FlashAir Android App

Development

Sep. 18 2013 Yuki Anzai uPhyca Inc.

Steps

• Access the FlashAir

• Display a list of files stored on the FlashAir

• Display thumbnail images

• Download images

Set up a Project

• [File] - [New] - [Android Application Project]

• Application Name: FlashAirSample

• Project Name: FlashAirSample

• Package Name: com.example.flashairsample

• Mininum Required SDK: API 9

• Use default settings for everything else

Access the FlashAir

Access the FlashAir #1

• Connect your Android device to the FlashAir's wireless network.

• Create a shortcut to open the WiFi configuration window.

res/menu/main.xml <menu xmlns:android="http://schemas.android.com/apk/res/android" > <item android:id="@+id/action_wifi_settings" android:showAsAction="never" android:title="@string/action_wifi_settings"/> </menu>

res/values/strings.xml <?xml version="1.0" encoding="utf-8"?> <resources> ... <string name="action_wifi_settings">WiFi Settings</string> </resources>

MainActivity.java

public class MainActivity extends Activity { ... @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { int itemId = item.getItemId(); switch (itemId) { case R.id.action_wifi_settings: Intent intent = new Intent(Settings.ACTION_WIFI_SETTINGS); startActivity(intent); return true; } return super.onOptionsItemSelected(item); } }

Access the FlashAir #2

• Since the FlashAir uses HTTP, your app will require android.permission.INTERNET.

• Default SSID: flashair_xxxxx

• Default Password: 12345678

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.flashairsample" android:versionCode="1" android:versionName="1.0" > <uses-permission android:name="android.permission.INTERNET"/> ... </manifest>

Access the FlashAir #3

• Use a library project

• FlashAirDev

• https://github.com/yanzm/FlashAirDev

• git clone https://github.com/yanzm/FlashAirDev.git

• [File] - [Import] - [Android] - [Existing Android Code Into Workspace]

• Select root directory:

• Set FlashAirDev folder

Access FlashAir #4

• Add the FlashAirDev library project

• [Android] - [Library] - [Add]

• Select FlashAirDev

Access FlashAir #5

• To get the number of files in a folder:

• Use http://flashair/command.cgi?op=101&DIR=[path]

• The number of files will be returned

• See: https://www.flashair-developers.com/ja/documents/api/commandcgi/#101

res/layout/activity_main.xml <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" ... tools:context=".MainActivity" > <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" /> </RelativeLayout>

res/menu/main.xml <menu xmlns:android="http://schemas.android.com/apk/res/android" > <item android:id="@+id/action_reload" android:showAsAction="ifRoom" android:title="@string/action_reload"/> ... </menu>

res/values/strings.xml <?xml version="1.0" encoding="utf-8"?> <resources> ... <string name="action_reload">Reload</string> <string name="image_count_format">%1$d images</string> </resources>

MainActivity.java public class MainActivity extends Activity { ... @Override public boolean onOptionsItemSelected(MenuItem item) { int itemId = item.getItemId(); switch (itemId) { ... case R.id.action_reload: String dir = "/DCIM"; getFileCount(dir); return true; } return super.onOptionsItemSelected(item); } ... }

MainActivity.java

public class MainActivity extends Activity { ... private void getFileCount(final String dir) { new AsyncTask<Void, Void, Integer>() { @Override protected Integer doInBackground(Void... params) { return FlashAirUtils.getFileCount(dir); } @Override protected void onPostExecute(Integer result) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText(getString(R.string.image_count_format, result)); } }.execute(); } }

FlashAirUtils.java

public class FlashAirUtils { public static final String BASE = "http://flashair/"; public static final String COMMAND = BASE + "command.cgi?"; public static final String FILE_COUNT = COMMAND + "op=101&DIR="; public static int getFileCount(String dir) { try { String result = Utils.accessToFlashAir(FILE_COUNT + dir); return Integer.parseInt(result); } catch (NumberFormatException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return -1; } ... }

Get the number of files

Utils.java

public class Utils { public static String accessToFlashAir(String uri) throws IOException { URL url = new URL(uri); HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); String result = null; try { InputStream in = new BufferedInputStream(urlConnection.getInputStream()); result = inputStreamToString(in); in.close(); } finally { urlConnection.disconnect(); } return result; } ... }

