1 /* 2 * Copyright (C) 2017 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.internal.widget.helper; 18 19 import android.graphics.Canvas; 20 import android.view.View; 21 22 import com.android.internal.R; 23 import com.android.internal.widget.RecyclerView; 24 25 /** 26 * Package private class to keep implementations. Putting them inside ItemTouchUIUtil makes them 27 * public API, which is not desired in this case. 28 */ 29 class ItemTouchUIUtilImpl implements ItemTouchUIUtil { 30 @Override onDraw(Canvas c, RecyclerView recyclerView, View view, float dX, float dY, int actionState, boolean isCurrentlyActive)31 public void onDraw(Canvas c, RecyclerView recyclerView, View view, 32 float dX, float dY, int actionState, boolean isCurrentlyActive) { 33 if (isCurrentlyActive) { 34 Object originalElevation = view.getTag( 35 R.id.item_touch_helper_previous_elevation); 36 if (originalElevation == null) { 37 originalElevation = view.getElevation(); 38 float newElevation = 1f + findMaxElevation(recyclerView, view); 39 view.setElevation(newElevation); 40 view.setTag(R.id.item_touch_helper_previous_elevation, 41 originalElevation); 42 } 43 } 44 view.setTranslationX(dX); 45 view.setTranslationY(dY); 46 } 47 findMaxElevation(RecyclerView recyclerView, View itemView)48 private float findMaxElevation(RecyclerView recyclerView, View itemView) { 49 final int childCount = recyclerView.getChildCount(); 50 float max = 0; 51 for (int i = 0; i < childCount; i++) { 52 final View child = recyclerView.getChildAt(i); 53 if (child == itemView) { 54 continue; 55 } 56 final float elevation = child.getElevation(); 57 if (elevation > max) { 58 max = elevation; 59 } 60 } 61 return max; 62 } 63 64 @Override clearView(View view)65 public void clearView(View view) { 66 final Object tag = view.getTag( 67 R.id.item_touch_helper_previous_elevation); 68 if (tag != null && tag instanceof Float) { 69 view.setElevation((Float) tag); 70 } 71 view.setTag(R.id.item_touch_helper_previous_elevation, null); 72 view.setTranslationX(0f); 73 view.setTranslationY(0f); 74 } 75 76 @Override onSelected(View view)77 public void onSelected(View view) { 78 } 79 80 @Override onDrawOver(Canvas c, RecyclerView recyclerView, View view, float dX, float dY, int actionState, boolean isCurrentlyActive)81 public void onDrawOver(Canvas c, RecyclerView recyclerView, 82 View view, float dX, float dY, int actionState, boolean isCurrentlyActive) { 83 } 84 } 85