1 /*
2  * Copyright (C) 2021 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 androidx.window.extensions.embedding;
18 
19 import android.app.Activity;
20 import android.os.Binder;
21 import android.os.IBinder;
22 import android.util.Pair;
23 import android.util.Size;
24 import android.window.TaskFragmentParentInfo;
25 import android.window.WindowContainerTransaction;
26 
27 import androidx.annotation.NonNull;
28 import androidx.annotation.Nullable;
29 import androidx.window.extensions.core.util.function.Function;
30 
31 /**
32  * Client-side descriptor of a split that holds two containers.
33  */
34 class SplitContainer {
35     @NonNull
36     private TaskFragmentContainer mPrimaryContainer;
37     @NonNull
38     private final TaskFragmentContainer mSecondaryContainer;
39     @NonNull
40     private final SplitRule mSplitRule;
41     /** @see SplitContainer#getCurrentSplitAttributes() */
42     @NonNull
43     private SplitAttributes mCurrentSplitAttributes;
44     /** @see SplitContainer#getDefaultSplitAttributes() */
45     @NonNull
46     private SplitAttributes mDefaultSplitAttributes;
47     @NonNull
48     private final IBinder mToken;
49 
50     /**
51      * Whether the selection of which container is primary can be changed at runtime. Runtime
52      * updates is currently possible only for {@link SplitPinContainer}
53      *
54      * @see SplitPinContainer
55      */
56     private final boolean mIsPrimaryContainerMutable;
57 
SplitContainer(@onNull TaskFragmentContainer primaryContainer, @NonNull Activity primaryActivity, @NonNull TaskFragmentContainer secondaryContainer, @NonNull SplitRule splitRule, @NonNull SplitAttributes splitAttributes)58     SplitContainer(@NonNull TaskFragmentContainer primaryContainer,
59             @NonNull Activity primaryActivity,
60             @NonNull TaskFragmentContainer secondaryContainer,
61             @NonNull SplitRule splitRule,
62             @NonNull SplitAttributes splitAttributes) {
63         this(primaryContainer, primaryActivity, secondaryContainer, splitRule, splitAttributes,
64                 false /* isPrimaryContainerMutable */);
65     }
66 
SplitContainer(@onNull TaskFragmentContainer primaryContainer, @NonNull Activity primaryActivity, @NonNull TaskFragmentContainer secondaryContainer, @NonNull SplitRule splitRule, @NonNull SplitAttributes splitAttributes, boolean isPrimaryContainerMutable)67     SplitContainer(@NonNull TaskFragmentContainer primaryContainer,
68             @NonNull Activity primaryActivity,
69             @NonNull TaskFragmentContainer secondaryContainer,
70             @NonNull SplitRule splitRule,
71             @NonNull SplitAttributes splitAttributes, boolean isPrimaryContainerMutable) {
72         mPrimaryContainer = primaryContainer;
73         mSecondaryContainer = secondaryContainer;
74         mSplitRule = splitRule;
75         mDefaultSplitAttributes = splitRule.getDefaultSplitAttributes();
76         mCurrentSplitAttributes = splitAttributes;
77         mToken = new Binder("SplitContainer");
78         mIsPrimaryContainerMutable = isPrimaryContainerMutable;
79 
80         if (shouldFinishPrimaryWithSecondary(splitRule)) {
81             if (mPrimaryContainer.getRunningActivityCount() == 1
82                     && mPrimaryContainer.hasActivity(primaryActivity.getActivityToken())) {
83                 mSecondaryContainer.addContainerToFinishOnExit(mPrimaryContainer);
84             } else {
85                 // Only adding the activity to be finished vs. the entire TaskFragment while
86                 // the secondary container exits because there are other unrelated activities in the
87                 // primary TaskFragment.
