| /* |
| * Copyright (C) 2013 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 android.transition; |
| |
| import android.animation.Animator; |
| import android.view.View; |
| import android.view.ViewGroup; |
| |
| /** |
| * This transition tracks changes to the visibility of target views in the |
| * start and end scenes. Visibility is determined not just by the |
| * {@link View#setVisibility(int)} state of views, but also whether |
| * views exist in the current view hierarchy. The class is intended to be a |
| * utility for subclasses such as {@link Fade}, which use this visibility |
| * information to determine the specific animations to run when visibility |
| * changes occur. Subclasses should implement one or both of the methods |
| * {@link #onAppear(ViewGroup, TransitionValues, int, TransitionValues, int)}, |
| * {@link #onDisappear(ViewGroup, TransitionValues, int, TransitionValues, int)}, |
| * |
| * <p>Note that a view's visibility change is determined by both whether the view |
| * itself is changing and whether its parent hierarchy's visibility is changing. |
| * That is, a view that appears in the end scene will only trigger a call to |
| * {@link #onAppear(android.view.ViewGroup, TransitionValues, int, TransitionValues, int) |
| * appear()} if its parent hierarchy was stable between the start and end scenes. |
| * This is done to avoid causing a visibility transition on every node in a hierarchy |
| * when only the top-most node is the one that should be transitioned in/out. |
| * Stability is determined by either the parent hierarchy views being the same |
| * between scenes or, if scenes are inflated from layout resource files and thus |
| * have result in different view instances, if the views represented by |
| * the ids of those parents are stable. This means that visibility determination |
| * is more effective with inflated view hierarchies if ids are used. |
| * The exception to this is when the visibility subclass transition is |
| * targeted at specific views, in which case the visibility of parent views |
| * is ignored.</p> |
| */ |
| public abstract class Visibility extends Transition { |
| |
| private static final String PROPNAME_VISIBILITY = "android:visibility:visibility"; |
| private static final String PROPNAME_PARENT = "android:visibility:parent"; |
| private static final String[] sTransitionProperties = { |
| PROPNAME_VISIBILITY, |
| PROPNAME_PARENT, |
| }; |
| |
| private static class VisibilityInfo { |
| boolean visibilityChange; |
| boolean fadeIn; |
| int startVisibility; |
| int endVisibility; |
| ViewGroup startParent; |
| ViewGroup endParent; |
| } |
| |
| @Override |
| public String[] getTransitionProperties() { |
| return sTransitionProperties; |
| } |
| |
| private void captureValues(TransitionValues transitionValues) { |
| int visibility = transitionValues.view.getVisibility(); |
| transitionValues.values.put(PROPNAME_VISIBILITY, visibility); |
| transitionValues.values.put(PROPNAME_PARENT, transitionValues.view.getParent()); |
| } |
| |
| @Override |
| public void captureStartValues(TransitionValues transitionValues) { |
| captureValues(transitionValues); |
| } |
| |
| @Override |
| public void captureEndValues(TransitionValues transitionValues) { |
| captureValues(transitionValues); |
| } |
| |
| /** |
| * Returns whether the view is 'visible' according to the given values |
| * object. This is determined by testing the same properties in the values |
| * object that are used to determine whether the object is appearing or |
| * disappearing in the {@link |
| * Transition#createAnimator(ViewGroup, TransitionValues, TransitionValues)} |
| * method. This method can be called by, for example, subclasses that want |
| * to know whether the object is visible in the same way that Visibility |
| * determines it for the actual animation. |
| * |
| * @param values The TransitionValues object that holds the information by |
| * which visibility is determined. |
| * @return True if the view reference by <code>values</code> is visible, |
| * false otherwise. |
| */ |
| public boolean isVisible(TransitionValues values) { |
| if (values == null) { |
| return false; |
| } |
| int visibility = (Integer) values.values.get(PROPNAME_VISIBILITY); |
| View parent = (View) values.values.get(PROPNAME_PARENT); |
| |
| return visibility == View.VISIBLE && parent != null; |
| } |
| |
| /** |
| * Tests whether the hierarchy, up to the scene root, changes visibility between |
| * start and end scenes. This is done to ensure that a view that changes visibility |
| * is only animated if that view's parent was stable between scenes; we should not |
| * fade an entire hierarchy, but rather just the top-most node in the hierarchy that |
| * changed visibility. Note that both the start and end parents are passed in |
| * because the instances may differ for the same view due to layout inflation |
| * between scenes. |
| * |
| * @param sceneRoot The root of the scene hierarchy |
| * @param startView The container view in the start scene |
| * @param endView The container view in the end scene |
| * @return true if the parent hierarchy experienced a visibility change, false |
| * otherwise |
| */ |
| private boolean isHierarchyVisibilityChanging(ViewGroup sceneRoot, ViewGroup startView, |
| ViewGroup endView) { |
| |
| if (startView == sceneRoot || endView == sceneRoot) { |
| return false; |
| } |
| TransitionValues startValues = startView != null ? |
| getTransitionValues(startView, true) : getTransitionValues(endView, true); |
| TransitionValues endValues = endView != null ? |
| getTransitionValues(endView, false) : getTransitionValues(startView, false); |
| |
| if (startValues == null || endValues == null) { |
| return true; |
| } |
