https://source.android.com/ 
/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.view;

import android.content.ClipData;
import android.content.ClipDescription;
import android.os.Parcel;
import android.os.Parcelable;

import com.android.internal.view.IDragAndDropPermissions;

//TODO: Improve Javadoc

Represents an event that is sent out by the system at various times during a drag and drop
operation. It is a data structure that contains several important pieces of data about
the operation and the underlying data.

 View objects that receive a DragEvent call getAction(), which returns an action type that indicates the state of the drag and drop operation. This allows a View object to react to a change in state by changing its appearance or performing other actions. For example, a View can react to the ACTION_DRAG_ENTERED action type by by changing one or more colors in its displayed image. 



 During a drag and drop operation, the system displays an image that the user drags. This image
 is called a drag shadow. Several action types reflect the position of the drag shadow relative
 to the View receiving the event.



 Most methods return valid data only for certain event actions. This is summarized in the following table. Each possible getAction() value is listed in the first column. The other columns indicate which method or methods return valid data for that getAction() value: 



 

     getAction() Value
     getClipDescription()
     getLocalState()
     getX()
     getY()
     getClipData()
     getResult()
 

 

     ACTION_DRAG_STARTED
     X
     X
     X
     X
      
      
 

 

     ACTION_DRAG_ENTERED
     X
     X
      
      
      
      
 

 

     ACTION_DRAG_LOCATION
     X
     X
     X
     X
      
      
 

 

     ACTION_DRAG_EXITED
     X
     X
      
      
      
      
 

 

     ACTION_DROP
     X
     X
     X
     X
     X
      
 

 

     ACTION_DRAG_ENDED
      
     X
      
      
      
     X
 




 The getAction(), getLocalState() describeContents(), writeToParcel(Parcel, int), and toString() methods always return valid data. 




Developer Guides


For a guide to implementing drag and drop features, read the
Drag and Drop developer guide.




/**
 * Represents an event that is sent out by the system at various times during a drag and drop
 * operation. It is a data structure that contains several important pieces of data about
 * the operation and the underlying data.
 * <p>
 *  View objects that receive a DragEvent call {@link #getAction()}, which returns
 *  an action type that indicates the state of the drag and drop operation. This allows a View
 *  object to react to a change in state by changing its appearance or performing other actions.
 *  For example, a View can react to the {@link #ACTION_DRAG_ENTERED} action type by
 *  by changing one or more colors in its displayed image.
 * </p>
 * <p>
 *  During a drag and drop operation, the system displays an image that the user drags. This image
 *  is called a drag shadow. Several action types reflect the position of the drag shadow relative
 *  to the View receiving the event.
 * </p>
 * <p>
 *  Most methods return valid data only for certain event actions. This is summarized in the
 *  following table. Each possible {@link #getAction()} value is listed in the first column. The
 *  other columns indicate which method or methods return valid data for that getAction() value:
 * </p>
 * <table>
 *  <tr>
 *      <th scope="col">getAction() Value</th>
 *      <th scope="col">getClipDescription()</th>
 *      <th scope="col">getLocalState()</th>
 *      <th scope="col">getX()</th>
 *      <th scope="col">getY()</th>
 *      <th scope="col">getClipData()</th>
 *      <th scope="col">getResult()</th>
 *  </tr>
 *  <tr>
 *      <td>ACTION_DRAG_STARTED</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *  </tr>
 *  <tr>
 *      <td>ACTION_DRAG_ENTERED</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *  </tr>
 *  <tr>
 *      <td>ACTION_DRAG_LOCATION</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *  </tr>
 *  <tr>
 *      <td>ACTION_DRAG_EXITED</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *  </tr>
 *  <tr>
 *      <td>ACTION_DROP</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *  </tr>
 *  <tr>
 *      <td>ACTION_DRAG_ENDED</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">X</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">&nbsp;</td>
 *      <td style="text-align: center;">X</td>
 *  </tr>
 * </table>
 * <p>
 *  The {@link android.view.DragEvent#getAction()},
 *  {@link android.view.DragEvent#getLocalState()}
 *  {@link android.view.DragEvent#describeContents()},
 *  {@link android.view.DragEvent#writeToParcel(Parcel,int)}, and
 *  {@link android.view.DragEvent#toString()} methods always return valid data.
 * </p>
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For a guide to implementing drag and drop features, read the
 * <a href="{@docRoot}guide/topics/ui/drag-drop.html">Drag and Drop</a> developer guide.</p>
 * </div>
 */
public class DragEvent implements Parcelable {
    private static final boolean TRACK_RECYCLED_LOCATION = false;

    int mAction;
    float mX, mY;
    ClipDescription mClipDescription;
    ClipData mClipData;
    IDragAndDropPermissions mDragAndDropPermissions;

