From a14eb65e82d226fe8b33ca23d29eeba02066357d Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Wed, 17 Nov 2021 09:42:11 +0100
Subject: Window: implement function to disable key repeat

---
 include/mgl/window/window.h |  2 ++
 src/mgl.c                   |  2 ++
 src/window/window.c         | 27 +++++++++++++++++++++++++--
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/include/mgl/window/window.h b/include/mgl/window/window.h
index 95e3273..2ce9a4b 100644
--- a/include/mgl/window/window.h
+++ b/include/mgl/window/window.h
@@ -31,6 +31,7 @@ struct mgl_window {
     mgl_view view;
     bool open;
     bool focused;
+    bool key_repeat_enabled;
     double frame_time_limit;
     mgl_clock frame_timer;
     char *clipboard_string;
@@ -81,5 +82,6 @@ void mgl_window_set_size_limits(mgl_window *self, mgl_vec2i minimum, mgl_vec2i m
 void mgl_window_set_clipboard(mgl_window *self, const char *str, size_t size);
 /* A malloc'ed and null terminated string is returned in |str|, it should be deallocated with free */
 bool mgl_window_get_clipboard(mgl_window *self, char **str, size_t *size);
+void mgl_window_set_key_repeat_enabled(mgl_window *self, bool enabled);
 
 #endif /* MGL_WINDOW_H */
diff --git a/src/mgl.c b/src/mgl.c
index 02fe8a5..f93704e 100644
--- a/src/mgl.c
+++ b/src/mgl.c
@@ -1,5 +1,6 @@
 #include "../include/mgl/mgl.h"
 #include <X11/Xutil.h>
+#include <X11/XKBlib.h>
 #include <stdio.h>
 #ifndef NDEBUG
 #include <stdlib.h>
@@ -67,6 +68,7 @@ int mgl_init(void) {
 
         prev_xerror = XSetErrorHandler(ignore_xerror);
         prev_xioerror = XSetIOErrorHandler(ignore_xioerror);
+        XkbSetDetectableAutoRepeat(context.connection, True, NULL);
 
         context.wm_delete_window_atom = XInternAtom(context.connection, "WM_DELETE_WINDOW", False);
         if(!context.wm_delete_window_atom) {
diff --git a/src/window/window.c b/src/window/window.c
index 3dbb81f..c6dab51 100644
--- a/src/window/window.c
+++ b/src/window/window.c
@@ -61,6 +61,8 @@ typedef struct {
     Atom incr_atom;
     Cursor default_cursor;
     Cursor invisible_cursor;
+    unsigned int prev_keycode_pressed;
+    bool key_was_released;
     /*
         Used to stack text event on top of key press/release events and other text events.
         For example pressing a key should give the user both key press and text events
@@ -89,6 +91,9 @@ static int x11_context_init(x11_context *self) {
     self->default_cursor = None;
     self->invisible_cursor = None;
 
+    self->prev_keycode_pressed = 0;
+    self->key_was_released = false;
+
     self->default_cursor = XCreateFontCursor(context->connection, XC_arrow);
     if(!self->default_cursor) {
         x11_context_deinit(self);
@@ -226,6 +231,7 @@ static int mgl_window_init(mgl_window *self, const char *title, const mgl_window
     self->context = NULL;
     self->open = false;
     self->focused = false;
+    self->key_repeat_enabled = true;
     self->frame_time_limit = 0.0;
     mgl_clock_init(&self->frame_timer);
     self->clipboard_string = NULL;
@@ -495,6 +501,7 @@ static void mgl_window_handle_text_event(mgl_window *self, XEvent *xev) {
         text_event.text.size = clen;
         memcpy(text_event.text.str, &buf[i], clen);
         text_event.text.str[clen] = '\0';
+        /* Text may contain multiple codepoints so they need to separated into multiple events */
         if(!x11_context_append_event(x11_context, &text_event))
             break;
 
@@ -502,17 +509,29 @@ static void mgl_window_handle_text_event(mgl_window *self, XEvent *xev) {
     }
 }
 
-/* Returns true if processed */
 static void mgl_window_on_receive_event(mgl_window *self, XEvent *xev, mgl_event *event, mgl_context *context) {
-    /* TODO: Handle wm_delete_window event */
     switch(xev->type) {
         case KeyPress: {
+            x11_context *x11_context = self->context;
+
+            if(!self->key_repeat_enabled && xev->xkey.keycode == x11_context->prev_keycode_pressed && !x11_context->key_was_released) {
+                event->type = MGL_EVENT_UNKNOWN;
+                return;
+            }
+
+            x11_context->prev_keycode_pressed = xev->xkey.keycode;
+            x11_context->key_was_released = false;
+
             event->type = MGL_EVENT_KEY_PRESSED;
             mgl_window_handle_key_event(self, &xev->xkey, event, context, true);
             mgl_window_handle_text_event(self, xev);
             return;
         }
         case KeyRelease: {
+            x11_context *x11_context = self->context;
+            if(xev->xkey.keycode == x11_context->prev_keycode_pressed)
+                x11_context->key_was_released = true;
+
             event->type = MGL_EVENT_KEY_RELEASED;
             mgl_window_handle_key_event(self, &xev->xkey, event, context, false);
             return;
@@ -891,3 +910,7 @@ bool mgl_window_get_clipboard(mgl_window *self, char **str, size_t *size) {
     /* Timed out waiting for clipboard */
     return false;
 }
+
+void mgl_window_set_key_repeat_enabled(mgl_window *self, bool enabled) {
+    self->key_repeat_enabled = enabled;
+}
-- 
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