DocumentListModel.java
/*
* Copyright 2021 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 androidx.appsearch.debugview.model;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.annotation.RestrictTo;
import androidx.appsearch.app.GenericDocument;
import androidx.appsearch.app.SearchResults;
import androidx.appsearch.debugview.DebugAppSearchManager;
import androidx.core.util.Preconditions;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
import androidx.lifecycle.ViewModelProvider;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListeningExecutorService;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ExecutorService;
/**
* Documents ViewModel for the database's {@link GenericDocument} objects.
*
* <p>This model captures the data for displaying lists of {@link GenericDocument} objects. Each
* {@link GenericDocument} object is truncated of all properties.
*
* <p>Instances of {@link DocumentListModel} are created by {@link DocumentListModelFactory}.
*
* @hide
*/
@RestrictTo(RestrictTo.Scope.LIBRARY)
public class DocumentListModel extends ViewModel {
private static final String TAG = "DocumentListModel";
private final ExecutorService mExecutor;
private final DebugAppSearchManager mDebugAppSearchManager;
final MutableLiveData<List<GenericDocument>> mDocumentsLiveData =
new MutableLiveData<>();
final MutableLiveData<SearchResults> mDocumentsSearchResultsLiveData =
new MutableLiveData<>();
volatile boolean mHasAdditionalPages = true;
public DocumentListModel(@NonNull ExecutorService executor,
@NonNull DebugAppSearchManager debugAppSearchManager) {
mExecutor = Preconditions.checkNotNull(executor);
mDebugAppSearchManager = Preconditions.checkNotNull(debugAppSearchManager);
}
/**
* Gets the {@link SearchResults} instance for a search over all documents in the AppSearch
* database.
*
* <p>Call {@link #addAdditionalResultsPage} to get the next page of documents from the
* {@link SearchResults} instance.
*
* <p>This should only be called once per fragment.
*/
@NonNull
public LiveData<SearchResults> getAllDocumentsSearchResults() {
Futures.addCallback(mDebugAppSearchManager.getAllDocumentsSearchResultsAsync(),
new FutureCallback<SearchResults>() {
@Override
public void onSuccess(SearchResults result) {
// There should only be one active observer to post this value to as its
// called only once per fragment, ensuring a safe null check.
if (mDocumentsSearchResultsLiveData.getValue() == null) {
mDocumentsSearchResultsLiveData.postValue(result);
}
}
@Override
public void onFailure(@NonNull Throwable t) {
Log.e(TAG, "Failed to get all documents.", t);
}
}, mExecutor);
return mDocumentsSearchResultsLiveData;
}
/**
* Adds the next page of documents for the provided {@link SearchResults} instance to the
* running list of retrieved {@link GenericDocument} objects.
*
* <p>Each page is represented as a list of {@link GenericDocument} objects.
*
* @return a {@link LiveData} encapsulating the list of {@link GenericDocument} objects for
* documents retrieved from all previous pages and this additional page.
*/
@NonNull
public LiveData<List<GenericDocument>> addAdditionalResultsPage(
@NonNull SearchResults results) {
Futures.addCallback(mDebugAppSearchManager.getNextPageAsync(results),
new FutureCallback<List<GenericDocument>>() {
@Override
public void onSuccess(List<GenericDocument> result) {
if (mDocumentsLiveData.getValue() == null) {
mDocumentsLiveData.postValue(result);
} else {
if (result.isEmpty()) {
mHasAdditionalPages = false;
}
mDocumentsLiveData.getValue().addAll(result);
mDocumentsLiveData.postValue(mDocumentsLiveData.getValue());
}
}
@Override
public void onFailure(@NonNull Throwable t) {
Log.e(TAG, "Failed to get next page of documents.", t);
}
}, mExecutor);
return mDocumentsLiveData;
}
/**
* Returns whether there are additional pages to load to the document list.
*/
public boolean hasAdditionalPages() {
return mHasAdditionalPages;
}
/**
* Gets all {@link GenericDocument} objects that have been loaded.
*
* <p>If the underlying list of the Documents LiveData is {@code null}, this returns an
* empty list as a placeholder.
*/
@NonNull
public List<GenericDocument> getAllLoadedDocuments() {
if (mDocumentsLiveData.getValue() == null) {
return Collections.emptyList();
}
return mDocumentsLiveData.getValue();
}
/**
* Factory for creating a {@link DocumentListModel} instance.
*/
public static class DocumentListModelFactory extends ViewModelProvider.NewInstanceFactory {
private final DebugAppSearchManager mDebugAppSearchManager;
private final ListeningExecutorService mExecutorService;
public DocumentListModelFactory(@NonNull ListeningExecutorService executor,
@NonNull DebugAppSearchManager debugAppSearchManager) {
mDebugAppSearchManager = debugAppSearchManager;
mExecutorService = executor;
}
@SuppressWarnings("unchecked")
@NonNull
@Override
public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
if (modelClass == DocumentListModel.class) {
return (T) new DocumentListModel(mExecutorService, mDebugAppSearchManager);
} else {
throw new IllegalArgumentException("Expected class: DocumentListModel.");
}
}
}
}