Big glfw refactor

I did a lot of this in a very ad-hoc fashion with no proper commit
history. As such, the kindest thing to do seemed to be to just squash it
into this one commit.

1 files changed, 118 insertions, 0 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
new file mode 100644
index 0000000..16b2c9d
--- /dev/null
+++ b/src/keyboard.c
@@ -0,0 +1,118 @@
+#include "keyboard.h"
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <xkbcommon/xkbcommon.h>
+
+struct imv_keyboard {
+  struct xkb_context *context;
+  struct xkb_keymap *keymap;
+  struct xkb_state *state;
+};
+
+struct imv_keyboard *imv_keyboard_create(void)
+{
+  struct imv_keyboard *keyboard = calloc(1, sizeof *keyboard);
+  keyboard->context = xkb_context_new(0);
+  assert(keyboard->context);
+
+  struct xkb_rule_names names = {
+    .rules = NULL,
+    .model = NULL,
+    .layout = "gb",
+    .variant = NULL,
+    .options = "caps:escape,compose:ralt"
+  };
+  keyboard->keymap = xkb_keymap_new_from_names(keyboard->context, &names, 0);
+  assert(keyboard->keymap);
+  keyboard->state = xkb_state_new(keyboard->keymap);
+  assert(keyboard->state);
+
+  return keyboard;
+}
+
+void imv_keyboard_free(struct imv_keyboard *keyboard)
+{
+  if (!keyboard) {
+    return;
+  }
+  xkb_state_unref(keyboard->state);
+  keyboard->state = NULL;
+  xkb_keymap_unref(keyboard->keymap);
+  keyboard->keymap = NULL;
+  xkb_context_unref(keyboard->context);
+  keyboard->context = NULL;
+  free(keyboard);
+}
+
+static const int scancode_offset = 8;
+
+void imv_keyboard_update_key(struct imv_keyboard *keyboard, int scancode, bool pressed)
+{
+  xkb_state_update_key(keyboard->state, scancode + scancode_offset, pressed ? XKB_KEY_DOWN : XKB_KEY_UP);
+}
+
+static const char *describe_prefix(struct imv_keyboard *keyboard)
+{
+  const bool ctrl = (xkb_state_mod_name_is_active(keyboard->state, XKB_MOD_NAME_CTRL, XKB_STATE_MODS_EFFECTIVE) > 0);
+  const bool alt = (xkb_state_mod_name_is_active(keyboard->state, XKB_MOD_NAME_ALT, XKB_STATE_MODS_EFFECTIVE) > 0);
+  const bool shift = (xkb_state_mod_name_is_active(keyboard->state, XKB_MOD_NAME_SHIFT, XKB_STATE_MODS_EFFECTIVE) > 0);
+
+  if (ctrl && !alt && !shift) {
+    return "Ctrl+";
+  } else if (!ctrl && alt && !shift) {
+    return "Meta+";
+  } else if (!ctrl && !alt && shift) {
+    return "Shift+";
+  } else if (ctrl && alt && !shift) {
+    return "Ctrl+Meta+";
+  } else if (ctrl && !alt && shift) {
+    return "Ctrl+Shift+";
+  } else if (!ctrl && alt && shift) {
+    return "Meta+Shift+";
+  } else if (ctrl && alt && shift) {
+    return "Ctrl+Meta+Shift+";
+  } else {
+    return "";
+  }
+}
+
+size_t imv_keyboard_keyname(struct imv_keyboard *keyboard, int scancode, char *buf, size_t buflen)
+{
+  xkb_keysym_t keysym = xkb_state_key_get_one_sym(keyboard->state, scancode + scancode_offset);
+  return xkb_keysym_get_name(keysym, buf, buflen);
+}
+
+char *imv_keyboard_describe_key(struct imv_keyboard *keyboard, int scancode)
+{
+  char keyname[128] = {0};
+  imv_keyboard_keyname(keyboard, scancode, keyname, sizeof keyname);
+
+  /* Modifier keys don't count on their own, only when pressed with another key */
+  if (!strcmp(keyname, "Control_L") ||
+      !strcmp(keyname, "Control_R") ||
+      !strcmp(keyname, "Alt_L") ||
+      !strcmp(keyname, "Alt_R") ||
+      !strcmp(keyname, "Shift_L") ||
+      !strcmp(keyname, "Shift_R") ||
+      !strcmp(keyname, "Meta_L") ||
+      !strcmp(keyname, "Meta_R") ||
+      !strcmp(keyname, "Super_L") ||
+      !strcmp(keyname, "Super_R")) {
+    return NULL;
+  }
+
+  const char *prefix = describe_prefix(keyboard);
+
+  char buf[128];
+  snprintf(buf, sizeof buf, "%s%s", prefix, keyname);
+  return strdup(buf);
+}
+
+size_t imv_keyboard_get_text(struct imv_keyboard *keyboard, int scancode, char *buf, size_t buflen)
+{
+  return xkb_state_key_get_utf8(keyboard->state, scancode + scancode_offset, buf, buflen);
+}