Show on map: draft via virtual file (with two content providers).

Exported content provider that temporary needs to grant access to the internal content provider.

src/main/AndroidManifest.xml

@@ -175,6 +175,11 @@ limitations under the License.
         <!-- Providers -->
         <provider
             android:name=".content.CustomContentProvider"
+            android:authorities="${applicationId}.content"
+            android:exported="false"
+            android:grantUriPermissions="true" />
+        <provider
+            android:name=".content.ShareContentProvider"
             android:authorities="${applicationId}"
             android:exported="false"
             android:grantUriPermissions="true" />

src/main/java/de/dennisguse/opentracks/TrackListActivity.java

@@ -18,6 +18,7 @@ package de.dennisguse.opentracks;
 
 import android.Manifest;
 import android.app.SearchManager;
+import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
@@ -25,9 +26,7 @@ import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.content.pm.PackageManager;
 import android.database.Cursor;
 import android.location.LocationManager;
-import android.net.Uri;
 import android.os.Bundle;
-import android.os.StrictMode;
 import android.provider.Settings;
 import android.util.Log;
 import android.view.ContextMenu;
@@ -47,30 +46,21 @@ import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.core.app.ActivityCompat;
-import androidx.core.content.FileProvider;
 import androidx.cursoradapter.widget.ResourceCursorAdapter;
 import androidx.loader.app.LoaderManager;
 import androidx.loader.app.LoaderManager.LoaderCallbacks;
 import androidx.loader.content.CursorLoader;
 import androidx.loader.content.Loader;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
 import java.util.Locale;
 
 import de.dennisguse.opentracks.content.ContentProviderUtils;
-import de.dennisguse.opentracks.content.Track;
+import de.dennisguse.opentracks.content.ShareContentProvider;
 import de.dennisguse.opentracks.content.TracksColumns;
 import de.dennisguse.opentracks.fragments.ConfirmDeleteDialogFragment;
-import de.dennisguse.opentracks.io.file.TrackFileFormat;
-import de.dennisguse.opentracks.io.file.exporter.FileTrackExporter;
-import de.dennisguse.opentracks.io.file.exporter.TrackExporter;
 import de.dennisguse.opentracks.services.ITrackRecordingService;
 import de.dennisguse.opentracks.services.TrackRecordingServiceConnection;
 import de.dennisguse.opentracks.settings.SettingsActivity;
-import de.dennisguse.opentracks.util.FileUtils;
 import de.dennisguse.opentracks.util.IntentUtils;
 import de.dennisguse.opentracks.util.ListItemUtils;
 import de.dennisguse.opentracks.util.PreferencesUtils;
@@ -257,17 +247,17 @@ public class TrackListActivity extends AbstractTrackActivity implements ConfirmD
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        if (BuildConfig.DEBUG) {
+//        if (BuildConfig.DEBUG) {
-            Log.d(TAG, "Enabling strict mode");
+//            Log.d(TAG, "Enabling strict mode");
-            StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
+//            StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
-                    .detectAll()
+//                    .detectAll()
-                    .penaltyLog()
+//                    .penaltyLog()
-                    .build());
+//                    .build());
-            StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
+//            StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
-                    .detectAll()
+//                    .detectAll()
-                    .penaltyLog()
+//                    .penaltyLog()
-                    .build());
+//                    .build());
-        }
+//        }
 
         contentProviderUtils = ContentProviderUtils.Factory.get(this);
         sharedPreferences = PreferencesUtils.getSharedPreferences(this);
@@ -566,8 +556,7 @@ public class TrackListActivity extends AbstractTrackActivity implements ConfirmD
     }
 
     /**
-     * Save tracks in one file and send an intent to show it with a map application.
+     * Send intent to show tracks on a map (needs an another app).
-     * TODO: Exported file is not deleted automatically.
      *
      * @param trackIds
      */
@@ -576,45 +565,14 @@ public class TrackListActivity extends AbstractTrackActivity implements ConfirmD
             return;
         }
 
