Java tutorial
/*** Copyright (c) 2015-2016 CommonsWare, LLC 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. Covered in detail in the book _The Busy Coder's Guide to Android Development_ https://commonsware.com/Android */ package com.commonsware.android.kbmouse.hotkeys; import android.Manifest; import android.app.Activity; import android.app.LoaderManager; import android.content.ClipData; import android.content.ContentUris; import android.content.CursorLoader; import android.content.Loader; import android.content.pm.PackageManager; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.provider.MediaStore; import android.support.annotation.StringRes; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.SparseArray; import android.view.DragEvent; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.Toast; import android.widget.VideoView; import com.squareup.picasso.Picasso; public class MainActivity extends Activity implements LoaderManager.LoaderCallbacks<Cursor>, View.OnDragListener, View.OnHoverListener, View.OnLongClickListener { private static final String STATE_IN_PERMISSION = "inPermission"; private static final int REQUEST_PERMS = 137; private static final long TOOLTIP_DELAY = 1000L; private RecyclerView videoList; private VideoView player; private ImageView thumbnailLarge; private boolean isInPermission = false; private VideoAdapter adapter; private SparseArray<Runnable> hoverTimers = new SparseArray<>(); private Toast tooltip; @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); player = (VideoView) findViewById(R.id.player); if (player != null) { player.setOnDragListener(this); player.setOnHoverListener(this); player.setOnLongClickListener(this); } thumbnailLarge = (ImageView) findViewById(R.id.thumbnail_large); if (thumbnailLarge != null) { thumbnailLarge.setOnDragListener(this); thumbnailLarge.setOnHoverListener(this); thumbnailLarge.setOnLongClickListener(this); } setLayoutManager(new LinearLayoutManager(this)); adapter = new VideoAdapter(getRecyclerView()); setAdapter(adapter); getRecyclerView().requestFocus(); if (icicle != null) { isInPermission = icicle.getBoolean(STATE_IN_PERMISSION, false); } if (hasFilesPermission()) { loadVideos(); } else if (!isInPermission) { isInPermission = true; ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.READ_EXTERNAL_STORAGE }, REQUEST_PERMS); } } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putBoolean(STATE_IN_PERMISSION, isInPermission); adapter.onSaveInstanceState(outState); } @Override public void onRestoreInstanceState(Bundle state) { adapter.onRestoreInstanceState(state); } @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { isInPermission = false; if (requestCode == REQUEST_PERMS) { if (hasFilesPermission()) { loadVideos(); } else { finish(); // denied permission, so we're done } } } @Override public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) { return (new CursorLoader(this, MediaStore.Video.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Video.Media.TITLE)); } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor c) { ((VideoAdapter) getAdapter()).setVideos(c); } @Override public void onLoaderReset(Loader<Cursor> loader) { ((VideoAdapter) getAdapter()).setVideos(null); } @Override public boolean onDrag(View v, DragEvent event) { boolean result = true; switch (event.getAction()) { case DragEvent.ACTION_DRAG_STARTED: applyDropHint(v, R.drawable.droppable); break; case DragEvent.ACTION_DRAG_ENTERED: applyDropHint(v, R.drawable.drop); break; case DragEvent.ACTION_DRAG_EXITED: applyDropHint(v, R.drawable.droppable); break; case DragEvent.ACTION_DRAG_ENDED: applyDropHint(v, -1); break; case DragEvent.ACTION_DROP: ClipData.Item clip = event.getClipData().getItemAt(0); Uri videoUri = clip.getUri(); if (v == player) { playVideo(videoUri); } else { showLargeThumbnail(videoUri); } break; } return (result); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT && event.getRepeatCount() == 0) { int position = adapter.getCheckedPosition(); if (position >= 0) { Uri videoUri = adapter.getVideoUri(position); if (event.isAltPressed()) { playVideo(videoUri); } else if (event.isCtrlPressed()) { showLargeThumbnail(videoUri); } return (true); } } return (super.onKeyDown(keyCode, event)); } @Override public boolean onHover(View v, MotionEvent event) { if (v == player) { onHover(event, R.string.tooltip_player, player); } else if (v == thumbnailLarge) { onHover(event, R.string.tooltip_thumbnail, thumbnailLarge); } else { return (false); } return (true); } @Override public boolean onLongClick(View v) { if (v == thumbnailLarge) { showTooltip(R.string.tooltip_thumbnail); } else if (v == player) { showTooltip(R.string.tooltip_player); } else { return (false); } return (true); } private void setAdapter(RecyclerView.Adapter adapter) { getRecyclerView().setAdapter(adapter); } private RecyclerView.Adapter getAdapter() { return (getRecyclerView().getAdapter()); } private void setLayoutManager(RecyclerView.LayoutManager mgr) { getRecyclerView().setLayoutManager(mgr); } private RecyclerView getRecyclerView() { if (videoList == null) { videoList = (RecyclerView) findViewById(R.id.video_list); } return (videoList); } private void applyDropHint(View v, int drawableId) { View parent = (View) v.getParent(); if (drawableId > -1) { parent.setBackgroundResource(drawableId); } else { parent.setBackground(null); } } private boolean hasFilesPermission() { return (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED); } private void loadVideos() { getLoaderManager().initLoader(0, null, this); } private void playVideo(Uri videoUri) { player.setVideoURI(videoUri); player.start(); } private void showLargeThumbnail(Uri videoUri) { Picasso.with(thumbnailLarge.getContext()).load(videoUri.toString()).fit().centerCrop() .placeholder(R.drawable.ic_media_video_poster).into(thumbnailLarge); } private void onHover(MotionEvent event, @StringRes final int message, final View anchor) { Runnable hover = hoverTimers.get(anchor.getId()); if (hover == null && (event.getAction() == MotionEvent.ACTION_HOVER_ENTER || event.getAction() == MotionEvent.ACTION_HOVER_MOVE)) { hover = new Runnable() { @Override public void run() { showTooltip(message); } }; hoverTimers.put(anchor.getId(), hover); thumbnailLarge.postDelayed(hover, TOOLTIP_DELAY); } else if (hover != null && event.getAction() == MotionEvent.ACTION_HOVER_EXIT) { thumbnailLarge.removeCallbacks(hover); hoverTimers.remove(anchor.getId()); } } private void showTooltip(@StringRes int message) { if (tooltip != null) { tooltip.cancel(); } tooltip = Toast.makeText(this, message, Toast.LENGTH_LONG); tooltip.show(); } private class VideoAdapter extends ChoiceCapableAdapter<RowController> { Cursor videos = null; VideoAdapter(RecyclerView rv) { super(rv, new SingleChoiceMode()); } @Override public RowController onCreateViewHolder(ViewGroup parent, int viewType) { return (new RowController(getLayoutInflater().inflate(R.layout.row, parent, false))); } void setVideos(Cursor videos) { this.videos = videos; notifyDataSetChanged(); } @Override public void onBindViewHolder(RowController holder, int position) { videos.moveToPosition(position); holder.bindModel(videos, isChecked(position)); } @Override public int getItemCount() { if (videos == null) { return (0); } return (videos.getCount()); } private Uri getVideoUri(int position) { videos.moveToPosition(position); return (ContentUris.withAppendedId(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, videos.getInt(videos.getColumnIndex(MediaStore.Video.Media._ID)))); } } }