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      1 /*
      2  * Copyright (C) 2016 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 com.android.documentsui;
     18 
     19 import android.app.Activity;
     20 import android.content.BroadcastReceiver;
     21 import android.content.Context;
     22 import android.content.Intent;
     23 import android.content.IntentFilter;
     24 import android.net.Uri;
     25 import android.support.v4.content.LocalBroadcastManager;
     26 
     27 import com.android.documentsui.AbstractActionHandler.CommonAddons;
     28 import com.android.documentsui.base.DocumentInfo;
     29 import com.android.documentsui.base.PairedTask;
     30 import com.android.documentsui.base.RootInfo;
     31 import com.android.documentsui.base.State;
     32 import com.android.documentsui.dirlist.AnimationView;
     33 import com.android.documentsui.queries.SearchViewManager;
     34 import com.android.documentsui.roots.ProvidersAccess;
     35 import com.android.documentsui.selection.SelectionManager;
     36 
     37 import java.util.Collection;
     38 
     39 /**
     40  * Monitors roots change and refresh the page when necessary.
     41  */
     42 final class RootsMonitor<T extends Activity & CommonAddons> {
     43 
     44     private final LocalBroadcastManager mManager;
     45     private final BroadcastReceiver mReceiver;
     46 
     47     RootsMonitor(
     48             final T activity,
     49             final ActionHandler actions,
     50             final ProvidersAccess providers,
     51             final DocumentsAccess docs,
     52             final State state,
     53             final SearchViewManager searchMgr,
     54             final Runnable actionModeFinisher) {
     55         mManager = LocalBroadcastManager.getInstance(activity);
     56 
     57         mReceiver = new BroadcastReceiver() {
     58             @Override
     59             public void onReceive(Context context, Intent intent) {
     60                 new HandleRootsChangedTask<T>(
     61                         activity,
     62                         actions,
     63                         providers,
     64                         docs,
     65                         state,
     66                         searchMgr,
     67                         actionModeFinisher).execute(activity.getCurrentRoot());
     68             }
     69         };
     70     }
     71 
     72     void start() {
     73         mManager.registerReceiver(mReceiver, new IntentFilter(ProvidersAccess.BROADCAST_ACTION));
     74     }
     75 
     76     void stop() {
     77         mManager.unregisterReceiver(mReceiver);
     78     }
     79 
     80     private static class HandleRootsChangedTask<T extends Activity & CommonAddons>
     81             extends PairedTask<T, RootInfo, RootInfo> {
     82         private final ActionHandler mActions;
     83         private final ProvidersAccess mProviders;
     84         private final DocumentsAccess mDocs;
     85         private final State mState;
     86         private final SearchViewManager mSearchMgr;
     87         private final Runnable mActionModeFinisher;
     88 
     89         private RootInfo mCurrentRoot;
     90         private DocumentInfo mDefaultRootDocument;
     91 
     92         private HandleRootsChangedTask(
     93                 T activity,
     94                 ActionHandler actions,
     95                 ProvidersAccess providers,
     96                 DocumentsAccess docs,
     97                 State state,
     98                 SearchViewManager searchMgr,
     99                 Runnable actionModeFinisher) {
    100             super(activity);
    101             mActions = actions;
    102             mProviders = providers;
    103             mDocs = docs;
    104             mState = state;
    105             mSearchMgr = searchMgr;
    106             mActionModeFinisher = actionModeFinisher;
    107         }
    108 
    109         @Override
    110         protected RootInfo run(RootInfo... roots) {
    111             assert (roots.length == 1);
    112             mCurrentRoot = roots[0];
    113             final Collection<RootInfo> cachedRoots = mProviders.getRootsBlocking();
    114             for (final RootInfo root : cachedRoots) {
    115                 if (root.getUri().equals(mCurrentRoot.getUri())) {
    116                     // We don't need to change the current root as the current root was not removed.
    117                     return null;
    118                 }
    119             }
    120 
    121             // Choose the default root.
    122             final RootInfo defaultRoot = mProviders.getDefaultRootBlocking(mState);
    123             assert (defaultRoot != null);
    124             if (!defaultRoot.isRecents()) {
    125                 mDefaultRootDocument = mDocs.getRootDocument(defaultRoot);
    126             }
    127             return defaultRoot;
    128         }
    129 
    130         @Override
    131         protected void finish(RootInfo defaultRoot) {
    132             if (defaultRoot == null) {
    133                 return;
    134             }
    135 
    136             // If the activity has been launched for the specific root and it is removed, finish the
    137             // activity.
    138             final Uri uri = mOwner.getIntent().getData();
    139             if (uri != null && uri.equals(mCurrentRoot.getUri())) {
    140                 mOwner.finish();
    141                 return;
    142             }
    143 
    144             // Clean action mode before changing root.
    145             mActionModeFinisher.run();
    146 
    147             // Clear entire backstack and start in new root.
    148             mState.stack.changeRoot(defaultRoot);
    149             mSearchMgr.update(mState.stack);
    150 
    151             if (defaultRoot.isRecents()) {
    152                 mOwner.refreshCurrentRootAndDirectory(AnimationView.ANIM_NONE);
    153             } else {
    154                 mActions.openContainerDocument(mDefaultRootDocument);
    155             }
    156         }
    157     }
    158 }
    159