For HTTP Access

Utils.java

public class Utils { ... private static String inputStreamToString(InputStream stream) throws IOException { Reader reader = new InputStreamReader(stream, "UTF-8"); StringBuilder sb = new StringBuilder(); char[] buffer = new char[1024]; int num; while (0 < (num = reader.read(buffer))) { sb.append(buffer, 0, num); } return sb.toString(); } ... }

For HTTP Access

Display a list of files stored on the FlashAir

Display a list of files #1

• Get a list of the DCIM folder

• Use: http://flashair/command.cgi?op=100&DIR=[path]

• See: https://www.flashair-developers.com/ja/documents/api/commandcgi/#100

• <directory>,<file name>,<file size>,<attribute>,<date>,and <time> are returned.

• e.g. /DCIM,100__TSB,0,16,9944,129

• NOTE: A comma could be returned as part of a filename.

Display a list of files #2

• The file's size is in bytes

• Attribute is a 16-bit integer

• Bit 5 : Archive

• Bit 4 : Directly

• Bit 3 : Volume

• Bit 2 : System file

• Bit 1 : Hidden file

• Bit 0 : Read only

Display a list of files #3

• Date is also a 16-bit integer

• Bit 15-9 : A value based on 0 as a 1980

• Bit 8-5 : Month from 1 to 12

• Bit 4-0 : Day from 1 to 31

• So is the Timestamp

• Bit 15-11 : Hour

• Bit 10-5 : Minute

• Bit 4-0 : Second/2

FlashAirFileInfo.java

public class FlashAirFileInfo { public FlashAirFileInfo(String info, String dir) { int start; int end; start = info.lastIndexOf(","); int time = Integer.parseInt(info.substring(start + 1).trim()); end = start; start = info.lastIndexOf(",", end - 1); int date = Integer.parseInt(info.substring(start + 1, end).trim()); end = start; start = info.lastIndexOf(",", end - 1); mAttribute = Integer.parseInt(info.substring(start + 1, end).trim()); end = start; start = info.lastIndexOf(",", end - 1); mSize = info.substring(start + 1, end); end = start; start = info.indexOf(",", dir.length()); mFileName = info.substring(start + 1, end); ...

Class for a file information

FlashAirFileInfo.java

... mDir = dir; int year = ((date >> 9) & 0x0000007f) + 1980; int month = (date >> 5) & 0x0000000f - 1; int day = (date) & 0x0000001f; int hourOfDay = (time >> 11) & 0x0000001f; int minute = (time >> 5) & 0x0000003f; int second = ((time) & 0x0000001f) * 2; mCalendar = Calendar.getInstance(); mCalendar.set(year, month, day, hourOfDay, minute, second); } public String mDir; public String mFileName; public String mSize; public int mAttribute; public Calendar mCalendar; ...

Class for a file information

FlashAirFileInfo.java

... public static final int ATTR_MASK_ARCHIVE = 0x00000020; public static final int ATTR_MASK_DIRECTORY = 0x00000010; public static final int ATTR_MASK_VOLUME = 0x00000008; public static final int ATTR_MASK_SYSTEM_FILE = 0x00000004; public static final int ATTR_MASK_HIDDEN_FILE = 0x00000002; public static final int ATTR_MASK_READ_ONLY = 0x00000001; public boolean isDirectory() { return (mAttribute & ATTR_MASK_DIRECTORY) > 0; } @Override public String toString() { return "DIR=" + mDir + " FILENAME=" + mFileName + " SIZE=" + mSize + " ATTRIBUTE=" + mAttribute + " DATE=" + DateFormat.format("yyyy-MM-dd kk:mm:ss", mCalendar); } }

Class for a file information

FlashAirUtils.java

public class FlashAirUtils { ... public static List<FlashAirFileInfo> getFileList(String dir) { try { String result = Utils.accessToFlashAir(FILE_LIST + dir); if (TextUtils.isEmpty(result)) { return null; } ArrayList<FlashAirFileInfo> list = new ArrayList<FlashAirFileInfo>(); for (String line : result.split("¥n")) { if (TextUtils.isEmpty(line)) { continue; } if (line.split(",").length < 6) { continue; } FlashAirFileInfo info = new FlashAirFileInfo(line, dir); list.add(info); } return list; ...

