{"record":{"id":"742cdcb82623f0b8","repo":"java-native-access/jna","slug":"this-x11-display-does-not-provide-a-32-bit-visual","errorCode":null,"errorMessage":"This X11 display does not provide a 32-bit visual","messagePattern":"This X11 display does not provide a 32-bit visual","errorType":"exception","errorClass":"UnsupportedOperationException","httpStatus":null,"severity":"error","filePath":"contrib/platform/src/com/sun/jna/platform/WindowUtils.java","lineNumber":1849,"sourceCode":"                }\n            }\n            return win;\n        }\n\n        private static X11.Window getDrawable(Component w) {\n            int id = (int)Native.getComponentID(w);\n            if (id == X11.None)\n                return null;\n            return new X11.Window(id);\n        }\n\n        private static final long OPAQUE = 0xFFFFFFFFL;\n        private static final String OPACITY = \"_NET_WM_WINDOW_OPACITY\";\n\n        @Override\n        public void setWindowAlpha(final Window w, final float alpha) {\n            if (!isWindowAlphaSupported()) {\n                throw new UnsupportedOperationException(\"This X11 display does not provide a 32-bit visual\");\n            }\n            Runnable action = new Runnable() {\n                @Override\n                public void run() {\n                    X11 x11 = X11.INSTANCE;\n                    Display dpy = x11.XOpenDisplay(null);\n                    if (dpy == null)\n                        return;\n                    try {\n                        X11.Window win = getDrawable(w);\n                        if (alpha == 1f) {\n                            x11.XDeleteProperty(dpy, win,\n                                                x11.XInternAtom(dpy, OPACITY,\n                                                                false));\n                        }\n                        else {\n                            int opacity = (int)((long)(alpha * OPAQUE) & 0xFFFFFFFF);\n                            IntByReference patom = new IntByReference(opacity);","sourceCodeStart":1831,"sourceCodeEnd":1867,"githubUrl":"https://github.com/java-native-access/jna/blob/d036ad9781adad4b66693e8fa7098e4ac665e0a3/contrib/platform/src/com/sun/jna/platform/WindowUtils.java#L1831-L1867","documentation":"Guard exception in setWindowAlpha: it fires when the X11 server provides no 32-bit (ARGB) visual, which JNA requires for per-window alpha compositing. Root cause is the display/server configuration (e.g. plain 16/24-bit visuals, no composite manager), not the alpha value passed in.","triggerScenarios":"Thrown at contrib/platform/src/com/sun/jna/platform/WindowUtils.java:1849 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Call WindowUtils.isWindowAlphaSupported() first and degrade gracefully to opaque rendering","Use a compositing window manager and ensure the X server offers a 32-bit visual (xdpyinfo | grep 'depth 32')","On unsupported displays, skip alpha effects instead of calling setWindowAlpha"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"d036ad9781adad4b66693e8fa7098e4ac665e0a3","analyzedAt":"2026-09-12T06:50:59.239Z","contentChangedAt":"2026-09-12T06:50:59.239Z","schemaVersion":2},"datasetVersion":"2026-09-19T12:17:13.211Z"}