I have a small function I found that takes a string from a textarea
and then puts it into a canvas
element and wraps the text when the line gets too long. But it doesn't detect line breaks. This is what it's doing and what it should do:
Input:
Hello
This is dummy text that could be inside the text area.
It will then get put into the canvas.
Wrong output:
Hello this is dummy text
that could be inside the
text area. It will then
get put into the canvas.
What it should output:
Hello
This is dummy text that
could be inside the text
area. It will then get
put into the canvas.
This is the function I'm using:
function wrapText(context, text, x, y, maxWidth, lineHeight) {
var words = text.split(' ');
var line = '';
for(var n = 0; n < words.length; n++) {
var testLine = line + words[n] + ' ';
var metrics = context.measureText(testLine);
var testWidth = metrics.width;
if (testWidth > maxWidth && n > 0) {
context.fillText(line, x, y);
line = words[n] + ' ';
y += lineHeight;
}
else {
line = testLine;
}
}
context.fillText(line, x, y);
}
Is it possible to achieve what I'm trying to get? Or is there a way to simply move the text area as is into the canvas?
This question is related to
javascript
string
canvas
split
line-breaks
You can use the split()
function to break input on the basis of line break.
yourString.split("\n")
In case you need to split a string from your JSON, the string has the \n special character replaced with \\n.
Split string by newline:
Result.split('\n');
Split string received in JSON, where special character \n was replaced with \\n during JSON.stringify(in javascript) or json.json_encode(in PHP). So, if you have your string in a AJAX response, it was processed for transportation. and if it is not decoded, it will sill have the \n replaced with \\n** and you need to use:
Result.split('\\n');
Note that the debugger tools from your browser might not show this aspect as you was expecting, but you can see that splitting by \\n resulted in 2 entries as I need in my case:
You should try detect the first line.
Then the:
if(n == 0){
line = words[n]+"\n";
}
I'm not sure, but maybe it helps.
Here's the final code I [OP] used. Probably not best practice, but it worked.
function wrapText(context, text, x, y, maxWidth, lineHeight) {
var breaks = text.split('\n');
var newLines = "";
for(var i = 0; i < breaks.length; i ++){
newLines = newLines + breaks[i] + ' breakLine ';
}
var words = newLines.split(' ');
var line = '';
console.log(words);
for(var n = 0; n < words.length; n++) {
if(words[n] != 'breakLine'){
var testLine = line + words[n] + ' ';
var metrics = context.measureText(testLine);
var testWidth = metrics.width;
if (testWidth > maxWidth && n > 0) {
context.fillText(line, x, y);
line = words[n] + ' ';
y += lineHeight;
}
else {
line = testLine;
}
}else{
context.fillText(line, x, y);
line = '';
y += lineHeight;
}
}
context.fillText(line, x, y);
}
This is what I used to print text to a canvas. The input is not coming from a textarea
, but from input
and I'm only splitting by space. Definitely not perfect, but works for my case. It returns the lines in an array:
splitTextToLines: function (text) {
var idealSplit = 7,
maxSplit = 20,
lineCounter = 0,
lineIndex = 0,
lines = [""],
ch, i;
for (i = 0; i < text.length; i++) {
ch = text[i];
if ((lineCounter >= idealSplit && ch === " ") || lineCounter >= maxSplit) {
ch = "";
lineCounter = -1;
lineIndex++;
lines.push("");
}
lines[lineIndex] += ch;
lineCounter++;
}
return lines;
}
Source: Stackoverflow.com