Struct kas::view::MatrixView

pub struct MatrixView<A, V>
where
    A: MatrixData,
    V: Driver<<A as SharedData>::Item, A>,
{ /* private fields */ }

Available on crate feature view only.

View controller for 2D indexable data (matrix)

This widget generates a view over a list of data items via the MatrixData trait. “View widgets” are constructed via a Driver to represent visible data items. These view widgets are reassigned as required when the matrix is scrolled, keeping the number of widgets in use roughly proportional to the number of data items within the view.

Each view widget has an Id corresponding to its current data item, and may handle events and emit messages like other widegts. See Driver documentation for more on event handling.

This widget is Scrollable, supporting keyboard, wheel and drag scrolling. You may wish to wrap this widget with ScrollBars.

Optionally, data items may be selected; see Self::set_selection_mode. If enabled, SelectionMsg messages are reported; view widgets may emit kas::messages::Select to have themselves be selected.

Implementations

impl<A, V> MatrixView<A, V>

where A: MatrixData, V: Driver<<A as SharedData>::Item, A>,

pub fn new(driver: V) -> MatrixView<A, V>

Construct a new instance

pub fn selection_mode(&self) -> SelectionMode

Get the current selection mode

pub fn set_selection_mode(&mut self, mode: SelectionMode) -> Action

Set the current selection mode

By default, selection is disabled. If enabled, items may be selected and deselected via mouse-click/touch or via a view widget emitting Select.

On selection and deselection, a SelectionMsg message is emitted. This is not sent to Driver::on_messages.

The driver may trigger selection by emitting Select from Driver::on_messages. The driver is not notified of selection except via Select from view widgets. (TODO: reconsider this.)

pub fn with_selection_mode(self, mode: SelectionMode) -> MatrixView<A, V>

Set the selection mode (inline)

See Self::set_selection_mode documentation.

pub fn selection_style(&self) -> SelectionStyle

Get the current selection style

pub fn set_selection_style(&mut self, style: SelectionStyle) -> Action

Set the current selection style

By default, SelectionStyle::Highlight is used. Other modes may add margin between elements.

pub fn with_selection_style(self, style: SelectionStyle) -> MatrixView<A, V>

Set the selection style (inline)

See Self::set_selection_style documentation.

pub fn selected_iter(&self) -> impl Iterator<Item = &<A as SharedData>::Key>

Read the list of selected entries

With mode SelectionMode::Single this may contain zero or one entry; use selected_iter().next() to extract only the first (optional) entry.

pub fn is_selected(&self, key: &<A as SharedData>::Key) -> bool

Check whether an entry is selected

pub fn clear_selected(&mut self) -> Action

Clear all selected items

pub fn select(&mut self, key: <A as SharedData>::Key) -> Action

Directly select an item

Does nothing if Self::selection_mode is SelectionMode::None. Does not verify the validity of key. Does not send SelectionMsg messages.

Returns Action::REDRAW if newly selected, Action::empty() if already selected. Fails if selection mode does not permit selection or if the key is invalid.

pub fn deselect(&mut self, key: &<A as SharedData>::Key) -> Action

Directly deselect an item

Returns Action::REDRAW if deselected, Action::empty() if not previously selected or if the key is invalid.

pub fn with_num_visible(self, cols: i32, rows: i32) -> MatrixView<A, V>

Set the preferred number of items visible (inline)

This affects the (ideal) size request and whether children are sized according to their ideal or minimum size but not the minimum size.

