How can I make a slider from App Designer change the background of a shape which is loaded from a text file, whilst moving it?

How can I make a slider from App Designer change the background of a shape which is loaded from a text file, whilst moving it?

[Rik]

Have you already figured out how to do the display?

[Mirena Kurteva]

Yes, I have the shape displayed on the canvas.

[Mirena Kurteva]

[Mirena Kurteva]

This is what I wrote for the slider, but it only fills the shape in yellow and it doesnt change the color when I move it

[Voss]

I'm not sure what that for loop is supposed to do. It looks like the entire loop can be replaced with this line:

fill(app.Canvas, coordinates_x, coordinates_y, cName{1+changingValue});

and it'll do the same thing. (Note that the code inside the loop doesn't depend on the loop index ind or the variable color in any way, so it will just do the same thing over and over several times.)

Regardless, the fact that the fill is always yellow indicates that changingValue is always 0 (or at least it is never 1, 2, or 3). Perhaps print the value of changingValue to the command line from within the callback and make sure you get the values you expect when interacting with the slider.

[Adam Danz]

I suggest using a discrete knob since you're referencing a discrete list of colors. Alternatively, see this answer to learn how to make a continuous slider behave as if it were discrete.

Answer 1

[Shanmukha Voggu]

Hi,

The above problem can be solved by using

1)Discrete Knobs

2)As Adam said try this to make a continuous slider as if it were discrete

3)If you are dealing with integers as ticks try rounding to nearest integer while sliding.

Refer to the this for more information