88                 mSecondaryContainer.addActivityToFinishOnExit(primaryActivity);
89             }
90         }
91         if (shouldFinishSecondaryWithPrimary(splitRule)) {
92             mPrimaryContainer.addContainerToFinishOnExit(mSecondaryContainer);
93         }
94     }
95 
setPrimaryContainer(@onNull TaskFragmentContainer primaryContainer)96     void setPrimaryContainer(@NonNull TaskFragmentContainer primaryContainer) {
97         if (!mIsPrimaryContainerMutable) {
98             throw new IllegalStateException("Cannot update primary TaskFragmentContainer");
99         }
100         mPrimaryContainer = primaryContainer;
101     }
102 
103     @NonNull
getPrimaryContainer()104     TaskFragmentContainer getPrimaryContainer() {
105         return mPrimaryContainer;
106     }
107 
108     @NonNull
getSecondaryContainer()109     TaskFragmentContainer getSecondaryContainer() {
110         return mSecondaryContainer;
111     }
112 
113     @NonNull
getSplitRule()114     SplitRule getSplitRule() {
115         return mSplitRule;
116     }
117 
118     /**
119      * Returns the current {@link SplitAttributes} this {@code SplitContainer} is showing.
120      * <p>
121      * If the {@code SplitAttributes} calculator function is not set by
122      * {@link SplitController#setSplitAttributesCalculator(Function)}, the current
123      * {@code SplitAttributes} is either to expand the containers if the size constraints of
124      * {@link #getSplitRule()} are not satisfied,
125      * or the {@link #getDefaultSplitAttributes()}, otherwise.
126      * </p><p>
127      * If the {@code SplitAttributes} calculator function is set, the current
128      * {@code SplitAttributes} will be customized by the function, which can be any
129      * {@code SplitAttributes}.
130      * </p>
131      *
132      * @see SplitAttributes.SplitType.ExpandContainersSplitType
133      */
134     @NonNull
getCurrentSplitAttributes()135     SplitAttributes getCurrentSplitAttributes() {
136         return mCurrentSplitAttributes;
137     }
138 
139     /**
140      * Returns the default {@link SplitAttributes} when the parent task container bounds satisfy
141      * {@link #getSplitRule()} constraints.
142      * <p>
143      * The value is usually from {@link SplitRule#getDefaultSplitAttributes} unless it is overridden
144      * by {@link SplitController#updateSplitAttributes(IBinder, SplitAttributes)}.
145      */
146     @NonNull
getDefaultSplitAttributes()147     SplitAttributes getDefaultSplitAttributes() {
148         return mDefaultSplitAttributes;
149     }
150 
151     @NonNull
getToken()152     IBinder getToken() {
153         return mToken;
154     }
155 
156     /**
157      * Updates the {@link SplitAttributes} to this container.
158      * It is usually used when there's a folding state change or
159      * {@link SplitController#onTaskFragmentParentInfoChanged(WindowContainerTransaction,
160      * int, TaskFragmentParentInfo)}.
161      */
updateCurrentSplitAttributes(@onNull SplitAttributes splitAttributes)162     void updateCurrentSplitAttributes(@NonNull SplitAttributes splitAttributes) {
163         mCurrentSplitAttributes = splitAttributes;
164     }
165 
166     /**
167      * Overrides the default {@link SplitAttributes} to this container, which may be different
168      * from {@link SplitRule#getDefaultSplitAttributes}.
169      */
updateDefaultSplitAttributes(@onNull SplitAttributes splitAttributes)170     void updateDefaultSplitAttributes(@NonNull SplitAttributes splitAttributes) {
171         mDefaultSplitAttributes = splitAttributes;
172     }
173 
174     @NonNull
getTaskContainer()175     TaskContainer getTaskContainer() {
176         return getPrimaryContainer().getTaskContainer();
177     }
178 
179     /** Returns the minimum dimension pair of primary container and secondary container. */
180     @NonNull
getMinDimensionsPair()181     Pair<Size, Size> getMinDimensionsPair() {
182         return new Pair<>(mPrimaryContainer.getMinDimensions(),
183                 mSecondaryContainer.getMinDimensions());
184     }
185 
isPlaceholderContainer()186     boolean isPlaceholderContainer() {
187         return (mSplitRule instanceof SplitPlaceholderRule);
188     }
189 
190     /**
191      * Returns the SplitInfo representing this container.
192      *
193      * @return the SplitInfo representing this container if the underlying TaskFragmentContainers
194      * are stable, or {@code null} if any TaskFragmentContainer is in an intermediate state.
