90d76fb5be
I noticed that color picker HTML element retains the last picked value from user even after the page is reloaded. This will cause inconsistency between `color` value and the actual `colorEl.value`. This commit will always initialize color picker default value to black, the same way that `color` variable was set originally.
87 lines
1.6 KiB
JavaScript
87 lines
1.6 KiB
JavaScript
const canvas = document.getElementById('canvas');
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const increaseBtn = document.getElementById('increase');
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const decreaseBtn = document.getElementById('decrease');
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const sizeEL = document.getElementById('size');
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const colorEl = document.getElementById('color');
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const clearEl = document.getElementById('clear');
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const ctx = canvas.getContext('2d');
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let size = 10
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let isPressed = false
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colorEl.value = 'black'
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let color = colorEl.value
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let x
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let y
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canvas.addEventListener('mousedown', (e) => {
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isPressed = true
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x = e.offsetX
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y = e.offsetY
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})
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canvas.addEventListener('mouseup', (e) => {
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isPressed = false
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x = undefined
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y = undefined
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})
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canvas.addEventListener('mousemove', (e) => {
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if(isPressed) {
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const x2 = e.offsetX
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const y2 = e.offsetY
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drawCircle(x2, y2)
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drawLine(x, y, x2, y2)
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x = x2
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y = y2
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}
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})
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function drawCircle(x, y) {
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ctx.beginPath();
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ctx.arc(x, y, size, 0, Math.PI * 2)
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ctx.fillStyle = color
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ctx.fill()
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}
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function drawLine(x1, y1, x2, y2) {
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ctx.beginPath()
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ctx.moveTo(x1, y1)
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ctx.lineTo(x2, y2)
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ctx.strokeStyle = color
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ctx.lineWidth = size * 2
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ctx.stroke()
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}
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function updateSizeOnScreen() {
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sizeEL.innerText = size
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}
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increaseBtn.addEventListener('click', () => {
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size += 5
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if(size > 50) {
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size = 50
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}
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updateSizeOnScreen()
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})
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decreaseBtn.addEventListener('click', () => {
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size -= 5
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if(size < 5) {
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size = 5
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}
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updateSizeOnScreen()
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})
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colorEl.addEventListener('change', (e) => color = e.target.value)
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clearEl.addEventListener('click', () => ctx.clearRect(0,0, canvas.width, canvas.height))
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