-        Track[] tracks = new Track[trackIds.length];
+        Intent intent = new Intent();
-        for (int i = 0; i < trackIds.length; i++) {
+        intent.setAction(android.content.Intent.ACTION_VIEW);
-            tracks[i] = contentProviderUtils.getTrack(trackIds[i]);
+        intent.setDataAndType(ShareContentProvider.createURI(trackIds), ShareContentProvider.MIME);
-        }
+        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
-
+        try {
-        TrackFileFormat trackFileFormat = TrackFileFormat.KML;
+            startActivity(intent);
-        TrackExporter trackExporter = new FileTrackExporter(contentProviderUtils, tracks,
+        } catch (ActivityNotFoundException e) {
-                trackFileFormat.newTrackWriter(this, tracks.length > 1), null);
+            Toast.makeText(this, "No app installed that can show the tracks on a map.", Toast.LENGTH_SHORT).show();
-
-        File directory = new File(FileUtils.getPath(trackFileFormat.getExtension()));
-        if (!FileUtils.ensureDirectoryExists(directory)) {
-            Toast.makeText(this, R.string.external_storage_not_writable, Toast.LENGTH_LONG).show();
-            finish();
-            return;
-        }
-
-        String fileName = FileUtils.buildUniqueFileName(directory, tracks[0].getName(), trackFileFormat.getExtension());
-        File file = new File(directory, fileName);
-
-        try (FileOutputStream fileOutputStream = new FileOutputStream(file)) {
-            if (trackExporter.writeTrack(fileOutputStream)) {
-                Uri fileUri = FileProvider.getUriForFile(this, FileUtils.FILEPROVIDER, file);
-
-                Intent intent = new Intent();
-                intent.setAction(android.content.Intent.ACTION_VIEW);
-                intent.setDataAndType(fileUri, "application/vnd.google-earth.kml+xml");
-
-                intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
-                startActivity(intent);
-            } else {
-                if (!file.delete()) {
-                    Log.d(TAG, "Unable to delete file");
-                }
-                Log.e(TAG, "Unable to export track");
-            }
-        } catch (FileNotFoundException e) {
-            Log.e(TAG, "Unable to open file " + file.getName(), e);
-        } catch (IOException e) {
-            Log.e(TAG, "Unable to close file output stream", e);
         }
     }
 

src/main/java/de/dennisguse/opentracks/content/ContentProviderUtils.java

@@ -39,7 +39,7 @@ public interface ContentProviderUtils {
      * The authority (the first part of the URI) for the app's content
      * provider.
      */
-    String AUTHORITY = BuildConfig.APPLICATION_ID;
+    String AUTHORITY = BuildConfig.APPLICATION_ID + ".content";
     /**
      * The default {@link LocationFactory} which creates a location each time.
      */

