Create DirectoryUtils.java

app/src/main/java/awais/instagrabber/utils/DirectoryUtils.java

@@ -0,0 +1,76 @@
+package awais.instagrabber.utils;
+
+import android.os.Build;
+import android.os.Environment;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+public class DirectoryUtils {
+    private static final Pattern DIR_SEPORATOR = Pattern.compile("/");
+
+    /**
+     * From: https://stackoverflow.com/a/18871043/1436766
+     *
+     * Returns all available SD-Cards in the system (include emulated)
+     * <p>
+     * Warning: Hack! Based on Android source code of version 4.3 (API 18)
+     * Because there is no standard way to get it.
+     * TODO: Test on future Android versions 4.4+
+     *
+     * @return paths to all available SD-Cards in the system (include emulated)
+     */
+    public static Set<String> getStorageDirectories() {
+        // Final set of paths
+        final Set<String> rv = new HashSet<>();
+        // Primary physical SD-CARD (not emulated)
+        final String rawExternalStorage = System.getenv("EXTERNAL_STORAGE");
+        // All Secondary SD-CARDs (all exclude primary) separated by ":"
+        final String rawSecondaryStoragesStr = System.getenv("SECONDARY_STORAGE");
+        // Primary emulated SD-CARD
+        final String rawEmulatedStorageTarget = System.getenv("EMULATED_STORAGE_TARGET");
+        if (TextUtils.isEmpty(rawEmulatedStorageTarget)) {
+            // Device has physical external storage; use plain paths.
+            if (TextUtils.isEmpty(rawExternalStorage)) {
+                // EXTERNAL_STORAGE undefined; falling back to default.
+                rv.add("/storage/sdcard0");
+            } else {
+                rv.add(rawExternalStorage);
+            }
+        } else {
+            // Device has emulated storage; external storage paths should have
+            // userId burned into them.
+            final String rawUserId;
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
+                rawUserId = "";
+            } else {
+                final String path = Environment.getExternalStorageDirectory().getAbsolutePath();
+                final String[] folders = DIR_SEPORATOR.split(path);
+                final String lastFolder = folders[folders.length - 1];
+                boolean isDigit = false;
+                try {
+                    Integer.valueOf(lastFolder);
+                    isDigit = true;
+                } catch (NumberFormatException ignored) {
+                }
+                rawUserId = isDigit ? lastFolder : "";
+            }
+            // /storage/emulated/0[1,2,...]
+            if (TextUtils.isEmpty(rawUserId)) {
+                rv.add(rawEmulatedStorageTarget);
+            } else {
+                rv.add(rawEmulatedStorageTarget + File.separator + rawUserId);
+            }
+        }
+        // Add all secondary storages
+        if (!TextUtils.isEmpty(rawSecondaryStoragesStr)) {
+            // All Secondary SD-CARDs splited into array
+            final String[] rawSecondaryStorages = rawSecondaryStoragesStr.split(File.pathSeparator);
+            Collections.addAll(rv, rawSecondaryStorages);
+        }
+        return rv;
+    }
+}