maybe Modifier.drawBehind?

# compose

[allan.conda]

maybe Modifier.drawBehind?

[Luis Daivid]

Could it be implemented using clips?

[Luis Daivid]

drawBehind is so difficult..

[allan.conda]

you wanted custom background behavior. I think it’s the only option

[Luis Daivid]

I don’t want a custom background. I just want to crop part of the view.

[robnik]

Crop or transparency? Those sound different to me. I just did something with cropping using Modifier.clip(myShape) where myShape is a GenericShape { ... } . In my preview I have a Slider that changes the width of the clip shape from 0 to 100%.

[Luis Daivid]

@robnik Can i see code of myShape??

[Luis Daivid]

I think that is What i want!

[robnik]

val myClip = GenericShape { size ->
    val right = size.width * fraction
    lineTo(right, 0f)
    lineTo(right, size.height)
    lineTo(0f, size.height)
    close()
}

And fraction is a float from state, getting moved by a slider.

[Luis Daivid]

Thank you 😃

[Nader Jawad]

Just FYI, GenericShape will work here as a parameter to the clip modifier, however, because this is a rectangle, using RectangleShape to provide the clipping bounds will be more efficient as it would avoid software rasterization of paths

[robnik]

@Nader Jawad The RectangleShape I see is a val. How do I use it? How do I give it a narrower width so that it actually clips the thing I'm trying to clip/crop?

[Nader Jawad]

Just pass in that instance of RectangleShape

[Nader Jawad]

Or you can create your own instance of Shape that creates a rectangle based on the percentage offset you wish to clip by

[robnik]

Okay, I see - override Shape and return an Outline that is a Rectangle instead of a Generic, and get that performance benefit. Thanks!

[Luis Daivid]

https://github.com/wooooooak/DragToPeekSurface-Compose
I did it thanks to you guys. Thank you.

[allan.conda]

cool