feature: Add action for showing the desktop site

src/contents/ui/WebView.qml

@@ -37,25 +37,37 @@ WebEngineView {
     /**
       * User agent used on mobile devices
       */
-    property string mobileUserAgent: "Mozilla/5.0 (Linux; Plasma Mobile, like Android 9.0 ) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/69.0.3497.128 Mobile Safari/537.36"
+    readonly property string mobileUserAgent: "Mozilla/5.0 (Linux; Plasma Mobile, like Android 9.0 ) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/75.0.3770.116 Mobile Safari/537.36"
 
     /**
       * User agent used on desktop devices,
       * Defaults to QtWebEngine's default (it is only supported on desktop devices by Qt currently)
       */
-    property string desktopUserAgent: profile.httpUserAgent
+    readonly property string desktopUserAgent: "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) QtWebEngine/5.14.0 Chrome/75.0.3770.116 Safari/537.36"
 
     width: pageWidth
     height: pageHeight
 
-    profile {
-        httpUserAgent: {
-            if (Kirigami.Settings.isMobile)
-                return mobileUserAgent
-            else
-                return desktopUserAgent
+    state: Kirigami.Settings.isMobile ? "mobile" : "desktop"
+
+    states: [
+        State {
+            name: "mobile"
+            PropertyChanges {
+                target: webEngineView
+                profile.httpUserAgent: mobileUserAgent
+            }
+        },
+        State {
+            name: "desktop"
+            PropertyChanges {
+                target: webEngineView
+                profile.httpUserAgent: desktopUserAgent
+            }
         }
+    ]
 
+    profile {
         offTheRecord: rootPage.privateMode
 
         onDownloadRequested: {

src/contents/ui/webbrowser.qml

@@ -273,6 +273,27 @@ Kirigami.ApplicationWindow {
                     request.bookmarked = true;
                     browserManager.addBookmark(request);
                 }
+            },
+            Kirigami.Action {
+                icon.name: "computer"
+                text: i18n("Show desktop site")
+                checkable: true
+                checked: {
+                    if (currentWebView.state === "mobile") {
+                        false
+                    } else if (currentWebView.state === "desktop") {
+                        true
+                    }
+                }
+                onTriggered: {
+                    if (currentWebView.state === "desktop") {
+                        currentWebView.state = "mobile"
+                    } else if (currentWebView.state === "mobile") {
+                        currentWebView.state = "desktop"
+                    }
+
+                    currentWebView.reload()
+                }
             }
         ]