Java tutorial
/* * This is the source code of Music Player Lite for Android v. 1.0.0. * You should have received a copy of the license in this archive (see LICENSE). * Copyright @CodeCrunch Team, 2016-2017. */ package co.codecrunch.musicplayerlite.childfragment; import android.app.Activity; import android.content.AsyncQueryHandler; import android.content.ContentResolver; import android.content.Context; import android.content.Intent; import android.content.res.Resources; import android.database.Cursor; import android.graphics.Bitmap; import android.net.Uri; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.provider.MediaStore; import android.support.v4.app.Fragment; import android.support.v7.widget.GridLayoutManager; import android.support.v7.widget.RecyclerView; import android.text.TextUtils; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AlphabetIndexer; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import android.widget.TextView; import co.codecrunch.musicplayerlite.R; import co.codecrunch.musicplayerlite.activities.AlbumAndArtisDetailsActivity; import co.codecrunch.musicplayerlite.adapter.CursorRecyclerViewAdapter; import co.codecrunch.musicplayerlite.utility.LogWriter; import co.codecrunch.musicplayerlite.phonemidea.MusicPlayerUtility; import co.codecrunch.musicplayerlite.phonemidea.MusicAlphabetIndexer; import co.codecrunch.musicplayerlite.phonemidea.PhoneMediaControl; import com.nostra13.universalimageloader.core.DisplayImageOptions; import com.nostra13.universalimageloader.core.ImageLoader; public class ChildFragmentAlbum extends Fragment { private static final String TAG = "ChildFragmentAlbum"; private static Context context; private RecyclerView recyclerView; boolean mIsUnknownArtist; boolean mIsUnknownAlbum; private AlbumRecyclerAdapter mAdapter; private Cursor mAlbumCursor; private String mArtistId; public static ChildFragmentAlbum newInstance(int position, Context mContext) { ChildFragmentAlbum f = new ChildFragmentAlbum(); context = mContext; return f; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragmentchild_album, null); setupView(view, savedInstanceState); return view; } private void setupView(View v, Bundle icicle) { recyclerView = (RecyclerView) v.findViewById(R.id.recyclerview_grid); recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2)); populateData(icicle); } public void resetView() { recyclerView.scrollToPosition(0); } private void populateData(Bundle icicle) { mAdapter = (AlbumRecyclerAdapter) getActivity().getLastNonConfigurationInstance(); if (mAdapter == null) { mAdapter = new AlbumRecyclerAdapter(getActivity(), null); recyclerView.setAdapter(mAdapter); getAlbumCursor(mAdapter.getQueryHandler(), null); } else { recyclerView.setAdapter(mAdapter); mAlbumCursor = mAdapter.getCursor(); if (mAlbumCursor != null) { init(mAlbumCursor); } else { getAlbumCursor(mAdapter.getQueryHandler(), null); } } } public void init(Cursor c) { if (mAdapter == null) { return; } mAdapter.changeCursor(c); // also sets mAlbumCursor if (mAlbumCursor == null) { MusicPlayerUtility.displayDatabaseError(getActivity()); mReScanHandler.sendEmptyMessageDelayed(0, 1000); return; } } private Handler mReScanHandler = new Handler() { @Override public void handleMessage(Message msg) { if (mAdapter != null) { getAlbumCursor(mAdapter.getQueryHandler(), null); } } }; private Cursor getAlbumCursor(AsyncQueryHandler async, String filter) { String[] cols = new String[] { MediaStore.Audio.Albums._ID, MediaStore.Audio.Albums.ARTIST, MediaStore.Audio.Albums.ALBUM, MediaStore.Audio.Albums.ALBUM_ART }; Cursor ret = null; Uri uri = MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI; if (!TextUtils.isEmpty(filter)) { uri = uri.buildUpon().appendQueryParameter("filter", Uri.encode(filter)).build(); } if (async != null) { async.startQuery(0, null, uri, cols, null, null, MediaStore.Audio.Albums.DEFAULT_SORT_ORDER); } else { ret = MusicPlayerUtility.query(getActivity(), uri, cols, null, null, MediaStore.Audio.Albums.DEFAULT_SORT_ORDER); } return ret; } public class AlbumRecyclerAdapter extends CursorRecyclerViewAdapter<AlbumRecyclerAdapter.ViewHolder> { private int mAlbumIdx; private int mArtistIdx; private final Resources mResources; private final String mUnknownAlbum; private final String mUnknownArtist; private AlphabetIndexer mIndexer; private