wip: refactor into crates

crates/suil/src/gtk.rs

@@ -0,0 +1,37 @@
+struct SuilX11Wrapper {
+    socket:           GtkSocket,
+    plug:             GtkPlug,
+    wrapper:          SuilWrapper,
+    instance:         SuilInstance,
+    idle_iface:       LV2UI_Idle_Interface,
+    idle_id:          usize,
+    idle_ms:          usize,
+    idle_size_req_id: usize,
+    initial_width:    usize,
+    initial_height:   usize,
+    req_width:        usize,
+    req_height:       usize,
+}
+
+struct SuilX11WrapperClass {
+    parent_class:     GtkSocketClass,
+}
+
+impl SuilX11Wrapper {
+    fn x_window_is_valid (&self) {
+        let window:      GdkWindow   = gtk_widget_get_window(self.plug);
+        let root:        X11Window   = Some(0);
+        let parent:      X11Window   = Some(0);
+        let children:    [X11Window] = None;
+        let child_count: usize       = 0;
+        x_query_tree(window.xdisplay, window.xid, root, parent, children, &mut childcount);
+        for i in 0..child_count {
+            if children[i] == self.instance.ui_widget {
+                x_free(children);
+                return true;
+            }
+        }
+        x_free(children);
+        return false;
+    }
+}