Chet Haase | faebd8f | 2012-05-18 14:17:57 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 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 | */ |
Chet Haase | 6ebe3de | 2013-06-17 16:50:50 -0700 | [diff] [blame] | 16 | |
Chet Haase | faebd8f | 2012-05-18 14:17:57 -0700 | [diff] [blame] | 17 | package android.view.transition; |
| 18 | |
| 19 | import android.content.Context; |
| 20 | import android.view.LayoutInflater; |
| 21 | import android.view.ViewGroup; |
| 22 | |
| 23 | /** |
| 24 | * A scene represents the collection of values that various properties in the |
| 25 | * View hierarchy will have when the scene is applied. A Scene can be |
| 26 | * configured to automatically run a Transition when it is applied, which will |
| 27 | * animate the various property changes that take place during the |
| 28 | * scene change. |
| 29 | */ |
| 30 | public final class Scene { |
| 31 | |
| 32 | private Context mContext; |
| 33 | private int mLayoutId = -1; |
| 34 | private ViewGroup mSceneRoot; |
| 35 | private ViewGroup mLayout; // alternative to layoutId |
| 36 | Runnable mEnterAction, mExitAction; |
| 37 | |
| 38 | /** |
| 39 | * Constructs a Scene with no information about how values will change |
| 40 | * when this scene is applied. This constructor might be used when |
| 41 | * a Scene is created with the intention of being dynamically configured, |
| 42 | * through setting {@link #setEnterAction(Runnable)} and possibly |
| 43 | * {@link #setExitAction(Runnable)}. |
| 44 | * |
| 45 | * @param sceneRoot The root of the hierarchy in which scene changes |
| 46 | * and transitions will take place. |
| 47 | */ |
| 48 | public Scene(ViewGroup sceneRoot) { |
| 49 | mSceneRoot = sceneRoot; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Constructs a Scene which, when entered, will remove any |
| 54 | * children from the sceneRoot container and will inflate and add |
| 55 | * the hierarchy specified by the layoutId resource file. |
| 56 | * |
| 57 | * @param sceneRoot The root of the hierarchy in which scene changes |
| 58 | * and transitions will take place. |
| 59 | * @param layoutId The id of a resource file that defines the view |
| 60 | * hierarchy of this scene. |
| 61 | * @param context The context used in the process of inflating |
| 62 | * the layout resource. |
| 63 | */ |
| 64 | public Scene(ViewGroup sceneRoot, int layoutId, Context context) { |
| 65 | mContext = context; |
| 66 | mSceneRoot = sceneRoot; |
| 67 | mLayoutId = layoutId; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Constructs a Scene which, when entered, will remove any |
| 72 | * children from the sceneRoot container and add the layout |
| 73 | * object as a new child of that container. |
| 74 | * |
| 75 | * @param sceneRoot The root of the hierarchy in which scene changes |
| 76 | * and transitions will take place. |
| 77 | * @param layout The view hiearrchy of this scene, added as a child |
| 78 | * of sceneRoot when this scene is entered. |
| 79 | */ |
| 80 | public Scene(ViewGroup sceneRoot, ViewGroup layout) { |
| 81 | mSceneRoot = sceneRoot; |
| 82 | mLayout = layout; |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Gets the root of the scene, which is the root of the view hierarchy |
| 87 | * affected by changes due to this scene, and which will be animated |
| 88 | * when this scene is entered. |
| 89 | * |
| 90 | * @return The root of the view hierarchy affected by this scene. |
| 91 | */ |
| 92 | public ViewGroup getSceneRoot() { |
| 93 | return mSceneRoot; |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Exits this scene, if it is the {@link ViewGroup#getCurrentScene() |
| 98 | * currentScene} on the scene's {@link #getSceneRoot() scene root}. |
| 99 | * Exiting a scene involves removing the layout added if the scene |
| 100 | * has either a layoutId or layout view group (set at construction |
| 101 | * time) and running the {@link #setExitAction(Runnable) exit action} |
| 102 | * if there is one. |