    Object mLocalState;
    boolean mDragResult;
    boolean mEventHandlerWasCalled;

    private DragEvent mNext;
    private RuntimeException mRecycledLocation;
    private boolean mRecycled;

    private static final int MAX_RECYCLED = 10;
    private static final Object gRecyclerLock = new Object();
    private static int gRecyclerUsed = 0;
    private static DragEvent gRecyclerTop = null;

    
Action constant returned by getAction(): Signals the start of a drag and drop operation. The View should return true from its onDragEvent() handler method or OnDragListener.onDrag() listener if it can accept a drop. The onDragEvent() or onDrag() methods usually inspect the metadata from getClipDescription() to determine if they can accept the data contained in this drag. For an operation that doesn't represent data transfer, these methods may perform other actions to determine whether or not the View should accept the data. If the View wants to indicate that it is a valid drop target, it can also react by changing its appearance. 

 Views added or becoming visible for the first time during a drag operation receive this
 event when they are added or becoming visible.



 A View only receives further drag events for the drag operation if it returns true in response to ACTION_DRAG_STARTED. 


See Also:
/**
     * Action constant returned by {@link #getAction()}: Signals the start of a
     * drag and drop operation. The View should return {@code true} from its
     * {@link View#onDragEvent(DragEvent) onDragEvent()} handler method or
     * {@link View.OnDragListener#onDrag(View,DragEvent) OnDragListener.onDrag()} listener
     * if it can accept a drop. The onDragEvent() or onDrag() methods usually inspect the metadata
     * from {@link #getClipDescription()} to determine if they can accept the data contained in
     * this drag. For an operation that doesn't represent data transfer, these methods may
     * perform other actions to determine whether or not the View should accept the data.
     * If the View wants to indicate that it is a valid drop target, it can also react by
     * changing its appearance.
     * <p>
     *  Views added or becoming visible for the first time during a drag operation receive this
     *  event when they are added or becoming visible.
     * </p>
     * <p>
     *  A View only receives further drag events for the drag operation if it returns {@code true}
     *  in response to ACTION_DRAG_STARTED.
     * </p>
     * @see #ACTION_DRAG_ENDED
     * @see #getX()
     * @see #getY()
     */
    public static final int ACTION_DRAG_STARTED = 1;

    
Action constant returned by getAction(): Sent to a View after ACTION_DRAG_ENTERED while the drag shadow is still within the View object's bounding box, but not within a descendant view that can accept the data. The getX() and getY() methods supply the X and Y position of of the drag point within the View object's bounding box. 
 A View receives an ACTION_DRAG_ENTERED event before receiving any ACTION_DRAG_LOCATION events. 



The system stops sending ACTION_DRAG_LOCATION events to a View once the user moves the
drag shadow out of the View object's bounding box or into a descendant view that can accept
the data. If the user moves the drag shadow back into the View object's bounding box or out
of a descendant view that can accept the data, the View receives an ACTION_DRAG_ENTERED again
before receiving any more ACTION_DRAG_LOCATION events.



See Also:
/**
     * Action constant returned by {@link #getAction()}: Sent to a View after
     * {@link #ACTION_DRAG_ENTERED} while the drag shadow is still within the View object's bounding
     * box, but not within a descendant view that can accept the data. The {@link #getX()} and
     * {@link #getY()} methods supply
     * the X and Y position of of the drag point within the View object's bounding box.
     * <p>
     * A View receives an {@link #ACTION_DRAG_ENTERED} event before receiving any
     * ACTION_DRAG_LOCATION events.
     * </p>
     * <p>
     * The system stops sending ACTION_DRAG_LOCATION events to a View once the user moves the
     * drag shadow out of the View object's bounding box or into a descendant view that can accept
     * the data. If the user moves the drag shadow back into the View object's bounding box or out
     * of a descendant view that can accept the data, the View receives an ACTION_DRAG_ENTERED again
     * before receiving any more ACTION_DRAG_LOCATION events.
     * </p>
     * @see #ACTION_DRAG_ENTERED
     * @see #getX()
     * @see #getY()
     */
    public static final int ACTION_DRAG_LOCATION = 2;

    
Action constant returned by getAction(): Signals to a View that the user has released the drag shadow, and the drag point is within the bounding box of the View and not within a descendant view that can accept the data. The View should retrieve the data from the DragEvent by calling getClipData(). The methods getX() and getY() return the X and Y position of the drop point within the View object's bounding box. 
 The View should return true from its View.onDragEvent(DragEvent) handler or OnDragListener.onDrag() listener if it accepted the drop, and false if it ignored the drop. 



