Updated storage handling

Let the user run termux-setup-storage, which will ensure that storage
permission has been granted and setup $HOME/storage/ folder with
symlinks to storage folders.

Author: fornwall

app/src/main/java/com/termux/app/TermuxActivity.java

@@ -92,6 +92,8 @@ public final class TermuxActivity extends Activity implements ServiceConnection
 
 	private static final int MAX_SESSIONS = 8;
 
+	private static final int REQUESTCODE_PERMISSION_STORAGE = 1234;
+
 	private static final String RELOAD_STYLE_ACTION = "com.termux.app.reload_style";
 
 	/** The main view of the activity showing the terminal. Initialized in onCreate(). */
@@ -130,6 +132,10 @@ public final class TermuxActivity extends Activity implements ServiceConnection
 		public void onReceive(Context context, Intent intent) {
 			if (mIsVisible) {
 				String whatToReload = intent.getStringExtra(RELOAD_STYLE_ACTION);
+				if ("storage".equals(whatToReload)) {
+					if (ensureStoragePermissionGranted()) TermuxInstaller.setupStorageSymlinks(TermuxActivity.this);
+					return;
+				}
 				if (whatToReload == null || "colors".equals(whatToReload)) mTerminalView.checkForColors();
 				if (whatToReload == null || "font".equals(whatToReload)) mTerminalView.checkForTypeface();
 				if (whatToReload == null || "settings".equals(whatToReload)) mSettings.reloadFromProperties(TermuxActivity.this);
@@ -139,11 +145,17 @@ public void onReceive(Context context, Intent intent) {
 
 	/** For processes to access shared internal storage (/sdcard) we need this permission. */
 	@TargetApi(Build.VERSION_CODES.M)
-	public void ensureStoragePermissionGranted() {
+	public boolean ensureStoragePermissionGranted() {
 		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-			if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
-				requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1234);
+			if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
+				return true;
+			} else {
+				requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUESTCODE_PERMISSION_STORAGE);
+				return false;
 			}
+		} else {
+			// Always granted before Android 6.0.
+			return true;
 		}
 	}
 
@@ -327,8 +339,6 @@ public void onClick(View v) {
 		mTerminalView.checkForTypeface();
 		mTerminalView.checkForColors();
 
-		TermuxInstaller.setupStorageSymlinks(this);
-
 		mBellSoundId = mBellSoundPool.load(this, R.raw.bell, 1);
 	}
 
@@ -772,6 +782,13 @@ public void onClick(DialogInterface dialog, int which) {
 		}
 	}
 
+	@Override
+	public void onRequestPermissionsResult(int requestCode,  String permissions[], int[] grantResults) {
+		if (requestCode == REQUESTCODE_PERMISSION_STORAGE && grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+			TermuxInstaller.setupStorageSymlinks(this);
+		}
+	}
+
 	void toggleImmersive() {
 		boolean newValue = !mSettings.isFullScreen();
 		mSettings.setFullScreen(this, newValue);

app/src/main/java/com/termux/app/TermuxInstaller.java

@@ -202,20 +202,21 @@ static void deleteFolder(File fileOrDirectory) {
 	}
 
 	public static void setupStorageSymlinks(final Context context) {
+		final String LOG_TAG = "termux-storage";
 		new Thread() {
 			public void run() {
 				try {
-					File storageDir = new File(TermuxService.FILES_PATH, "storage");
+					File storageDir = new File(TermuxService.HOME_PATH, "storage");
 
-					if (storageDir.exists()) {
-						if (storageDir.isDirectory()) {
-							return;
-						} else {
-							storageDir.delete();
-						}
+					if (storageDir.exists() && !storageDir.delete()) {
+						Log.e(LOG_TAG, "Could not delete old $HOME/storage");
+						return;
 					}
 
-					storageDir.mkdirs();
+					if (!storageDir.mkdirs()) {
+						Log.e(LOG_TAG, "Unable to mkdirs() for $HOME/storage");
+						return;
+					}
 
 					File sharedDir = Environment.getExternalStorageDirectory();
 					Os.symlink(sharedDir.getAbsolutePath(), new File(storageDir, "shared").getAbsolutePath());
@@ -226,9 +227,6 @@ public void run() {
 					File dcimDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);
 					Os.symlink(dcimDir.getAbsolutePath(), new File(storageDir, "dcim").getAbsolutePath());
 
-					File documentsDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS);
-					Os.symlink(documentsDir.getAbsolutePath(), new File(storageDir, "documents").getAbsolutePath());
-
 					File picturesDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
 					Os.symlink(picturesDir.getAbsolutePath(), new File(storageDir, "pictures").getAbsolutePath());
 
@@ -244,7 +242,7 @@ public void run() {
 						Os.symlink(externalDir.getAbsolutePath(), new File(storageDir, "external").getAbsolutePath());
 					}
 				} catch (Exception e) {
-					Log.e("termux", "Error setting up link", e);
+					Log.e(LOG_TAG, "Error setting up link", e);
 				}
 			}
 		}.start();