| 103 | */ |
| 104 | public void exit() { |
| 105 | if (mSceneRoot.getCurrentScene() == this) { |
| 106 | if (mLayoutId >= 0 || mLayout != null) { |
| 107 | // Undo layout change caused by entering this scene |
| 108 | getSceneRoot().removeAllViews(); |
| 109 | } |
| 110 | if (mExitAction != null) { |
| 111 | mExitAction.run(); |
| 112 | } |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Enters this scene, which entails changing all values that |
| 118 | * are specified by this scene. These may be values associated |
| 119 | * with a layout view group or layout resource file which will |
| 120 | * now be added to the scene root, or it may be values changed by |
| 121 | * an {@link #setEnterAction(Runnable)} enter action}, or a |
| 122 | * combination of the these. No transition will be run when the |
| 123 | * scene is entered. To get transition behavior in scene changes, |
| 124 | * use one of the methods in {@link TransitionManager} instead. |
| 125 | */ |
| 126 | public void enter() { |
| 127 | |
| 128 | // Apply layout change, if any |
| 129 | if (mLayoutId >= 0 || mLayout != null) { |
| 130 | // redundant with exit() action of previous scene, but must |
| 131 | // empty out that parent container before adding to it |
| 132 | getSceneRoot().removeAllViews(); |
| 133 | |
| 134 | if (mLayoutId >= 0) { |
| 135 | LayoutInflater.from(mContext).inflate(mLayoutId, mSceneRoot); |
| 136 | } else { |
| 137 | mSceneRoot.addView(mLayout); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | // Notify next scene that it is entering. Subclasses may override to configure scene. |
| 142 | if (mEnterAction != null) { |
| 143 | mEnterAction.run(); |
| 144 | } |
| 145 | |
| 146 | mSceneRoot.setCurrentScene(this ); |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * Scenes that are not defined with layout resources or |
| 151 | * hierarchies, or which need to perform additional steps |
| 152 | * after those hierarchies are changed to, should set an enter |
| 153 | * action, and possibly an exit action as well. An enter action |
| 154 | * will cause Scene to call back into application code to do |
| 155 | * anything else the application needs after transitions have |
| 156 | * captured pre-change values and after any other scene changes |
| 157 | * have been applied, such as the layout (if any) being added to |
| 158 | * the view hierarchy. After this method is called, Transitions will |
| 159 | * be played. |
| 160 | * |
| 161 | * @param action The runnable whose {@link Runnable#run() run()} method will |
| 162 | * be called when this scene is entered |
| 163 | * @see #setExitAction(Runnable) |
| 164 | * @see Scene#Scene(ViewGroup, int, Context) |
| 165 | * @see Scene#Scene(ViewGroup, ViewGroup) |
| 166 | */ |
| 167 | public void setEnterAction(Runnable action) { |
| 168 | mEnterAction = action; |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Scenes that are not defined with layout resources or |
| 173 | * hierarchies, or which need to perform additional steps |
| 174 | * after those hierarchies are changed to, should set an enter |
| 175 | * action, and possibly an exit action as well. An exit action |
| 176 | * will cause Scene to call back into application code to do |
| 177 | * anything the application needs to do after applicable transitions have |
| 178 | * captured pre-change values, but before any other scene changes |
| 179 | * have been applied, such as the new layout (if any) being added to |
| 180 | * the view hierarchy. After this method is called, the next scene |
| 181 | * will be entered, including a call to {@link #setEnterAction(Runnable)} |
| 182 | * if an enter action is set. |
| 183 | * |
| 184 | * @see #setEnterAction(Runnable) |
| 185 | * @see Scene#Scene(ViewGroup, int, Context) |
| 186 | * @see Scene#Scene(ViewGroup, ViewGroup) |
| 187 | */ |
| 188 | public void setExitAction(Runnable action) { |
| 189 | mExitAction = action; |
| 190 | } |
| 191 | |
| 192 | } |