Add reusable bounded integer inputs for JavaFX editors

2026-11-07 16:10:54 +01:00
parent 188a6f38a5
commit bb90b2c060
2 changed files with 65 additions and 0 deletions
@@ -0,0 +1,51 @@
+package de.neitzel.fx.control;
+
+import javafx.scene.control.Spinner;
+import javafx.scene.control.TextFormatter;
+
+/** Factories for bounded integer inputs that commit valid typing immediately. */
+public final class IntegerSpinners {
+    private IntegerSpinners() {
+    }
+
+    /**
+     * Creates a nonnegative bounded input. Valid typing immediately updates its value;
+     * incomplete values below the minimum revert to the committed value on focus loss.
+     *
+     * @param min inclusive nonnegative minimum
+     * @param max inclusive maximum
+     * @param value initial value
+     * @return an editable spinner
+     */
+    public static Spinner<Integer> nonNegative(int min, int max, int value) {
+        if (min < 0 || max < min || value < min || value > max) {
+            throw new IllegalArgumentException("Invalid nonnegative spinner bounds or value");
+        }
+        Spinner<Integer> spinner = new Spinner<>(min, max, value);
+        spinner.setEditable(true);
+        spinner.getEditor().setTextFormatter(new TextFormatter<String>(change -> {
+            String text = change.getControlNewText();
+            if (!text.matches("\\d{0,10}")) {
+                return null;
+            }
+            if (!text.isEmpty() && Long.parseLong(text) > max) {
+                return null;
+            }
+            return change;
+        }));
+        spinner.getEditor().textProperty().addListener((observable, old, text) -> {
+            if (!text.isEmpty()) {
+                int parsed = Integer.parseInt(text);
+                if (parsed >= min) {
+                    spinner.getValueFactory().setValue(parsed);
+                }
+            }
+        });
+        spinner.getEditor().focusedProperty().addListener((observable, old, focused) -> {
+            if (!focused) {
+                spinner.getEditor().setText(spinner.getValue().toString());
+            }
+        });
+        return spinner;
+    }
+}