Get a file information

FlashAirUtils.java

... } catch (IOException e) { e.printStackTrace(); } return null; }

Get a file information

res/layout/activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" ... tools:context=".MainActivity" > <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" /> <ListView android:id="@+id/listView1" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_below="@+id/textView1" /> </RelativeLayout>

Add ListView

MainActivity.java public class MainActivity extends Activity { ... @Override public boolean onOptionsItemSelected(MenuItem item) { int itemId = item.getItemId(); switch (itemId) { ... case R.id.action_reload: String dir = "/DCIM"; getFileCount(dir); getFileList(dir); return true; } return super.onOptionsItemSelected(item); } ... }

Get a file list

MainActivity.java public class MainActivity extends Activity { ... private void getFileList(final String dir) { new AsyncTask<Void, Void, List<FlashAirFileInfo>>() { @Override protected List<FlashAirFileInfo> doInBackground(Void... params) { return FlashAirUtils.getFileList(dir); } @Override protected void onPostExecute(List<FlashAirFileInfo> result) { ListView lv = (ListView) findViewById(R.id.listView1); lv.setAdapter(new FileListAdapter(MainActivity.this, result)); } }.execute(); } public class FileListAdapter extends ArrayAdapter<FlashAirFileInfo> { public FileListAdapter(Context context, List<FlashAirFileInfo> data) { super(context, android.R.layout.simple_list_item_1, data); } } }

Set a file list to ListView

Display thumbnail of images

Display thumbnails #1

• To get thumbnails from image files:

• Use http://flashair/thumbnail.cgi?[path]

• e.g. http://flashair/thumbnail.cgi?/DCIM/IMG_xxx.jpg

• See: https://www.flashair-developers.com/ja/documents/api/thumbnailcgi/

• Thumbnail images are defined by EXIF standard, and are only available in JPEG format

• If a file is not JPEG or no thumbnails are defined, a 404 error is returned

Display thumbnails #2

• Display the thumbnails in a ListView

• Use Volley!

• A network processing library for Android

• https://android.googlesource.com/platform/frameworks/volley/

• http://y-anz-m.blogspot.jp/2013/05/google-io-2013-android-volley-easy-fast.html

• NetworkImageView is available

• NetworkImageView is an ImageView with communication processing

Display thumbnails #3

• NetworkImagView of Vollay

• <com.android.volley.toolbox.NetworkImageView>

• setImageUrl(String url, ImageLoader loader)

• Volley is a library project, so we need to add it.

• git clone https://android.googlesource.com/platform/frameworks/volley

• [File] - [Import] - [Android] - [Existing Android Code Into Workspace]

• Select root directory:

• Set volley folder

Display thumbnails #4

• Open Properties for FlashAirSample

• [Android] - [Library] - [Add]

• Select volley

Display thumbnails #5

If Volley is not appear on the list, make sure Is Library od Volley project is checked!

res/layout/list_row.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <com.android.volley.toolbox.NetworkImageView android:id="@+id/imageView1" android:layout_width="100dp" android:layout_height="80dp" android:src="@drawable/ic_launcher" /> <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Medium Text" android:textAppearance="?android:attr/textAppearanceMedium" /> </LinearLayout>

Layout for list

MainActivity.java

public class MainActivity extends Activity { private RequestQueue mQueue; private ImageLoader mImageLoader; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mQueue = Volley.newRequestQueue(getApplicationContext()); mImageLoader = new ImageLoader(mQueue, new BitmapCache()); } ...

Prepare Volley

MainActivity.java ... public class BitmapCache implements ImageCache { private LruCache<String, Bitmap> mCache; public BitmapCache() { int maxSize = 5 * 1024 * 1024; // 5MB mCache = new LruCache<String, Bitmap>(maxSize) { @Override protected int sizeOf(String key, Bitmap value) { return value.getRowBytes() * value.getHeight(); } }; } @Override public Bitmap getBitmap(String url) { return mCache.get(url); } @Override public void putBitmap(String url, Bitmap bitmap) { mCache.put(url, bitmap); } }

Prepare Volley

MainActivity.java

public class MainActivity extends Activity { ... public class FileListAdapter extends ArrayAdapter<FlashAirFileInfo> { LayoutInflater mInflater; public FileListAdapter(Context context, List<FlashAirFileInfo> data) { super(context, 0, data); mInflater = LayoutInflater.from(context); } @Override public View getView(int position, View convertView, ViewGroup parent) { if (convertView == null) { convertView = mInflater.inflate(R.layout.list_row, parent, false); } FlashAirFileInfo item = getItem(position); TextView tv = (TextView) convertView.findViewById(R.id.textView1); tv.setText(item.mFileName); ...

