another UI attempt, I guess.

sorry.

src/libui_sdl/libui/common/control.c

@@ -0,0 +1,101 @@
+// 26 may 2015
+#include "../ui.h"
+#include "uipriv.h"
+
+void uiControlDestroy(uiControl *c)
+{
+	(*(c->Destroy))(c);
+}
+
+uintptr_t uiControlHandle(uiControl *c)
+{
+	return (*(c->Handle))(c);
+}
+
+uiControl *uiControlParent(uiControl *c)
+{
+	return (*(c->Parent))(c);
+}
+
+void uiControlSetParent(uiControl *c, uiControl *parent)
+{
+	(*(c->SetParent))(c, parent);
+}
+
+int uiControlToplevel(uiControl *c)
+{
+	return (*(c->Toplevel))(c);
+}
+
+int uiControlVisible(uiControl *c)
+{
+	return (*(c->Visible))(c);
+}
+
+void uiControlShow(uiControl *c)
+{
+	(*(c->Show))(c);
+}
+
+void uiControlHide(uiControl *c)
+{
+	(*(c->Hide))(c);
+}
+
+int uiControlEnabled(uiControl *c)
+{
+	return (*(c->Enabled))(c);
+}
+
+void uiControlEnable(uiControl *c)
+{
+	(*(c->Enable))(c);
+}
+
+void uiControlDisable(uiControl *c)
+{
+	(*(c->Disable))(c);
+}
+
+#define uiControlSignature 0x7569436F
+
+uiControl *uiAllocControl(size_t size, uint32_t OSsig, uint32_t typesig, const char *typenamestr)
+{
+	uiControl *c;
+
+	c = (uiControl *) uiAlloc(size, typenamestr);
+	c->Signature = uiControlSignature;
+	c->OSSignature = OSsig;
+	c->TypeSignature = typesig;
+	return c;
+}
+
+void uiFreeControl(uiControl *c)
+{
+	if (uiControlParent(c) != NULL)
+		userbug("You cannot destroy a uiControl while it still has a parent. (control: %p)", c);
+	uiFree(c);
+}
+
+void uiControlVerifySetParent(uiControl *c, uiControl *parent)
+{
+	uiControl *curParent;
+
+	if (uiControlToplevel(c))
+		userbug("You cannot give a toplevel uiControl a parent. (control: %p)", c);
+	curParent = uiControlParent(c);
+	if (parent != NULL && curParent != NULL)
+		userbug("You cannot give a uiControl a parent while it already has one. (control: %p; current parent: %p; new parent: %p)", c, curParent, parent);
+	if (parent == NULL && curParent == NULL)
+		implbug("attempt to double unparent uiControl %p", c);
+}
+
+int uiControlEnabledToUser(uiControl *c)
+{
+	while (c != NULL) {
+		if (!uiControlEnabled(c))
+			return 0;
+		c = uiControlParent(c);
+	}
+	return 1;
+}