A drawer on Back: HUD, frame generation, on-screen controls, background, stop

Back used to background the app outright. It now opens a slim panel on the
right with the switches a player reaches for mid-game — the performance HUD,
the frame-generation picker (shared with the main screen), the on-screen
controls' mode (auto / always / never, replacing the file-only override) —
and the two things that leave the session: send it to the background, or stop
it. Back again, or a tap outside, closes it.

README.md

@@ -70,9 +70,10 @@ Pick an engine and 2×/3×/4× on the main screen; it applies immediately, mid-g
 A session belongs to a foreground service, not to the activity, so leaving Big Picture does not
 end it: the process stays at perceptible priority, a partial wake lock keeps the CPU from dropping
 the guest's threads, and a high-performance WiFi lock keeps a backgrounded download from being
-throttled to nothing. Back puts the app away and leaves Steam running; the (silent) notification
-brings it back. A session ends only when you say so — the notification's **Stop session** action —
-or when the app is swiped out of recents.
+throttled to nothing. **Back opens the drawer**: the performance HUD switch, frame generation, on-screen controls
+(auto / always / never), *Send to background* and *Stop session*. Backgrounded, Steam keeps
+running and the (silent) notification brings it back. A session ends only when you say so — the
+drawer or the notification's **Stop session** — or when the app is swiped out of recents.
 
 ## Device switches
 

app/src/main/java/com/steamdeck/launcher/MainActivity.kt

@@ -44,7 +44,7 @@ class MainActivity : Activity() {
         playButton = findViewById(R.id.play)
         runtimeButton = findViewById(R.id.runtime)
         frameGenButton = findViewById(R.id.frame_gen)
-        frameGenButton.setOnClickListener { pickFrameGen() }
+        frameGenButton.setOnClickListener { FrameGen.showPicker(this) { render() } }
 
         playButton.setOnClickListener { startActivity(Intent(this, SessionActivity::class.java)) }
         runtimeButton.setOnClickListener { onRuntimeButton() }
@@ -123,34 +123,6 @@ class MainActivity : Activity() {
         ui.post { render() }
     }
 
-    /** Off, or an engine at 2x/3x/4x. Saved, and pushed to a running session on the next resume. */
-    private fun pickFrameGen() {
-        val choices = arrayOf("Off",
-            "Win-FG 2×", "Win-FG 3×", "Win-FG 4×",
-            "LSFG 2× (needs Lossless Scaling)", "LSFG 3× (needs Lossless Scaling)", "LSFG 4× (needs Lossless Scaling)")
-        val engine = FrameGen.engine(this)
-        val current = when (engine) {
-            FrameGen.ENGINE_WINFG -> FrameGen.multiplier(this) - 1
-            FrameGen.ENGINE_LSFG -> FrameGen.multiplier(this) + 2
-            else -> 0
-        }
-        AlertDialog.Builder(this)
-            .setTitle(R.string.frame_gen_title)
-            .setSingleChoiceItems(choices, current) { dialog, which ->
-                when (which) {
-                    0 -> FrameGen.set(this, FrameGen.ENGINE_OFF, 2)
-                    in 1..3 -> FrameGen.set(this, FrameGen.ENGINE_WINFG, which + 1)
-                    else -> FrameGen.set(this, FrameGen.ENGINE_LSFG, which - 2)
-                }
-                dialog.dismiss()
-                render()
-            }
-            .setNeutralButton(android.R.string.ok, null)
-            .setMessage(null)
-            .show()
-        Log.i(TAG, "frame generation picker: " + FrameGen.label(this))
-    }
-
     private fun render() {
         frameGenButton.text = getString(R.string.frame_gen, FrameGen.label(this))
         val installed = LinuxRuntimeInstaller.installedVersion(this)

