session-android/src/org/thoughtcrime/securesms/util/AbstractCursorLoader.java

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package org.thoughtcrime.securesms.util;
import android.annotation.SuppressLint;
import android.content.Context;
import android.database.Cursor;
import androidx.loader.content.AsyncTaskLoader;
/**
* A Loader similar to CursorLoader that doesn't require queries to go through the ContentResolver
* to get the benefits of reloading when content has changed.
*/
public abstract class AbstractCursorLoader extends AsyncTaskLoader<Cursor> {
@SuppressWarnings("unused")
private static final String TAG = AbstractCursorLoader.class.getSimpleName();
@SuppressLint("StaticFieldLeak")
protected final Context context;
private final ForceLoadContentObserver observer;
protected Cursor cursor;
public AbstractCursorLoader(Context context) {
super(context);
this.context = context.getApplicationContext();
this.observer = new ForceLoadContentObserver();
}
public abstract Cursor getCursor();
@Override
public void deliverResult(Cursor newCursor) {
if (isReset()) {
if (newCursor != null) {
newCursor.close();
}
return;
}
Cursor oldCursor = this.cursor;
this.cursor = newCursor;
if (isStarted()) {
super.deliverResult(newCursor);
}
if (oldCursor != null && oldCursor != cursor && !oldCursor.isClosed()) {
oldCursor.close();
}
}
@Override
protected void onStartLoading() {
if (cursor != null) {
deliverResult(cursor);
}
if (takeContentChanged() || cursor == null) {
forceLoad();
}
}
@Override
protected void onStopLoading() {
cancelLoad();
}
@Override
public void onCanceled(Cursor cursor) {
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
}
@Override
public Cursor loadInBackground() {
Cursor newCursor = getCursor();
if (newCursor != null) {
newCursor.getCount();
newCursor.registerContentObserver(observer);
}
return newCursor;
}
@Override
protected void onReset() {
super.onReset();
onStopLoading();
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
cursor = null;
}
}