Expand Adapter for list

MainActivity.java ... NetworkImageView niv = (NetworkImageView) convertView .findViewById(R.id.imageView1); if (item.mFileName.endsWith(".jpg") || item.mFileName.endsWith(".jpeg")) { niv.setImageUrl( FlashAirUtils.getThumbnailUrl(item.mDir, item.mFileName), mImageLoader); } else { niv.setImageUrl(null, mImageLoader); } return convertView; } } }

Set URL at NetworkImageView

FlashAirUtils.java public class FlashAirUtils { public static final String BASE = "http://flashair/"; public static final String THUMBNAIL = BASE + "thumbnail.cgi?"; public static String getThumbnailUrl(String dir, String fileName) { return THUMBNAIL + dir + "/" + fileName; } ... }

Download images

Download images #1

• To get an image file

• Use http://flashair/[path]

• e.g. http://flashair/DCIM/IMG_xxx.jpg

• Use DownloadManager

• http://developer.android.com/reference/android/app/DownloadManager.html

Download images #2

• Using DownloadManager

• Get an instance with getSystemService(Context.DOWNLOAD_SERVICE)

• Create a download request with Request request = new DownloadManager.Request(uri)

• Add the request with downloadManager.enqueue(request)

• To save image to your device, you will need android.permission.WRITE_EXTERNAL_STORAGE.

AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.flashairsample" android:versionCode="1" android:versionName="1.0" > <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> ... </manifest>

MainActivity.java

public class MainActivity extends Activity implements OnItemClickListener { ... private void getFileList(final String dir) { new AsyncTask<Void, Void, List<FlashAirFileInfo>>() { @Override protected List<FlashAirFileInfo> doInBackground(Void... params) { return FlashAirUtils.getFileList(dir); } @Override protected void onPostExecute(List<FlashAirFileInfo> result) { ListView lv = (ListView) findViewById(R.id.listView1); lv.setAdapter(new FileListAdapter(MainActivity.this, result)); lv.setOnItemClickListener(MainActivity.this); } }.execute(); } ...

Set Listener in list

MainActivity.java

public class MainActivity extends Activity implements OnItemClickListener { ... @Override public void onItemClick(AdapterView<?> adapter, View v, int position, long l) { FlashAirFileInfo info = (FlashAirFileInfo) adapter .getItemAtPosition(position); File path = Environment .getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM); File file = new File(path, info.mFileName); if (!file.exists()) { startDownload(info); return; } openDownloadedFile(file.toString()); } ...

Set Listener in list

MainActivity.java ... private void openDownloadedFile(String filePath) { MediaScannerConnection.scanFile(this, new String[] { filePath }, null, new MediaScannerConnection.OnScanCompletedListener() { public void onScanCompleted(String path, Uri uri) { Intent intent = new Intent(Intent.ACTION_VIEW); intent.setData(uri); startActivity(intent); } }); } private void startDownload(FlashAirFileInfo info) { Uri uri = FlashAirUtils.getFileUri(info.mDir, info.mFileName); DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); DownloadManager.Request request = new DownloadManager.Request(uri); request.allowScanningByMediaScanner(); request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DCIM, info.mFileName); manager.enqueue(request); } ...

MainActivity.java

... @Override protected void onResume() { super.onResume(); IntentFilter filter = new IntentFilter( DownloadManager.ACTION_DOWNLOAD_COMPLETE); registerReceiver(receiver, filter); } @Override protected void onPause() { super.onPause(); unregisterReceiver(receiver); } ...

MainActivity.java

... BroadcastReceiver receiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { long id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1); if (id > 0) { DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); Uri fileUri = manager.getUriForDownloadedFile(id); openDownloadedFile(fileUri.getPath()); } } }; }