fix: prevent duplicate app launches by adding QML click debouncing and single-instance Python launcher script

quickshell/services/TaskService.qml

@@ -139,51 +139,25 @@ Item {
         }
     }
 
+    property real lastLaunchTime: 0
+    property string lastLaunchCmd: ""
+
     function launchApp(cmd) {
         if (!cmd) return;
         let cleanCmd = cmd.trim()
         if (cleanCmd === "") return;
 
+        let now = Date.now()
+        if (cleanCmd === lastLaunchCmd && (now - lastLaunchTime) < 600) {
+            return; // Ignore rapid double-clicks within 600ms
+        }
+        lastLaunchTime = now
+        lastLaunchCmd = cleanCmd
+
         let execCmd = cleanCmd.replace(/%[a-zA-Z]/g, "").trim()
         root.activeAppId = execCmd.toLowerCase()
 
-        if (execCmd.startsWith("flatpak run ") || execCmd.includes("flatpak ")) {
+        Quickshell.execDetached(["python3", Quickshell.env("HOME") + "/.config/quickshell/services/python/launch_app.py", cleanCmd])
-            Quickshell.execDetached(["sh", "-c", execCmd + " &"])
-            return;
-        }
-
-        let baseName = execCmd.replace(/\.desktop$/, "").trim()
-
-        // Build universal Flatpak + desktop launcher + native binary fallback chain
-        let shellCmd = ""
-        if (baseName.startsWith("org.") || baseName.startsWith("io.") || baseName.startsWith("com.") || baseName.startsWith("app.")) {
-            let shortName = baseName.split(".").pop()
-            shellCmd = "flatpak run " + baseName + " 2>/dev/null || flatpak run " + shortName + " 2>/dev/null || gtk-launch " + baseName + " 2>/dev/null || gtk-launch " + shortName + " 2>/dev/null || " + shortName + " 2>/dev/null || " + execCmd + " &"
-        } else {
-            // Known reverse domain mappings for common Flatpak apps like spotify, feishin, zen, vesktop, discord, etc.
-            let flatpakMapping = {
-                "spotify": "com.spotify.Client",
-                "feishin": "io.github.jeffvli.feishin",
-                "zen": "io.github.zen_browser.zen",
-                "zen-browser": "io.github.zen_browser.zen",
-                "vesktop": "dev.vencord.Vesktop",
-                "discord": "com.discordapp.Discord",
-                "code": "com.visualstudio.code",
-                "vscodium": "com.vscodium.codium",
-                "obs": "com.obsproject.Studio",
-                "steam": "com.valvesoftware.Steam",
-                "heroic": "com.heroicgameslauncher.hgl"
-            }
-
-            let mappedFlatpak = flatpakMapping[baseName.toLowerCase()] || ""
-            if (mappedFlatpak !== "") {
-                shellCmd = "flatpak run " + mappedFlatpak + " 2>/dev/null || flatpak run " + baseName + " 2>/dev/null || gtk-launch " + mappedFlatpak + " 2>/dev/null || gtk-launch " + baseName + " 2>/dev/null || " + execCmd + " &"
-            } else {
-                shellCmd = "flatpak run " + baseName + " 2>/dev/null || gtk-launch " + baseName + " 2>/dev/null || " + execCmd + " &"
-            }
-        }
-
-        Quickshell.execDetached(["sh", "-c", shellCmd])
     }
 
     function closeApp(appId) {

quickshell/services/python/launch_app.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+import sys
+import os
+import subprocess
+import shutil
+import re
+
+def launch():
+    if len(sys.argv) < 2:
+        return
+    cmd = sys.argv[1].strip()
+    if not cmd:
+        return
+
+    # Strip desktop field codes (%u, %U, %f, %F, etc.)
+    clean_cmd = re.sub(r'%[a-zA-Z]', '', cmd).strip()
+    base_name = clean_cmd.replace('.desktop', '').strip()
+    lower_name = base_name.lower()
+
+    flatpak_mappings = {
+        "spotify": "com.spotify.Client",
+        "feishin": "io.github.jeffvli.feishin",
+        "zen": "io.github.zen_browser.zen",
+        "zen-browser": "io.github.zen_browser.zen",
+        "vesktop": "dev.vencord.Vesktop",
+        "discord": "com.discordapp.Discord",
+        "code": "com.visualstudio.code",
+        "vscodium": "com.vscodium.codium",
+        "obs": "com.obsproject.Studio",
+        "steam": "com.valvesoftware.Steam",
+        "heroic": "com.heroicgameslauncher.hgl"
+    }
+
+    # 1. Flatpak launch check (launch exactly once if Flatpak ID is installed)
+    candidates_flatpak = []
+    if base_name in flatpak_mappings:
+        candidates_flatpak.append(flatpak_mappings[base_name])
+    if lower_name in flatpak_mappings:
+        candidates_flatpak.append(flatpak_mappings[lower_name])
+    if base_name.startswith(("org.", "io.", "com.", "app.")):
+        candidates_flatpak.append(base_name)
+
+    for fp_id in candidates_flatpak:
+        check = subprocess.run(["flatpak", "info", fp_id], capture_output=True, text=True)
+        if check.returncode == 0:
+            subprocess.Popen(["flatpak", "run", fp_id], start_new_session=True)
+            return
+
+    # 2. GTK Desktop launcher check
+    if shutil.which("gtk-launch"):
+        for gtk_id in [base_name, f"{base_name}.desktop"]:
+            res = subprocess.run(["gtk-launch", gtk_id], capture_output=True, text=True)
+            if res.returncode == 0:
+                return
+
+    # 3. Direct binary execution
+    bin_name = clean_cmd.split()[0]
+    if shutil.which(bin_name):
+        subprocess.Popen(clean_cmd, shell=True, start_new_session=True)
+        return
+
+    # 4. Fallback execution
+    subprocess.Popen(f"{clean_cmd} &", shell=True, start_new_session=True)
+
+if __name__ == '__main__':
+    launch()