How to keep child qwidget aspect ratio.

doodle

I know this question has been answered many times, but there is no one satisfied to me,

I hope that the aspect = width/height == 1.5, and the code is below.

QSize size = widget->size();

float aspect = 1.5;
int hintHeight = sz.height() * aspect;
if(size.width() > hintHeight ) {
  size.rwidth() = hintHeight ;
} else {
  size.rheight() = size.width() / aspect;
}
widget->resize(size);

I have try this in resizeEvent() but the resize() will cause infinity loop, and the heightForWidth(int w) solution can't be applied in this situation, since I need the height depend on width when height is longer than width, and width depend on height when width is longer than height.
I need that work like the gif in the link
Thanks!

SGaist

Hi,

That links is not a git but a gif. What exactly is your child widget ?

doodle

Sorry, I typed wrong, I mean I need the child widget could scale like the picture in the gif.

SGaist

Can you show how you are handling this currently ?

doodle

The gif is a photo viewer software in win10, I need a qt widget work like that, I haven't handle this yet.

VRonin

I implemented this back in the days when I was learning Qt (so be aware the code quality is probably below par and might be bugged):

doodle

Thank you, that's work!