The View can also react to this action by changing its appearance.



See Also:
/**
     * Action constant returned by {@link #getAction()}: Signals to a View that the user
     * has released the drag shadow, and the drag point is within the bounding box of the View and
     * not within a descendant view that can accept the data.
     * The View should retrieve the data from the DragEvent by calling {@link #getClipData()}.
     * The methods {@link #getX()} and {@link #getY()} return the X and Y position of the drop point
     * within the View object's bounding box.
     * <p>
     * The View should return {@code true} from its {@link View#onDragEvent(DragEvent)}
     * handler or {@link View.OnDragListener#onDrag(View,DragEvent) OnDragListener.onDrag()}
     * listener if it accepted the drop, and {@code false} if it ignored the drop.
     * </p>
     * <p>
     * The View can also react to this action by changing its appearance.
     * </p>
     * @see #getClipData()
     * @see #getX()
     * @see #getY()
     */
    public static final int ACTION_DROP = 3;

    
Action constant returned by getAction(): Signals to a View that the drag and drop operation has concluded. A View that changed its appearance during the operation should return to its usual drawing state in response to this event. 

 All views with listeners that returned boolean true for the ACTION_DRAG_STARTED
 event will receive the ACTION_DRAG_ENDED event even if they are not currently visible when
 the drag ends. Views removed during the drag operation won't receive the ACTION_DRAG_ENDED
 event.



 The View object can call getResult() to see the result of the operation. If a View returned true in response to ACTION_DROP, then getResult() returns true, otherwise it returns false. 


See Also:
/**
     * Action constant returned by {@link #getAction()}:  Signals to a View that the drag and drop
     * operation has concluded.  A View that changed its appearance during the operation should
     * return to its usual drawing state in response to this event.
     * <p>
     *  All views with listeners that returned boolean <code>true</code> for the ACTION_DRAG_STARTED
     *  event will receive the ACTION_DRAG_ENDED event even if they are not currently visible when
     *  the drag ends. Views removed during the drag operation won't receive the ACTION_DRAG_ENDED
     *  event.
     * </p>
     * <p>
     *  The View object can call {@link #getResult()} to see the result of the operation.
     *  If a View returned {@code true} in response to {@link #ACTION_DROP}, then
     *  getResult() returns {@code true}, otherwise it returns {@code false}.
     * </p>
     * @see #ACTION_DRAG_STARTED
     * @see #getResult()
     */
    public static final int ACTION_DRAG_ENDED = 4;

    
Action constant returned by getAction(): Signals to a View that the drag point has entered the bounding box of the View. 

 If the View can accept a drop, it can react to ACTION_DRAG_ENTERED
 by changing its appearance in a way that tells the user that the View is the current
 drop target.


The system stops sending ACTION_DRAG_LOCATION events to a View once the user moves the
drag shadow out of the View object's bounding box or into a descendant view that can accept
the data. If the user moves the drag shadow back into the View object's bounding box or out
of a descendant view that can accept the data, the View receives an ACTION_DRAG_ENTERED again
before receiving any more ACTION_DRAG_LOCATION events.



See Also:
/**
     * Action constant returned by {@link #getAction()}: Signals to a View that the drag point has
     * entered the bounding box of the View.
     * <p>
     *  If the View can accept a drop, it can react to ACTION_DRAG_ENTERED
     *  by changing its appearance in a way that tells the user that the View is the current
     *  drop target.
     * </p>
     * The system stops sending ACTION_DRAG_LOCATION events to a View once the user moves the
     * drag shadow out of the View object's bounding box or into a descendant view that can accept
     * the data. If the user moves the drag shadow back into the View object's bounding box or out
     * of a descendant view that can accept the data, the View receives an ACTION_DRAG_ENTERED again
     * before receiving any more ACTION_DRAG_LOCATION events.
     * </p>
     * @see #ACTION_DRAG_ENTERED
     * @see #ACTION_DRAG_LOCATION
     */
    public static final int ACTION_DRAG_ENTERED = 5;

    
Action constant returned by getAction(): Signals that the user has moved the drag shadow out of the bounding box of the View or into a descendant view that can accept the data. The View can react by changing its appearance in a way that tells the user that View is no longer the immediate drop target. 

