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Java

Posted by Ferin Patel
Ferin Patel
6,832 Points

Javafx -- dynamically adding buttons and calling setonAction() on it

So I am currently doing a personal project where I encountered this situation... A user inputs a data (numeric) this generates a no. of Labels and buttons on to a javafx scene.. Now What i did is inside a controller's Initialization interface I started a for loop that run to the size of data (numeric) that the user inputs, inside the loop I was able to create labels and buttons dynamically...for instance this way -- gridPane is a id of GridPane from an fxml file...

@FXML private GridPane gridpane; . <....Some Code goes here...> . for (int i=0 ; i < userInput ; i++){ gridPane.add (new Label (String.valueOf(101+i)) , 0, i ) ; gridPane.add (new Button ("Describe"), 1, i ) ; }

Now my question is how do I call setOnAction() on this buttons...

2 Answers

Ferin Patel
Ferin Patel
6,832 Points

Ok I figured even efficient method to solve this solution...

I created an arrayList added buttons to it then added on gridPane and now I can use ..

ArrayList<Button> buttons = new ArrayList<>();

gridPane.add(buttons.get(i), 1,i);

buttons.get(i).setOnAction( e -> { .. insert if conditions here.. or search for what button user clicked in a for each loop via e.getsource() function...}

Seth Kroger
Seth Kroger
56,416 Points
Seth Kroger
Seth Kroger
56,416 Points

You could store the Button on each loop in a local variable so you can both add it to the GridPane and call setOnAction. 

Button button = new Button("Describe");
gridPane.add (button, 1, i );
button.setOnAction();

Also GridPane as a Parent has a getManagedChildern() method that returns a List of what's inside.

Ferin Patel
Ferin Patel
6,832 Points

yup but then how should I know which button user clicked ... say for example userInuput was 5 then we get 5 buttons but then how can i know user clicked 2nd button?? Hope you understand what I'm asking here now..