2019js13k/js/MouseInput.js

class MouseInput {

	constructor() {
		this.mouseListener = {};
		this.mouseCanvas = {};
		this.position = {x: 0, y: 0};
		this.handlers = {};
	}

	attachHandler(eventName, handleFunction) {
		this.handlers[eventName] = handleFunction;
		this.mouseCanvas.addEventListener(eventName, handleFunction);
	}

	detachHandler(eventName) {
		this.mouseCanvas.removeEventListener(eventName, this.handlers[eventName]);
		delete this.handlers[eventName];
	}

	attach(canvas, listener) {
		this.mouseListener = listener;
		this.mouseCanvas = canvas;

		this.attachHandler('mousemove', (event) => {this.handleMouseMove(event)});
		this.attachHandler('mousedown', (event) => this.handleMouseDown(event));
		this.attachHandler('mouseup', (event) => this.handleMouseUp(event));

		this.attachHandler('contextmenu', (event) => this.handleContextMenu(event));

		this.attachHandler('touchstart', (event) => this.handleTouchStart(event));
		this.attachHandler('touchmove', (event) => this.handleTouchMove(event));
		this.attachHandler('touchend', (event) => this.handleTouchEnd(event));
	}

	detach() {
		this.detachHandler('mousemove');
		this.detachHandler('mousedown');
		this.detachHandler('mouseup');

		this.detachHandler('contextmenu');

		this.detachHandler('touchstart');
		this.detachHandler('touchmove');
		this.detachHandler('touchend');
	};

	handleMouseMove(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		if (!this.mouseListener.mouseMove) { return; }
		this.mouseListener.mouseMove(this.mouseCanvas, event.offsetX, event.offsetY);
	}

	handleMouseDown(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		if (!this.mouseListener.mouseDown) { return; }
		this.mouseListener.mouseDown(this.mouseCanvas, event.button, event.offsetX, event.offsetY);
	}

	handleMouseUp(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		if (!this.mouseListener.mouseUp) { return; }
		this.mouseListener.mouseUp(this.mouseCanvas, event.button, event.offsetX, event.offsetY);
	};

	handleTouchStart(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		if (!this.mouseListener.touchStart) { return; }
		this.mouseListener.touchStart(this.mouseCanvas, event.touches[0].clientX, event.touches[0].clientY);
	}

	handleTouchMove(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		if (!this.mouseListener.touchMove) { return; }
		this.mouseListener.touchMove(this.mouseCanvas, event.touches[0].clientX, event.touches[0].clientY);
	}

	handleTouchEnd(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		if (!this.mouseListener.touchEnd) { return; }
		this.mouseListener.touchEnd(this.mouseCanvas, event.offsetX, event.offsetY);
	}

	handleContextMenu(event) {
		this.position.x = event.clientX;
		this.position.y = event.clientY;
		event.preventDefault();
		if (!this.mouseListener.contextMenu) { return false; }
		this.mouseListener.touchEnd(this.mouseCanvas, event);
		return false;
	}
};