Overflow (overflow)

The Overflow allows the elements to overflow along a given axis.

It's important to note that the overflow is an unbounded element. This means that elements can be laid out infinitely along a given axis.

Providing the overflow with a very large collection would produce a very large element tree.

An Overflow offset has to be changed via events rather than template values (if the offset came from a State it wouldn't be possible to know when the offset was exceeded should it change as a result of a key press for example. Even though the Offset could clamp the offset, the offset it self would not be clamped).

Example

border [height: 4, width: 10]
    overflow
        text "1"
        text "2"
        text "3"
        text "4"

┌────────┐
│1       │
│2       │
└────────┘

struct MyComponent {
    // ...
    fn on_key(
        &mut self,
        key: KeyEvent,
        state: &mut Self::State,
        mut elements: Elements<'_, '_>,
        mut context: Context<'_, Self::State>,
    ) {
        if let Some(c) = key.get_char() {
            elements.by_tag("overflow").first(|el, _| {
                let overflow = el.to::<Overflow>();
                match c {
                    'k' => overflow.scroll_up(),
                    'j' => overflow.scroll_down(),
                    _ => {}
                }
            });
        }
    }
}

Attributes

direction

Specifies the direction to lay out the elements.

Default value: "forwards"

Valid values:

• "back" or "backwards" or "backward"
• "fwd" or "forwards" or "forward"

border [height: 5, width: 10]
    overflow [direction: "backward"]
        text "1"
        text "2"

┌────────┐
│        │
│2       │
│1       │
└────────┘

axis

Specify along which axis to layout the children.

Valid values:

• "horz" | "horizontal"
• "vert" | "vertical"

clamp

Clamp the offset, preventing the content to scroll out of view

Default value: true

unconstrained

If this is set to true, both axis are unconstrained. If this is false, only the given axis is unconstrained.

Default value: false

• false

Methods

scroll_up()

Scroll the Overflow forward.

This is analogous to Overflow::scroll(Direction::Forward, 1).

scroll_up_by(n: u32)

Scroll the Overflow forward n number of lines.

This is analogous to Overflow::scroll(Direction::Forward, n).

scroll_down()

Scroll the overflow backward.

This is analogous to Overflow::scroll(Direction::Backward, 1).

scroll_down_by(n: u32)

Scroll the overflow backward n number of lines.

This is analogous to Overflow::scroll(Direction::Backward, n).

scroll_right()

Scroll the overflow forward.

This is analogous to Overflow::scroll(Direction::Forward, 1).

scroll_right_by(n: u32)

Scroll the overflow forward n number of lines.

This is analogous to Overflow::scroll(Direction::Forward, n).

scroll_left()

Scroll the overflow backward.

This is analogous to Overflow::scroll(Direction::Backward, 1).

scroll_left_by(n: u32)

Scroll the overflow backward n number of lines.

This is analogous to Overflow::scroll(Direction::Backward, n).

scroll_to(pos: Pos)

Scroll the overflow to a given position.