Dolphin from the rail: guide toggles full screen (its window and settings), drawn in the main window

app/src/main/java/com/droiddeck/launcher/SessionActivity.kt

@@ -736,6 +736,20 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
             return super.dispatchKeyEvent(event)
         }
         if (pcKeyboardOpen && event.device != null && PadBridge.isFromController(event.device)) return super.dispatchKeyEvent(event)
+        // Dolphin (PC) has no controller menu of its own: in a Dolphin game from the rail the guide
+        // button is its Toggle Fullscreen hotkey (Alt+Return, Dolphin's default) instead, which
+        // brings up Dolphin's window with its Config / Graphics / Stop buttons, and back again.
+        if (event.keyCode == KeyEvent.KEYCODE_BUTTON_MODE && guideIsDolphinFullscreen() &&
+            event.device != null && PadBridge.isFromController(event.device)
+        ) {
+            if (event.action == KeyEvent.ACTION_DOWN && event.repeatCount == 0 && CompositorHost.isStarted) {
+                WaylandCompositor.nativeSendKey(KEY_LEFTALT, 1)
+                WaylandCompositor.nativeSendKey(KEY_ENTER, 1)
+                WaylandCompositor.nativeSendKey(KEY_ENTER, 0)
+                WaylandCompositor.nativeSendKey(KEY_LEFTALT, 0)
+            }
+            return true
+        }
         if (event.keyCode != KeyEvent.KEYCODE_BACK && padBridge?.onKeyEvent(event) == true) return true
         // A hardware keyboard, forwarded to the compositor's wl_keyboard. Back is left to the
         // activity, which opens the drawer.
@@ -994,6 +1008,10 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
         if (reset) secondScreenMode = SecondScreenMode.NONE
     }
 
+    private fun guideIsDolphinFullscreen(): Boolean =
+        SessionState.mode == SessionService.MODE_RUN &&
+            SessionState.program?.substringAfterLast('/')?.startsWith("dolphin") == true
+
     /** Touchpad on the desktop, direct in Steam, unless the drawer says otherwise. */
     private fun usingTouchpad(): Boolean = when (SessionPrefs.touchMode(this)) {
         SessionPrefs.TOUCH_PAD -> true
@@ -1191,6 +1209,9 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
     }
 
     companion object {
+        // evdev codes (linux/input-event-codes.h) for the Alt+Return sent to Dolphin.
+        private const val KEY_LEFTALT = 56
+        private const val KEY_ENTER = 28
         private const val TAG = "SessionActivity"
         private const val BACK_DOUBLE_PRESS_TIMEOUT_MS = 500L
         private const val DRAWER_HAT_THRESHOLD = 0.5f

app/src/main/java/com/droiddeck/launcher/frontend/Library.kt

@@ -219,13 +219,16 @@ object Library {
         "armsx2" -> listOf("-batch", "-bigpicture", "-fullscreen", "--", guestPath)
         // DuckStation shares PCSX2's flags (src/duckstation-qt/qthost.cpp): the same launch and exit.
         "duckstation" -> listOf("-batch", "-bigpicture", "-fullscreen", "--", guestPath)
-        // Dolphin: full screen, and gone when the game stops (-b), without its "stop the emulation?"
+        // Dolphin: full screen, drawn inside its own main window, without its "stop the emulation?"
         // question; no warning boxes either, which wait for a click a controller cannot give
-        // (they still go to Dolphin's log). -C sets a Dolphin.ini value for this run only, so
-        // Dolphin started from the desktop keeps its window and its warnings.
+        // (they still go to Dolphin's log). The guide button toggles full screen (SessionActivity),
+        // which shows Dolphin's window and its settings - so no -b, which hides that window.
+        // Closing Dolphin ends the session. -C sets a Dolphin.ini value for this run only, so
+        // Dolphin started from the desktop keeps its own window and its warnings.
         "dolphin" -> listOf(
-            "-b", "-C", "Dolphin.Display.Fullscreen=True", "-C", "Dolphin.Interface.ConfirmStop=False",
-            "-C", "Dolphin.Interface.UsePanicHandlers=False", "-e", guestPath,
+            "-C", "Dolphin.Display.Fullscreen=True", "-C", "Dolphin.Display.RenderToMain=True",
+            "-C", "Dolphin.Interface.ConfirmStop=False", "-C", "Dolphin.Interface.UsePanicHandlers=False",
+            "-e", guestPath,
         )
         "cemu" -> listOf("-g", guestPath)
         else -> listOf(guestPath)