Osmdroid - from offline folder - datasource

Question

I am using OSMdroid to display both online and offline data in my app. The offline data are stored in a .zip file with the required structure.
Is it possible to have these offline tiles stored in a directory (extracted .zip file with the same structure)?
Could somebody please tell me how could I achive this?
Thank you.

Answer 1

I am sorry. I should try more before asking. But I am leaving this question here, somebody could find it useful.
Solution:
New MapTileFileProvider. I called it MapTileFileFolderProvider, it is a lightly modified MapTileFileArchiveProvider. It is using folders instead of archives. The modifications are not perfect, it is a "hot solution" that needs someone more experienced in Java/Android to make it properly.
Benefits from loading Tiles from folders:
Faster loading of tiles (I know, I won't recognize the difference).
Easier updates focused only on changed tiles not whole map plans.
Application can download tiles when is in "online mode" and then use the downloaded Tiles offline.
MapTileFileFolderProvider - only modifications
public class MapTileFileArchiveProvider extends MapTileFileStorageProviderBase
public class MapTileFileFolderProvider extends MapTileFileStorageProviderBase {
private final boolean mSpecificFoldersProvided;
private final ArrayList<String> mFolders = new ArrayList<String>();
private final AtomicReference<ITileSource> mTileSource = new AtomicReference<ITileSource>();
...
}
public MapTileFileArchiveProvider(...)
public MapTileFileFolderProvider(final IRegisterReceiver pRegisterReceiver,
final ITileSource pTileSource,
final String[] pFolders) {
super(pRegisterReceiver, NUMBER_OF_TILE_FILESYSTEM_THREADS,
TILE_FILESYSTEM_MAXIMUM_QUEUE_SIZE);
setTileSource(pTileSource);
if (pFolders == null) {
mSpecificFoldersProvided = false;
findFolders();
} else {
mSpecificFoldersProvided = true;
for (int i = pFolders.length - 1; i >= 0; i--) {
mFolders.add(pFolders[i]);
}
}
}
findArchiveFiles()
private void findFolders() {
mFolders.clear();
if (!getSdCardAvailable()) {
return;
}
String baseDirPath = Environment.getExternalStorageDirectory().toString()+"/ctu_navigator"; // TODO get from Config
File dir=new File(baseDirPath);
final File[] files = dir.listFiles();
if (files != null) {
String fileName;
for (File file : files) {
if (file.isDirectory()) {
fileName = baseDirPath + '/' + file.getName();
mFolders.add(fileName);
Utils.log(PlanTileProviderFactory.class, "Added map source: " + fileName);
}
}
}
}
#Override
protected String getName() {
return "Folders Provider";
}
#Override
protected String getThreadGroupName() {
return "folder";
}
protected class TileLoader extends MapTileModuleProviderBase.TileLoader {
#Override
public Drawable loadTile(final MapTileRequestState pState) {
ITileSource tileSource = mTileSource.get();
if (tileSource == null) {
return null;
}
final MapTile pTile = pState.getMapTile();
// if there's no sdcard then don't do anything
if (!getSdCardAvailable()) {
Utils.log("No sdcard - do nothing for tile: " + pTile);
return null;
}
InputStream inputStream = null;
try {
inputStream = getInputStream(pTile, tileSource);
if (inputStream != null) {
Utils.log("Use tile from folder: " + pTile);
final Drawable drawable = tileSource.getDrawable(inputStream);
return drawable;
}
} catch (final Throwable e) {
Utils.log("Error loading tile");
Utils.logError(getClass(), (Exception) e);
} finally {
if (inputStream != null) {
StreamUtils.closeStream(inputStream);
}
}
return null;
}
private synchronized InputStream getInputStream(final MapTile pTile, final ITileSource tileSource) {
for (final String folder : mFolders) {
final String path = folder + '/' + tileSource.getTileRelativeFilenameString(pTile);
File mapTileFile = new File(path);
InputStream in = null;
try {
in = new BufferedInputStream(new FileInputStream(mapTileFile));
} catch (IOException e) {
//Utils.log("Tile " + pTile + " not found in " + path);
}
if (in != null) {
Utils.log("Found tile " + pTile + " in " + path);
return in;
}
}
Utils.log("Tile " + pTile + " not found.");
return null;
}
}

Answer 2

Well, as far as I understand what you are trying to get... this is more or less what the standard XYTileSource is already doing.
So if you simply use a ready-to-use tile source like this one:
map.setTileSource(TileSourceFactory.MAPNIK);
you will see downloaded tiles files stored in /sdcard/osmdroid/tiles/Mapnik/
The main difference is that it adds a ".tile" extension at the end of each tile file (probably to prevent tools like Android gallery to index all those images).
If you have a ZIP file with tiles ready to use, you could extract them in this directory, and add .tile extension to each tile (355.png => 355.png.tile)
And TileSourceFactory.MAPNIK will be able to use them.