Just another update

Task/GUI-enabling-disabling-of-controls/Java/gui-enabling-disabling-of-controls-2.java

@@ -0,0 +1,78 @@
+import javafx.application.Application;
+import javafx.beans.property.LongProperty;
+import javafx.beans.property.SimpleLongProperty;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.control.TextField;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.VBox;
+import javafx.stage.Stage;
+import javafx.util.converter.NumberStringConverter;
+
+public class InteractFX extends Application {
+
+    public static void main(String[] args) {
+        launch(args);
+    }
+
+    @Override
+    public void start(Stage stage) throws Exception {
+
+        TextField input = new TextField("0"){
+            // only accept numbers as input
+            @Override public void replaceText(int start, int end, String text) {
+                if (text.matches("[0-9]*")) {
+                    super.replaceText(start, end, text);
+                }
+            }
+
+            // only accept numbers on copy+paste
+            @Override public void replaceSelection(String text) {
+                if (text.matches("[0-9]*")) {
+                    super.replaceSelection(text);
+                }
+            }
+        };
+
+        // when the textfield is empty, replace text with "0"
+        input.textProperty().addListener((observable, oldValue, newValue)->{
+            if(newValue == null || newValue.trim().isEmpty()){
+                input.setText("0");
+            }
+        });
+
+
+        // get a bi-directional bound long-property of the input value
+        LongProperty inputValue = new SimpleLongProperty();
+        input.textProperty().bindBidirectional(inputValue, new NumberStringConverter());
+
+        // textfield is disabled when the current value is other than "0"
+        input.disableProperty().bind(inputValue.isNotEqualTo(0));
+
+
+        Button increment = new Button("Increment");
+        increment.setOnAction(event-> inputValue.set(inputValue.get() + 1));
+
+        // incr-button is disabled when input is >= 0
+        increment.disableProperty().bind(inputValue.greaterThanOrEqualTo(10));
+
+
+        Button decrement = new Button("Decrement");
+        decrement.setOnAction(event-> inputValue.set(inputValue.get() - 1));
+
+        // decrement button is disabled when input is <=0
+        decrement.disableProperty().bind(inputValue.lessThanOrEqualTo(0));
+
+
+        // layout
+        VBox root = new VBox();
+        root.getChildren().add(input);
+        HBox buttons = new HBox();
+        buttons.getChildren().addAll(increment,decrement);
+        root.getChildren().add(buttons);
+
+        stage.setScene(new Scene(root));
+        stage.sizeToScene();
+        stage.show();
+    }
+}