Grid layout breaks if it contains horizontal

[micfong-z]

Describe the bug Grid layout show incorrect margin when ui.horizontal() is used inside as a cell.

In the following screenshot:

• Row 1 is slightly away from the upper border of the window, and covers some parts of Row 2.
• There is a gap between Row 2 and Row 3.

My guess for the reason

Note: I have not checked or verified if this is the actual problem, and it is only my best guess.

Looking at the first row only, I'm thinking that egui may have pre-calculated the size of horizontal once and put Label 1 into the correct position, however egui falsely shifted the horizontal downwards as well to match the top of Label 1. This applies to the rest of the rows.

To Reproduce Here's the code used to reproduce the problem

egui::Window::new("Window").show(ctx, |ui| {
    egui::Grid::new("grid_test").show(ui, |ui| {
        ui.label("Label1");  
        ui.horizontal(|ui| {  
            ui.label("This is the longest label\nwith 4 lines\nthis is the 3rd line\nand the last line here.");
        });
        ui.end_row();

        ui.label("Label2");
        ui.horizontal(|ui| {  
            ui.label("This is a shorter label\nwith 2 lines only.");
        });
        ui.end_row();

        ui.label("Label3");
        ui.horizontal(|ui| {               
            ui.label("This is a long label\nwith 3 lines\nand here is the last line.");
        });
        ui.end_row();
    })
});

Expected behavior The grid layout should function as normal, with correct margins between each line.

Desktop information

• OS: macOS Ventura 13.2.1
• egui Version: 0.22.0

[micfong-z]

Might be related to #1830, but only RetainedImage is mentioned there.

[yrns]

I think this is a limitation of immediate mode. Ui::horizontal assumes your content is spacing().interact_size.y tall and centers vertically based on that. If you know the height of your content you can set that value, or try Ui:horizontal_top. Ui::horizontal_centered can also work, but that eats up all available vertical height, which might also be problematic depending on your layout.

I believe this is the same issue at #1830 as you pointed out. Grid uses Ui::horizontal internally.