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Javafx- Mouse click event that undoes what the previous mouse click did

So I currently have a 3x3 gridpane of which I add a pane with a white background to each space on the grid.
What I am trying to do is have it so that if a user clicks on one of these spaces, the white pane will change to another color. Then if the user were to click on the space again, the pane would change back to white. If clicked again, then it would change to that color again, and so on.
In short, a click would cause an action, and the next click, and those after it would reverse/undo the previous action.
However, I can only get the initial click to work with this. Everything else I've thought to add to this hasn't worked.
#Override
public void handle(MouseEvent me) {
if (me.getClickCount() == 1) {
pane.setBackground(new Background(new BackgroundFill(Color.RED, CornerRadii.EMPTY, Insets.EMPTY)));}
Any help would be really appreciated!

If it really has to be a Pane, you could try to write a custom Pane which will make it easier for you to control its behaviour:
class MyPane extends Pane{
private Background standard, other;
public MyPane(){
standard = new Background(new BackgroundFill(Color.WHITE, CornerRadii.EMPTY, Insets.EMPTY));
other = new Background(new BackgroundFill(Color.RED, CornerRadii.EMPTY, Insets.EMPTY));
this.setBackground(standard);
}
public void changeColor(){
if(this.getBackground().equals(standard){
this.setBackground(other);
else{
this.setBackground(standard);
}
}
public void setBackground(Background bckgrnd){
this.other = bckgrnd;
}
If you use this class instead of a standard Pane, you are able to control the color changing simply via
#Override
public void handle(MouseEvent me){
myPane.changeColor();
}
If you would use the Rectangleclass, you could use the following code:
#Override
public void handle(MouseEvent me){
if(rectangle.getFill() == standard){
rectangle.setFill(other);
}else{
rectangle.setFill(standard);
}
provided that you defined the 2 Paint variables standard and other, e.g. :
private final Paint standard = Color.WHITE;
private Paint other = Color.RED;
see Color

Javafx listview disable horizontal scrolling

I'm trying to avoid horizontal scrolling in ListView. The ListView instance holds list of HBox items, each item has a different width.
So far I'm using such a cell factory:
public class ListViewCell extends ListCell<Data>
{
#Override
public void updateItem(Data data, boolean empty)
{
super.updateItem(data, empty);
if(empty || data == null){
setGraphic(null);
setText(null);
}
if(data != null)
{
Region region = createRow(data);
region.prefWidthProperty().bind(mListView.widthProperty().subtract(20));
region.maxWidthProperty().bind(mListView.widthProperty().subtract(20));
setGraphic(region);
}
}
}
Unfortunately it is not enough. Usually after adding several items ListView's horizontal scrollbar appears. Even if it seems to be unnecessary.
How can I assure, that ListViewCell will not exceed it's parent width and horizontal scrollbar will not appear?

