Finding Text Height from a Text Area

Programming Questions

bourdonpr..

Finding Text Height from a Text Area

in Programming Questions • 1 year ago

Hello.

I have looked the forum but no clear answer.

How is it possible to create a text area based on the lines of the text? As in the following example, you may notice that I enter the variables for the text area (x, y, width, height). However, in my case, I would like to know if there is a specific method of calculating the height of the text area automatically based on the number of lines.

Any ideas?

Copy code

String a1;
String a2;
size(200, 200);
a1 = "This is a message written in Processing and it is displayed on the main window";
a2 = "Another message written in Processing and it is displayed on the main window";
text(a1, 10, 10, 150, 100);
text(a2, 10, 100, 150, 100, 101);

Replies(5)

quarks

Re: Finding Text Height from a Text Area

1 year ago

You could use textWidth() to get the length of the string and the line height is textAscent()+textDescent() frm these you cold calculate the number of lines and multiply this by the line height.

The only problem is that it is likely to underestimate the number of lines because it assumes line breaks can occur anywhere in the text including partway through a character.

So the answer is no Processing does not have a method to do this.

calsign

Re: Finding Text Height from a Text Area

1 year ago

This has been asked many times, and there have been lots of answers... mostly in the Beta forums. This one worked for me: http://processing.org/discourse/beta/num_1195937999.html

bourdonpr..

Re: Finding Text Height from a Text Area

1 year ago

Thank you all for the responses, as you suggested, I have to make one solution for my problem!

tabbed

Re: Finding Text Height from a Text Area

11 months ago

Trying to work out an algorithm that works for different fonts + sizes is quite a mission. Using the textAscent() + textDescent() proved ineffective when working with all the variations. Also none of the old forum post examples take into consideration line breaks '\n'.

I modified one of the old examples so you pass in the text, the width, and the leading (which MUST be set before calling textHeight with 'textLeading(someNumber)' function). This has worked pretty well for me so far.

Copy code

// in setup or wherever call setLeading()

float myLeading = 24;

setLeading(myLeading);

float myTextHeight = textHeight(someString, someWidth, myLeading);
int textHeight(String str, int specificWidth, int leading) {
// split by new lines first
String[] paragraphs = split(str, "\n");
int numberEmptyLines = 0;
int numTextLines = 0;
for (int i=0; i < paragraphs.length; i++) {
// anything with length 0 ignore and increment empty line count
if(paragraphs[i].length() == 0) {
numberEmptyLines++;
} else {
numTextLines++;
// word wrap
String[] wordsArray = split(paragraphs[i], " ");
String tempString = "";
for (int k=0; k < wordsArray.length; k++) {
if (textWidth(tempString + wordsArray[k]) < specificWidth) {
tempString += wordsArray[k] + " ";
}
else {
tempString = wordsArray[k] + " ";
numTextLines++;
}
}
}
}
float totalLines = numTextLines + numberEmptyLines;
return round(totalLines * leading);
}

adilapapa..

Re: Finding Text Height from a Text Area

6 months ago

Hey,

Not sure if anyone's still following this thread but I found the info here really helpful. I posted an example of this in action here just in case anyone else would like to reuse it. It's a modification of tabbed's algorithm (thanks!), but I placed it in a class named 'Tex' instead and added a few other metrics that might be of use (e.g. number of total lines, etc).

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