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.util.AttributeSet; 23 import android.view.View; 24 import android.view.ViewGroup; 25 26 /** 27 * This transition captures the scroll properties of targets before and after 28 * the scene change and animates any changes. 29 */ 30 public class ChangeScroll extends Transition { 31 32 private static final String PROPNAME_SCROLL_X = "android:changeScroll:x"; 33 private static final String PROPNAME_SCROLL_Y = "android:changeScroll:y"; 34 35 private static final String[] PROPERTIES = { 36 PROPNAME_SCROLL_X, 37 PROPNAME_SCROLL_Y, 38 }; 39 ChangeScroll()40 public ChangeScroll() {} 41 ChangeScroll(Context context, AttributeSet attrs)42 public ChangeScroll(Context context, AttributeSet attrs) { 43 super(context, attrs); 44 } 45 46 @Override captureStartValues(TransitionValues transitionValues)47 public void captureStartValues(TransitionValues transitionValues) { 48 captureValues(transitionValues); 49 } 50 51 @Override captureEndValues(TransitionValues transitionValues)52 public void captureEndValues(TransitionValues transitionValues) { 53 captureValues(transitionValues); 54 } 55 56 @Override getTransitionProperties()57 public String[] getTransitionProperties() { 58 return PROPERTIES; 59 } 60 captureValues(TransitionValues transitionValues)61 private void captureValues(TransitionValues transitionValues) { 62 transitionValues.values.put(PROPNAME_SCROLL_X, transitionValues.view.getScrollX()); 63 transitionValues.values.put(PROPNAME_SCROLL_Y, transitionValues.view.getScrollY()); 64 } 65 66 @Override createAnimator(ViewGroup sceneRoot, TransitionValues startValues, TransitionValues endValues)67 public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues, 68 TransitionValues endValues) { 69 if (startValues == null || endValues == null) { 70 return null; 71 } 72 final View view = endValues.view; 73 int startX = (Integer) startValues.values.get(PROPNAME_SCROLL_X); 74 int endX = (Integer) endValues.values.get(PROPNAME_SCROLL_X); 75 int startY = (Integer) startValues.values.get(PROPNAME_SCROLL_Y); 76 int endY = (Integer) endValues.values.get(PROPNAME_SCROLL_Y); 77 Animator scrollXAnimator = null; 78 Animator scrollYAnimator = null; 79 if (startX != endX) { 80 view.setScrollX(startX); 81 scrollXAnimator = ObjectAnimator.ofInt(view, "scrollX", startX, endX); 82 } 83 if (startY != endY) { 84 view.setScrollY(startY); 85 scrollYAnimator = ObjectAnimator.ofInt(view, "scrollY", startY, endY); 86 } 87 return TransitionUtils.mergeAnimators(scrollXAnimator, scrollYAnimator); 88 } 89 } 90