Viewport

Scrollable container for oversized content.

Constructor: NewViewport(id, class, title string) *Viewport

Methods

• Add(widget Widget) — sets single scrollable child
• Children() []Widget — returns child widget
• Layout() — positions child with current scroll offsets

Scroll axes

By default the viewport scrolls both axes. Set a flag to restrict to one axis; the child then fills the viewport on the disabled axis instead of using its own preferred size.

Flag	Behaviour
FlagVertical	Vertical scrolling only — child fills viewport width, no horizontal scrollbar
FlagHorizontal	Horizontal scrolling only — child fills viewport height, no vertical scrollbar

// Vertical-only — natural for a long VFlex
vp := NewViewport("vp", "", "")
vp.SetFlag(FlagVertical, true)
vp.Add(myLongFlex)

Builder and Compose APIs use their existing SetFlag support.

Notes

Scroll via arrow keys and Home/End. Arrow keys for the disabled axis are ignored and passed to the next handler.