X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5503a51cac96518f384565baea2bb271866dbf6d..6bdeda4785ad7313926a79d8c900ff8019d54f64:/src/gtk/toplevel.cpp

diff --git a/src/gtk/toplevel.cpp b/src/gtk/toplevel.cpp
index a60402b336..bf4cec07be 100644
--- a/src/gtk/toplevel.cpp
+++ b/src/gtk/toplevel.cpp
@@ -1300,3 +1300,71 @@ void wxTopLevelWindowGTK::SetWindowStyleFlag( long style )
     }
 #endif // GTK+ 2.2
 }
+
+#include <X11/Xlib.h>
+
+/* Get the X Window between child and the root window.
+   This should usually be the WM managed XID */
+static Window wxGetTopmostWindowX11(Display *dpy, Window child)
+{
+    Window root, parent;
+    Window* children;
+    unsigned int nchildren;
+
+    XQueryTree(dpy, child, &root, &parent, &children, &nchildren);
+    XFree(children);
+
+    while (parent != root) {
+        child = parent;
+        XQueryTree(dpy, child, &root, &parent, &children, &nchildren);
+        XFree(children);
+    }
+
+    return child;
+}
+
+bool wxTopLevelWindowGTK::SetTransparent(wxByte alpha)
+{
+    if (!m_widget || !m_widget->window)
+        return false;
+
+    Display* dpy = GDK_WINDOW_XDISPLAY (m_widget->window);
+    // We need to get the X Window that has the root window as the immediate parent
+    // and m_widget->window as a child. This should be the X Window that the WM manages and
+    // from which the opacity property is checked from.
+    Window win = wxGetTopmostWindowX11(dpy, GDK_WINDOW_XID (m_widget->window));
+
+    unsigned int opacity = alpha * 0x1010101;
+
+    // Using pure Xlib to not have a GTK version check mess due to gtk2.0 not having GdkDisplay
+    if (alpha == 0xff)
+        XDeleteProperty(dpy, win, XInternAtom(dpy, "_NET_WM_WINDOW_OPACITY", False));
+    else
+        XChangeProperty(dpy, win, XInternAtom(dpy, "_NET_WM_WINDOW_OPACITY", False),
+                        XA_CARDINAL, 32, PropModeReplace,
+                        (unsigned char *) &opacity, 1L);
+    XSync(dpy, False);
+    return true;
+}
+
+bool wxTopLevelWindowGTK::CanSetTransparent()
+{
+#if GTK_CHECK_VERSION(2,10,0)
+    if (!gtk_check_version(2,10,0))
+    {
+        if (gtk_widget_is_composited (m_widget))
+            return true;
+    }
+    else
+#endif // In case of lower versions than gtk+-2.10.0 we could look for _NET_WM_CM_Sn ourselves
+    {
+        return false;
+    }
+
+#if 0 // Don't be optimistic here for the sake of wxAUI
+    int opcode, event, error;
+    // Check for the existence of a RGBA visual instead?
+    return XQueryExtension(gdk_x11_get_default_xdisplay (),
+                           "Composite", &opcode, &event, &error);
+#endif
+}