@nativescript-community/gesturehandler

@nativescript-community/gesturehandler

Declarative API exposing platform native touch and gesture system to NativeScript.

Table of Contents

• Installation
• API * TypeScript
• GestureRootView
• Overriding Nativescript gestures
• Credits
  • Examples:
• Demos and Development
  • Repo Setup
  • Build
  • Demos
• Contributing
  • Update repo
  • Update readme
  • Update doc
  • Publish
  • modifying submodules
• Questions

Installation

Run the following command from the root of your project:

ns plugin add @nativescript-community/gesturehandler

API

We need to do some wiring when your app starts, so open app.ts and add this before creating any View/App/Frame:

TypeScript

import { install } from '@nativescript-community/gesturehandler';
install();

You create a gesture handler using something like this:

import { GestureHandlerTouchEvent, GestureHandlerStateEvent, GestureStateEventData, GestureTouchEventData, HandlerType, Manager } from '@nativescript-community/gesturehandler';

function onGestureTouch(args: GestureTouchEventData) {
    const { state, extraData, view } = args.data;
    view.translateX = extraData.translationX;
    view.translateY = extraData.translationY;
}
function onGestureState(args: GestureStateEventData) {
    const { state, prevState, extraData, view } = args.data;
    console.log('onGestureState', state, prevState, view, extraData);
}
const manager = Manager.getInstance();
const gestureHandler = manager.createGestureHandler(HandlerType.PAN, 10, {
    shouldCancelWhenOutside: false
});
gestureHandler.on(GestureHandlerTouchEvent, onGestureTouch, this);
gestureHandler.on(GestureHandlerStateEvent, onGestureState, this);
gestureHandler.attachToView(view);

Right now you must not forget to store the gestureHandler somewhere or the gesture won't work on iOS (native object being released). This will be fixed in future versions.

Now about the API. All the gestures for the react counterpart exist with the same options and the same event extraData.

GestureRootView

For the gestures to work correctly we need a root view which knows how to handle the gestures. If using Page (thus Frame) you don't need to do anything. In case you don't (drawer root view, modals, ...) then you can wrap your views in a GestureRootView which inherits GridLayout

Overriding Nativescript gestures

This plugin can also override N gestures completely. This would give much more control over gestures and especially would allow to correctly handle simultaneous gestures likes tap and longpress.

To do that

Credits

This is a port of react-native-gesturehandler. The source is based on the source code by Krzysztof Magiera. Don't hesitate to go and thank him for his work!

Examples:

• Basic
  • A basic example showing that overriding N gestures works, even in modals

Demos and Development

Repo Setup

The repo uses submodules. If you did not clone with --recursive then you need to call

git submodule update --init

The package manager used to install and link dependencies must be pnpm or yarn. npm wont work.

To develop and test: if you use yarn then run yarn if you use pnpm then run pnpm i

Interactive Menu:

To start the interactive menu, run npm start (or yarn start or pnpm start). This will list all of the commonly used scripts.

Build

npm run build.all

WARNING: it seems yarn build.all wont always work (not finding binaries in node_modules/.bin) which is why the doc explicitly uses npm run

Demos

npm run demo.[ng|react|svelte|vue].[ios|android]

npm run demo.svelte.ios # Example

Demo setup is a bit special in the sense that if you want to modify/add demos you dont work directly in demo-[ng|react|svelte|vue] Instead you work in demo-snippets/[ng|react|svelte|vue] You can start from the install.ts of each flavor to see how to register new demos

Contributing

Update repo

You can update the repo files quite easily

First update the submodules

npm run update

Then commit the changes Then update common files

npm run sync

Then you can run yarn|pnpm, commit changed files if any

Update readme

npm run readme

Update doc

npm run doc

Publish

The publishing is completely handled by lerna (you can add -- --bump major to force a major release) Simply run

npm run publish

modifying submodules

The repo uses https:// for submodules which means you won't be able to push directly into the submodules. One easy solution is t modify ~/.gitconfig and add

[url "ssh://[e-mail]/"]
	pushInsteadOf = https://github.com/

Questions

If you have any questions/issues/comments please feel free to create an issue or start a conversation in the NativeScript Community Discord.