more doc

python/gui/auto_generated/qgisinterface.sip.in

@@ -602,7 +602,9 @@ status bar (do not use the native Qt statusBar() method).
 
     virtual void takeAppScreenShots( const QString &saveDirectory, const int categories = 0 );
 %Docstring
-Take screenshots for the user documentation
+Take screenshots for user documentation
+@param saveDirectory path were the screenshots will be saved
+@param categories an int as a flag value of QgsAppScreenShots.Categories
 
 .. versionadded:: 3.4
 %End

src/app/qgisapp.h

@@ -696,7 +696,11 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     //! Returns pointer to the identify map tool - used by identify tool in 3D view
     QgsMapToolIdentifyAction *identifyMapTool() const { return mMapTools.mIdentify; }
 
-    //! Take screenshots for user documentation
+    /**
+     * Take screenshots for user documentation
+     * @param saveDirectory path were the screenshots will be saved
+     * @param categories an int as a flag value of QgsAppScreenShots::Categories
+     */
     void takeAppScreenShots( const QString &saveDirectory, const int categories = 0 );
 
   public slots:

src/gui/qgisinterface.h

@@ -529,7 +529,9 @@ class GUI_EXPORT QgisInterface : public QObject
     virtual QgsStatusBar *statusBarIface() = 0;
 
     /**
-     * Take screenshots for the user documentation
+     * Take screenshots for user documentation
+     * @param saveDirectory path were the screenshots will be saved
+     * @param categories an int as a flag value of QgsAppScreenShots::Categories
      * \since QGIS 3.4
      */
     virtual void takeAppScreenShots( const QString &saveDirectory, const int categories = 0 ) {Q_UNUSED( saveDirectory ); Q_UNUSED( categories );}