From 074f882d7e9b2db37cd8ef86d486e3655d7e2dcd Mon Sep 17 00:00:00 2001
From: Carter Li <zhangsongcui3371@sina.com>
Date: Fri, 29 May 2026 15:40:27 +0800
Subject: [PATCH] Wallpaper (Linux): adds COSMIC support

---
 src/detection/wallpaper/wallpaper_linux.c | 75 +++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/src/detection/wallpaper/wallpaper_linux.c b/src/detection/wallpaper/wallpaper_linux.c
index ee709b1cd..f5ad4eca7 100644
--- a/src/detection/wallpaper/wallpaper_linux.c
+++ b/src/detection/wallpaper/wallpaper_linux.c
@@ -1,8 +1,83 @@
 #include "wallpaper.h"
+#include "common/io.h"
 #include "common/settings.h"
+#include "detection/displayserver/displayserver.h"
 #include "detection/gtk_qt/gtk_qt.h"
 
+static const char* detectCosmicComp(FFstrbuf* result) {
+    FF_STRBUF_AUTO_DESTROY path = ffStrbufCreateCopy(FF_LIST_FIRST(FFstrbuf, instance.state.platform.configDirs));
+    ffStrbufAppendS(&path, "cosmic/com.system76.CosmicBackground/v1/");
+    uint32_t basePathLength = path.length;
+
+    FF_STRBUF_AUTO_DESTROY backgrounds = ffStrbufCreate();
+    ffStrbufAppendS(&path, "backgrounds");
+    bool sharedWallpaper = true;
+    FF_STRBUF_AUTO_DESTROY monitorName = ffStrbufCreate();
+    if (ffReadFileBuffer(path.chars, &backgrounds)) {
+        FF_STRBUF_AUTO_DESTROY cleaned = ffStrbufCreateCopy(&backgrounds);
+        ffStrbufRemoveStrings(&cleaned, 4, (const char*[]){ " ", "\n", "\r", "\t" });
+
+        if (!ffStrbufEqualS(&cleaned, "[]")) {
+            const char* firstQuote = strchr(backgrounds.chars, '"');
+            if (firstQuote != NULL) {
+                const char* secondQuote = strchr(firstQuote + 1, '"');
+                if (secondQuote != NULL && secondQuote > firstQuote + 1) {
+                    ffStrbufAppendNS(&monitorName, (uint32_t) (secondQuote - firstQuote - 1), firstQuote + 1);
+                    sharedWallpaper = false;
+                }
+            }
+        }
+    }
+    ffStrbufSubstrBefore(&path, basePathLength);
+
+    if (sharedWallpaper) {
+        ffStrbufAppendS(&path, "all");
+    } else {
+        ffStrbufAppendS(&path, "output.");
+        ffStrbufAppend(&path, &monitorName);
+    }
+
+    FF_STRBUF_AUTO_DESTROY output = ffStrbufCreate();
+    if (!ffReadFileBuffer(path.chars, &output)) {
+        return "Failed to read COSMIC wallpaper config";
+    }
+
+    const char* sourceStart = strstr(output.chars, "source:");
+    if (sourceStart == NULL) {
+        return "COSMIC wallpaper config doesn't contain source";
+    }
+
+    const char* pathStart = strstr(sourceStart, "Path(");
+    if (pathStart == NULL) {
+        return "COSMIC wallpaper source is not a Path value";
+    }
+
+    pathStart += strlen("Path(");
+    while (*pathStart == ' ' || *pathStart == '\t') {
+        ++pathStart;
+    }
+
+    if (*pathStart != '\'' && *pathStart != '"') {
+        return "COSMIC wallpaper Path format is invalid";
+    }
+
+    char quote = *pathStart;
+    ++pathStart;
+    const char* pathEnd = strchr(pathStart, quote);
+    if (pathEnd == NULL || pathEnd == pathStart) {
+        return "COSMIC wallpaper path is empty";
+    }
+
+    ffStrbufAppendNS(result, (uint32_t) (pathEnd - pathStart), pathStart);
+    return NULL;
+}
+
 const char* ffDetectWallpaper(FFstrbuf* result) {
+    const FFDisplayServerResult* wm = ffConnectDisplayServer();
+    if (ffStrbufIgnCaseEqualS(&wm->wmPrettyName, FF_WM_PRETTY_COSMIC_COMP)) {
+        return detectCosmicComp(result);
+    }
+
     const FFstrbuf* wallpaper = NULL;
     const FFGTKResult* gtk = ffDetectGTK4();
     if (gtk->wallpaper.length) {