Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 | 3x 4x 4x 4x 4x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 4x 1x 1x 1x 1x 1x 4x 1x 1x 1x 1x 4x 4x 1x 1x 1x 1x 4x 4x 4x | import { palette } from "@palette";
import React, { useCallback, useEffect, useRef, useState } from "react";
type TMousePosition = {
x: number;
y: number;
};
type DrawingEvent =
| React.MouseEvent<HTMLCanvasElement>
| React.TouchEvent<HTMLCanvasElement>;
const useDrawOnCanvas = ({
height,
width,
onSave,
}: {
height: number;
width: number;
onSave?: (canvas: HTMLCanvasElement) => void;
}) => {
const canvasRef = useRef<HTMLCanvasElement>(null);
const contextRef = useRef<CanvasRenderingContext2D | null>(null);
const [isDrawing, setIsDrawing] = useState(false);
useEffect(() => {
const canvas = canvasRef.current;
Iif (!canvas) return;
canvas.width = width * 2;
canvas.height = height * 2;
canvas.style.width = `${width}px`;
canvas.style.height = `${height}px`;
canvas.style.background = "#fff";
canvas.style.borderRadius = "12px";
const context = canvas.getContext("2d");
Iif (!context) return;
context.scale(2, 2);
context.lineCap = "round";
context.strokeStyle = palette.neutral[80];
context.lineWidth = 3;
contextRef.current = context;
}, []);
const onDrawStart = useCallback((event: DrawingEvent) => {
const coordinates = getCoordinates(event);
Eif (coordinates) {
setIsDrawing(true);
contextRef.current?.beginPath();
contextRef.current?.moveTo(coordinates.x, coordinates.y);
}
}, []);
const onDrawEnd = useCallback(() => {
Iif (!canvasRef.current || !contextRef.current) return;
contextRef.current.closePath();
Eif (onSave) onSave(canvasRef.current);
setIsDrawing(false);
}, []);
const onDraw = useCallback(
(event: DrawingEvent) => {
if (!isDrawing) return;
const newPosition = getCoordinates(event);
if (!newPosition) return;
drawLine(newPosition);
},
[isDrawing],
);
const getCoordinates = (event: any) => {
Iif (!canvasRef.current) return null;
Eif (["mousedown", "mouseup", "mousemove"].includes(event.type)) {
const { offsetX, offsetY } = event.nativeEvent;
return {
x: offsetX,
y: offsetY,
};
}
event.stopPropagation();
const rect = canvasRef.current.getBoundingClientRect();
return {
x: event.touches[0].pageX - rect.x,
y: event.touches[0].pageY - rect.y,
};
};
const drawLine = (newPosition: TMousePosition) => {
if (!canvasRef.current || !contextRef.current) return;
contextRef.current?.lineTo(newPosition.x, newPosition.y);
contextRef.current?.stroke();
};
const clear = () => contextRef.current?.clearRect(0, 0, width, height);
return {
canvasRef,
onDrawStart,
onDraw,
onDrawEnd,
isDrawing,
clear,
};
};
export default useDrawOnCanvas;
|