 After the system sends an ACTION_DRAG_EXITED event to the View, the View receives no more
 ACTION_DRAG_LOCATION events until the user drags the drag shadow back over the View.



/**
     * Action constant returned by {@link #getAction()}: Signals that the user has moved the
     * drag shadow out of the bounding box of the View or into a descendant view that can accept
     * the data.
     * The View can react by changing its appearance in a way that tells the user that
     * View is no longer the immediate drop target.
     * <p>
     *  After the system sends an ACTION_DRAG_EXITED event to the View, the View receives no more
     *  ACTION_DRAG_LOCATION events until the user drags the drag shadow back over the View.
     * </p>
     *
     */
     public static final int ACTION_DRAG_EXITED = 6;

    private DragEvent() {
    }

    private void init(int action, float x, float y, ClipDescription description, ClipData data,
            IDragAndDropPermissions dragAndDropPermissions, Object localState, boolean result) {
        mAction = action;
        mX = x;
        mY = y;
        mClipDescription = description;
        mClipData = data;
        this.mDragAndDropPermissions = dragAndDropPermissions;
        mLocalState = localState;
        mDragResult = result;
    }

    static DragEvent obtain() {
        return DragEvent.obtain(0, 0f, 0f, null, null, null, null, false);
    }

    
@hide
/** @hide */
    public static DragEvent obtain(int action, float x, float y, Object localState,
            ClipDescription description, ClipData data,
            IDragAndDropPermissions dragAndDropPermissions, boolean result) {
        final DragEvent ev;
        synchronized (gRecyclerLock) {
            if (gRecyclerTop == null) {
                ev = new DragEvent();
                ev.init(action, x, y, description, data, dragAndDropPermissions, localState,
                        result);
                return ev;
            }
            ev = gRecyclerTop;
            gRecyclerTop = ev.mNext;
            gRecyclerUsed -= 1;
        }
        ev.mRecycledLocation = null;
        ev.mRecycled = false;
        ev.mNext = null;

        ev.init(action, x, y, description, data, dragAndDropPermissions, localState, result);

        return ev;
    }

    
@hide
/** @hide */
    public static DragEvent obtain(DragEvent source) {
        return obtain(source.mAction, source.mX, source.mY, source.mLocalState,
                source.mClipDescription, source.mClipData, source.mDragAndDropPermissions,
                source.mDragResult);
    }

    
Inspect the action value of this event.

Returns:One of the following action constants, in the order in which they usually occur
during a drag and drop operation:

/**
     * Inspect the action value of this event.
     * @return One of the following action constants, in the order in which they usually occur
     * during a drag and drop operation:
     * <ul>
     *  <li>{@link #ACTION_DRAG_STARTED}</li>
     *  <li>{@link #ACTION_DRAG_ENTERED}</li>
     *  <li>{@link #ACTION_DRAG_LOCATION}</li>
     *  <li>{@link #ACTION_DROP}</li>
     *  <li>{@link #ACTION_DRAG_EXITED}</li>
     *  <li>{@link #ACTION_DRAG_ENDED}</li>
     * </ul>
     */
    public int getAction() {
        return mAction;
    }

    
Gets the X coordinate of the drag point. The value is only valid if the event action is ACTION_DRAG_STARTED, ACTION_DRAG_LOCATION or ACTION_DROP. 
Returns:The current drag point's X coordinate
/**
     * Gets the X coordinate of the drag point. The value is only valid if the event action is
     * {@link #ACTION_DRAG_STARTED}, {@link #ACTION_DRAG_LOCATION} or {@link #ACTION_DROP}.
     * @return The current drag point's X coordinate
     */
    public float getX() {
        return mX;
    }

    
Gets the Y coordinate of the drag point. The value is only valid if the event action is ACTION_DRAG_STARTED, ACTION_DRAG_LOCATION or ACTION_DROP. 
Returns:The current drag point's Y coordinate
/**
     * Gets the Y coordinate of the drag point. The value is only valid if the event action is
     * {@link #ACTION_DRAG_STARTED}, {@link #ACTION_DRAG_LOCATION} or {@link #ACTION_DROP}.
     * @return The current drag point's Y coordinate
     */
    public float getY() {
        return mY;
    }

