Split the UI code into multiple files

globals.c

@@ -0,0 +1,81 @@
+#include "maturita.h"
+
+GtkStack *main_stack;
+
+GtkWindow *main_window;
+
+GtkWidget *welcome_heading;
+
+GtkCssProvider *theme_provider;
+
+ThemeId   app_theme_id = THEME_CATPPUCCIN;
+
+ColorMode app_color_mode = MODE_DARK;
+
+UiLang    app_lang = LANG_CS;
+
+ThemePalette app_theme;
+
+const char *theme_names[THEME_COUNT] = {
+    "Catppuccin",
+    "Nord",
+    "Dracula",
+    "Rose Pine",
+    "Ocean",
+    "Gruvbox",
+    "Solarized",
+    "Everforest",
+    "Monokai",
+    "One Dark",
+};
+
+GtkWidget *theme_swatch_areas[THEME_COUNT];
+
+UnitCtx units[NUM_UNITS] = {0};
+
+const char *const u1_ex_names[MAX_UNIT_EX + 1] = {
+    NULL,
+    "Dialog", "Sätze bilden", "Was ist richtig?", "Freie Antwort",
+    "Zahlen", "Wie viel?", "Zahlenreihe", "Verb einsetzen",
+    "Wer? Wie? Wo?", "Wörter trennen", "Grußformen",
+    "Was macht er/sie?", "Länder",
+};
+
+const char *const u2_ex_names[MAX_UNIT_EX + 1] = {
+    NULL,
+    "Verben konjugieren", "aus oder in", "Fragewörter", "sprechen",
+    "Nationalitäten", "Woher?", "Länder schreiben", "Verben einsetzen",
+    "Freie Antwort", "Euro", "Wörter suchen", "Was ist richtig?",
+    "Ordne zu", "Lückentext", "Verbinde", "Zahlen",
+    "Steckbrief", "Berufe", "Nationalität",
+};
+
+const char *const u3_ex_names[MAX_UNIT_EX + 1] = {
+    NULL,
+    "Familienpaare", "mein oder dein", "ein / kein", "Lückentext",
+    "Marcos Familie", "Sortieren", "Possessivtabelle", "Akkusativ",
+    "kein / nicht", "Sätze bauen", "Was siehst du?", "Wem gehört das?",
+    "Es gibt …", "Beschreiben", "Wochenende",
+};
+
+GtkWidget *road_scroll;
+
+GtkWidget *road_fixed;
+
+GtkWidget *road_rail;
+
+GtkWidget *road_nodes[NUM_UNITS];
+
+GtkWidget *road_labels[NUM_UNITS];
+
+double road_cx[NUM_UNITS];
+
+double road_cy[NUM_UNITS];
+
+int road_cols = NUM_UNITS;
+
+int road_rows = 1;
+
+int road_cw = (int)(2.0 * ROAD_MX + (NUM_UNITS - 1) * PATH_SPAC);
+
+int road_ch = (int)(2.0 * ROAD_MY);