Only show either the "install tool" or "remove tool" buttons

It doesn't make sense to show both, the compatibility tool is either
installed *or* not installed yet.

launcher/include/compatibilitytoolinstaller.h

@@ -13,16 +13,21 @@ class CompatibilityToolInstaller : public QObject
     QML_ELEMENT
     QML_UNCREATABLE("Use LauncherCore.createCompatInstaller")
 
+    Q_PROPERTY(bool isInstalled READ isInstalled NOTIFY isInstalledChanged)
+
 public:
     explicit CompatibilityToolInstaller(LauncherCore &launcher, QObject *parent = nullptr);
 
     Q_INVOKABLE void installCompatibilityTool();
     Q_INVOKABLE void removeCompatibilityTool();
 
+    bool isInstalled() const;
+
 Q_SIGNALS:
     void installFinished();
     void error(QString message);
     void removalFinished();
+    void isInstalledChanged();
 
 private:
     LauncherCore &m_launcher;

launcher/src/compatibilitytoolinstaller.cpp

@@ -86,6 +86,7 @@ void CompatibilityToolInstaller::installCompatibilityTool()
     compatibilityToolFile.close();
 
     Q_EMIT installFinished();
+    Q_EMIT isInstalledChanged();
 }
 
 void CompatibilityToolInstaller::removeCompatibilityTool()
@@ -108,6 +109,21 @@ void CompatibilityToolInstaller::removeCompatibilityTool()
     }
 
     Q_EMIT removalFinished();
+    Q_EMIT isInstalledChanged();
+}
+
+bool CompatibilityToolInstaller::isInstalled() const
+{
+    const QDir appDataDir = QStandardPaths::standardLocations(QStandardPaths::StandardLocation::HomeLocation)[0];
+    const QDir steamDir = appDataDir.absoluteFilePath(QStringLiteral(".steam"));
+    const QDir steamSteamDir = steamDir.absoluteFilePath(QStringLiteral("steam"));
+    if (!steamSteamDir.exists()) {
+        return false;
+    }
+
+    const QDir compatToolDir = steamSteamDir.absoluteFilePath(QStringLiteral("compatibilitytools.d"));
+    const QDir astraToolDir = compatToolDir.absoluteFilePath(QStringLiteral("astra"));
+    return astraToolDir.exists();
 }
 
 #include "moc_compatibilitytoolinstaller.cpp"

launcher/ui/Settings/CompatibilityToolSetup.qml

@@ -24,29 +24,26 @@ FormCard.FormCardPage {
         FormCard.FormTextDelegate {
             text: i18n("Press the button below to install the compatibility tool for Steam.")
         }
-
-        FormCard.FormDelegateSeparator {
-            below: installToolButton
     }
 
+    FormCard.FormCard {
+        Layout.topMargin: Kirigami.Units.largeSpacing
+
         FormCard.FormButtonDelegate {
             id: installToolButton
 
             text: i18n("Install Tool")
             icon.name: "install"
+            visible: !page.installer.isInstalled
             onClicked: page.installer.installCompatibilityTool()
         }
 
-        FormCard.FormDelegateSeparator {
-            above: installToolButton
-            below: removeToolButton
-        }
-
         FormCard.FormButtonDelegate {
             id: removeToolButton
 
             text: i18n("Remove Tool")
             icon.name: "delete"
+            visible: page.installer.isInstalled
             onClicked: page.installer.removeCompatibilityTool()
         }
     }