There is a lot at play here that make customizing ListView horizontal scrollbar behavior difficult to deal with. In addition to that, common misunderstandings on how ListView works can cause other problems.
The main issue to address is that the width of the ListCells will not automatically adapt when the vertical scrollbar becomes visible. Therefore, the moment it is, suddenly the contents are too wide to fit between the left edge of the ListView and the left edge of the vertical scrollbar, triggering a horizontal scrollbar. There is also the default padding of a ListCell as well as the border widths of the ListView itself to consider when determining the proper binding to set.
The following class that extends ListView:
public class WidthBoundList extends ListView {
private final BooleanProperty vbarVisibleProperty = new SimpleBooleanProperty(false);
private final boolean bindPrefWidth;
private final double scrollbarThickness;
private final double sumBorderSides;
public WidthBoundList(double scrollbarThickness, double sumBorderSides, boolean bindPrefWidth) {
this.scrollbarThickness = scrollbarThickness;
this.sumBorderSides = sumBorderSides;
this.bindPrefWidth = bindPrefWidth;
Platform.runLater(()->{
findScroller();
});
}
private void findScroller() {
if (!this.getChildren().isEmpty()) {
VirtualFlow flow = (VirtualFlow)this.getChildren().get(0);
if (flow != null) {
List<Node> flowChildren = flow.getChildrenUnmodifiable();
int len = flowChildren .size();
for (int i = 0; i < len; i++) {
Node n = flowChildren .get(i);
if (n.getClass().equals(VirtualScrollBar.class)) {
final ScrollBar bar = (ScrollBar) n;
if (bar.getOrientation().equals(Orientation.VERTICAL)) {
vbarVisibleProperty.bind(bar.visibleProperty());
bar.setPrefWidth(scrollbarThickness);
bar.setMinWidth(scrollbarThickness);
bar.setMaxWidth(scrollbarThickness);
} else if (bar.getOrientation().equals(Orientation.HORIZONTAL)) {
bar.setPrefHeight(scrollbarThickness);
bar.setMinHeight(scrollbarThickness);
bar.setMaxHeight(scrollbarThickness);
}
}
}
} else {
Platform.runLater(()->{
findScroller();
});
}
} else {
Platform.runLater(()->{
findScroller();
});
}
}
public void bindWidthScrollCondition(Region node) {
node.maxWidthProperty().unbind();
node.prefWidthProperty().unbind();
node.maxWidthProperty().bind(
Bindings.when(vbarVisibleProperty)
.then(this.widthProperty().subtract(scrollbarThickness).subtract(sumBorderSides))
.otherwise(this.widthProperty().subtract(sumBorderSides))
);
if (bindPrefWidth) {
node.prefWidthProperty().bind(node.maxWidthProperty());
}
}
}
Regarding your code, your bindings could cause problems. A ListCell's updateItem() method is not only called when the ListCell is created. A ListView can contain a pretty large list of data, so to improve the performance only the ListCells scrolled into view (and possibly a few before and after) need their graphic rendered. The updateItem() method handles this. In your code, a Region is being created over and over again and each and every one of them is being bound to the width of your ListView. Instead, the ListCell itself should be bound.
The following class extends ListCell and the method to bind the HBox is called in the constructor:
public class BoundListCell extends ListCell<String> {
private final HBox hbox;
private final Label label;
public BoundListCell(WidthBoundList widthBoundList) {
this.setPadding(Insets.EMPTY);
hbox = new HBox();
label = new Label();
hbox.setPadding(new Insets(2, 4, 2, 4));
hbox.getChildren().add(label);
widthBoundList.bindWidthScrollCondition(this);
}
#Override
public void updateItem(String data, boolean empty) {
super.updateItem(data, empty);
if (empty || data == null) {
label.setText("");
setGraphic(null);
setText(null);
} else {
label.setText(data);
setGraphic(hbox);
}
}
}
The scrollbarThickness parameter of WidthBoundList constructor has been set to 12. The sumBorderSides parameter has been set to 2 because my WidthBoundList has a one pixel border on the right and left. The bindPrefWidth parameter has been set to true to prevent the horizontal scroller from showing at all (labels have ellipses, any non-text nodes that you might add to the hbox will simply be clipped). Set bindPrefWidth to false to allow a horizontal scrollbar, and with these proper bindings it should only show when needed. An implementation:
private final WidthBoundList myListView = new WidthBoundList(12, 2, true);
public static void main(final String... a) {
Application.launch(a);
}
#Override
public void start(final Stage primaryStage) throws Exception {
myListView.setCellFactory(c -> new BoundListCell(myListView));
VBox vBox = new VBox();
vBox.setFillWidth(true);
vBox.setAlignment(Pos.CENTER);
vBox.setSpacing(5);
Button button = new Button("APPEND");
button.setOnAction((e)->{
myListView.getItems().add("THIS IS LIST ITEM NUMBER " + myListView.getItems().size());
});
vBox.getChildren().addAll(myListView, button);
myListView.maxWidthProperty().bind(vBox.widthProperty().subtract(20));
myListView.prefHeightProperty().bind(vBox.heightProperty().subtract(20));
primaryStage.setScene(new Scene(vBox, 200, 400));
primaryStage.show();
}

