This crate is a part of rat-salsa.

• Changes

Rat-Reloc(ate)

RelocatableState enables rendering StatefulWidget's to a temporary buffer.

After rendering a stateful widget all areas derived from the render area will be wrong if the temporary buffer is rendered to screen at a different location and with some clipping.

This trait defines a relocate function that corrects the areas at some point after rendering the widget.

• Doesn't impact normal rendering of the widget. It can just use the area and be done with it.

• Straightforward

    use rat_reloc::{RelocatableState, relocate_area};
    use ratatui::layout::Rect;
  
    # struct ButtonState{ area:Rect, inner:Rect}
  
    impl RelocatableState for ButtonState {
        fn relocate(&mut self, shift: (i16, i16), clip: Rect) {
            self.area = relocate_area(self.area, shift, clip);
            self.inner = relocate_area(self.inner, shift, clip);
        }
    }
  

• Decent to implement for a view widget

    use ratatui::layout::Rect;
    use ratatui::buffer::Buffer;
    use ratatui::widgets::StatefulWidget;
    use rat_reloc::RelocatableState;
  
    pub struct RelocatedRender;
  
    impl RelocatedRender {
        fn render<W, S>(widget: W, area: Rect, state: &mut S)
        where
            W: StatefulWidget<State = S>,
            S: RelocatableState,
        {
            // remap area
            let area = Rect::default();
            // use inner buffer
            let mut buf = Buffer::default();
  
            // render to buffer
            widget.render(area, &mut buf, state);
  
            // calculate shift and clip
            let shift = (-1, -1);
            let clip = Rect::default();
  
            // correct state
            state.relocate(shift, clip);
        }
    }