| Integer visibility = (Integer) startValues.values.get(PROPNAME_VISIBILITY); |
| int startVisibility = (visibility != null) ? visibility : -1; |
| ViewGroup startParent = (ViewGroup) startValues.values.get(PROPNAME_PARENT); |
| visibility = (Integer) endValues.values.get(PROPNAME_VISIBILITY); |
| int endVisibility = (visibility != null) ? visibility : -1; |
| ViewGroup endParent = (ViewGroup) endValues.values.get(PROPNAME_PARENT); |
| if (startVisibility != endVisibility || startParent != endParent) { |
| return true; |
| } |
| |
| if (startParent != null || endParent != null) { |
| return isHierarchyVisibilityChanging(sceneRoot, startParent, endParent); |
| } |
| return false; |
| } |
| |
| private VisibilityInfo getVisibilityChangeInfo(TransitionValues startValues, |
| TransitionValues endValues) { |
| final VisibilityInfo visInfo = new VisibilityInfo(); |
| visInfo.visibilityChange = false; |
| visInfo.fadeIn = false; |
| if (startValues != null) { |
| visInfo.startVisibility = (Integer) startValues.values.get(PROPNAME_VISIBILITY); |
| visInfo.startParent = (ViewGroup) startValues.values.get(PROPNAME_PARENT); |
| } else { |
| visInfo.startVisibility = -1; |
| visInfo.startParent = null; |
| } |
| if (endValues != null) { |
| visInfo.endVisibility = (Integer) endValues.values.get(PROPNAME_VISIBILITY); |
| visInfo.endParent = (ViewGroup) endValues.values.get(PROPNAME_PARENT); |
| } else { |
| visInfo.endVisibility = -1; |
| visInfo.endParent = null; |
| } |
| if (startValues != null && endValues != null) { |
| if (visInfo.startVisibility == visInfo.endVisibility && |
| visInfo.startParent == visInfo.endParent) { |
| return visInfo; |
| } else { |
| if (visInfo.startVisibility != visInfo.endVisibility) { |
| if (visInfo.startVisibility == View.VISIBLE) { |
| visInfo.fadeIn = false; |
| visInfo.visibilityChange = true; |
| } else if (visInfo.endVisibility == View.VISIBLE) { |
| visInfo.fadeIn = true; |
| visInfo.visibilityChange = true; |
| } |
| // no visibilityChange if going between INVISIBLE and GONE |
| } else if (visInfo.startParent != visInfo.endParent) { |
| if (visInfo.endParent == null) { |
| visInfo.fadeIn = false; |
| visInfo.visibilityChange = true; |
| } else if (visInfo.startParent == null) { |
| visInfo.fadeIn = true; |
| visInfo.visibilityChange = true; |
| } |
| } |
| } |
| } |
| if (startValues == null) { |
| visInfo.fadeIn = true; |
| visInfo.visibilityChange = true; |
| } else if (endValues == null) { |
| visInfo.fadeIn = false; |
| visInfo.visibilityChange = true; |
| } |
| return visInfo; |
| } |
| |
| @Override |
| public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues, |
| TransitionValues endValues) { |
| VisibilityInfo visInfo = getVisibilityChangeInfo(startValues, endValues); |
| if (visInfo.visibilityChange) { |
| // Only transition views that are either targets of this transition |
| // or whose parent hierarchies remain stable between scenes |
| boolean isTarget = false; |
| if (mTargets.size() > 0 || mTargetIds.size() > 0) { |
| View startView = startValues != null ? startValues.view : null; |
| View endView = endValues != null ? endValues.view : null; |
| int startId = startView != null ? startView.getId() : -1; |
| int endId = endView != null ? endView.getId() : -1; |
| isTarget = isValidTarget(startView, startId) || isValidTarget(endView, endId); |
| } |
| if (isTarget || ((visInfo.startParent != null || visInfo.endParent != null) && |
| !isHierarchyVisibilityChanging(sceneRoot, |
| visInfo.startParent, visInfo.endParent))) { |
| if (visInfo.fadeIn) { |
| return onAppear(sceneRoot, startValues, visInfo.startVisibility, |
| endValues, visInfo.endVisibility); |
| } else { |
| return onDisappear(sceneRoot, startValues, visInfo.startVisibility, |
| endValues, visInfo.endVisibility |
| ); |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * The default implementation of this method does nothing. Subclasses |
| * should override if they need to create an Animator when targets appear. |
| * The method should only be called by the Visibility class; it is |
| * not intended to be called from external classes. |
| * |
| * @param sceneRoot The root of the transition hierarchy |
| * @param startValues The target values in the start scene |
| * @param startVisibility The target visibility in the start scene |
| * @param endValues The target values in the end scene |
| * @param endVisibility The target visibility in the end scene |
| * @return An Animator to be started at the appropriate time in the |
| * overall transition for this scene change. A null value means no animation |
| * should be run. |
| */ |
| public Animator onAppear(ViewGroup sceneRoot, |
| TransitionValues startValues, int startVisibility, |
| TransitionValues endValues, int endVisibility) { |
| return null; |
| } |
| |
| /** |
| * The default implementation of this method does nothing. Subclasses |
| * should override if they need to create an Animator when targets disappear. |
| * The method should only be called by the Visibility class; it is |
| * not intended to be called from external classes. |
| * |
| * |
| * @param sceneRoot The root of the transition hierarchy |
| * @param startValues The target values in the start scene |
| * @param startVisibility The target visibility in the start scene |
| * @param endValues The target values in the end scene |
| * @param endVisibility The target visibility in the end scene |
| * @return An Animator to be started at the appropriate time in the |
| * overall transition for this scene change. A null value means no animation |
| * should be run. |
| */ |
| public Animator onDisappear(ViewGroup sceneRoot, |
| TransitionValues startValues, int startVisibility, |
| TransitionValues endValues, int endVisibility) { |
| return null; |
| } |
| } |
