[DisplayServer] Add method to check if window transparency is supported and enabled.

2 files changed, 18 insertions, 0 deletions

diff --git a/platform/linuxbsd/x11/display_server_x11.cpp b/platform/linuxbsd/x11/display_server_x11.cpp
index fb22cf5983..2491064a58 100644
--- a/platform/linuxbsd/x11/display_server_x11.cpp
+++ b/platform/linuxbsd/x11/display_server_x11.cpp
@@ -5192,6 +5192,22 @@ void DisplayServerX11::set_context(Context p_context) {
 	}
 }
 
+bool DisplayServerX11::is_window_transparency_available() const {
+	CharString net_wm_cm_name = vformat("_NET_WM_CM_S%d", XDefaultScreen(x11_display)).ascii();
+	Atom net_wm_cm = XInternAtom(x11_display, net_wm_cm_name.get_data(), False);
+	if (net_wm_cm == None) {
+		return false;
+	}
+	if (XGetSelectionOwner(x11_display, net_wm_cm) == None) {
+		return false;
+	}
+
+	if (rendering_device && !rendering_device->is_composite_alpha_supported()) {
+		return false;
+	}
+	return OS::get_singleton()->is_layered_allowed();
+}
+
 void DisplayServerX11::set_native_icon(const String &p_filename) {
 	WARN_PRINT("Native icon not supported by this display server.");
 }
diff --git a/platform/linuxbsd/x11/display_server_x11.h b/platform/linuxbsd/x11/display_server_x11.h
index 0861789b4a..7c69df3df0 100644
--- a/platform/linuxbsd/x11/display_server_x11.h
+++ b/platform/linuxbsd/x11/display_server_x11.h
@@ -530,6 +530,8 @@ public:
 
 	virtual void set_context(Context p_context) override;
 
+	virtual bool is_window_transparency_available() const override;
+
 	virtual void set_native_icon(const String &p_filename) override;
 	virtual void set_icon(const Ref<Image> &p_icon) override;