Dock: any way to set a size range for panels?

[marceloadsj]

https://gpui-kit.com/component/dock/
For example, I want the sidebar to be between 100 and 500 pixels wide. Is there a way to do that?

https://gpui-kit.com/component/resizable/#panel-size-constraints
It seems the resizable supports that via the .size_range(px(150.)..px(300.)) method.

[kgeminicdev]

Not as a builder option in v0.7.3. Edge docks don't go through the Resizable panel constraints. Their drag size is clamped by DockSizing::clamp, which only enforces a fixed floor of PANEL_MIN_SIZE (100px) and a ceiling that leaves 100px for the center and the opposite dock. So your 100px lower bound is already the default. Only the 500px max needs work.

Workaround: the component skin emits DockEvent::LayoutChanged when a dock resize drag ends. Subscribe and clamp with set_dock_size:

use gpui_kit::component::dock::{DockEvent, DockPlacement};

cx.subscribe_in(&dock_area, window, |_, area, event: &DockEvent, window, cx| {
    if let DockEvent::LayoutChanged = event {
        area.update(cx, |area, cx| {
            if let Some(size) = area.dock_size(DockPlacement::Left) {
                let clamped = size.clamp(px(100.), px(500.));
                if clamped != size {
                    area.set_dock_size(DockPlacement::Left, clamped, window, cx);
                }
            }
        });
    }
})
.detach();

This won't loop: set_dock_size only emits again when the size actually changes. The catch is that during the drag the dock can still go past 500px, then snap back on release, because the live resize path doesn't emit events. Clamping during the drag would need a custom DockAreaRenderer that clamps the pointer before calling DockContext::resize_to. I haven't compiled the snippet above, so check the closure signature against your gpui version.

[marceloadsj]

Thanks, the snippet works.

Is this a feature you think can be added to the Dock component directly?

Apart of facilitating the API it would improve the UX as, like you said, it would allow clamping during the drag, not jumping back in after drag ends.

[kgeminicdev]

I think it would fit well, and the change looks small. The natural place is DockSizing::clamp in crates/base/src/dock/dock_placement.rs. It already clamps every drag between a hardcoded PANEL_MIN_SIZE and the space left over, so per-dock min_size / max_size stored on the dock and used there instead of the constant would apply during the drag, not only on release. Dock::set_size would need the same bounds so programmatic resizes respect them too.

That's a maintainer decision, so I'd open an issue describing the use case, or a PR if you're up for it.