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

@@ -24,6 +24,8 @@ import com.steamdeck.launcher.input.PadBridge
 import com.steamdeck.launcher.runtime.LinuxRuntime
 import com.steamdeck.launcher.session.LoadingPanel
 import com.steamdeck.launcher.session.PerfHud
+import com.steamdeck.launcher.session.SessionDrawer
+import com.steamdeck.launcher.session.SessionPrefs
 import com.steamdeck.launcher.session.SessionService
 import com.steamdeck.launcher.session.SessionState
 import com.steamdeck.launcher.wayland.CompositorHost
@@ -44,6 +46,7 @@ class SessionActivity : Activity(), SurfaceHolder.Callback {
     private lateinit var surfaceView: SurfaceView
     private lateinit var loading: LoadingPanel
     private lateinit var hud: PerfHud
+    private lateinit var drawer: SessionDrawer
     private var padBridge: PadBridge? = null
     private var onScreenControls: OnScreenControls? = null
     private var watching = true
@@ -83,6 +86,13 @@ class SessionActivity : Activity(), SurfaceHolder.Callback {
         // client's first frame, since before that there is nothing to count.
         hud = PerfHud(this)
         root.addView(hud.view, root.indexOfChild(panel))
+        // Back opens this; it sits above everything, the loading panel included.
+        drawer = SessionDrawer(this, root,
+            onHudChanged = { hud.refresh() },
+            onOscChanged = { updateOnScreenControls() },
+            onFrameGenChanged = { applyFrameGen() },
+            onBackground = { moveTaskToBack(true) },
+            onStop = { SessionService.stop(this); finish() })
         // A session that has already drawn is past its milestones; do not cover its picture.
         if (SessionState.running && SessionState.firstFrameSeen) {
             loading.hide()
@@ -259,26 +269,27 @@ class SessionActivity : Activity(), SurfaceHolder.Callback {
     // ── Lifecycle ───────────────────────────────────────────────────────────────────────────
 
     /**
-     * Back leaves the session running and puts the app behind whatever the user wants next; the
-     * notification brings it back. Ending a session is done deliberately — from the
-     * notification's Stop action, or by swiping the app out of recents.
+     * Back opens the drawer (and closes it again). Leaving the session running in the background
+     * and ending it are both actions in there, so neither can happen by accident from a button
+     * a game might also be reading.
      */
     @Suppress("DEPRECATION")
     override fun onBackPressed() {
-        moveTaskToBack(true)
+        drawer.toggle()
     }
 
     /**
-     * `steamdeck-osc` in Downloads forces the matter either way ("always" / "never"); with no such
-     * file the controls follow what is attached.
+     * The drawer's mode ("always" / "never") decides outright; on "auto" the controls follow
+     * what is attached. `steamdeck-osc` in Downloads still overrides, for a device we cannot reach.
      */
     private fun updateOnScreenControls() {
         val forced = File(Environment.getExternalStorageDirectory(), "Download/steamdeck-osc")
             .takeIf { it.isFile }
             ?.let { FileUtils.readString(it)?.trim()?.lowercase() }
-        val show = when {
-            forced == "always" -> true
-            forced == "never" -> false
+            ?: SessionPrefs.oscMode(this)
+        val show = when (forced) {
+            SessionPrefs.OSC_ALWAYS -> true
+            SessionPrefs.OSC_NEVER -> false
             else -> !PadBridge.anyControllerConnected()
         }
         val controls = onScreenControls ?: return

app/src/main/java/com/steamdeck/launcher/gpu/FrameGen.kt

@@ -82,5 +82,30 @@ object FrameGen {
         return problem
     }
 
+    /** Off, or an engine at 2x/3x/4x; saved on pick, then [onChanged]. */
+    fun showPicker(activity: android.app.Activity, onChanged: () -> Unit) {
+        val choices = arrayOf("Off",
+            "Win-FG 2×", "Win-FG 3×", "Win-FG 4×",
+            "LSFG 2× (needs Lossless Scaling)", "LSFG 3× (needs Lossless Scaling)", "LSFG 4× (needs Lossless Scaling)")
+        val current = when (engine(activity)) {
+            ENGINE_WINFG -> multiplier(activity) - 1
+            ENGINE_LSFG -> multiplier(activity) + 2
+            else -> 0
+        }
+        android.app.AlertDialog.Builder(activity)
+            .setTitle(com.steamdeck.launcher.R.string.frame_gen_title)
+            .setSingleChoiceItems(choices, current) { dialog, which ->
+                when (which) {
+                    0 -> set(activity, ENGINE_OFF, 2)
+                    in 1..3 -> set(activity, ENGINE_WINFG, which + 1)
+                    else -> set(activity, ENGINE_LSFG, which - 2)
+                }
+                dialog.dismiss()
+                onChanged()
+            }
+            .setNeutralButton(android.R.string.ok, null)
+            .show()
+    }
+
     private const val TAG = "FrameGen"
 }

