yposition expression to control a text layers position in a list

[Filip Vandueren]

I think making an array of the checkboxes first is a good idea,
maybe something along these lines:

For opacity (hiding text-layers):

controls = thisComp.layer("Null 1")("Effects");
checks = [];
for (i=1; i <=controls.numProperties; i++) {
	if (controls(i)(1).name=="Checkbox") checks.push(controls(i)(1).value);
}
firstTextLayerIndex=2;
myIndex = index-firstTextLayerIndex;
checks[myIndex]*100;

For position (text-layers):

controls = thisComp.layer("Null 1")("Effects");
checks = [];
for (i=1; i <= controls.numProperties; i++) {
	if (controls(i)(1).name=="Checkbox") checks.push(controls(i)(1).value);
}
numActive = checks.reduce((a,b) => a+b ,0);
firstTextLayerIndex=2;
myIndex = index-firstTextLayerIndex;
linespacing = 980/numActive;
top = 0;
for(i=0; i < myIndex; i++) {
	if (checks[i]) top+=linespacing;
}
thisComp.layer(firstTextLayerIndex).position + [0,top];

Of course this is assuming the texts are never breaking to be more than 1 line high, that would make it a bit more complex, looping through all the sourceRectAtTimes to calculate a better top-value.

[Henry Gaunt]

Thank you for the reply Filip. I appreciate your time.

For the life of me I can’t get this to work.

I currently have a “Null 1” with 9 checkboxes to activate/deactivate each layer.

As a test, I pasted the opacity expression (in the text layer opacity), but get the error “couldn’t turn result into a numeric value”.

I also pasted the position expression (in the text layer position) and it piles each text layer on top of each other at the top of the list.

I’m obviously doing everything wrong, can you please let me know how to correctly apply these expressions?

Thanks again,

[Filip Vandueren]

Can you first check that in your project settings the JavaScript Engine is set to “JavaScript” ? Legacy extendscript would fail on the reduce() method.

Also if your after effects is not in English, name==“Checkbox” would be a bad check.

[Henry Gaunt]

Thank you.

I’ve been working for hours to try and simplify the setup, I’m hoping this is an easier/more stable solution….

The user is now presented with a dropdown menu with an option of list consisting of 1, 2, or 3 text layers. The layer below those text layers needs to move up or down on the Y axis depending on how many text layers the user has selected so there are no line spaces when a text layer is turned off.

I tried this, but kept getting the error unexpected token ‘else’.

I want it to basically work as…

• is index-1 100 opacity? if yes, stay in your position, if no, move to index-1 position

• then is index-3 100 opacity? if yes, stay in index-1 position, if no, move to index-3 position

End.

(It’s index-3 as there is another text layer in-between which I need it to ignore).

p = thisComp.layer(index-1).transform.opacity; 
d = thisComp.layer(index-3).transform.opacity; 
if (p ==0) z = thisComp.layer(index-1).position[1];
[value[0], z];
else  if (d == 0) f = thisComp.layer(index-3).position[1];
[value[0], f];
else {
	value;
}

Thank you – I’m hoping I was close….

[Henry Gaunt]

I actually freaking did it, it’s a Christmas miracle..

p = thisComp.layer(index-1).transform.opacity; 
d = thisComp.layer(index-3).transform.opacity; 
if (p==0 && d==100){
z=thisComp.layer(index-1).transform.position[1];
[value[0], z];
}
else if (p==0 && d==0){
z=thisComp.layer(index-3).transform.position[1];
[value[0], z];
}
else {
	value;
}