javafx-gestures-touch-input

name	javafx-gestures-touch-input
description	Handle JavaFX gestures, pinch-to-zoom, panning, and multi-touch interaction with explicit transform ownership.
triggers	["javafx pinch zoom","gesturefx","javafx touch input","tuiofx"]
compatibility	{"java":"17+","javafx":"21+"}
category	ui-advanced
tags	["gestures","touch","zoom","pan","input"]
metadata	{"scope":"repository","maturity":"starter"}
allowed-tools	["view","rg","apply_patch"]

JavaFX Gestures and Touch Input

Use this skill when the UI needs touch-aware interaction: zoomable viewports, pannable canvases, or multi-touch surfaces. Libraries such as GestureFX and TuioFX are useful once gestures become central to the product.

Example

import javafx.application.ConditionalFeature;
import javafx.application.Platform;
import javafx.scene.image.ImageView;
import javafx.scene.input.ScrollEvent;
import javafx.scene.layout.StackPane;

public class ZoomPane extends StackPane {

    public ZoomPane(ImageView imageView) {
        getChildren().add(imageView);

        addEventFilter(ScrollEvent.SCROLL, event -> {
            if (!event.isControlDown()) {
                return;
            }

            double factor = event.getDeltaY() > 0 ? 1.1 : 0.9;
            imageView.setScaleX(imageView.getScaleX() * factor);
            imageView.setScaleY(imageView.getScaleY() * factor);
            event.consume();
        });

        if (Platform.isSupported(ConditionalFeature.INPUT_TOUCH)) {
            setStyle("-fx-background-color: derive(cornflowerblue, 80%);");
        }
    }
}

Setup notes

• Centralize transform state so zoom, pan, and selection logic do not fight each other.
• Keep pointer, mouse, and touch interactions aligned instead of implementing separate inconsistent behaviors.
• Use library support when gesture orchestration becomes more complex than a single zoomable pane.

Gotchas

• Gesture input availability varies by hardware and target.
• Coordinate transforms affect hit-testing, overlays, and annotation logic.
• Touch-friendly targets need larger hit areas and clearer feedback than mouse-first UIs.