1 /* 2 * Copyright (C) 2008 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.launcher; 18 19 import android.view.View; 20 21 /** 22 * Interface for initiating a drag within a view or across multiple views. 23 * 24 */ 25 public interface DragController { 26 27 /** 28 * Interface to receive notifications when a drag starts or stops 29 */ 30 interface DragListener { 31 32 /** 33 * A drag has begun 34 * 35 * @param v The view that is being dragged 36 * @param source An object representing where the drag originated 37 * @param info The data associated with the object that is being dragged 38 * @param dragAction The drag action: either {@link DragController#DRAG_ACTION_MOVE} 39 * or {@link DragController#DRAG_ACTION_COPY} 40 */ onDragStart(View v, DragSource source, Object info, int dragAction)41 void onDragStart(View v, DragSource source, Object info, int dragAction); 42 43 /** 44 * The drag has eneded 45 */ onDragEnd()46 void onDragEnd(); 47 } 48 49 /** 50 * Indicates the drag is a move. 51 */ 52 public static int DRAG_ACTION_MOVE = 0; 53 54 /** 55 * Indicates the drag is a copy. 56 */ 57 public static int DRAG_ACTION_COPY = 1; 58 59 /** 60 * Starts a drag 61 * 62 * @param v The view that is being dragged 63 * @param source An object representing where the drag originated 64 * @param info The data associated with the object that is being dragged 65 * @param dragAction The drag action: either {@link #DRAG_ACTION_MOVE} or 66 * {@link #DRAG_ACTION_COPY} 67 */ startDrag(View v, DragSource source, Object info, int dragAction)68 void startDrag(View v, DragSource source, Object info, int dragAction); 69 70 /** 71 * Sets the drag listner which will be notified when a drag starts or ends. 72 */ setDragListener(DragListener l)73 void setDragListener(DragListener l); 74 75 /** 76 * Remove a previously installed drag listener. 77 */ removeDragListener(DragListener l)78 void removeDragListener(DragListener l); 79 } 80