    
Returns the ClipData object sent to the system as part of the call to 
startDragAndDrop(). This method only returns valid data if the event action is ACTION_DROP. 
Returns:The ClipData sent to the system by startDragAndDrop().
/**
     * Returns the {@link android.content.ClipData} object sent to the system as part of the call
     * to
     * {@link android.view.View#startDragAndDrop(ClipData,View.DragShadowBuilder,Object,int)
     * startDragAndDrop()}.
     * This method only returns valid data if the event action is {@link #ACTION_DROP}.
     * @return The ClipData sent to the system by startDragAndDrop().
     */
    public ClipData getClipData() {
        return mClipData;
    }

    
Returns the ClipDescription object contained in the ClipData object sent to the system as part of the call to 
startDragAndDrop(). The drag handler or listener for a View can use the metadata in this object to decide if the View can accept the dragged View object's data. 
 This method returns valid data for all event actions except for ACTION_DRAG_ENDED. 
Returns:The ClipDescription that was part of the ClipData sent to the system by
    startDragAndDrop().
/**
     * Returns the {@link android.content.ClipDescription} object contained in the
     * {@link android.content.ClipData} object sent to the system as part of the call to
     * {@link android.view.View#startDragAndDrop(ClipData,View.DragShadowBuilder,Object,int)
     * startDragAndDrop()}.
     * The drag handler or listener for a View can use the metadata in this object to decide if the
     * View can accept the dragged View object's data.
     * <p>
     * This method returns valid data for all event actions except for {@link #ACTION_DRAG_ENDED}.
     * @return The ClipDescription that was part of the ClipData sent to the system by
     *     startDragAndDrop().
     */
    public ClipDescription getClipDescription() {
        return mClipDescription;
    }

    
@hide
/** @hide */
    public IDragAndDropPermissions getDragAndDropPermissions() {
        return mDragAndDropPermissions;
    }

    
Returns the local state object sent to the system as part of the call to 
startDragAndDrop(). The object is intended to provide local information about the drag and drop operation. For example, it can indicate whether the drag and drop operation is a copy or a move. 

The local state is available only to views in the activity which has started the drag
operation. In all other activities this method will return null




 This method returns valid data for all event actions.



Returns:The local state object sent to the system by startDragAndDrop().
/**
     * Returns the local state object sent to the system as part of the call to
     * {@link android.view.View#startDragAndDrop(ClipData,View.DragShadowBuilder,Object,int)
     * startDragAndDrop()}.
     * The object is intended to provide local information about the drag and drop operation. For
     * example, it can indicate whether the drag and drop operation is a copy or a move.
     * <p>
     * The local state is available only to views in the activity which has started the drag
     * operation. In all other activities this method will return null
     * </p>
     * <p>
     *  This method returns valid data for all event actions.
     * </p>
     * @return The local state object sent to the system by startDragAndDrop().
     */
    public Object getLocalState() {
        return mLocalState;
    }

    
 Returns an indication of the result of the drag and drop operation. This method only returns valid data if the action type is ACTION_DRAG_ENDED. The return value depends on what happens after the user releases the drag shadow. 


 If the user releases the drag shadow on a View that can accept a drop, the system sends an ACTION_DROP event to the View object's drag event listener. If the listener returns true, then getResult() will return true. If the listener returns false, then getResult() returns false. 


 Notice that getResult() also returns false if no ACTION_DROP is sent. This happens, for example, when the user releases the drag shadow over an area outside of the application. In this case, the system sends out ACTION_DRAG_ENDED for the current operation, but never sends out ACTION_DROP. 


Returns:true if a drag event listener returned true in response to ACTION_DROP. If the system did not send ACTION_DROP before ACTION_DRAG_ENDED, or if the listener returned false in response to ACTION_DROP, then false is returned.
/**
     * <p>
     * Returns an indication of the result of the drag and drop operation.
     * This method only returns valid data if the action type is {@link #ACTION_DRAG_ENDED}.
     * The return value depends on what happens after the user releases the drag shadow.
     * </p>
     * <p>
     * If the user releases the drag shadow on a View that can accept a drop, the system sends an
     * {@link #ACTION_DROP} event to the View object's drag event listener. If the listener
     * returns {@code true}, then getResult() will return {@code true}.
     * If the listener returns {@code false}, then getResult() returns {@code false}.
     * </p>
     * <p>
     * Notice that getResult() also returns {@code false} if no {@link #ACTION_DROP} is sent. This
     * happens, for example, when the user releases the drag shadow over an area outside of the
     * application. In this case, the system sends out {@link #ACTION_DRAG_ENDED} for the current
     * operation, but never sends out {@link #ACTION_DROP}.
     * </p>
     * @return {@code true} if a drag event listener returned {@code true} in response to
     * {@link #ACTION_DROP}. If the system did not send {@link #ACTION_DROP} before
     * {@link #ACTION_DRAG_ENDED}, or if the listener returned {@code false} in response to
     * {@link #ACTION_DROP}, then {@code false} is returned.
     */
    public boolean getResult() {
        return mDragResult;
    }

    
Recycle the DragEvent, to be re-used by a later caller.  After calling
this function you must never touch the event again.

