Added basic channel subscription and feed pages (#620)

Added basic channel subscription and feed pages

- Room Persistence for sqlite support.
- RxJava2 for reactive async support.
- Stetho for database inspection support.
- Enabled Multidex for debug build.

app/src/main/java/org/schabi/newpipe/database/AppDatabase.java

@@ -0,0 +1,15 @@
+package org.schabi.newpipe.database;
+
+import android.arch.persistence.room.Database;
+import android.arch.persistence.room.RoomDatabase;
+
+import org.schabi.newpipe.database.subscription.SubscriptionDAO;
+import org.schabi.newpipe.database.subscription.SubscriptionEntity;
+
+@Database(entities = {SubscriptionEntity.class}, version = 1, exportSchema = false)
+public abstract class AppDatabase extends RoomDatabase{
+
+    public static final String DATABASE_NAME = "newpipe.db";
+
+    public abstract SubscriptionDAO subscriptionDAO();
+}

app/src/main/java/org/schabi/newpipe/database/BasicDAO.java

@@ -0,0 +1,48 @@
+package org.schabi.newpipe.database;
+
+import android.arch.persistence.room.Dao;
+import android.arch.persistence.room.Delete;
+import android.arch.persistence.room.Insert;
+import android.arch.persistence.room.OnConflictStrategy;
+import android.arch.persistence.room.Update;
+
+import java.util.Collection;
+import java.util.List;
+
+import io.reactivex.Completable;
+import io.reactivex.Flowable;
+
+@Dao
+public interface BasicDAO<Entity> {
+    /* Inserts */
+    @Insert(onConflict = OnConflictStrategy.FAIL)
+    long insert(final Entity entity);
+
+    @Insert(onConflict = OnConflictStrategy.FAIL)
+    List<Long> insertAll(final Entity... entities);
+
+    @Insert(onConflict = OnConflictStrategy.FAIL)
+    List<Long> insertAll(final Collection<Entity> entities);
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    long upsert(final Entity entity);
+
+    /* Searches */
+    Flowable<List<Entity>> findAll();
+
+    Flowable<List<Entity>> listByService(int serviceId);
+
+    /* Deletes */
+    @Delete
+    int delete(final Entity entity);
+
+    @Delete
+    int delete(final Collection<Entity> entities);
+
+    /* Updates */
+    @Update
+    int update(final Entity entity);
+
+    @Update
+    int update(final Collection<Entity> entities);
+}

app/src/main/java/org/schabi/newpipe/database/subscription/SubscriptionDAO.java

@@ -0,0 +1,30 @@
+package org.schabi.newpipe.database.subscription;
+
+import android.arch.persistence.room.Dao;
+import android.arch.persistence.room.Query;
+
+import org.schabi.newpipe.database.BasicDAO;
+
+import java.util.List;
+
+import io.reactivex.Flowable;
+
+import static org.schabi.newpipe.database.subscription.SubscriptionEntity.SUBSCRIPTION_SERVICE_ID;
+import static org.schabi.newpipe.database.subscription.SubscriptionEntity.SUBSCRIPTION_TABLE;
+import static org.schabi.newpipe.database.subscription.SubscriptionEntity.SUBSCRIPTION_URL;
+
+@Dao
+public interface SubscriptionDAO extends BasicDAO<SubscriptionEntity> {
+    @Override
+    @Query("SELECT * FROM " + SUBSCRIPTION_TABLE)
+    Flowable<List<SubscriptionEntity>> findAll();
+
+    @Override
+    @Query("SELECT * FROM " + SUBSCRIPTION_TABLE + " WHERE " + SUBSCRIPTION_SERVICE_ID + " = :serviceId")
+    Flowable<List<SubscriptionEntity>> listByService(int serviceId);
+
+    @Query("SELECT * FROM " + SUBSCRIPTION_TABLE + " WHERE " +
+            SUBSCRIPTION_URL + " LIKE :url AND " +
+            SUBSCRIPTION_SERVICE_ID + " = :serviceId")
+    Flowable<List<SubscriptionEntity>> findAll(int serviceId, String url);
+}

app/src/main/java/org/schabi/newpipe/database/subscription/SubscriptionEntity.java

@@ -0,0 +1,113 @@
+package org.schabi.newpipe.database.subscription;
+
+import android.arch.persistence.room.ColumnInfo;
+import android.arch.persistence.room.Entity;
+import android.arch.persistence.room.Ignore;
+import android.arch.persistence.room.Index;
+import android.arch.persistence.room.PrimaryKey;
+
+import static org.schabi.newpipe.database.subscription.SubscriptionEntity.SUBSCRIPTION_SERVICE_ID;
+import static org.schabi.newpipe.database.subscription.SubscriptionEntity.SUBSCRIPTION_TABLE;
+import static org.schabi.newpipe.database.subscription.SubscriptionEntity.SUBSCRIPTION_URL;
+
+@Entity(tableName = SUBSCRIPTION_TABLE,
+        indices = {@Index(value = {SUBSCRIPTION_SERVICE_ID, SUBSCRIPTION_URL}, unique = true)})
+public class SubscriptionEntity {
+
+    final static String SUBSCRIPTION_TABLE              = "subscriptions";
+    final static String SUBSCRIPTION_SERVICE_ID         = "service_id";
+    final static String SUBSCRIPTION_URL                = "url";
+    final static String SUBSCRIPTION_TITLE              = "title";
+    final static String SUBSCRIPTION_THUMBNAIL_URL      = "thumbnail_url";
+    final static String SUBSCRIPTION_SUBSCRIBER_COUNT   = "subscriber_count";
+    final static String SUBSCRIPTION_DESCRIPTION        = "description";
+
+    @PrimaryKey(autoGenerate = true)
+    private long uid = 0;
+
+    @ColumnInfo(name = SUBSCRIPTION_SERVICE_ID)
+    private int serviceId = -1;
+
+    @ColumnInfo(name = SUBSCRIPTION_URL)
+    private String url;
+
+    @ColumnInfo(name = SUBSCRIPTION_TITLE)
+    private String title;
+
+    @ColumnInfo(name = SUBSCRIPTION_THUMBNAIL_URL)
+    private String thumbnailUrl;
+
+    @ColumnInfo(name = SUBSCRIPTION_SUBSCRIBER_COUNT)
+    private Long subscriberCount;
+
+    @ColumnInfo(name = SUBSCRIPTION_DESCRIPTION)
+    private String description;
+
+    public long getUid() {
+        return uid;
+    }
+
+    /* Keep this package-private since UID should always be auto generated by Room impl */
+    void setUid(long uid) {
+        this.uid = uid;
+    }
+
+    public int getServiceId() {
+        return serviceId;
+    }
+
+    public void setServiceId(int serviceId) {
+        this.serviceId = serviceId;
+    }
+
+    public String getUrl() {
+        return url;
+    }
+
+    public void setUrl(String url) {
+        this.url = url;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getThumbnailUrl() {
+        return thumbnailUrl;
+    }
+
+    public void setThumbnailUrl(String thumbnailUrl) {
+        this.thumbnailUrl = thumbnailUrl;
+    }
+
+    public Long getSubscriberCount() {
+        return subscriberCount;
+    }
+
+    public void setSubscriberCount(Long subscriberCount) {
+        this.subscriberCount = subscriberCount;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    @Ignore
+    public void setData(final String title,
+                        final String thumbnailUrl,
+                        final String description,
+                        final Long subscriberCount) {
+        this.setTitle(title);
+        this.setThumbnailUrl(thumbnailUrl);
+        this.setDescription(description);
+        this.setSubscriberCount(subscriberCount);
+    }
+}