src/main/java/de/dennisguse/opentracks/content/ShareContentProvider.java

@@ -0,0 +1,175 @@
+package de.dennisguse.opentracks.content;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ProviderInfo;
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.ParcelFileDescriptor;
+import android.provider.OpenableColumns;
+import android.util.Log;
+import android.widget.Toast;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+
+import de.dennisguse.opentracks.BuildConfig;
+import de.dennisguse.opentracks.io.file.TrackFileFormat;
+import de.dennisguse.opentracks.io.file.exporter.FileTrackExporter;
+import de.dennisguse.opentracks.io.file.exporter.TrackWriter;
+
+/**
+ * A content provider that mimics the behavior of {@link androidx.core.content.FileProvider}, which shares virtual (non-existing) files.
+ * The actual content is generated by accessing {@link CustomContentProvider} on request.
+ */
+public class ShareContentProvider extends ContentProvider {
+
+    public static final String TAG = ShareContentProvider.class.getCanonicalName();
+
+    public static final String SHAREPROVIDER = BuildConfig.APPLICATION_ID;
+
+    private static final String[] COLUMNS = {OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE};
+
+    public static String MIME = "application/kml+xml";
+
+    public static Uri createURI(long[] trackIds) {
+        if (trackIds.length == 0) {
+            throw new UnsupportedOperationException();
+        }
+
+        StringBuilder builder = new StringBuilder();
+        for (long trackId : trackIds) {
+            builder.append(trackId).append(",");
+        }
+        builder.deleteCharAt(builder.lastIndexOf(","));
+
+        return Uri.parse("content://" + SHAREPROVIDER + "/" + builder + ".kml");
+    }
+
+    private static long[] parseURI(Uri uri) {
+        String lastPathSegment = uri.getLastPathSegment();
+        if (lastPathSegment == null) {
+            return new long[]{};
+        }
+
+        String[] lastPathSegmentSplit = lastPathSegment.replace(".kml", "").split(",");
+        long[] trackIds = new long[lastPathSegmentSplit.length];
+        for (int i = 0; i < trackIds.length; i++) {
+            trackIds[i] = Long.valueOf(lastPathSegmentSplit[i]);
+        }
+        return trackIds;
+    }
+
+    @Override
+    public boolean onCreate() {
+        return true;
+    }
+
+    @Override
+    public void attachInfo(Context context, ProviderInfo info) {
+        super.attachInfo(context, info);
+        if (!info.grantUriPermissions) {
+            throw new SecurityException("Provider must grant uri permissions");
+        }
+    }
+
+    @Override
+    public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
+        // ContentProvider has already checked granted permissions
+        if (projection == null) {
+            projection = COLUMNS;
+        }
+
+        String[] cols = new String[projection.length];
+        Object[] values = new Object[projection.length];
+        int i = 0;
+        for (String col : projection) {
+            if (OpenableColumns.DISPLAY_NAME.equals(col)) {
+                cols[i] = OpenableColumns.DISPLAY_NAME;
+                values[i++] = uri.getLastPathSegment();
+            } else if (OpenableColumns.SIZE.equals(col)) {
+                cols[i] = OpenableColumns.SIZE;
+                values[i++] = -1;
+            }
+        }
+
+        cols = Arrays.copyOf(cols, i);
+        values = Arrays.copyOf(values, i);
+
+        final MatrixCursor cursor = new MatrixCursor(cols, 1);
+        cursor.addRow(values);
+        return cursor;
+    }
+
+    @Nullable
+    @Override
+    public String getType(@NonNull Uri uri) {
+        return MIME;
+    }
+
+    @Nullable
+    @Override
+    public ParcelFileDescriptor openFile(@NonNull Uri uri, @NonNull String mode) throws FileNotFoundException {
+        ContentProviderUtils contentProviderUtils = ContentProviderUtils.Factory.get(getContext());
+
+        final Uri customContentProviderURI = Uri.parse("content://" + ContentProviderUtils.AUTHORITY + "/tracks");
+        getContext().grantUriPermission(getCallingPackage(), customContentProviderURI, Intent.FLAG_GRANT_READ_URI_PERMISSION);
+
+        long[] trackIds = parseURI(uri);
+        final Track[] tracks = new Track[trackIds.length];
+        for (int i = 0; i < trackIds.length; i++) {
+            tracks[i] = contentProviderUtils.getTrack(trackIds[i]);
+        }
+
+        TrackWriter kmlTrackWriter = TrackFileFormat.KML.newTrackWriter(getContext(), false);
+        final FileTrackExporter fileTrackExporter = new FileTrackExporter(contentProviderUtils, tracks, kmlTrackWriter, null);
+
+        PipeDataWriter pipeDataWriter = new PipeDataWriter<String>() {
+            @Override
+            public void writeDataToPipe(@NonNull ParcelFileDescriptor output, @NonNull Uri uri, @NonNull String mimeType, @Nullable Bundle opts, @Nullable String args) {
+                try (FileOutputStream fileOutputStream = new FileOutputStream(output.getFileDescriptor())) {
+                    fileTrackExporter.writeTrack(fileOutputStream);
+                } catch (IOException e) {
+                    Log.w(TAG, "Oops closing " + e);
+                    Toast.makeText(getContext(), "", Toast.LENGTH_SHORT).show();
+                } finally {
+
+                    getContext().revokeUriPermission(customContentProviderURI, Intent.FLAG_GRANT_READ_URI_PERMISSION);
+                }
+            }
+        };
+
+        return openPipeHelper(uri, getType(uri), null, null, pipeDataWriter);
+    }
+
+    @Nullable
+    @Override
+    public String[] getStreamTypes(@NonNull Uri uri, @NonNull String mimeTypeFilter) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Nullable
+    @Override
+    public Uri insert(@NonNull Uri uri, @Nullable ContentValues values) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public int delete(@NonNull Uri uri, @Nullable String selection, @Nullable String[] selectionArgs) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public int update(@NonNull Uri uri, @Nullable ContentValues values, @Nullable String selection, @Nullable String[] selectionArgs) {
+        throw new UnsupportedOperationException();
+    }
+}

