1 /* 2 * Copyright (C) 2020 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.Rect; 20 21 import androidx.annotation.NonNull; 22 23 import com.android.launcher3.util.SafeCloseable; 24 25 /** 26 * Interface defining methods required for drawing and previewing DragViews, drag previews, and 27 * related animations 28 */ 29 public interface DraggableView { 30 int DRAGGABLE_ICON = 0; 31 int DRAGGABLE_WIDGET = 1; 32 33 /** 34 * Static ctr for a simple instance which just returns the view type. 35 */ ofType(int type)36 static DraggableView ofType(int type) { 37 return () -> type; 38 } 39 40 /** 41 * Certain handling of DragViews depend only on whether this is an Icon Type item or a Widget 42 * Type item. 43 * 44 * @return DRAGGABLE_ICON or DRAGGABLE_WIDGET as appropriate 45 */ getViewType()46 int getViewType(); 47 48 /** 49 * Before rendering as a DragView bitmap, some views need a preparation step. Returns a 50 * callback to clear any preparation work 51 */ prepareDrawDragView()52 @NonNull default SafeCloseable prepareDrawDragView() { 53 return () -> { }; 54 } 55 56 /** 57 * If an actual View subclass, this method returns the rectangle (within the View's coordinates) 58 * of the visual region that should get dragged. This is used to extract exactly that element 59 * as well as to offset that element as appropriate for various animations 60 * 61 * @param bounds Visual bounds in the views coordinates will be written here. 62 */ getWorkspaceVisualDragBounds(Rect bounds)63 default void getWorkspaceVisualDragBounds(Rect bounds) { } 64 65 /** 66 * Same as above, but accounts for differing icon sizes between source and destination 67 * 68 * @param bounds Visual bounds in the views coordinates will be written here. 69 */ getSourceVisualDragBounds(Rect bounds)70 default void getSourceVisualDragBounds(Rect bounds) { 71 getWorkspaceVisualDragBounds(bounds); 72 } 73 } 74