app/src/main/java/com/steamdeck/launcher/session/PerfHud.kt

@@ -49,7 +49,10 @@ class PerfHud(context: Context) {
     private var lastTick = 0L
     private var running = false
     private val handler = Handler(Looper.getMainLooper())
-    private val enabled = !File(Environment.getExternalStorageDirectory(), "Download/steamdeck-no-hud").exists()
+    /** The session's own switch (drawer), with the Downloads file as a device-side override. */
+    private val enabled: Boolean
+        get() = SessionPrefs.hudEnabled(context)
+            && !File(Environment.getExternalStorageDirectory(), "Download/steamdeck-no-hud").exists()
 
     private val listener = object : WaylandCompositor.GameListener {
         override fun onGameSurface(window: String?, gpuName: String?) {}
@@ -68,6 +71,11 @@ class PerfHud(context: Context) {
         }
     }
 
+    /** Re-reads the switch: starts or stops to match it. */
+    fun refresh() {
+        if (enabled) start() else stop()
+    }
+
     fun start() {
         if (!enabled || running) return
         running = true

app/src/main/java/com/steamdeck/launcher/session/SessionDrawer.kt

@@ -0,0 +1,89 @@
+package com.steamdeck.launcher.session
+
+import android.app.Activity
+import android.view.View
+import android.view.ViewGroup
+import android.widget.Button
+import android.widget.Switch
+import com.steamdeck.launcher.R
+import com.steamdeck.launcher.gpu.FrameGen
+
+/**
+ * The drawer Back opens over a running session. It owns nothing: every control reads and writes
+ * a preference or calls back into the activity, so closing it changes nothing by itself.
+ */
+class SessionDrawer(
+    private val activity: Activity,
+    parent: ViewGroup,
+    private val onHudChanged: (Boolean) -> Unit,
+    private val onOscChanged: () -> Unit,
+    private val onFrameGenChanged: () -> Unit,
+    private val onBackground: () -> Unit,
+    private val onStop: () -> Unit,
+) {
+    private val root: View = activity.layoutInflater.inflate(R.layout.session_drawer, parent, false)
+    private val hud = root.findViewById<Switch>(R.id.drawer_hud)
+    private val frameGen = root.findViewById<Button>(R.id.drawer_frame_gen)
+    private val osc = root.findViewById<Button>(R.id.drawer_osc)
+
+    init {
+        root.visibility = View.GONE
+        parent.addView(root)
+        // The dimmed area closes; the panel itself swallows its touches.
+        root.setOnClickListener { close() }
+        root.findViewById<View>(R.id.drawer_panel).setOnClickListener { }
+        hud.setOnCheckedChangeListener { _, on ->
+            SessionPrefs.setHudEnabled(activity, on)
+            onHudChanged(on)
+        }
+        frameGen.setOnClickListener {
+            FrameGen.showPicker(activity) {
+                refresh()
+                onFrameGenChanged()
+            }
+        }
+        osc.setOnClickListener {
+            val next = when (SessionPrefs.oscMode(activity)) {
+                SessionPrefs.OSC_AUTO -> SessionPrefs.OSC_ALWAYS
+                SessionPrefs.OSC_ALWAYS -> SessionPrefs.OSC_NEVER
+                else -> SessionPrefs.OSC_AUTO
+            }
+            SessionPrefs.setOscMode(activity, next)
+            refresh()
+            onOscChanged()
+        }
+        root.findViewById<View>(R.id.drawer_background).setOnClickListener {
+            close()
+            onBackground()
+        }
+        root.findViewById<View>(R.id.drawer_stop).setOnClickListener {
+            close()
+            onStop()
+        }
+    }
+
+    val isOpen: Boolean get() = root.visibility == View.VISIBLE
+
+    fun open() {
+        refresh()
+        root.visibility = View.VISIBLE
+        root.bringToFront()
+    }
+
+    fun close() {
+        root.visibility = View.GONE
+    }
+
+    fun toggle() = if (isOpen) close() else open()
+
+    private fun refresh() {
+        hud.isChecked = SessionPrefs.hudEnabled(activity)
+        frameGen.text = activity.getString(R.string.frame_gen, FrameGen.label(activity))
+        val mode = when (SessionPrefs.oscMode(activity)) {
+            SessionPrefs.OSC_ALWAYS -> activity.getString(R.string.osc_always)
+            SessionPrefs.OSC_NEVER -> activity.getString(R.string.osc_never)
+            else -> activity.getString(R.string.osc_auto)
+        }
+        osc.text = activity.getString(R.string.drawer_osc, mode)
+    }
+}

