How to create a ruler using Konva.js?

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2mo ago

How to create a ruler using Konva.js?

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Engineering

Art

Computer Science

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6 steps completed!19.16 sec

Answer

To create a ruler using Konva.js, you can draw a horizontal or vertical line along with tick marks to represent measurements. Below is a simple example of how to achieve this. The code assumes you are familiar with HTML and JavaScript and have included the Konva.js library in your project.

Example of a Horizontal Ruler with Konva.js

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Konva Ruler Example</title>
    <script src="https://cdn.rawgit.com/konvajs/konva/kenvjs@latest/konva.min.js"></script>
    <style>
        body {
            margin: 0;
            padding: 0;
            overflow: hidden;
        }
    </style>
</head>
<body>
    <div id="container"></div>

    <script>
        const stage = new Konva.Stage({
            container: 'container',
            width: window.innerWidth,
            height: 100 // Ruler height
        });

        const layer = new Konva.Layer();
        stage.add(layer);

        // Draw the ruler (horizontal line)
        const rulerLine = new Konva.Line({
            points: [0, 50, window.innerWidth, 50],
            stroke: 'black',
            strokeWidth: 2
        });
        layer.add(rulerLine);

        // Draw tick marks
        const tickLength = 20;
        const numberOfTicks = 10; // Number of ticks
        
        for (let i = 0; i <= numberOfTicks; i++) {
            const x = (i / numberOfTicks) * window.innerWidth; // Calculate x position
            
            // Tick mark
            const tick = new Konva.Line({
                points: [x, 50 - tickLength, x, 50], // Vertical tick line
                stroke: 'black',
                strokeWidth: 2
            });
            layer.add(tick);
            
            // Tick label
            const label = new Konva.Text({
                x: x - 10, // Center the label
                y: 55, // Slightly below the tick
                text: `${i}`, // Tick label
                fontSize: 12,
                fontFamily: 'Calibri',
                fill: 'black'
            });
            layer.add(label);
        }

        layer.draw();
    </script>
</body>
</html>

Explanation:

This code creates a Konva stage in a full-width container.
It draws a horizontal line as the main ruler.
It adds tick marks at regular intervals along the ruler.
Each tick is labeled with its corresponding measurement (0 to 10 in this case).

You can further customize the tick lengths, colors, labels, and positions according to your design needs. If you want to create a vertical ruler, you can adjust the points and x/y coordinates accordingly.

Suggestions

AAAnonymous

2mo ago