Pilling two obj with OnMousePressed on top of each other in javafx

Been trying around and searching but couldn't find any solution, so I finally decided to give up and ask further...
Creating a javafx app, I load tiles in a TilePane.
This tiles are clickable and lead to a details page of their respective content.
On each tile, if they do belong to a certain pack, I do display the pack name, that is also clickable and lead to a page showing that specific pack content.
So that means the container, the tile, that is a Pane is clickable and on top of it I have a Label that is claickable also. What happens is when I do click the Label, it also triggers the Pane onMousePressed()... Here is a part of the tile creation code, the part focused on the onMousePressed(). I tried to make the Pane react by double click and the Label by single, it works, but I want to Pane to open with a single click.
I would be more than thankfull for any ideas how to solve that.
public DownloadTile (Downloadable upload, MainApp mainApp) {
_mainApp = mainApp;
_upload = upload;
_tile = new Pane();
_tile.setPrefHeight(100);
_tile.setPrefWidth(296);
_tile.setStyle("-fx-background-color: #ffffff;");
_tile.setCursor(Cursor.HAND);
}
public void refresh() {
_tile.getChildren().clear();
_tile.setOnMousePressed(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) {
if (event.isPrimaryButtonDown() /*&& event.getClickCount() == 2*/) {
_mainApp.showDownloadDialog(dt, _upload);
}
}
});
if (_upload.getPack() != null) {
Label pack = new Label();
pack.setText(_upload.getPack());
pack.getStyleClass().add("pack-link");
pack.setCursor(Cursor.HAND);
pack.relocate(10, 48);
_tile.getChildren().add(pack);
pack.setOnMousePressed(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) {
if (event.isPrimaryButtonDown()) {
_mainApp.showPackPage(_upload);
}
}
});
}
}

Your label will receive the mouseclick first (since it's on top), so after you have processed the click, you can stop it from being passed down the chain using 'consume':
pane.setOnMouseClicked(
(Event event) -> {
// process your click here
System.out.println("Panel clicked");
pane.requestFocus();
event.consume();
};

Java / JavaFX getting around final or effectively final, is this a good approach?

this feels like I am cheating or doing something wrong. I am a Java student working on a simple JavaFX project.
As I loop through and create buttons in a flowPane, I was having trouble using the loop counter i inside an inner class. It's the part where I assign event handlers. I have dealt with this issue before, I get the difference between "final" and "effectively final" so I don't believe I am asking that.
It's just that creating this copy of i by using "int thisI = i" just feels wrong, design-wise. Is there not a better way to do this? I looked into lambdas and they also have the "final or effectively final" requirement.
Here's my code, any level or criticism or suggestion for improvement is welcome, thanks!
private FlowPane addFlowPaneCenter() {
FlowPane flow = new FlowPane();
flow.setPadding(new Insets(0, 0, 0, 0));
flow.setVgap(0);
flow.setHgap(0);
flow.setPrefWrapLength(WIDTH_OF_CENTER); // width of function buttons
Button centerButtons[] = new Button[NUM_BUTTONS];
ImageView centerImages[] = new ImageView[NUM_BUTTONS];
for (int i=0; i < NUM_BUTTONS; i++) {
centerImages[i] = new ImageView(
new Image(Calculator.class.getResourceAsStream(
"images/button-"+(i)+".png")));
centerButtons[i] = new Button();
centerButtons[i].setGraphic(centerImages[i]);
centerButtons[i].setPadding(Insets.EMPTY);
centerButtons[i].setId("button-"+(i));
flow.getChildren().add(centerButtons[i]);
// add a drop shadow on mouseenter
DropShadow shadow = new DropShadow();
// ***** here's the workaround is this really a good approach
// to use this in the inner class instead of i? thanks *****
int thisI = i;
// set event handlers for click, mousein, mouseout
centerButtons[i].setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
// change graphic of button to down graphic
ImageView downImage = new ImageView(new
Image(Calculator.class.getResourceAsStream(
"images/button-"+(thisI)+"D.png")));
// call function to effect button press
System.out.println("Button click");
// change graphic back
centerButtons[thisI].setGraphic(centerImages[thisI]);
}});
centerButtons[i].addEventHandler(MouseEvent.MOUSE_ENTERED,
new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent e) {
centerButtons[thisI].setEffect(shadow);
}
});
centerButtons[i].addEventHandler(MouseEvent.MOUSE_EXITED,
new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent e) {
centerButtons[thisI].setEffect(null);
}
});
}
return flow;
}

