Module stack 

Stack layout widget, nodes and properties.

The Stack! widget is a layout panel stacks children, in Z and in a direction.

The example below declares a stack that animates between directions.

use zng::prelude::*;

let direction = var(StackDirection::top_to_bottom());
Stack! {
    direction = direction.easing(1.secs(), |t| easing::ease_out(easing::expo, t));
    spacing = 10;
    children_align = layout::Align::CENTER;

    toggle::selector = toggle::Selector::single(direction);
    children =
        [
            ("top_to_bottom", StackDirection::top_to_bottom()),
            ("left_to_right", StackDirection::left_to_right()),
            ("bottom_to_top", StackDirection::bottom_to_top()),
            ("right_to_left", StackDirection::right_to_left()),
            (
                "diagonal",
                StackDirection {
                    place: layout::Point::bottom_right(),
                    origin: layout::Point::top_left(),
                    is_rtl_aware: false,
                },
            ),
        ]
        .into_iter()
        .map(|(label, direction)| {
            Toggle! {
                child = Text!(label);
                value::<StackDirection> = direction;
            }
        }),
    ;
}

Note that the StackDirection is defined by two points, the stack widget resolves the place point in the previous child and the origin point in the next child and then positions the next child so that both points overlap. This enables custom layouts like partially overlapping children and the traditional horizontal and vertical stack.

Full API

See zng_wgt_stack for the full widget API.

Structs

Stack

W Stack layout.

StackDirection

Defines a placement point in the previous item and the origin point of the next.

Traits

WidgetInfoStackExt

Extension methods for WidgetInfo that may represent a Stack! instance.

Functions

get_index

P Get the child index in the parent stack.

get_index_len

P Get the child index and number of children.

get_rev_index

P Get the child index, starting from the last child at 0.

is_even

P If the child index is even.

is_first

P If the child is the first.

is_last

P If the child is the last.

is_odd

P If the child index is odd.

lazy_sample

Create a node that estimates the size of stack panel children.

lazy_size

Create a node that estimates the size of stack panel children.

node

Stack node.

stack_nodes

Basic Z-stack node sized by one of the items.