app.js

//200813

const canvas = document.getElementById("jsCanvas");
const ctx = canvas.getContext("2d");
const colors = document.getElementsByClassName("jsColor")
const range = document.getElementById("jsRange");
const mode = document.getElementById("jsMode");
const saveBtn = document.getElementById("jsSave");

const INITIAL_COLOR = "#2c2c2c";
const CANVAS_SIZE = 500;

canvas.width = CANVAS_SIZE;
canvas.height = CANVAS_SIZE;

ctx.fillStyle = "white";
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.strokeStyle = INITIAL_COLOR;
ctx.fillStyle = INITIAL_COLOR;
ctx.lineWidth = 2.5;

let painting = false;
let filling = false;

function stopPainting() {
    painting = false;
}

function startPainting() {
    painting = true;
}

function onMouseMove(event) {
    const x = event.offsetX;
    const y = event.offsetY;
    if (!painting) {
        //console.log("creating path in ", x, y);
        ctx.beginPath();
        ctx.moveTo(x, y);
    } else {
        //console.log("creating line in ", x, y);
        ctx.lineTo(x, y);
        ctx.stroke();
    }
}

function handleColorClick(event) {
    const color = event.target.style.backgroundColor;
    //console.log(color);
    ctx.strokeStyle = color;
    ctx.fillStyle = color;
}

function hadleRangeChange(event) {
    const strokeSize = event.target.value
    //console.log(strokeSize);
    ctx.lineWidth = strokeSize;
}

function hadleModeClick(event) {
    //const modeText = event.target.textContent;
    //console.log(modeText);
    if (filling === true) {
        filling = false;
        mode.innerText = "Fill";
    } else {
        filling = true;
        mode.innerText = "Paint";
    }
}

function handleCanvasClick(event) {
    if (filling) {
        ctx.fillRect(0, 0, canvas.width, canvas.height);
    }
}

function handleCM(event) {
    console.log(event);
    event.preventDefault();
}

function handleSaveClick(event) {
    const image = canvas.toDataURL();
    const link = document.createElement("a");
    link.href = image;
    link.download = "PainJS";
    link.click();
}

if (canvas) {
    canvas.addEventListener("mousemove", onMouseMove);
    canvas.addEventListener("mousedown", startPainting);
    canvas.addEventListener("mouseup", stopPainting);
    canvas.addEventListener("mouseleave", stopPainting);
    canvas.addEventListener("click", handleCanvasClick);
    canvas.addEventListener("contextmenu", handleCM);
}

Array.from(colors).forEach(color => color.addEventListener("click", handleColorClick));

if (range) {
    range.addEventListener("input", hadleRangeChange)
}

if (mode) {
    mode.addEventListener("click", hadleModeClick)
}

if (saveBtn) {
    saveBtn.addEventListener("click", handleSaveClick)
}