Support open/closed apple tap events from touch keyboard

src/video/gltouchjoy_kpad.c

@@ -123,11 +123,6 @@ static inline void _press_key(subvariant_s *subvariant, keypad_press_t pressIdx)
     ++(subvariant->keyPressCount);
 }
 
-// No-op callback
-static void touchkpad_nopCallback(uint8_t textFlashCounter) {
-    (void)textFlashCounter;
-}
-
 // End-of-video-frame callback (handling tap delay and auto-strobe)
 static void touchkpad_frameCallback(uint8_t textFlashCounter) {
 
@@ -224,7 +219,7 @@ static void touchkpad_frameCallback(uint8_t textFlashCounter) {
     if ((kpad.axis.currEventType == TOUCH_UP) && (kpad.butt.currEventType == TOUCH_UP)) {
         // all touch up occurred -- unlatch the callback
         TOUCH_JOY_LOG("\t\t+++kpad callback done");
-        kpad.frameCallback = touchkpad_nopCallback;
+        kpad.frameCallback = NULL;
         kpad.axis.scancodes[REPEAT_IDX_A] = -1;
         kpad.axis.scancodes[REPEAT_IDX_B] = -1;
         kpad.butt.scancodes[REPEAT_IDX_A] = -1;

src/video/gltouchkbd.c

@@ -41,6 +41,8 @@
 #define KBD_OBJ_W GL_MODEL_MAX // model width fits screen
 #define KBD_OBJ_H_LANDSCAPE GL_MODEL_MAX
 
+#define KBD_BUTTON_HOLD_FRAMES 7 // >= 1/10 sec (seems reasonable for AppleSoft BASIC sampling ;)
+
 typedef enum keyboard_variant_t {
     KBD_VARIANT_DEFAULT=0,
     KBD_VARIANT_LOWERCASE,
@@ -122,6 +124,8 @@ static struct {
 static struct {
     GLModel *model;
 
+    video_frame_callback_fn frameCallback;
+
     GLfloat modelHeight;
     GLfloat modelSkewY;
     bool modelDirty;
@@ -141,6 +145,9 @@ static struct {
 
     struct timespec timingBegin;
 
+    uint8_t button0Count;
+    uint8_t button1Count;
+
     bool prefsChanged;
 } kbd = { 0 };
 
@@ -149,6 +156,54 @@ static void gltouchkbd_applyPrefs(void);
 // ----------------------------------------------------------------------------
 // Misc internal methods
 
+// End-of-video-frame callback ...
+//
+// NOTE : Currently this is only handling the joystick buttons being pressed for a set number of frames.
+//
+// But could we augment the touch keyboard to implement full auto-repeat functionality (following a similar state machine to
+// gltouchjoy_kpad variant)?
+//
+// At present time, the show-stopper for auto-repeat is that it breaks fundamental existing UI/UX:
+//
+//      - It is possible now with this touch keyboard to place a thumb down indefinitely, keeping the keyboard lit up rather than
+//        invisible, while you then hunt for the key you want to select on the touch up.  This is fundamental UI/UX that has always
+//        been supported, and auto-repeat functionality directly challenges that!
+//
+//      - Presumably an auto-repeat keyboard would press the key tapped on touch down (possibly after a delay to detect either
+//        long-press or motion beyond the x/y threshold of the touch down key) ... and this would break the existing "hold-and-hunt"
+//        functionality.
+//
+//      - It's worth noting that auto-repeat is implicitly handled by hardware keyboards on all major platforms we compile on.
+//        Presumably if auto-repeat is important, then just use a hardware keyboard...
+//
+//      - What about a special gesture or special sticky (AUTO-LOCK) key that engages the auto-repeat behavior?
+//
+static void touchkbd_frameCallback(uint8_t textFlashCounter) {
+
+    // When activated, this is called every video frame -- ~16.688 millis
+
+    ASSERT_ON_CPU_THREAD();
+
+    if (kbd.button0Count) {
+        --kbd.button0Count;
+    }
+    if (!kbd.button0Count) {
+        run_args.joy_button0 = 0x0;
+    }
+
+    if (kbd.button1Count) {
+        --kbd.button1Count;
+    }
+    if (!kbd.button1Count) {
+        run_args.joy_button1 = 0x0;
+    }
+
+    if (!kbd.button0Count && !kbd.button1Count) {
+        // unlatch frame callback ...
+        kbd.frameCallback = NULL;
+    }
+}
+
 #warning FIXME TODO ... make this a generic GLModelHUDElement function
 static void _rerender_character(int col, int row) {
     GLModelHUDElement *hudKeyboard = (GLModelHUDElement *)(kbd.model->custom);
@@ -407,13 +462,15 @@ static inline int64_t _tap_key_at_point(float x, float y) {
             break;
 
         case MOUSETEXT_OPENAPPLE:
-            run_args.joy_button0 = run_args.joy_button0 ? 0x0 : 0x80;
-            scancode = SCODE_L_ALT;
+            run_args.joy_button0 = 0x80;
+            kbd.button0Count = KBD_BUTTON_HOLD_FRAMES;
+            kbd.frameCallback = touchkbd_frameCallback;
             break;
 
         case MOUSETEXT_CLOSEDAPPLE:
-            run_args.joy_button1 = run_args.joy_button1 ? 0x0 : 0x80;
-            scancode = SCODE_R_ALT;
+            run_args.joy_button1 = 0x80;
+            kbd.button1Count = KBD_BUTTON_HOLD_FRAMES;
+            kbd.frameCallback = touchkbd_frameCallback;
             break;
 
         case MOUSETEXT_CURSOR0:
@@ -1146,6 +1203,8 @@ static void _init_gltouchkbd(void) {
     prefs_registerListener(PREF_DOMAIN_KEYBOARD, &gltouchkbd_prefsChanged);
     prefs_registerListener(PREF_DOMAIN_TOUCHSCREEN, &gltouchkbd_prefsChanged);
     prefs_registerListener(PREF_DOMAIN_INTERFACE, &gltouchkbd_prefsChanged);
+
+    video_registerFrameCallback(&kbd.frameCallback);
 }
 
 static __attribute__((constructor)) void __init_gltouchkbd(void) {