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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.launcher3.dragndrop;
     18 
     19 import android.graphics.Point;
     20 
     21 /**
     22  * Set of options to control the drag and drop behavior.
     23  */
     24 public class DragOptions {
     25 
     26     /** Whether or not an accessible drag operation is in progress. */
     27     public boolean isAccessibleDrag = false;
     28 
     29     /** Specifies the start location for the system DnD, null when using internal DnD */
     30     public Point systemDndStartPoint = null;
     31 
     32     /** Determines when a deferred drag should start. By default, drags aren't deferred at all. */
     33     public DeferDragCondition deferDragCondition = new DeferDragCondition();
     34 
     35     /**
     36      * Specifies a condition that must be met before DragListener#onDragStart() is called.
     37      * By default, there is no condition and onDragStart() is called immediately following
     38      * DragController#startDrag().
     39      *
     40      * This condition can be overridden, and callbacks are provided for the following cases:
     41      * - The drag starts, but onDragStart() is deferred (onDeferredDragStart()).
     42      * - The drag ends before the condition is met (onDropBeforeDeferredDrag()).
     43      * - The condition is met (onDragStart()).
     44      */
     45     public static class DeferDragCondition {
     46         public boolean shouldStartDeferredDrag(double distanceDragged) {
     47             return true;
     48         }
     49 
     50         /**
     51          * The drag has started, but onDragStart() is deferred.
     52          * This happens when shouldStartDeferredDrag() returns true.
     53          */
     54         public void onDeferredDragStart() {
     55             // Do nothing.
     56         }
     57 
     58         /**
     59          * User dropped before the deferred condition was met,
     60          * i.e. before shouldStartDeferredDrag() returned true.
     61          */
     62         public void onDropBeforeDeferredDrag() {
     63             // Do nothing
     64         }
     65 
     66         /** onDragStart() has been called, now we are in a normal drag. */
     67         public void onDragStart() {
     68             // Do nothing
     69         }
     70     }
     71 }
     72