@hide
/**
     * Recycle the DragEvent, to be re-used by a later caller.  After calling
     * this function you must never touch the event again.
     *
     * @hide
     */
    public final void recycle() {
        // Ensure recycle is only called once!
        if (TRACK_RECYCLED_LOCATION) {
            if (mRecycledLocation != null) {
                throw new RuntimeException(toString() + " recycled twice!", mRecycledLocation);
            }
            mRecycledLocation = new RuntimeException("Last recycled here");
        } else {
            if (mRecycled) {
                throw new RuntimeException(toString() + " recycled twice!");
            }
            mRecycled = true;
        }

        mClipData = null;
        mClipDescription = null;
        mLocalState = null;
        mEventHandlerWasCalled = false;

        synchronized (gRecyclerLock) {
            if (gRecyclerUsed < MAX_RECYCLED) {
                gRecyclerUsed++;
                mNext = gRecyclerTop;
                gRecyclerTop = this;
            }
        }
    }

    
Returns a string containing a concise, human-readable representation of this DragEvent
object.

Returns:A string representation of the DragEvent object.
/**
     * Returns a string containing a concise, human-readable representation of this DragEvent
     * object.
     * @return A string representation of the DragEvent object.
     */
    @Override
    public String toString() {
        return "DragEvent{" + Integer.toHexString(System.identityHashCode(this))
        + " action=" + mAction + " @ (" + mX + ", " + mY + ") desc=" + mClipDescription
        + " data=" + mClipData + " local=" + mLocalState + " result=" + mDragResult
        + "}";
    }

    /* Parcelable interface */

    
Returns information about the Parcel representation of this DragEvent object. 
Returns:Information about the Parcel representation.
/**
     * Returns information about the {@link android.os.Parcel} representation of this DragEvent
     * object.
     * @return Information about the {@link android.os.Parcel} representation.
     */
    public int describeContents() {
        return 0;
    }

    
Creates a Parcel object from this DragEvent object. 
Params:
  • dest – A Parcel object in which to put the DragEvent object.
  • flags – Flags to store in the Parcel.
/**
     * Creates a {@link android.os.Parcel} object from this DragEvent object.
     * @param dest A {@link android.os.Parcel} object in which to put the DragEvent object.
     * @param flags Flags to store in the Parcel.
     */
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(mAction);
        dest.writeFloat(mX);
        dest.writeFloat(mY);
        dest.writeInt(mDragResult ? 1 : 0);
        if (mClipData == null) {
            dest.writeInt(0);
        } else {
            dest.writeInt(1);
            mClipData.writeToParcel(dest, flags);
        }
        if (mClipDescription == null) {
            dest.writeInt(0);
        } else {
            dest.writeInt(1);
            mClipDescription.writeToParcel(dest, flags);
        }
        if (mDragAndDropPermissions == null) {
            dest.writeInt(0);
        } else {
            dest.writeInt(1);
            dest.writeStrongBinder(mDragAndDropPermissions.asBinder());
        }
    }

    
A container for creating a DragEvent from a Parcel.

/**
     * A container for creating a DragEvent from a Parcel.
     */
    public static final Parcelable.Creator<DragEvent> CREATOR =
        new Parcelable.Creator<DragEvent>() {
        public DragEvent createFromParcel(Parcel in) {
            DragEvent event = DragEvent.obtain();
            event.mAction = in.readInt();
            event.mX = in.readFloat();
            event.mY = in.readFloat();
            event.mDragResult = (in.readInt() != 0);
            if (in.readInt() != 0) {
                event.mClipData = ClipData.CREATOR.createFromParcel(in);
            }
            if (in.readInt() != 0) {
                event.mClipDescription = ClipDescription.CREATOR.createFromParcel(in);
            }
            if (in.readInt() != 0) {
                event.mDragAndDropPermissions =
                        IDragAndDropPermissions.Stub.asInterface(in.readStrongBinder());;
            }
            return event;
        }

        public DragEvent[] newArray(int size) {
            return new DragEvent[size];
        }
    };
}