragEvent extends DragSourceEvent {
private static final long serialVersionUID = 481346297933902471L;
/**
* Constructs a <code>DragSourceDragEvent</code>.
* This class is typically
* instantiated by the <code>DragSourceContextPeer</code>
* rather than directly
* by client code.
* The coordinates for this <code>DragSourceDragEvent</code>
* are not specified, so <code>getLocation</code> will return
* <code>null</code> for this event.
* <p>
* The arguments <code>dropAction</code> and <code>action</code> should
* be one of <code>DnDConstants</code> that represents a single action.
* The argument <code>modifiers</code> should be either a bitwise mask
* of old <code>java.awt.event.InputEvent.*_MASK</code> constants or a
* bitwise mask of extended <code>java.awt.event.InputEvent.*_DOWN_MASK</code>
* constants.
* This constructor does not throw any exception for invalid <code>dropAction</code>,
* <code>action</code> and <code>modifiers</code>.
*
* @param dsc the <code>DragSourceContext</code> 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 <code>IllegalArgumentException</code> if <code>dsc</code> is <code>null</code>.
*
* @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 <code>DragSourceDragEvent</code> given the specified
* <code>DragSourceContext</code>, user drop action, target drop action,
* modifiers and coordinates.
* <p>
* The arguments <code>dropAction</code> and <code>action</code> should
* be one of <code>DnDConstants</code> that represents a single action.
* The argument <code>modifiers</code> should be either a bitwise mask
* of old <code>java.awt.event.InputEvent.*_MASK</code> constants or a
* bitwise mask of extended <code>java.awt.event.InputEvent.*_DOWN_MASK</code>
* constants.
* This constructor does not throw any exception for invalid <code>dropAction</code>,
* <code>action</code> and <code>modifiers</code>.
*
* @param dsc the <code>DragSourceContext</code> 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 <code>IllegalArgumentException</code> if <code>dsc</code> is <code>null</code>.
*
* @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.
*
* @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 <code>int</code> 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</code> 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 <code>int</code> 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</code> 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.
*
* @return the user drop action.
*/
public int getUserAction() { return dropAction; }
/**
* This method returns the logical intersection of the user drop action,
* the target drop action and the set of drop actions supported by
* the drag source.
*
* @return the logical intersection of the user drop action, the target drop
* action and the set of drop actions supported by the drag source.
*/
public int getDropAction() {
return dropAction & targetActions & getDragSourceContext().getSourceActions();
}
/*
* fields
*/
/**
* The target drop action.
*
* @serial
*/
private int targetActions = DnDConstants.ACTION_NONE;
/**
* The user drop action.
*
* @serial
*/
private int dropAction = DnDConstants.ACTION_NONE;
/**
* The state of the input device modifiers associated with the user
* gesture.
*
* @serial
*/
private int gestureModifiers = 0;
/**
* Indicates whether the <code>gestureModifiers</code> are invalid.
*
* @serial
*/
private boolean invalidModifiers;
/**
* Sets new modifiers by the old ones.
* The mouse modifiers have higher priority than overlaying key
* modifiers.
*/
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.
*/
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;
}
}
}
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