1 /* 2 * Copyright (C) 2014 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 android.transition; 18 19 import android.animation.Animator; 20 import android.animation.ObjectAnimator; 21 import android.content.Context; 22 import android.transition.Transition; 23 import android.transition.TransitionValues; 24 import android.util.AttributeSet; 25 import android.view.View; 26 import android.view.ViewGroup; 27 28 /** 29 * This transition captures the scroll properties of targets before and after 30 * the scene change and animates any changes. 31 * 32 * @hide 33 */ 34 public class ChangeScroll extends Transition { 35 36 private static final String PROPNAME_SCROLL_X = "android:changeScroll:x"; 37 private static final String PROPNAME_SCROLL_Y = "android:changeScroll:y"; 38 ChangeScroll()39 public ChangeScroll() {} 40 ChangeScroll(Context context, AttributeSet attrs)41 public ChangeScroll(Context context, AttributeSet attrs) { 42 super(context, attrs); 43 } 44 45 @Override captureStartValues(TransitionValues transitionValues)46 public void captureStartValues(TransitionValues transitionValues) { 47 captureValues(transitionValues); 48 } 49 50 @Override captureEndValues(TransitionValues transitionValues)51 public void captureEndValues(TransitionValues transitionValues) { 52 captureValues(transitionValues); 53 } 54 captureValues(TransitionValues transitionValues)55 private void captureValues(TransitionValues transitionValues) { 56 transitionValues.values.put(PROPNAME_SCROLL_X, transitionValues.view.getScrollX()); 57 transitionValues.values.put(PROPNAME_SCROLL_Y, transitionValues.view.getScrollY()); 58 } 59 60 @Override createAnimator(ViewGroup sceneRoot, TransitionValues startValues, TransitionValues endValues)61 public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues, 62 TransitionValues endValues) { 63 if (startValues == null || endValues == null) { 64 return null; 65 } 66 final View view = endValues.view; 67 int startX = (Integer) startValues.values.get(PROPNAME_SCROLL_X); 68 int endX = (Integer) endValues.values.get(PROPNAME_SCROLL_X); 69 int startY = (Integer) startValues.values.get(PROPNAME_SCROLL_Y); 70 int endY = (Integer) endValues.values.get(PROPNAME_SCROLL_Y); 71 Animator scrollXAnimator = null; 72 Animator scrollYAnimator = null; 73 if (startX != endX) { 74 view.setScrollX(startX); 75 scrollXAnimator = ObjectAnimator.ofInt(view, "scrollX", startX, endX); 76 } 77 if (startY != endY) { 78 view.setScrollY(startY); 79 scrollYAnimator = ObjectAnimator.ofInt(view, "scrollY", startY, endY); 80 } 81 return TransitionUtils.mergeAnimators(scrollXAnimator, scrollYAnimator); 82 } 83 } 84