| /* |
| * Copyright 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.recyclerview.widget; |
| |
| import android.graphics.Canvas; |
| import android.os.Build; |
| import android.view.View; |
| |
| import androidx.core.view.ViewCompat; |
| import androidx.recyclerview.R; |
| |
| /** |
| * Package private class to keep implementations. Putting them inside ItemTouchUIUtil makes them |
| * public API, which is not desired in this case. |
| */ |
| class ItemTouchUIUtilImpl implements ItemTouchUIUtil { |
| static final ItemTouchUIUtil INSTANCE = new ItemTouchUIUtilImpl(); |
| |
| @Override |
| public void onDraw(Canvas c, RecyclerView recyclerView, View view, float dX, float dY, |
| int actionState, boolean isCurrentlyActive) { |
| if (Build.VERSION.SDK_INT >= 21) { |
| if (isCurrentlyActive) { |
| Object originalElevation = view.getTag(R.id.item_touch_helper_previous_elevation); |
| if (originalElevation == null) { |
| originalElevation = ViewCompat.getElevation(view); |
| float newElevation = 1f + findMaxElevation(recyclerView, view); |
| ViewCompat.setElevation(view, newElevation); |
| view.setTag(R.id.item_touch_helper_previous_elevation, originalElevation); |
| } |
| } |
| } |
| |
| view.setTranslationX(dX); |
| view.setTranslationY(dY); |
| } |
| |
| private static float findMaxElevation(RecyclerView recyclerView, View itemView) { |
| final int childCount = recyclerView.getChildCount(); |
| float max = 0; |
| for (int i = 0; i < childCount; i++) { |
| final View child = recyclerView.getChildAt(i); |
| if (child == itemView) { |
| continue; |
| } |
| final float elevation = ViewCompat.getElevation(child); |
| if (elevation > max) { |
| max = elevation; |
| } |
| } |
| return max; |
| } |
| |
| @Override |
| public void onDrawOver(Canvas c, RecyclerView recyclerView, View view, float dX, float dY, |
| int actionState, boolean isCurrentlyActive) { |
| } |
| |
| @Override |
| public void clearView(View view) { |
| if (Build.VERSION.SDK_INT >= 21) { |
| final Object tag = view.getTag(R.id.item_touch_helper_previous_elevation); |
| if (tag instanceof Float) { |
| ViewCompat.setElevation(view, (Float) tag); |
| } |
| view.setTag(R.id.item_touch_helper_previous_elevation, null); |
| } |
| |
| view.setTranslationX(0f); |
| view.setTranslationY(0f); |
| } |
| |
| @Override |
| public void onSelected(View view) { |
| } |
| } |