| /* |
| * Copyright (C) 2016 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.support.transition; |
| |
| import android.content.Context; |
| import android.support.annotation.LayoutRes; |
| import android.support.annotation.NonNull; |
| import android.support.annotation.Nullable; |
| import android.util.SparseArray; |
| import android.view.LayoutInflater; |
| import android.view.View; |
| import android.view.ViewGroup; |
| |
| /** |
| * A scene represents the collection of values that various properties in the |
| * View hierarchy will have when the scene is applied. A Scene can be |
| * configured to automatically run a Transition when it is applied, which will |
| * animate the various property changes that take place during the |
| * scene change. |
| */ |
| public class Scene { |
| |
| private Context mContext; |
| private int mLayoutId = -1; |
| private ViewGroup mSceneRoot; |
| private View mLayout; // alternative to layoutId |
| private Runnable mEnterAction, mExitAction; |
| |
| /** |
| * Returns a Scene described by the resource file associated with the given |
| * <code>layoutId</code> parameter. If such a Scene has already been created for |
| * the given <code>sceneRoot</code>, that same Scene will be returned. |
| * This caching of layoutId-based scenes enables sharing of common scenes |
| * between those created in code and those referenced by {@link TransitionManager} |
| * XML resource files. |
| * |
| * @param sceneRoot The root of the hierarchy in which scene changes |
| * and transitions will take place. |
| * @param layoutId The id of a standard layout resource file. |
| * @param context The context used in the process of inflating |
| * the layout resource. |
| * @return The scene for the given root and layout id |
| */ |
| @NonNull |
| public static Scene getSceneForLayout(@NonNull ViewGroup sceneRoot, @LayoutRes int layoutId, |
| @NonNull Context context) { |
| @SuppressWarnings("unchecked") |
| SparseArray<Scene> scenes = |
| (SparseArray<Scene>) sceneRoot.getTag(R.id.transition_scene_layoutid_cache); |
| if (scenes == null) { |
| scenes = new SparseArray<>(); |
| sceneRoot.setTag(R.id.transition_scene_layoutid_cache, scenes); |
| } |
| Scene scene = scenes.get(layoutId); |
| if (scene != null) { |
| return scene; |
| } else { |
| scene = new Scene(sceneRoot, layoutId, context); |
| scenes.put(layoutId, scene); |
| return scene; |
| } |
| } |
| |
| /** |
| * Constructs a Scene with no information about how values will change |
| * when this scene is applied. This constructor might be used when |
| * a Scene is created with the intention of being dynamically configured, |
| * through setting {@link #setEnterAction(Runnable)} and possibly |
| * {@link #setExitAction(Runnable)}. |
| * |
| * @param sceneRoot The root of the hierarchy in which scene changes |
| * and transitions will take place. |
| */ |
| public Scene(@NonNull ViewGroup sceneRoot) { |
| mSceneRoot = sceneRoot; |
| } |
| |
| /** |
| * Constructs a Scene which, when entered, will remove any |
| * children from the sceneRoot container and will inflate and add |
| * the hierarchy specified by the layoutId resource file. |
| * |
| * <p>This method is hidden because layoutId-based scenes should be |
| * created by the caching factory method {@link Scene#getCurrentScene(View)}.</p> |
| * |
| * @param sceneRoot The root of the hierarchy in which scene changes |
| * and transitions will take place. |
| * @param layoutId The id of a resource file that defines the view |
| * hierarchy of this scene. |
| * @param context The context used in the process of inflating |
| * the layout resource. |
| */ |
| private Scene(ViewGroup sceneRoot, int layoutId, Context context) { |
| mContext = context; |
| mSceneRoot = sceneRoot; |
| mLayoutId = layoutId; |
| } |
| |
| /** |
| * Constructs a Scene which, when entered, will remove any |
| * children from the sceneRoot container and add the layout |
| * object as a new child of that container. |
| * |
| * @param sceneRoot The root of the hierarchy in which scene changes |
| * and transitions will take place. |
| * @param layout The view hierarchy of this scene, added as a child |
| * of sceneRoot when this scene is entered. |
| */ |
| public Scene(@NonNull ViewGroup sceneRoot, @NonNull View layout) { |
| mSceneRoot = sceneRoot; |
| mLayout = layout; |
| } |
| |
| /** |
| * Gets the root of the scene, which is the root of the view hierarchy |
| * affected by changes due to this scene, and which will be animated |
| * when this scene is entered. |
| * |
| * @return The root of the view hierarchy affected by this scene. |
| */ |
| @NonNull |
| public ViewGroup getSceneRoot() { |
| return mSceneRoot; |
