I have need to scroll a webview when the user has focus in a different window.

The only way i found to achieve what i needed was via an "unsafe" reflections call. I tried first getting the scrollbar and setting value to it, its value changed but it had no effect on what was shown in the webview.


After a lot of trial and error i finally came up with this solution:

Platform.runLater(new Runnable() {

            @Override
            public void run() {
                try {
                    final Method declaredMethod = webView.getClass().getDeclaredMethod("processKeyEvent", KeyEvent.class);
                    final KeyEvent keyEvent = new KeyEvent(null, null, KeyEvent.KEY_PRESSED, null, null, KeyCode.PAGE_DOWN, false, false, false, false);
                    declaredMethod.setAccessible(true);
                    declaredMethod.invoke(webView, keyEvent);
                } catch (NoSuchMethodException ex) {
                    Logger.getLogger(JavaFXBrowserImplementation.class.getName()).log(Level.SEVERE, null, ex);
                } catch (SecurityException ex) {
                    Logger.getLogger(JavaFXBrowserImplementation.class.getName()).log(Level.INFO, null, ex);
                } catch (IllegalAccessException ex) {
                    Logger.getLogger(JavaFXBrowserImplementation.class.getName()).log(Level.SEVERE, null, ex);
                } catch (IllegalArgumentException ex) {
                    Logger.getLogger(JavaFXBrowserImplementation.class.getName()).log(Level.SEVERE, null, ex);
                } catch (InvocationTargetException ex) {
                    Logger.getLogger(JavaFXBrowserImplementation.class.getName()).log(Level.SEVERE, null, ex);
                }

            }

        });

It should be possible to in some way scroll to a specific x,y coordinate without the use of javascripts or reflection


attempt that change the value of the scrollbar but not what is actually shown in the webview


public ScrollBar getVerticalScrollBar() {
        final Set<Node> nodes = webView.lookupAll(".scroll-bar");
        for (Node node : nodes) {
            if (ScrollBar.class.isInstance(node)) {
                final ScrollBar scroll = (ScrollBar) node;
                if (scroll.getOrientation() == Orientation.VERTICAL) {
                    return scroll;
                }
            }
        }

        return null;
    }
 
    public void scrollPageDown() {
         final ScrollBar scroll = getVerticalScrollBar();

         final double min = scroll.getMin();
         final double max = scroll.getMax();
         final double value = scroll.getValue();
         final double pageHeight = webView.getBoundsInParent().getHeight() - 10;
         final double scrollX = Math.min(max, value + pageHeight);
         System.out.println("scrollPageDown()");
         System.out.println(" min: " + min);
         System.out.println(" max: " + max);
         System.out.println(" value: " + value);

         System.out.println(" pageHeight: " + pageHeight);

         System.out.println(" Math.min(max, value + pageHeight) = " + scrollX);
        Platform.runLater(new Runnable() {
            @Override
            public void run() {
              scroll.setValue(Math.min(max, value + pageHeight));

      }

        });