CODEWITHSUNDEEP
javascripthtmlhtml5-canvas
Jamesking56
Jamesking56

Reputation: 3901

Word Wrapping in HTML5 Canvas

I'm trying to word wrap in HTML5 Canvas but I'm struggling!

I've created a TextTyper object which will manage multiple lines of word wrapped text.

The problem I'm having is I'm getting an infinite loop!

I need a solution that uses pure JavaScript (no jQuery) and HTML5 Canvas.

I've made a JSFiddle to help solve my problems and test different strategies: http://jsfiddle.net/Jamesking56/eECar/

Here's my TextTyper Object so far:

function TextTyper(text, x, y, font, colour) 
{
    this.text = text || "";
    this.x = x || 20;
    this.y = y || 20;
    this.font = font || false;
    this.colour = colour || [0, 0, 0];
    this.lines = 0;

    // Calculate and draw the lines
    this.draw = function () 
    {
        canvas.width = canvas.width;

        var maxWidth = (canvas.width - 40);

        var words = this.text.split(' ');
        var line = [words[0]]; //begin with a single word

        for (var i = 1; i < words.length; i++) 
        {
            while (ctx.measureText(line.join(' ')) < maxWidth && i < words.length - 1) 
            {
                line.push(words[i++]);
            }

            if (i < words.length - 1) 
            { 
                //Loop ended because line became too wide
                line.pop(); //Remove last word
                i--; //Take one step back
            }
            this.lines++;
        }
    }
}

Any Ideas?

Upvotes: 11

Views: 9000

Answers (1)

Vincent Thibault
Vincent Thibault

Reputation: 601

Well, this is what I used for my HTML5 Game : http://jsfiddle.net/eECar/16/

while ( text.length ) {
    for( i=text.length; ctx.measureText(text.substr(0,i)).width > max_width; i-- );

    result = text.substr(0,i);

    if ( i !== text.length )
        for( j=0; result.indexOf(" ",j) !== -1; j=result.indexOf(" ",j)+1 );

    lines.push( result.substr(0, j|| result.length) );
    width = Math.max( width, ctx.measureText(lines[ lines.length-1 ]).width );
    text  = text.substr( lines[ lines.length-1 ].length, text.length );
}

Hope it help.

Upvotes: 11

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