| } |
| |
| /** |
| * Exits this scene, if it is the current scene |
| * on the scene's {@link #getSceneRoot() scene root}. The current scene is |
| * set when {@link #enter() entering} a scene. |
| * Exiting a scene runs the {@link #setExitAction(Runnable) exit action} |
| * if there is one. |
| */ |
| public void exit() { |
| if (getCurrentScene(mSceneRoot) == this) { |
| if (mExitAction != null) { |
| mExitAction.run(); |
| } |
| } |
| } |
| |
| /** |
| * Enters this scene, which entails changing all values that |
| * are specified by this scene. These may be values associated |
| * with a layout view group or layout resource file which will |
| * now be added to the scene root, or it may be values changed by |
| * an {@link #setEnterAction(Runnable)} enter action}, or a |
| * combination of the these. No transition will be run when the |
| * scene is entered. To get transition behavior in scene changes, |
| * use one of the methods in {@link android.support.transition.TransitionManager} instead. |
| */ |
| public void enter() { |
| // Apply layout change, if any |
| if (mLayoutId > 0 || mLayout != null) { |
| // empty out parent container before adding to it |
| getSceneRoot().removeAllViews(); |
| |
| if (mLayoutId > 0) { |
| LayoutInflater.from(mContext).inflate(mLayoutId, mSceneRoot); |
| } else { |
| mSceneRoot.addView(mLayout); |
| } |
| } |
| |
| // Notify next scene that it is entering. Subclasses may override to configure scene. |
| if (mEnterAction != null) { |
| mEnterAction.run(); |
| } |
| |
| setCurrentScene(mSceneRoot, this); |
| } |
| |
| /** |
| * Set the scene that the given view is in. The current scene is set only |
| * on the root view of a scene, not for every view in that hierarchy. This |
| * information is used by Scene to determine whether there is a previous |
| * scene which should be exited before the new scene is entered. |
| * |
| * @param view The view on which the current scene is being set |
| */ |
| static void setCurrentScene(View view, Scene scene) { |
| view.setTag(R.id.transition_current_scene, scene); |
| } |
| |
| /** |
| * Gets the current {@link Scene} set on the given view. A scene is set on a view |
| * only if that view is the scene root. |
| * |
| * @return The current Scene set on this view. A value of null indicates that |
| * no Scene is currently set. |
| */ |
| static Scene getCurrentScene(View view) { |
| return (Scene) view.getTag(R.id.transition_current_scene); |
| } |
| |
| /** |
| * Scenes that are not defined with layout resources or |
| * hierarchies, or which need to perform additional steps |
| * after those hierarchies are changed to, should set an enter |
| * action, and possibly an exit action as well. An enter action |
| * will cause Scene to call back into application code to do |
| * anything else the application needs after transitions have |
| * captured pre-change values and after any other scene changes |
| * have been applied, such as the layout (if any) being added to |
| * the view hierarchy. After this method is called, Transitions will |
| * be played. |
| * |
| * @param action The runnable whose {@link Runnable#run() run()} method will |
| * be called when this scene is entered |
| * @see #setExitAction(Runnable) |
| * @see android.support.transition.Scene(android.view.ViewGroup, android.view.ViewGroup) |
| */ |
| public void setEnterAction(@Nullable Runnable action) { |
| mEnterAction = action; |
| } |
| |
| /** |
| * Scenes that are not defined with layout resources or |
| * hierarchies, or which need to perform additional steps |
| * after those hierarchies are changed to, should set an enter |
| * action, and possibly an exit action as well. An exit action |
| * will cause Scene to call back into application code to do |
| * anything the application needs to do after applicable transitions have |
| * captured pre-change values, but before any other scene changes |
| * have been applied, such as the new layout (if any) being added to |
| * the view hierarchy. After this method is called, the next scene |
| * will be entered, including a call to {@link #setEnterAction(Runnable)} |
| * if an enter action is set. |
| * |
| * @see #setEnterAction(Runnable) |
| * @see android.support.transition.Scene(android.view.ViewGroup, android.view.ViewGroup) |
| */ |
| public void setExitAction(@Nullable Runnable action) { |
| mExitAction = action; |
| } |
| |
| /** |
| * Returns whether this Scene was created by a layout resource file, determined |
| * by the layoutId passed into |
| * {@link #getSceneForLayout(ViewGroup, int, Context)}. |
| */ |
| boolean isCreatedFromLayoutResource() { |
| return (mLayoutId > 0); |
| } |
| |
| } |