195      */
196     @Nullable
toSplitInfoIfStable()197     SplitInfo toSplitInfoIfStable() {
198         final ActivityStack primaryActivityStack = mPrimaryContainer.toActivityStackIfStable();
199         final ActivityStack secondaryActivityStack = mSecondaryContainer.toActivityStackIfStable();
200         if (primaryActivityStack == null || secondaryActivityStack == null) {
201             return null;
202         }
203         return new SplitInfo(primaryActivityStack, secondaryActivityStack,
204                 mCurrentSplitAttributes, SplitInfo.Token.createFromBinder(mToken));
205     }
206 
shouldFinishPrimaryWithSecondary(@onNull SplitRule splitRule)207     static boolean shouldFinishPrimaryWithSecondary(@NonNull SplitRule splitRule) {
208         final boolean isPlaceholderContainer = splitRule instanceof SplitPlaceholderRule;
209         final boolean shouldFinishPrimaryWithSecondary = (splitRule instanceof SplitPairRule)
210                 && ((SplitPairRule) splitRule).getFinishPrimaryWithSecondary()
211                 != SplitRule.FINISH_NEVER;
212         return shouldFinishPrimaryWithSecondary || isPlaceholderContainer;
213     }
214 
shouldFinishSecondaryWithPrimary(@onNull SplitRule splitRule)215     static boolean shouldFinishSecondaryWithPrimary(@NonNull SplitRule splitRule) {
216         final boolean isPlaceholderContainer = splitRule instanceof SplitPlaceholderRule;
217         final boolean shouldFinishSecondaryWithPrimary = (splitRule instanceof SplitPairRule)
218                 && ((SplitPairRule) splitRule).getFinishSecondaryWithPrimary()
219                 != SplitRule.FINISH_NEVER;
220         return shouldFinishSecondaryWithPrimary || isPlaceholderContainer;
221     }
222 
shouldFinishAssociatedContainerWhenStacked(int finishBehavior)223     static boolean shouldFinishAssociatedContainerWhenStacked(int finishBehavior) {
224         return finishBehavior == SplitRule.FINISH_ALWAYS;
225     }
226 
shouldFinishAssociatedContainerWhenAdjacent(int finishBehavior)227     static boolean shouldFinishAssociatedContainerWhenAdjacent(int finishBehavior) {
228         return finishBehavior == SplitRule.FINISH_ALWAYS
229                 || finishBehavior == SplitRule.FINISH_ADJACENT;
230     }
231 
getFinishPrimaryWithSecondaryBehavior(@onNull SplitRule splitRule)232     static int getFinishPrimaryWithSecondaryBehavior(@NonNull SplitRule splitRule) {
233         if (splitRule instanceof SplitPlaceholderRule) {
234             return ((SplitPlaceholderRule) splitRule).getFinishPrimaryWithSecondary();
235         }
236         if (splitRule instanceof SplitPairRule) {
237             return ((SplitPairRule) splitRule).getFinishPrimaryWithSecondary();
238         }
239         return SplitRule.FINISH_NEVER;
240     }
241 
getFinishSecondaryWithPrimaryBehavior(@onNull SplitRule splitRule)242     static int getFinishSecondaryWithPrimaryBehavior(@NonNull SplitRule splitRule) {
243         if (splitRule instanceof SplitPlaceholderRule) {
244             return SplitRule.FINISH_ALWAYS;
245         }
246         if (splitRule instanceof SplitPairRule) {
247             return ((SplitPairRule) splitRule).getFinishSecondaryWithPrimary();
248         }
249         return SplitRule.FINISH_NEVER;
250     }
251 
isStickyPlaceholderRule(@onNull SplitRule splitRule)252     static boolean isStickyPlaceholderRule(@NonNull SplitRule splitRule) {
253         if (!(splitRule instanceof SplitPlaceholderRule)) {
254             return false;
255         }
256         return ((SplitPlaceholderRule) splitRule).isSticky();
257     }
258 
259     @Override
toString()260     public String toString() {
261         return "SplitContainer{"
262                 + " primaryContainer=" + mPrimaryContainer
263                 + ", secondaryContainer=" + mSecondaryContainer
264                 + ", splitRule=" + mSplitRule
265                 + ", currentSplitAttributes" + mCurrentSplitAttributes
266                 + ", defaultSplitAttributes" + mDefaultSplitAttributes
267                 + "}";
268     }
269 }
270