Struct nannou::ui::prelude::widget::List

pub struct List<D, S> {
    pub common: CommonBuilder,
    pub style: Style,
    pub item_instantiation: ItemInstantiation,
    // some fields omitted
}

A helper widget, useful for instantiating a sequence of widgets in a vertical list.

The List widget simplifies this process by:

• Generating widget::Ids.
• Simplifying the positioning and sizing of items.
• Optimised widget instantiation by only instantiating visible items. This is very useful for lists containing many items, i.e. a FileNavigator over a directory with thousands of files.

Fields

common: CommonBuilder

Common widget building params for the List.

style: Style

Unique styling for the List.

item_instantiation: ItemInstantiation

Whether all or only visible items should be instantiated.

Methods

impl<D> List<D, Dynamic> where
    D: Direction, 

pub fn new(num_items: usize) -> List<D, Dynamic>

Begin building a new List.

impl List<Left, Dynamic>

pub fn flow_left(num_items: usize) -> List<Left, Dynamic>

Begin building a new List flowing from right to left.

impl List<Right, Dynamic>

pub fn flow_right(num_items: usize) -> List<Right, Dynamic>

Begin building a new List flowing from left to right.

impl List<Up, Dynamic>

pub fn flow_up(num_items: usize) -> List<Up, Dynamic>

Begin building a new List flowing from bottom to top.

impl List<Down, Dynamic>

pub fn flow_down(num_items: usize) -> List<Down, Dynamic>

Begin building a new List flowing from top to bottom.

impl<D, S> List<D, S> where
    D: Direction,
    S: ItemSize, 

pub fn from_item_size(num_items: usize, item_size: S) -> List<D, S>

Begin building a new List given some direction and item size.

pub fn item_size(self, length: f64) -> List<D, Fixed>

Specify a fixed item size, where size is a Scalar in the direction that the List is flowing. When a List is constructed with this method, all items will have a fixed, equal length.

impl<D> List<D, Fixed> where
    D: Direction, 

pub fn instantiate_all_items(self) -> List<D, Fixed>

Indicates that an Item should be instantiated for every element in the list, regardless of whether or not the Item would be visible.

This is the default (and only) behaviour for Lists with dynamic item sizes. This is because a List cannot know the total length of its combined items in advanced when each item is dynamically sized and their size is not given until they are set.

Note: This may cause significantly heavier CPU load for lists containing many items (100+). We only recommend using this when absolutely necessary as large lists may cause unnecessary bloating within the widget graph, and in turn result in greater traversal times.

pub fn instantiate_only_visible_items(self) -> List<D, Fixed>

Indicates that only Items that are visible should be instantiated. This ensures that we avoid bloating the widget graph with unnecessary nodes and in turn keep traversal times to a minimum.

This is the default behaviour for Lists with fixed item sizes.

impl<D, S> List<D, S> where
    D: Direction,
    S: ItemSize, 

pub fn scrollbar_next_to(self) -> List<D, S>

Specifies that the List should be scrollable and should provide a Scrollbar to the right of the items.

pub fn scrollbar_on_top(self) -> List<D, S>

Specifies that the List should be scrollable and should provide a Scrollbar that hovers above the right edge of the items and automatically hides when the user is not scrolling.

pub fn scrollbar_thickness(self, w: f64) -> List<D, S>

The width of the Scrollbar.

pub fn scrollbar_color(self, color: Color) -> List<D, S>

The color of the Scrollbar.

Trait Implementations

impl<D, S> Clone for List<D, S> where
    D: Clone,
    S: Clone, 

fn clone(&self) -> List<D, S>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<D, S> Common for List<D, S>

fn common(&self) -> &CommonBuilder

Borrows the CommonBuilder field.

fn common_mut(&mut self) -> &mut CommonBuilder

Mutably borrows the CommonBuilder field.

impl<D, S> Widget for List<D, S> where
    D: Direction,
    S: ItemSize, 

type State = State

State to be stored within the Uis widget cache.

type Style = Style

Every widget is required to have its own associated Style type. This type is intended to contain high-level styling information for the widget that can be optionally specified by a user of the widget.

type Event = (Items<D, S>, Option<Scrollbar<<D as Direction>::Axis>>)

The type of event yielded by the widget, returned via the Widget::set function.

fn init_state(&self, id_gen: Generator) -> <List<D, S> as Widget>::State

Return the initial State of the Widget.

fn style(&self) -> <List<D, S> as Widget>::Style

Return the styling of the widget.

fn update(self, args: UpdateArgs<List<D, S>>) -> <List<D, S> as Widget>::Event

Update our Widget's unique Widget::State via the State wrapper type (the state field within the UpdateArgs).

fn default_x_position(&self, ui: &Ui) -> Position

The default Position for the widget along the x axis.

fn default_y_position(&self, ui: &Ui) -> Position

The default Position for the widget along the y axis.

fn default_x_dimension(&self, ui: &Ui) -> Dimension

The default width for the Widget.

fn default_y_dimension(&self, ui: &Ui) -> Dimension

The default height of the widget.

fn drag_area(
    &self,
    _dim: [f64; 2],
    _style: &Self::Style,
    _theme: &Theme
) -> Option<Rect>

If the widget is draggable, implement this method and return the position and dimensions of the draggable space. The position should be relative to the center of the widget.

fn kid_area(&self, args: KidAreaArgs<Self>) -> KidArea

The area on which child widgets will be placed when using the Place Position methods.

fn is_over(&self) -> fn(&Container, [f64; 2], &Theme) -> IsOver

Returns either of the following:

fn parent(self, parent_id: NodeIndex<u32>) -> Self

Set the parent widget for this Widget by passing the WidgetId of the parent.

fn no_parent(self) -> Self

Specify that this widget has no parent widgets.

fn place_on_kid_area(self, b: bool) -> Self

Set whether or not the Widget should be placed on the kid_area.

fn graphics_for(self, id: NodeIndex<u32>) -> Self

Indicates that the Widget is used as a non-interactive graphical element for some other widget.

fn floating(self, is_floating: bool) -> Self

Set whether or not the widget is floating (the default is false). A typical example of a floating widget would be a pop-up or alert window.

fn crop_kids(self) -> Self

Indicates that all widgets who are children of this widget should be cropped to the kid_area of this widget.

fn scroll_kids(self) -> Self

Makes the widget's KidArea scrollable.

fn scroll_kids_vertically(self) -> Self

Makes the widget's KidArea scrollable.

fn scroll_kids_horizontally(self) -> Self

Set whether or not the widget's KidArea is scrollable (the default is false).

fn and<F>(self, build: F) -> Self where
    F: FnOnce(Self) -> Self, 

A builder method that "lifts" the Widget through the given build function.

fn and_mut<F>(self, mutate: F) -> Self where
    F: FnOnce(&mut Self), 

A builder method that mutates the Widget with the given mutate function.

fn and_if<F>(self, cond: bool, build: F) -> Self where
    F: FnOnce(Self) -> Self, 

A method that conditionally builds the Widget with the given build function.

fn and_then<T, F>(self, maybe: Option<T>, build: F) -> Self where
    F: FnOnce(Self, T) -> Self, 

A method that optionally builds the Widget with the given build function.

fn set(self, id: NodeIndex<u32>, ui_cell: &'a mut UiCell<'b>) -> Self::Event

Note: There should be no need to override this method.