GestureFX

A lightweight gesture enabled pane for JavaFX

Features

• Accepts any Node or implementations of net.kurobako.gesturefx.GesturePane.Transformable
• Pinch-to-zoom
• Configurable behavior for trackpad events
• Works with touch screen devices
• Works in Swing via JFXPanel
• Zoom/scroll to coordinate with animations
• Mostly works in SceneBuilder*
• Zero dependency
• Works with both Java 8 and OpenJFX 11+

For comparison, this library is similar to PhotoView for Android but supports gestures on any Node subclass.

*SceneBuilder renders the control properly and all the exposed properties are editable in the sidebar. Unfortunately, I have no idea how to make SceneBuilder treat this control as a container/control so the only way to add GesturePane to your FXML is to add it in XML and then open it in SceneBuilder. Pull requests welcome on solving this.

How to use

For Maven users, add the following to pom

<dependency>
    <groupId>net.kurobako</groupId>
    <artifactId>gesturefx</artifactId>
    <version>0.6.0</version>
</dependency>

You also need to add jcenter repo to your pom:

<repositories>
    <repository>
        <id>jcenter</id>
        <url>https://jcenter.bintray.com/</url>
    </repository>
</repositories>

For SBT

"net.kurobako" % "gesturefx" % "0.6.0"    

And also jcenter:

resolvers ++= Seq(Resolver.jcenterRepo)

Alternatively, you can download the jar here and add it to your classpath. This library has no dependencies so you do not need to download anything else.

Version history in available in CHANGELOG.md

Quick start

Adding an ImageView to GesturePane:

Node node = new ImageView(getClass().getResource("/lena.png").toExternalForm());
GesturePane pane = new GesturePane(node);

Translate or zoom:

GesturePane pane = //...

// zoom to 1x 
pane.zoomTo(1);

// centre on point [42,42] 
pane.centreOn(new Point2D(42, 42));

And with animations:

pane.animate(Duration.millis(200)).zoomTo(1);
// animate with some options
pane.animate(Duration.millis(200))
		.interpolateWith(Interpolator.EASE_BOTH)
		.beforeStart(() -> System.out.println("Starting..."))
		.afterFinished(() -> System.out.println("Done!"))
		.centreOn(new Point2D(42, 42));

Double click to zoom in:

// zoom*2 on double-click
GesturePane pane = //...
pane.setOnMouseClicked(e -> {
	if (e.getButton() == MouseButton.PRIMARY && e.getClickCount() == 2) {
		Point2D pivotOnTarget = pane.targetPointAt(new Point2D(e.getX(), e.getY()))
				                        .orElse(pane.targetPointAtViewportCentre());
		// increment of scale makes more sense exponentially instead of linearly 
		pane.animate(Duration.millis(200))
				.interpolateWith(Interpolator.EASE_BOTH)
				.zoomBy(pane.getCurrentScale(), pivotOnTarget);
	}
});

For more interesting examples, take a look at the samples.

Samples

Several samples have been included demoing interesting uses of the gesture pane.

JavaFX 8

You can download the sample jar here or clone the project and run:

./mvnw install
./mvnw exec:java -pl gesturefx-sample

OpenJFX 11+

Make sure you have at least JDK 11 installed:

> java -version
openjdk version "11.0.4" 2019-07-16
OpenJDK Runtime Environment 18.9 (build 11.0.4+11)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.4+11, mixed mode, sharing)

Run the sample jar with the following:

java -Dglass.gtk.uiScale=200% --module-path path/to/javafx-sdk-13/lib --add-modules javafx.controls,javafx.fxml,javafx.web,javafx.swing -jar gesturefx-sample-0.6.0-jar-with-dependencies.jar

See https://openjfx.io/openjfx-docs/#install-javafx for more details.

The -Dglass.gtk.uiScale=200% flag is optional if OpenJFX does not detect HiDPI monitors automatically. On Windows the flag should be -Dglass.win.uiScale=N%.

How to build

To ensure the project is usable with Java 8 and OpenJFX, you must build against Java 8.

Prerequisites:

• JDK 8 with JavaFX

Be aware that some OpenJDK distributions does not include JavaFX or have missing webkit libraries which is required for the sample to build.

Clone the project and then in project root:

# *nix:
./mvnw clean package 
# Windows:
mvnw clean package

If JDK 8 is not your main JDK, prepend the correct JAVA_HOME before any maven command (e.g JAVA_HOME=/usr/java/jdk1.8.0_161/ mvn clean compile).

This project uses maven wrapper so you do not need to install maven beforehand.

For testing on new platforms, it is recommended to run tests headful. Add the headful flag to test with real window:

mvnw test -Dheadful

NOTE: Be aware that running the tests headful will spawn actual windows and take over the mouse and keyboard; you will see the test window flicker while different unit tests are invoked.

Release process

1. Commit all changes before release

2. Make sure ${user.home}/.m2/settings.xml exist, if not copy it from maven home (i.e cp usr/share/maven/conf/settings.xml ~/.m2/settings.xml ) and add the following section to <servers></servers>:

   <server>
     <id>bintray-${bintray.user}-maven</id>
     <username>${bintray-username}</username>
     <password>${bintray-api-key}</password>
   </server>

   Look up bintray-api-key and bintray-username in the bintray profile page, also make sure machine has SSH access to GitHub

3. Run mvn release:prepare -DdryRun=true, make sure it succeeds and then run mvn release:clean

4. Run mvn release:prepare, maven will tag and commit the new version. Inspect the commits and do a push, also push the tags via git push --tags

5. Finally, run mvn clean release:perform to create docs and sources and upload to bintray

Motivation

Someone has to do it.

Acknowledgements

Features or designs of this library was originally developed as part of an undergraduate coursework assignment at the University of Bristol.

YourKit supports the GestureFX project with its full-featured Java Profiler. YourKit, LLC is the creator YourKit Java Profiler and YourKit .NET Profiler, innovative and intelligent tools for profiling Java and .NET applications.

Licence

Copyright 2020 WeiChen Lin

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.