app/src/main/java/com/steamdeck/launcher/session/SessionPrefs.kt

@@ -0,0 +1,24 @@
+package com.steamdeck.launcher.session
+
+import android.content.Context
+
+/** The in-session switches: the HUD and how the on-screen controls decide to appear. */
+object SessionPrefs {
+    const val OSC_AUTO = "auto"
+    const val OSC_ALWAYS = "always"
+    const val OSC_NEVER = "never"
+
+    private fun prefs(context: Context) = context.getSharedPreferences("session", Context.MODE_PRIVATE)
+
+    fun hudEnabled(context: Context): Boolean = prefs(context).getBoolean("hud", true)
+
+    fun setHudEnabled(context: Context, on: Boolean) {
+        prefs(context).edit().putBoolean("hud", on).apply()
+    }
+
+    fun oscMode(context: Context): String = prefs(context).getString("osc", OSC_AUTO) ?: OSC_AUTO
+
+    fun setOscMode(context: Context, mode: String) {
+        prefs(context).edit().putString("osc", mode).apply()
+    }
+}

app/src/main/res/layout/session_drawer.xml

@@ -0,0 +1,82 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    The in-session drawer, opened with Back. A tap on the dimmed area or Back again closes it.
+    Small on purpose: the switches a player reaches for mid-game, nothing that needs the main
+    screen.
+-->
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/drawer_scrim"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="#66000000"
+    android:clickable="true"
+    android:focusable="true">
+
+    <LinearLayout
+        android:id="@+id/drawer_panel"
+        android:layout_width="264dp"
+        android:layout_height="match_parent"
+        android:layout_gravity="end"
+        android:orientation="vertical"
+        android:background="#F2151A22"
+        android:clickable="true"
+        android:focusable="true"
+        android:padding="16dp">
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/app_name"
+            android:textColor="#FFFFFFFF"
+            android:textSize="16sp"
+            android:layout_marginBottom="12dp" />
+
+        <Switch
+            android:id="@+id/drawer_hud"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:minHeight="40dp"
+            android:text="@string/drawer_hud"
+            android:textColor="#FFDDDDDD"
+            android:textSize="13sp" />
+
+        <Button
+            android:id="@+id/drawer_frame_gen"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:minHeight="40dp"
+            android:textSize="13sp" />
+
+        <Button
+            android:id="@+id/drawer_osc"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="6dp"
+            android:minHeight="40dp"
+            android:textSize="13sp" />
+
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
+
+        <Button
+            android:id="@+id/drawer_background"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:minHeight="40dp"
+            android:textSize="13sp"
+            android:text="@string/drawer_background" />
+
+        <Button
+            android:id="@+id/drawer_stop"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="6dp"
+            android:minHeight="40dp"
+            android:textSize="13sp"
+            android:textColor="#FFFF8A80"
+            android:text="@string/stop_session" />
+    </LinearLayout>
+</FrameLayout>

app/src/main/res/values/strings.xml

@@ -36,6 +36,12 @@
     <string name="frame_gen">Frame generation: %1$s</string>
     <string name="frame_gen_title">Frame generation</string>
     <string name="frame_gen_help">Extra frames are generated between the real ones on the way to the screen, so a game running at 30 fps looks like 60. Win-FG is built in. LSFG uses the shaders from your own copy of Lossless Scaling — install it from the Steam client in this app first. Takes effect immediately, even mid-game.</string>
+    <string name="drawer_hud">Performance HUD</string>
+    <string name="drawer_osc">On-screen controls: %1$s</string>
+    <string name="drawer_background">Send to background</string>
+    <string name="osc_auto">auto</string>
+    <string name="osc_always">always</string>
+    <string name="osc_never">never</string>
     <string name="credits_line">by The412Banner and maxjivi05 · credits</string>
     <string name="credits_title">Credits</string>
     <string name="credits_body">SteamDeck\n\nThe412Banner — the app, the Wayland compositor, the runtime and the Steam session.\n\nmaxjivi05 (Max) — the gamescope runtime this is built on: the proot session, the session shim, the fake-evdev interposer and the controller work, from WinNative.\n\nGPL-3.0. Valve, Steam, Steam Deck and Proton are trademarks of Valve Corporation; this project is not affiliated with Valve. gamescope, Mesa, Turnip, Xwayland, PulseAudio, proot and Arch Linux ARM are their authors\' own.</string>