java - In WebView, perform zoom in and out function while I press + and - key

Question

As I'm making JavaFX application three in three WebView in my application, I have to perform zoom in and out function while I press + and - key. Code is given below:

  StackPane root = new StackPane();

        HBox hbox = new HBox(30); // create a HBox to hold 2 vboxes        

        // create a vbox with a textarea that grows vertically
        VBox vbox = new VBox(10);  
        //Label label1 = new Label("");

        final WebView img = new WebView();
         final WebEngine Img = img.getEngine();
         final DoubleProperty zoomProperty = new SimpleDoubleProperty(200);
 img.addEventFilter(KeyEvent.KEY_RELEASED, (KeyEvent e) -> {
            if (e.getCode() == KeyCode.ADD || e.getCode() == KeyCode.EQUALS || e.getCode() == KeyCode.PLUS) {
                System.out.println("YES");
                    zoomProperty.set(zoomProperty.get() * 1.1);
            }
            else if(e.getCode()== KeyCode.SUBTRACT||e.getCode() == KeyCode.MINUS ){
                System.out.println("YES");
                zoomProperty.set(zoomProperty.get() / 1.1);
            }
        });

As through this code im able to listen to the key but zoom in and zoom out is not working. Please help as I have to change mouse pointer to double headed arrow then listen to arrow and + and - key for zoom in and out.

Answer 1

It looks you want to alter the zoom state of the WebView based on an event, so you should update the zoom property held by the WebView itself. Starting form this example, I added the following EventFilter based on your example. It appears to work as expected.

webView.addEventFilter(KeyEvent.KEY_RELEASED, (KeyEvent e) -> {
    if (e.getCode() == KeyCode.ADD || e.getCode() == KeyCode.EQUALS
            || e.getCode() == KeyCode.PLUS) {
        System.out.println("+");
        webView.setZoom(webView.getZoom() * 1.1);
    }
    else if(e.getCode() == KeyCode.SUBTRACT || e.getCode() == KeyCode.MINUS ){
        System.out.println("-");
        webView.setZoom(webView.getZoom() / 1.1);
    }
});