Fix the QAM button doing nothing when the pad is an Xbox or PlayStation controller (#631)

app/src/main/java/com/droiddeck/launcher/input/FakeInputWriter.java

@@ -566,6 +566,16 @@ public class FakeInputWriter {
         }
     }
 
+    /**
+     * Whether the pad, as the Steam client now sees it, has a Quick Access button: a Deck's or a
+     * Steam Controller's does, an Xbox or PlayStation pad's does not (libfakeinput drops the bit).
+     * Unset is the Deck, libfakeinput's default.
+     */
+    public static boolean padHasQam() {
+        int type = padType;
+        return type < 0 || type == PAD_TYPE_DECK || type == PAD_TYPE_STEAM;
+    }
+
     /**
      * Switches what the pad is to the Steam client while the session runs ([PAD_TYPE_DECK],
      * [PAD_TYPE_STEAM] or [PAD_TYPE_XBOX]); libfakeinput unplugs the old device and plugs in the new.

app/src/main/java/com/droiddeck/launcher/input/PadBridge.java

@@ -400,8 +400,8 @@ public final class PadBridge {
         boolean qamStarted = qamPressed && !systemQamPressed;
         systemGuidePressed = guidePressed;
         systemQamPressed = qamPressed;
-        // A Deck controller's QAM button is held for as long as the touch one is.
-        if (qamStarted && !SessionState.getDeckPad()) startQamChord();
+        // A Deck or Steam Controller's QAM button is held for as long as the touch one is.
+        if (qamStarted && !nativeQam()) startQamChord();
         else publish();
     }
 
@@ -426,9 +426,18 @@ public final class PadBridge {
         }
     }
 
-    /** Opens the client's Quick Access menu: a tap of the Deck's button, or the Guide-then-A chord. */
+    /**
+     * Whether the client's pad has its own QAM button to press. The Deck's sysfs being up is not
+     * enough: the drawer can make the pad an Xbox or PlayStation one, which has none, and a press
+     * of it never reaches the client.
+     */
+    private static boolean nativeQam() {
+        return SessionState.getDeckPad() && FakeInputWriter.padHasQam();
+    }
+
+    /** Opens the client's Quick Access menu: a tap of the pad's button, or the Guide-then-A chord. */
     public synchronized void triggerQam() {
-        if (!SessionState.getDeckPad()) {
+        if (!nativeQam()) {
             startQamChord();
             return;
         }
@@ -571,7 +580,7 @@ public final class PadBridge {
             return;
         }
         boolean guide = systemGuidePressed || qamChordActive;
-        boolean qam = SessionState.getDeckPad() && (systemQamPressed || qamTapPressed);
+        boolean qam = nativeQam() && (systemQamPressed || qamTapPressed);
         if (!guide && !qam) {
             writer.writePad(state);
             return;