AsyncQueryHandler mQueryHandler; private String mConstraint = null; private boolean mConstraintIsValid = false; private DisplayImageOptions options; private ImageLoader imageLoader = ImageLoader.getInstance(); protected AlbumRecyclerAdapter(Context context, Cursor cursor) { super(context, cursor); this.mQueryHandler = new QueryHandler(context.getContentResolver()); this.mUnknownAlbum = context.getString(R.string.unknown_album_name); this.mUnknownArtist = context.getString(R.string.unknown_artist_name); this.mResources = context.getResources(); this.options = new DisplayImageOptions.Builder().showImageOnLoading(R.drawable.bg_default_album_art) .showImageForEmptyUri(R.drawable.bg_default_album_art) .showImageOnFail(R.drawable.bg_default_album_art).cacheInMemory(true).cacheOnDisk(true) .considerExifParams(true).bitmapConfig(Bitmap.Config.RGB_565).build(); getColumnIndices(cursor); } private class QueryHandler extends AsyncQueryHandler { QueryHandler(ContentResolver res) { super(res); } @Override protected void onQueryComplete(int token, Object cookie, Cursor cursor) { init(cursor); } } public AsyncQueryHandler getQueryHandler() { return mQueryHandler; } @Override public void changeCursor(Cursor cursor) { if (getActivity().isFinishing() && cursor != null) { cursor.close(); cursor = null; } if (cursor != mAlbumCursor) { mAlbumCursor = cursor; getColumnIndices(cursor); super.changeCursor(cursor); } } public Cursor runQueryOnBackgroundThread(CharSequence constraint) { String s = constraint.toString(); if (mConstraintIsValid && ((s == null && mConstraint == null) || (s != null && s.equals(mConstraint)))) { return getCursor(); } Cursor c = getAlbumCursor(null, s); mConstraint = s; mConstraintIsValid = true; return c; } private void getColumnIndices(Cursor cursor) { if (cursor != null) { mAlbumIdx = cursor.getColumnIndexOrThrow(MediaStore.Audio.Albums.ALBUM); mArtistIdx = cursor.getColumnIndexOrThrow(MediaStore.Audio.Albums.ARTIST); if (mIndexer != null) { mIndexer.setCursor(cursor); } else { mIndexer = new MusicAlphabetIndexer(cursor, mAlbumIdx, mResources.getString(R.string.fast_scroll_alphabet)); } } } @Override public void onBindViewHolder(ViewHolder viewHolder, Cursor cursor) { String displayname = cursor.getString(mAlbumIdx); String artistname = cursor.getString(mArtistIdx); boolean unknown = displayname == null || displayname.equals(MediaStore.UNKNOWN_STRING); viewHolder.albumName.setText(unknown ? mUnknownAlbum : displayname); viewHolder.albumName.setTag(mAlbumIdx); unknown = (artistname == null || artistname.equals(MediaStore.UNKNOWN_STRING)); viewHolder.artistName.setText(unknown ? mUnknownArtist : artistname); viewHolder.artistName.setTag(mArtistIdx); String contentURI = "content://media/external/audio/albumart/" + cursor.getLong(0); imageLoader.displayImage(contentURI, viewHolder.icon, options); } @Override public ViewHolder onCreateViewHolder(ViewGroup viewgroup, int position) { return new ViewHolder(LayoutInflater.from(viewgroup.getContext()).inflate(R.layout.inflate_grid_item, viewgroup, false)); } protected class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { TextView albumName; TextView artistName; ImageView icon; public ViewHolder(View itemView) { super(itemView); albumName = (TextView) itemView.findViewById(R.id.line1); artistName = (TextView) itemView.findViewById(R.id.line2); icon = (ImageView) itemView.findViewById(R.id.icon); icon.setScaleType(ScaleType.CENTER_CROP); itemView.setOnClickListener(this); } @Override public void onClick(View view) { try { long albumID = getAlbumID(getPosition()); Intent mIntent = new Intent(context, AlbumAndArtisDetailsActivity.class); Bundle mBundle = new Bundle(); mBundle.putLong("id", albumID); mBundle.putLong("tagfor", PhoneMediaControl.SonLoadFor.Album.ordinal()); mBundle.putString("albumname", ((TextView) view.findViewById(R.id.line1)).getText().toString().trim()); mBundle.putString("title_one", ((TextView) view.findViewById(R.id.line2)).getText().toString().trim()); mBundle.putString("title_sec", ""); mIntent.putExtras(mBundle); ((Activity) context).startActivity(mIntent); ((Activity) context).overridePendingTransition(0, 0); } catch (Exception e) { e.printStackTrace(); LogWriter.info(TAG, e.toString()); } } } private long getAlbumID(int position) { return getItemId(position); } } }