110 lines
3.2 KiB
HTML
110 lines
3.2 KiB
HTML
|
<!DOCTYPE html>
|
||
|
<html>
|
||
|
<head>
|
||
|
<title>Tax forms: Bar chart with lines</title>
|
||
|
<meta charset="UTF-8">
|
||
|
<script src="taxForms.js"></script>
|
||
|
</head>
|
||
|
<body>
|
||
|
|
||
|
<canvas id="chart" width="700" height="550"></canvas>
|
||
|
|
||
|
<script>
|
||
|
const canvas = document.getElementById('chart');
|
||
|
const context = canvas.getContext('2d');
|
||
|
|
||
|
/* Draw a line from (fromX, fromY) to (toX, toY) */
|
||
|
function drawLine(fromX, fromY, toX, toY) {
|
||
|
context.beginPath();
|
||
|
context.moveTo(toX, toY);
|
||
|
context.lineTo(fromX, fromY);
|
||
|
context.stroke();
|
||
|
}
|
||
|
|
||
|
/* Draw a text (string) on (x, y) */
|
||
|
function drawText(text, x, y) {
|
||
|
context.fillStyle = 'black';
|
||
|
context.fillText(text, x, y);
|
||
|
}
|
||
|
|
||
|
/* Draw a text and with a line to its right */
|
||
|
function drawLineWithText(text, fromX, fromY, toX, toY) {
|
||
|
drawText(text, fromX - 50, fromY + 10);
|
||
|
drawLine(fromX, fromY, toX, toY);
|
||
|
}
|
||
|
|
||
|
/* Insert your code here. */
|
||
|
|
||
|
/**
|
||
|
* Draw lines on the y axis of the canvas
|
||
|
*
|
||
|
* @param {number} n - Number of lines to draw
|
||
|
* @param {number} step - Number to add to y axis
|
||
|
*/
|
||
|
const drawNLines = (n, step) => {
|
||
|
for (let i = 1; i <= n; i++) {
|
||
|
const y = canvas.height * (n - i + 1 ) / (n+1);
|
||
|
const text = step * i;
|
||
|
drawLineWithText(text, 50, y, canvas.width - 100, y);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Draws a rectangle onto the canvas
|
||
|
*
|
||
|
* @param {number} x - x value of the upper left corner of the rectangle
|
||
|
* @param {number} y - y value of the upper left corner of the rectangle
|
||
|
* @param {number} width - Width of the rectangle
|
||
|
* @param {number} height - Height of the rectangle (DOWNWARDS)
|
||
|
* @param {string} color - Color of the rectangle
|
||
|
*/
|
||
|
const drawRectangle = (x, y, width, height, color='red') => {
|
||
|
context.fillStyle = color;
|
||
|
context.fillRect(x, y, width, height);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Cycle a list of colors
|
||
|
*
|
||
|
* @generator
|
||
|
*
|
||
|
* @param {string[]} colors - List of colors to cycle
|
||
|
* @yields {string} A color
|
||
|
*/
|
||
|
function* colorCycler(colors) {
|
||
|
let i = 0;
|
||
|
while (true) {
|
||
|
yield colors[i];
|
||
|
i = (i + 1) % colors.length;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Draw a legend entry on the canvas
|
||
|
*
|
||
|
* @param {string[]} properties - An array of labels
|
||
|
* @param {[string[]} colorList - An array of colors to cycle when making labels
|
||
|
*/
|
||
|
const drawLabels = (properties, colorList) => {
|
||
|
const colors = colorCycler(colorList);
|
||
|
|
||
|
const drawLabel = (text, color, y) => {
|
||
|
drawText(text, canvas.width-45, y + 15)
|
||
|
drawRectangle(canvas.width - 90, y, 40, 20, color);
|
||
|
}
|
||
|
|
||
|
const yOffset = canvas.height / 12
|
||
|
for (i in properties) {
|
||
|
drawLabel(properties[i], colors.next().value, yOffset+30*i);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
drawNLines(10, 100000);
|
||
|
const taxData = taxForms;
|
||
|
taxData.forEach(form => delete form.realName);
|
||
|
drawLabels(Object.getOwnPropertyNames(taxData[0]), ['red', 'blue']);
|
||
|
|
||
|
</script>
|
||
|
</body>
|
||
|
</html>
|