feat: multi window support

app/src/main/AndroidManifest.xml

@@ -35,6 +35,7 @@
     <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.PACKAGE_USAGE_STATS" tools:ignore="ProtectedPermissions" />
+    <uses-permission android:name="android.permission.REORDER_TASKS" />
     <uses-permission android:name="com.android.alarm.permission.SET_ALARM" />
 
     <application
@@ -55,7 +56,7 @@
             android:exported="true"
             android:configChanges="orientation|screenSize|smallestScreenSize|density|screenLayout|keyboard|keyboardHidden|navigation"
             android:label="@string/application_name"
-            android:launchMode="singleTask"
+            android:launchMode="standard"
             android:resizeableActivity="true"
             android:theme="@style/Theme.TermuxActivity.DayNight.NoActionBar"
             tools:targetApi="n">

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

@@ -10,6 +10,7 @@
 import android.content.IntentFilter;
 import android.content.ServiceConnection;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.view.ContextMenu;
@@ -22,6 +23,7 @@
 import android.view.WindowManager;
 import android.widget.EditText;
 import android.widget.ImageButton;
+import android.widget.LinearLayout;
 import android.widget.ListView;
 import android.widget.RelativeLayout;
 import android.widget.Toast;
@@ -175,6 +177,11 @@ public final class TermuxActivity extends AppCompatActivity implements ServiceCo
 
     private float mTerminalToolbarDefaultHeight;
 
+    /**
+     * Unique identifier for this activity instance. Used for session attachment tracking.
+     */
+    private final int mActivityId = System.identityHashCode(this);
+
 
     private static final int CONTEXT_MENU_SELECT_URL_ID = 0;
     private static final int CONTEXT_MENU_SHARE_TRANSCRIPT_ID = 1;
@@ -251,6 +258,8 @@ public void onCreate(Bundle savedInstanceState) {
 
         setToggleKeyboardView();
 
+        setNewWindowButtonView();
+
         registerForContextMenu(mTerminalView);
 
         FileReceiverActivity.updateFileReceiverActivityComponentsState(this);
@@ -352,9 +361,22 @@ public void onDestroy() {
 
         if (mIsInvalidState) return;
 
+        // Detach all sessions owned by this activity and reset their clients
         if (mTermuxService != null) {
-            // Do not leave service and session clients with references to activity.
-            mTermuxService.unsetTermuxTerminalSessionClient();
+            TerminalSession currentSession = getCurrentSession();
+            if (currentSession != null) {
+                // Reset this session's client to the service client
+                mTermuxService.resetSessionClient(currentSession);
+            }
+            if (mTerminalView != null) {
+                mTerminalView.detachSession();
+            }
+
+            // Detach all sessions owned by this activity (single source of truth)
+            mTermuxService.detachAllSessionsForActivity(mActivityId);
+
+            // Remove this activity's client from the service's set
+            mTermuxService.removeTermuxTerminalSessionClient(mTermuxTerminalSessionActivityClient);
             mTermuxService = null;
         }
 
@@ -374,6 +396,23 @@ public void onSaveInstanceState(@NonNull Bundle savedInstanceState) {
         savedInstanceState.putBoolean(ARG_ACTIVITY_RECREATED, true);
     }
 
+    @Override
+    public void onMultiWindowModeChanged(boolean isInMultiWindowMode) {
+        super.onMultiWindowModeChanged(isInMultiWindowMode);
+        Logger.logDebug(LOG_TAG, "onMultiWindowModeChanged: " + isInMultiWindowMode);
+    }
+
+    /** Add a new window */
+    public void addNewWindow() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            Intent intent = new Intent(this, TermuxActivity.class);
+            intent.addFlags(Intent.FLAG_ACTIVITY_LAUNCH_ADJACENT |
+                           Intent.FLAG_ACTIVITY_NEW_TASK |
+                           Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
+            startActivity(intent);
+        }
+    }
+
 
 
 
@@ -417,11 +456,33 @@ public void onServiceConnected(ComponentName componentName, IBinder service) {
             // then the original intent will be re-delivered, resulting in a new session being re-added
             // each time.
             if (!mIsActivityRecreated && intent != null && Intent.ACTION_RUN.equals(intent.getAction())) {
-                // Android 7.1 app shortcut from res/xml/shortcuts.xml.
-                boolean isFailSafe = intent.getBooleanExtra(TERMUX_ACTIVITY.EXTRA_FAILSAFE_SESSION, false);
-                mTermuxTerminalSessionActivityClient.addNewSession(isFailSafe, null);
-            } else {
-                mTermuxTerminalSessionActivityClient.setCurrentSession(mTermuxTerminalSessionActivityClient.getCurrentStoredSessionOrLast());
+                if (intent.getBooleanExtra(TERMUX_ACTIVITY.EXTRA_NEW_WINDOW, false)) {
+                    // Android 7.1 app shortcut: open a new window
+                    addNewWindow();
+                } else {
+                    // Android 7.1 app shortcut from res/xml/shortcuts.xml.
+                    boolean isFailSafe = intent.getBooleanExtra(TERMUX_ACTIVITY.EXTRA_FAILSAFE_SESSION, false);
+                    mTermuxTerminalSessionActivityClient.addNewSession(isFailSafe, null);
+                }
+            }
+
+            // Ensure this activity is attached to a session
+            if (getCurrentSession() == null) {
+                TerminalSession sessionToAttach = mTermuxService.claimFirstUnattachedSession(mActivityId);
+                if (sessionToAttach != null) {
+                    mTermuxTerminalSessionActivityClient.setCurrentSession(sessionToAttach);
+                } else {
+                    // All sessions are attached, create a new one or use stored session
+                    TerminalSession storedSession = mTermuxTerminalSessionActivityClient.getCurrentStoredSessionOrLast();
+                    if (storedSession != null && !mTermuxService.isSessionAttached(storedSession)) {
+                        mTermuxTerminalSessionActivityClient.setCurrentSession(storedSession);
+                    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && isInMultiWindowMode()) {
+                        // In multi-window mode with all sessions attached, create a new session
+                        mTermuxTerminalSessionActivityClient.addNewSession(false, null);
+                    } else {
+                        mTermuxTerminalSessionActivityClient.setCurrentSession(storedSession);
+                    }
+                }
             }
         }
 
@@ -594,6 +655,21 @@ private void setToggleKeyboardView() {
         });
     }
 
+    private void setNewWindowButtonView() {
+        View newWindowButton = findViewById(R.id.new_window_button);
+        if (newWindowButton != null) {
+            newWindowButton.setOnClickListener(v -> addNewWindow());
+            // Show if multi-window API is available (N+)
+            newWindowButton.setVisibility(Build.VERSION.SDK_INT >= Build.VERSION_CODES.N ? View.VISIBLE : View.GONE);
+        }
+
+        // Use vertical orientation for drawer buttons if multi-window is available
+        LinearLayout drawerButtons = findViewById(R.id.drawer_buttons);
+        if (drawerButtons != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            drawerButtons.setOrientation(LinearLayout.VERTICAL);
+        }
+    }
+
 
 
 
@@ -877,6 +953,10 @@ public TermuxService getTermuxService() {
         return mTermuxService;
     }
 
+    public int getActivityId() {
+        return mActivityId;
+    }
+
     public TerminalView getTerminalView() {
         return mTerminalView;
     }