src/main/java/de/dennisguse/opentracks/content/TrackPointsColumns.java

@@ -19,8 +19,6 @@ package de.dennisguse.opentracks.content;
 import android.net.Uri;
 import android.provider.BaseColumns;
 
-import de.dennisguse.opentracks.BuildConfig;
-
 /**
  * Constants for the track points table.
  *
@@ -29,7 +27,7 @@ import de.dennisguse.opentracks.BuildConfig;
 public interface TrackPointsColumns extends BaseColumns {
 
     String TABLE_NAME = "trackpoints";
-    Uri CONTENT_URI = Uri.parse("content://" + BuildConfig.APPLICATION_ID + "/trackpoints");
+    Uri CONTENT_URI = Uri.parse("content://" + ContentProviderUtils.AUTHORITY + "/trackpoints");
     String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.de.dennisguse.trackpoint";
     String CONTENT_ITEMTYPE = "vnd.android.cursor.item/vnd.de.dennisguse.trackpoint";
     String DEFAULT_SORT_ORDER = "_id";

src/main/java/de/dennisguse/opentracks/content/TracksColumns.java

@@ -19,8 +19,6 @@ package de.dennisguse.opentracks.content;
 import android.net.Uri;
 import android.provider.BaseColumns;
 
-import de.dennisguse.opentracks.BuildConfig;
-
 /**
  * Constants for the tracks table.
  *
@@ -33,7 +31,7 @@ public interface TracksColumns extends BaseColumns {
     /**
      * Tracks provider uri.
      */
-    Uri CONTENT_URI = Uri.parse("content://" + BuildConfig.APPLICATION_ID + "/tracks");
+    Uri CONTENT_URI = Uri.parse("content://" + ContentProviderUtils.AUTHORITY + "/tracks");
 
     /**
      * Track content type.

src/main/java/de/dennisguse/opentracks/content/WaypointsColumns.java

@@ -19,8 +19,6 @@ package de.dennisguse.opentracks.content;
 import android.net.Uri;
 import android.provider.BaseColumns;
 
-import de.dennisguse.opentracks.BuildConfig;
-
 /**
  * Constants for waypoints table.
  *
@@ -29,7 +27,7 @@ import de.dennisguse.opentracks.BuildConfig;
 public interface WaypointsColumns extends BaseColumns {
 
     String TABLE_NAME = "waypoints";
-    Uri CONTENT_URI = Uri.parse("content://" + BuildConfig.APPLICATION_ID + "/waypoints");
+    Uri CONTENT_URI = Uri.parse("content://" + ContentProviderUtils.AUTHORITY + "/waypoints");
     String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.de.dennisguse.waypoint";
     String CONTENT_ITEMTYPE = "vnd.android.cursor.item/vnd.de.dennisguse.waypoint";
     String DEFAULT_SORT_ORDER = "_id";