You can remove the arrays centerButtons and centerImages completely. Instead create local variables for the image and the button within the loop and use those, e.g.
final ImageView image = new ImageView(...);
final Button button = new Button();
button.setGraphic(centerImages[i]);
...
You can use the local variables in your eventhandlers, e.g.
button.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
...
// change graphic back
button.setGraphic(image);
}});
Two minor improvements I noticed:
Try to avoid creating an Image more than once, because every time you create an Image, the actual data will be loaded again. Your handler will create a new Image for each click. I usually create Images in static final fields.
Event handlers are a nice opportunity to practice lambda expressions. :)

Add touch gestures to legacy swing application

I have a legacy swing application that I need to add touch gestures to,specifically pinch to zoom and touch and drag.
I tried the SwingNode of JDK 8 and I can run the swing application there, but the display performance was cut by more than 50% which won't work. SwingTextureRenderer in MT4J has the same issue and that is without even trying to redispatch touch events as mouse events.
I thought about a glass pane approach using a JavaFX layer on top and capturing the touch events and attempting to dispatch them as mouse events to the Swing app underneath.
Does anyone have an alternative approach? The target platform is windows 8.
Bounty coming as soon as Stackoverflow opens it up. I need this one pretty rapidly.
EDIT:
Here is what I tried with SwingNode (the mouse redispatch didn't work). The SwingNode stuff might be a distraction from the best solution so ignore this if you have a better idea for getting touch into swing:
#Override
public void start(Stage stage) {
final SwingNode swingNode = new SwingNode();
createAndSetSwingContent(swingNode);
StackPane pane = new StackPane();
pane.getChildren().add(swingNode);
stage.setScene(new Scene(pane, 640, 480));
stage.show();
}
private void createAndSetSwingContent(final SwingNode swingNode) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
UILib.setPlatformLookAndFeel();
// create GraphViewTouch
String datafile = null;
String label = "label";
final JPanel frame = GraphView.demoFrameless(datafile, label);
swingNode.setContent(frame);
swingNode.setOnZoom(new EventHandler<ZoomEvent>() {
#Override public void handle(ZoomEvent event) {
MouseWheelEvent me = new MouseWheelEvent(frame, 1, System.currentTimeMillis(), 0, (int)Math.round(event.getSceneX()), (int)Math.round(event.getSceneY()), (int)Math.round(event.getScreenX()), (int)Math.round(event.getScreenY()), (int)Math.round(event.getZoomFactor()), false, MouseWheelEvent.WHEEL_UNIT_SCROLL, (int)Math.round(event.getZoomFactor()), (int)Math.round(event.getZoomFactor()), event.getZoomFactor());
frame.dispatchEvent(me);
System.out.println("GraphView: Zoom event" +
", inertia: " + event.isInertia() +
", direct: " + event.isDirect());
event.consume();
}
});
}
});
}

You can use JNA to parse the messages from Windows.
Some documentation on the multi touch events from Microsoft:
https://learn.microsoft.com/en-us/windows/desktop/wintouch/wm-touchdown
Some documentation on how to do it in Java and sample code:
https://github.com/fmsbeekmans/jest/wiki/Native-Multitouch-for-AWT-component-(Windows)

hmm... this is a tough one, but there is a chance.
What I would do is make multiple MouseListener classes (relative to the number of mouse events you want to pick up), and than create some sort of system to detect certain adjustments, eg. (zoom)
1st listener:
public void mousePressed(MouseEvent e){
//Set click to true
clk = true;
//set first mouse position
firstPos = window.getMousePosition();
}
public void mouseReleased(MouseEvent e){
//set second mouse position
secondPos = window.getMousePosition();
}
Second Listener
public void mousePressed(MouseEvent e){
//set clicked to true
clk = true;
//set first mouse position (listener 2)
firstPos = window.getMousePosition();
}
public void mouseReleased(MouseEvent e){
//set second mouse position
secondPos = window.getMousePosition();
}
Main handler
if(Listener1.get1stMousePos() < Listener1.get2ndMousePos() && Listener2.get1stMousePos() < Listener2.get2ndMousePos() && Listener1.clk && Listener2.clk){
zoomMethod((Listener1.get1stMousePos - Listener1.get2ndMousePos()) + (Listener1.get1stListener2.get2ndMousePos());
}
And than just do this to add it to the window:
window.addMouseListener(Listener1);
window.addMouseListener(Listener2);
Hope you find a way.

For the pinch-to-zoom:
Try the GestureMagnificationListener by guigarage.com. It provides a method:
public void magnify(GestureMagnificationEvent me){...}