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 import android.support.annotation.CallSuper; 21 import android.view.View; 22 23 import com.android.launcher3.DropTarget; 24 25 /** 26 * Set of options to control the drag and drop behavior. 27 */ 28 public class DragOptions { 29 30 /** Whether or not an accessible drag operation is in progress. */ 31 public boolean isAccessibleDrag = false; 32 33 /** Specifies the start location for the system DnD, null when using internal DnD */ 34 public Point systemDndStartPoint = null; 35 36 /** Determines when a pre-drag should transition to a drag. By default, this is immediate. */ 37 public PreDragCondition preDragCondition = null; 38 39 /** 40 * Specifies a condition that must be met before DragListener#onDragStart() is called. 41 * By default, there is no condition and onDragStart() is called immediately following 42 * DragController#startDrag(). 43 * 44 * This condition can be overridden, and callbacks are provided for the following cases: 45 * - The pre-drag starts, but onDragStart() is deferred (onPreDragStart()). 46 * - The pre-drag ends before the condition is met (onPreDragEnd(false)). 47 * - The actual drag starts when the condition is met (onPreDragEnd(true)). 48 */ 49 public interface PreDragCondition { 50 shouldStartDrag(double distanceDragged)51 public boolean shouldStartDrag(double distanceDragged); 52 53 /** 54 * The pre-drag has started, but onDragStart() is 55 * deferred until shouldStartDrag() returns true. 56 */ onPreDragStart(DropTarget.DragObject dragObject)57 void onPreDragStart(DropTarget.DragObject dragObject); 58 59 /** 60 * The pre-drag has ended. This gets called at the same time as onDragStart() 61 * if the condition is met, otherwise at the same time as onDragEnd(). 62 * @param dragStarted Whether the pre-drag ended because the actual drag started. 63 * This will be true if the condition was met, otherwise false. 64 */ onPreDragEnd(DropTarget.DragObject dragObject, boolean dragStarted)65 void onPreDragEnd(DropTarget.DragObject dragObject, boolean dragStarted); 66 } 67 } 68