1 files changed, 56 insertions, 0 deletions
diff --git a/src/x11_util.c b/src/x11_util.c
new file mode 100644
index 0000000..f5f1c87
--- /dev/null
+++ b/src/x11_util.c
@@ -0,0 +1,56 @@
+// Copyright 2020-2024 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#include "x11_util.h"
+
+#include <X11/X.h>
+#include <X11/Xlib.h>
+
+#include <stddef.h>
+
+bool
+suil_x11_is_valid_child(Display* const display,
+                        const Window   parent,
+                        const Window   child)
+{
+  Window   root        = 0U;
+  Window   grandparent = 0U;
+  Window*  children    = NULL;
+  unsigned n_children  = 0U;
+
+  XQueryTree(display, parent, &root, &grandparent, &children, &n_children);
+
+  for (unsigned i = 0U; i < n_children; ++i) {
+    if (children[i] == child) {
+      if (children) {
+        XFree(children);
+      }
+      return true;
+    }
+  }
+
+  if (children) {
+    XFree(children);
+  }
+
+  return false;
+}
+
+Window
+suil_x11_get_parent(Display* display, Window child)
+{
+  Window   root     = 0U;
+  Window   parent   = 0U;
+  Window*  children = NULL;
+  unsigned count    = 0U;
+
+  if (child) {
+    if (XQueryTree(display, child, &root, &parent, &children, &count)) {
+      if (children) {
+        XFree(children);
+      }
+    }
+  }
+
+  return (parent == root) ? 0 : parent;
+}