Scroll text when it reaches the bottom of the window.

Programming Questions

bavarskis

Scroll text when it reaches the bottom of the window.

in Programming Questions • 2 years ago

Hey everyone,

could anyone give me some tips how to make the text scroll.

At the moment when the text exceeds the bottom of the window it becomes invisible, cos it goes down to an imaginary space below.

I am trying to think of how to delete the first line and shift the whole text up, so there is a new empty line for more text. Basically making text scroll while typing.

Thanks in advance.

import fullscreen.*;
FullScreen fs;
PFont f1;
String txt="";
int fntSz=100;
int fntNum=1;
void setup() {
size(screen.width, screen.height); // set size
smooth();
background(255);
fs = new FullScreen(this); // Create the fullscreen object
fs.enter(); // enter fullscreen mode
f1 = loadFont("SOUND_08_07-48.vlw");
}
void draw() {
noCursor();
background(255);
textFont(f1, fntSz);
//textFont(f2, 36);
fill(0);
stroke(0);
textAlign(LEFT);
text(txt, width/20, height/20, width-width/10, height);
}
void keyPressed() {
if (keyCode == BACKSPACE) {
if (txt.length() > 0) {
txt = txt.substring(0, txt.length()-1);
}
}
else if (keyCode == DELETE) {
txt = "";
}
else if (keyCode != SHIFT) {
txt = txt + key;
}
}

Replies(4)

PhiLho

Re: Scroll text when it reaches the bottom of the window.

2 years ago

Among other things, you can draw the text at negative height positions.

bavarskis

Re: Scroll text when it reaches the bottom of the window.

2 years ago

Thanks. That's clever.

But now i am getting another problem. I count how many times i ENTER,

but how can I detect when text jumps to a new line without ENTER?

Also, how to precisely get the size of one line, so when i displace textbox to negative height position, it's exactly the size of a new line?

I tried this:

ascent=textAscent();

descent=textDescent();

lineSz=ascent+descent;

I tried fontSize.

but it still gives too large value - the text box jumps too much.

Any ideas are very appreciated.

calsign

Re: Scroll text when it reaches the bottom of the window.

2 years ago

textLeading() sets the distance between new lines.
You could find the width of text by using textWidth() and then inserting a newline character where it is necessary.