Started doing the C rewrite. Defined the basic initialization and main loop and window API and implemented them on GTK+.

test.c

@@ -0,0 +1,32 @@
+// 6 april 2015
+#include "ui.h"
+#include <stdio.h>
+
+// #qo pkg-config: gtk+-3.0
+
+int onClosing(uiWindow *w, void *data)
+{
+	printf("in closing!\n");
+	uiQuit();
+	return 1;
+}
+
+int main(void)
+{
+	uiInitError *err;
+	uiWindow *w;
+
+	err = uiInit(NULL);
+	if (err != NULL) {
+		fprintf(stderr, "error initializing ui: %s\n", uiInitErrorMessage(err));
+		uiInitErrorFree(err);
+		return 1;
+	}
+
+	w = uiNewWindow("Hello", 320, 240);
+	uiWindowOnClosing(w, onClosing, NULL);
+	uiWindowShow(w);
+
+	uiMain();
+	return 0;
+}

ui.h

@@ -0,0 +1,27 @@
+// 6 april 2015
+
+#ifndef __UI_UI_H__
+#define __UI_UI_H__
+
+#include <stdint.h>
+
+typedef struct uiInitError uiInitError;
+typedef struct uiInitOptions uiInitOptions;
+
+uiInitError *uiInit(uiInitOptions *);
+const char *uiInitErrorMessage(uiInitError *);
+void uiInitErrorFree(uiInitError *);
+
+void uiMain(void);
+void uiQuit(void);
+
+typedef struct uiWindow uiWindow;
+uiWindow *uiNewWindow(char *, int, int);
+void uiWindowDestroy(uiWindow *);
+uintptr_t uiWindowHandle(uiWindow *);
+// TODO titles
+void uiWindowShow(uiWindow *);
+void uiWindowHide(uiWindow *);
+void uiWindowOnClosing(uiWindow *, int (*)(uiWindow *, void *), void *);
+
+#endif

ui_unix.h

@@ -0,0 +1,13 @@
+// 6 april 2015
+
+#ifndef __UI_UI_UNIX_H__
+#define __UI_UI_UNIX_H__
+
+#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_32
+#define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_32
+#define GDK_VERSION_MIN_REQUIRED GDK_VERSION_3_4
+#define GDK_VERSION_MAX_ALLOWED GDK_VERSION_3_4
+#include <gtk/gtk.h>
+#include "ui.h"
+
+#endif

uiinit_unix.c

@@ -0,0 +1,27 @@
+// 6 april 2015
+#include "ui_unix.h"
+
+struct uiInitError {
+	GError *err;
+};
+
+uiInitError *uiInit(uiInitOptions *o)
+{
+	uiInitError *e;
+
+	e = g_new0(uiInitError, 1);
+	if (gtk_init_with_args(NULL, NULL, NULL, NULL, NULL, &(e->err)) == FALSE)
+		return e;
+	uiInitErrorFree(e);
+	return NULL;
+}
+
+const char *uiInitErrorMessage(uiInitError *e)
+{
+	return e->err->message;
+}
+
+void uiInitErrorFree(uiInitError *e)
+{
+	g_free(e);
+}

uimain_unix.c

@@ -0,0 +1,12 @@
+// 6 april 2015
+#include "ui_unix.h"
+
+void uiMain(void)
+{
+	gtk_main();
+}
+
+void uiQuit(void)
+{
+	gtk_main_quit();
+}

window_unix.c

@@ -0,0 +1,59 @@
+// 6 april 2015
+#include "ui_unix.h"
+
+struct uiWindow {
+	GtkWidget *widget;
+	int (*onClosing)(uiWindow *, void *);
+	void *onClosingData;
+};
+
+uiWindow *uiNewWindow(char *title, int width, int height)
+{
+	uiWindow *w;
+
+	w = g_new0(uiWindow, 1);
+	w->widget = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+	gtk_window_set_title(GTK_WINDOW(w->widget), title);
+	gtk_window_resize(GTK_WINDOW(w->widget), width, height);
+	return w;
+}
+
+void uiWindowDestroy(uiWindow *w)
+{
+	gtk_widget_destroy(w->widget);
+	g_free(w);
+}
+
+uintptr_t uiWindowHandle(uiWindow *w)
+{
+	return (uintptr_t) (w->widget);
+}
+
+// TODO titles
+
+void uiWindowShow(uiWindow *w)
+{
+	gtk_widget_show_all(w->widget);
+}
+
+void uiWindowHide(uiWindow *w)
+{
+	gtk_widget_hide(w->widget);
+}
+
+static gboolean onClosing(GtkWidget *win, GdkEvent *e, gpointer data)
+{
+	uiWindow *w = (uiWindow *) data;
+
+	// return exact values just in case
+	if ((*(w->onClosing))(w, w->onClosingData))
+		return FALSE;
+	return TRUE;
+}
+
+void uiWindowOnClosing(uiWindow *w, int (*f)(uiWindow *, void *), void *data)
+{
+	w->onClosing = f;
+	w->onClosingData = data;
+	g_signal_connect(w->widget, "delete-event", G_CALLBACK(onClosing), w);
+}