Java tutorial
/* * This is the source code of DMPLayer for Android v. 1.0.0. * You should have received a copy of the license in this archive (see LICENSE). * Copyright @Dibakar_Mistry, 2015. */ package com.dmplayer.childfragment; import com.dmplayer.R; import com.dmplayer.activities.AlbumAndArtisDetailsActivity; import com.dmplayer.adapter.CursorRecyclerViewAdapter; import com.dmplayer.utility.LogWriter; import com.dmplayer.phonemidea.DMPlayerUtility; import com.dmplayer.phonemidea.MusicAlphabetIndexer; import com.dmplayer.phonemidea.PhoneMediaControl; 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.drawable.BitmapDrawable; 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.ImageView; import android.widget.TextView; public class ChildFragmentGenres extends Fragment { private static final String TAG = "ChildFragmentArtists"; private static Context context; private RecyclerView recyclerView; boolean mIsUnknownArtist; boolean mIsUnknownAlbum; private GenersRecyclerAdapter mAdapter; public static ChildFragmentGenres newInstance(int position, Context mContext) { ChildFragmentGenres f = new ChildFragmentGenres(); 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); return view; } private void setupView(View v) { recyclerView = (RecyclerView) v.findViewById(R.id.recyclerview_grid); recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2)); populateData(); } private void populateData() { mAdapter = (GenersRecyclerAdapter) getActivity().getLastNonConfigurationInstance(); if (mAdapter == null) { mAdapter = new GenersRecyclerAdapter(getActivity(), null); recyclerView.setAdapter(mAdapter); getGenersCursor(mAdapter.getQueryHandler(), null); } else { recyclerView.setAdapter(mAdapter); mArtistCursor = mAdapter.getCursor(); if (mArtistCursor != null) { init(mArtistCursor); } else { getGenersCursor(mAdapter.getQueryHandler(), null); } } } public void resetView() { recyclerView.scrollToPosition(0); } private Cursor mArtistCursor; public void init(Cursor c) { if (mAdapter == null) { return; } mAdapter.changeCursor(c); // also sets mArtistCursor if (mArtistCursor == null) { DMPlayerUtility.displayDatabaseError(getActivity()); mReScanHandler.sendEmptyMessageDelayed(0, 1000); return; } } private Handler mReScanHandler = new Handler() { @Override public void handleMessage(Message msg) { if (mAdapter != null) { getGenersCursor(mAdapter.getQueryHandler(), null); } } }; private Cursor getGenersCursor(AsyncQueryHandler async, String filter) { String[] cols = new String[] { MediaStore.Audio.Genres._ID, MediaStore.Audio.Genres.NAME }; Uri uri = MediaStore.Audio.Genres.EXTERNAL_CONTENT_URI; if (!TextUtils.isEmpty(filter)) { uri = uri.buildUpon().appendQueryParameter("filter", Uri.encode(filter)).build(); } Cursor ret = null; if (async != null) { async.startQuery(0, null, uri, cols, null, null, null); } else { ret = DMPlayerUtility.query(getActivity(), uri, cols, null, null, null); } return ret; } public class GenersRecyclerAdapter extends CursorRecyclerViewAdapter<GenersRecyclerAdapter.ViewHolder> { private final BitmapDrawable mDefaultAlbumIcon; private int genenrsIdIdx; private int genersIdx; private final Context mContext; private final Resources mResources; private final String mUnknownArtist; private final StringBuilder mBuffer = new StringBuilder(); private MusicAlphabetIndexer mIndexer; private AsyncQueryHandler mQueryHandler; private String mConstraint = null; private boolean mConstraintIsValid = false; protected GenersRecyclerAdapter(Context context, Cursor cursor) { super(context, cursor); mQueryHandler = new QueryHandler(context.getContentResolver()); Resources r = context.getResources(); mDefaultAlbumIcon = (BitmapDrawable) r.getDrawable(R.drawable.bg_default_album_art); // no filter or dither, it's a lot faster and we can't tell the // difference mDefaultAlbumIcon.setFilterBitmap(false); mDefaultAlbumIcon.setDither(false); mContext = context; getColumnIndices(cursor); mResources = context.getResources(); mUnknownArtist = context.getString(R.string.unknown_artist_name); } 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 != mArtistCursor) { mArtistCursor = 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 = getGenersCursor(null, s); mConstraint = s; mConstraintIsValid = true; return c; } private void getColumnIndices(Cursor cursor) { if (cursor != null) { genenrsIdIdx = cursor.getColumnIndexOrThrow(MediaStore.Audio.Genres._ID); genersIdx = cursor.getColumnIndexOrThrow(MediaStore.Audio.Genres.NAME); if (mIndexer != null) { mIndexer.setCursor(cursor); } else { mIndexer = new MusicAlphabetIndexer(cursor, genersIdx, mResources.getString(R.string.fast_scroll_alphabet)); } } } @Override public void onBindViewHolder(ViewHolder viewHolder, Cursor cursor) { String displaygeners = cursor.getString(genersIdx); int genenrsId = cursor.getInt(genenrsIdIdx); boolean unknown = displaygeners == null || displaygeners.equals(MediaStore.UNKNOWN_STRING); if (unknown) { displaygeners = mUnknownArtist; } viewHolder.line1.setText(displaygeners); viewHolder.line2.setVisibility(View.GONE); } @Override public ViewHolder onCreateViewHolder(ViewGroup viewgroup, int position) { return new ViewHolder(LayoutInflater.from(viewgroup.getContext()).inflate(R.layout.inflate_grid_item, viewgroup, false)); } private long getGenerID(int position) { return getItemId(position); } protected class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { TextView line1; TextView line2; ImageView icon; public ViewHolder(View itemView) { super(itemView); line1 = (TextView) itemView.findViewById(R.id.line1); line2 = (TextView) itemView.findViewById(R.id.line2); icon = (ImageView) itemView.findViewById(R.id.icon); icon.setScaleType(ImageView.ScaleType.CENTER_CROP); itemView.setOnClickListener(this); } @Override public void onClick(View view) { try { long generid = getGenerID(getPosition()); Intent mIntent = new Intent(context, AlbumAndArtisDetailsActivity.class); Bundle mBundle = new Bundle(); mBundle.putLong("id", generid); mBundle.putLong("tagfor", PhoneMediaControl.SonLoadFor.Gener.ordinal()); mBundle.putString("albumname", ((TextView) view.findViewById(R.id.line1)).getText().toString().trim()); mBundle.putString("title_one", "All my songs"); mBundle.putString("title_sec", ((TextView) view.findViewById(R.id.line2)).getText().toString().trim()); mIntent.putExtras(mBundle); ((Activity) context).startActivity(mIntent); ((Activity) context).overridePendingTransition(0, 0); } catch (Exception e) { e.printStackTrace(); LogWriter.info(TAG, e.toString()); } } } } }