Java tutorial
/* * Copyright (C) 2012,2013 Renard Wellnitz * * 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. */ package com.example.linhdq.test.main_menu.language; import android.app.AlertDialog.Builder; import android.app.DownloadManager; import android.app.DownloadManager.Query; import android.app.DownloadManager.Request; import android.content.BroadcastReceiver; import android.content.Context; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.content.Intent; import android.content.IntentFilter; import android.database.Cursor; import android.net.Uri; import android.os.AsyncTask; import android.support.v4.app.NavUtils; import android.view.MenuItem; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListView; import android.widget.Toast; import android.widget.ViewSwitcher; import com.example.linhdq.test.MonitoredActivity; import com.example.linhdq.test.R; import java.util.Iterator; import java.util.List; public class OCRLanguageActivity extends MonitoredActivity { private BroadcastReceiver mDownloadReceiver; private ListView mList; private OCRLanguageAdapter mAdapter; private ViewSwitcher mSwitcher; private BroadcastReceiver mFailedReceiver; private boolean mReceiverRegistered; private final DownloadManagerResolver mDownloadManagerResolver = new DownloadManagerResolver(); private class LoadListAsyncTask extends AsyncTask<Void, Void, OCRLanguageAdapter> { @Override protected void onPostExecute(OCRLanguageAdapter result) { super.onPostExecute(result); registerDownloadReceiver(); mAdapter = result; mList.setAdapter(result); mSwitcher.setDisplayedChild(1); mList.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { OcrLanguage language = (OcrLanguage) mAdapter.getItem(position); if (!language.isInstalled()) { if (mDownloadManagerResolver.resolve(OCRLanguageActivity.this)) { startDownload(language); } } else { deleteLanguage(position); } } }); } private void startDownload(OcrLanguage language) { final DownloadManager dm = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); List<Uri> uris = language.getDownloadUris(); for (Uri uri : uris) { Request request = new Request(uri); request.setTitle(language.getDisplayText()); dm.enqueue(request); } language.setDownloading(true); mAdapter.notifyDataSetChanged(); } protected void deleteLanguage(int position) { final OcrLanguage language = (OcrLanguage) mAdapter.getItem(position); Builder b = new Builder(OCRLanguageActivity.this); String msg = getString(R.string.delete_language_message); String title = getString(R.string.delete_language_title); title = String.format(title, language.getDisplayText()); msg = String.format(msg, language.getSize() / 1024); b.setTitle(title); b.setMessage(msg); b.setCancelable(true); b.setNegativeButton(R.string.cancel, new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); b.setPositiveButton(R.string.ocr_language_delete, new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { OcrLanguageDataStore.deleteLanguage(language, OCRLanguageActivity.this); mAdapter.notifyDataSetChanged(); } }); b.show(); } @Override protected OCRLanguageAdapter doInBackground(Void... params) { return initLanguageList(); } } protected void onCreate(android.os.Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_ocr_language); mList = (ListView) findViewById(R.id.list_ocr_languages); mSwitcher = (ViewSwitcher) findViewById(R.id.viewSwitcher_language_list); initToolbar(); getSupportActionBar().setDisplayHomeAsUpEnabled(true); setToolbarMessage(R.string.ocr_language_title); new LoadListAsyncTask().execute(); } @Override protected int getHintDialogId() { return -1; } private OCRLanguageAdapter initLanguageList() { OCRLanguageAdapter adapter = new OCRLanguageAdapter(getApplicationContext(), false); List<OcrLanguage> languages = OcrLanguageDataStore.getAvailableOcrLanguages(this); hideArabicDownload(languages); adapter.addAll(languages); updateLanguageListWithDownloadManagerStatus(adapter); return adapter; } private void hideArabicDownload(List<OcrLanguage> languages) { Iterator<OcrLanguage> it = languages.iterator(); while (it.hasNext()) { final OcrLanguage lang = it.next(); if (lang.getValue().equalsIgnoreCase("ara")) { it.remove(); return; } } } @Override protected synchronized void onDestroy() { super.onDestroy(); if (mReceiverRegistered) { unregisterReceiver(mDownloadReceiver); unregisterReceiver(mFailedReceiver); mReceiverRegistered = false; } } private void updateLanguageListWithDownloadManagerStatus(OCRLanguageAdapter adapter) { if (adapter != null) { // find languages that are currently being downloaded Query query = new Query(); query.setFilterByStatus(DownloadManager.STATUS_RUNNING | DownloadManager.STATUS_PENDING | DownloadManager.STATUS_PAUSED); final DownloadManager dm = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); Cursor c = dm.query(query); if (c == null) { return; } int columnIndex = c.getColumnIndex(DownloadManager.COLUMN_TITLE); while (c.moveToNext()) { final String title = c.getString(columnIndex); adapter.setDownloading(title, true); } adapter.notifyDataSetChanged(); c.close(); } } private void registerDownloadReceiver() { mDownloadReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String lang = intent.getStringExtra(OCRLanguageInstallService.EXTRA_OCR_LANGUAGE); int status = intent.getIntExtra(OCRLanguageInstallService.EXTRA_STATUS, -1); updateLanguageList(lang, status); } }; mFailedReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String lang = intent.getStringExtra(OCRLanguageInstallService.EXTRA_OCR_LANGUAGE_DISPLAY); int status = intent.getIntExtra(OCRLanguageInstallService.EXTRA_STATUS, -1); updateLanguageListByDisplayValue(lang, status); } }; registerReceiver(mFailedReceiver, new IntentFilter(OCRLanguageInstallService.ACTION_INSTALL_FAILED)); registerReceiver(mDownloadReceiver, new IntentFilter(OCRLanguageInstallService.ACTION_INSTALL_COMPLETED)); mReceiverRegistered = true; } protected void updateLanguageListByDisplayValue(String displayValue, int status) { for (int i = 0; i < mAdapter.getCount(); i++) { final OcrLanguage language = (OcrLanguage) mAdapter.getItem(i); if (language.getDisplayText().equalsIgnoreCase(displayValue)) { updateLanguage(language, status); return; } } } protected void updateLanguageList(String lang, int status) { for (int i = 0; i < mAdapter.getCount(); i++) { final OcrLanguage language = (OcrLanguage) mAdapter.getItem(i); if (language.getValue().equalsIgnoreCase(lang)) { updateLanguage(language, status); return; } } } private void updateLanguage(final OcrLanguage language, int status) { if (status == DownloadManager.STATUS_SUCCESSFUL) { final InstallStatus installStatus = OcrLanguageDataStore.isLanguageInstalled(language.getValue(), OCRLanguageActivity.this); language.setInstallStatus(installStatus); if (installStatus.isInstalled()) { language.setDownloading(false); mAdapter.notifyDataSetChanged(); } } else { language.setDownloading(false); mAdapter.notifyDataSetChanged(); runOnUiThread(new Runnable() { @Override public void run() { String msg = getString(R.string.download_failed); msg = String.format(msg, language.getDisplayText()); Toast.makeText(OCRLanguageActivity.this, msg, Toast.LENGTH_LONG).show(); } }); } } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: NavUtils.navigateUpFromSameTask(this); return true; } return super.onOptionsItemSelected(item); } @Override protected void onPause() { super.onPause(); overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right); } @Override public String getScreenName() { return "Ocr Languages"; } }