Trait Implementations

impl<A, V> Clone for MatrixView<A, V>

where A: Clone + MatrixData, V: Clone + Driver<<A as SharedData>::Item, A>, <A as SharedData>::Key: Clone, <V as Driver<<A as SharedData>::Item, A>>::Widget: Clone,

fn clone(&self) -> MatrixView<A, V>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<A, V> Debug for MatrixView<A, V>

where A: Debug + MatrixData, V: Debug + Driver<<A as SharedData>::Item, A>, <A as SharedData>::Key: Debug, <V as Driver<<A as SharedData>::Item, A>>::Widget: Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<A, V> Events for MatrixView<A, V>

where A: MatrixData, V: Driver<<A as SharedData>::Item, A>,

fn make_child_id(&mut self, _: usize) -> Id

Make an identifier for a child

fn configure(&mut self, cx: &mut ConfigCx<'_>)

Configure self

fn configure_recurse( &mut self, _: &mut ConfigCx<'_>, _: &<MatrixView<A, V> as Widget>::Data )

Configure children

fn update(&mut self, cx: &mut ConfigCx<'_>, data: &A)

Update self using input data

fn update_recurse( &mut self, _: &mut ConfigCx<'_>, _: &<MatrixView<A, V> as Widget>::Data )

Update children

fn handle_event( &mut self, cx: &mut EventCx<'_>, data: &A, event: Event ) -> IsUsed

Handle an Event

fn handle_messages(&mut self, cx: &mut EventCx<'_>, data: &A)

Handler for messages from children/descendants

fn handle_scroll(&mut self, cx: &mut EventCx<'_>, data: &A, scroll: Scroll)

Handler for scrolling

fn steal_event( &mut self, _: &mut EventCx<'_>, _: &<MatrixView<A, V> as Widget>::Data, _: &Id, _: &Event ) -> IsUsed

Potentially steal an event before it reaches a child

fn navigable(&self) -> bool

Is this widget navigable via Tab key?

fn handle_hover(&mut self, cx: &mut EventCx<'_>, state: bool) -> IsUsed

Mouse focus handler

impl<A, V> Layout for MatrixView<A, V>

where A: MatrixData, V: Driver<<A as SharedData>::Item, A>,

fn num_children(&self) -> usize

Get the number of child widgets

fn get_child(&self, index: usize) -> Option<&dyn Layout>

Access a child as a dyn Layout

fn find_child_index(&self, id: &Id) -> Option<usize>

Find the child which is an ancestor of this id, if any

fn size_rules(&mut self, sizer: SizeCx<'_>, axis: AxisInfo) -> SizeRules

Get size rules for the given axis

fn set_rect(&mut self, cx: &mut ConfigCx<'_>, rect: Rect)

Set size and position

fn translation(&self) -> Offset

Get translation of children relative to this widget

fn find_id(&mut self, coord: Coord) -> Option<Id>

Translate a coordinate to an Id

fn draw(&mut self, draw: DrawCx<'_>)

Draw a widget and its children

fn as_layout(&self) -> &dyn Layout

Get as a dyn Layout

fn id_ref(&self) -> &Id

Get the widget’s identifier

fn rect(&self) -> Rect

Get the widget’s region, relative to its parent.

fn widget_name(&self) -> &'static str

Get the name of the widget struct

fn nav_next(&self, reverse: bool, from: Option<usize>) -> Option<usize>

Navigation in spatial order

impl<A, V> Scrollable for MatrixView<A, V>

where A: MatrixData, V: Driver<<A as SharedData>::Item, A>,

fn scroll_axes(&self, size: Size) -> (bool, bool)

Given size size, returns whether (horiz, vert) scrolling is required

fn max_scroll_offset(&self) -> Offset

Get the maximum scroll offset

fn scroll_offset(&self) -> Offset

Get the current scroll offset

fn set_scroll_offset(&mut self, cx: &mut EventCx<'_>, offset: Offset) -> Offset

Set the scroll offset

impl<A, V> Widget for MatrixView<A, V>

where A: MatrixData, V: Driver<<A as SharedData>::Item, A>,

type Data = A

Input data type

fn for_child_node( &mut self, data: &A, index: usize, closure: Box<dyn FnOnce(Node<'_>) + '_> )

Call closure on child with given index, if index < self.num_children().

fn as_node<'a>( &'a mut self, data: &'a <MatrixView<A, V> as Widget>::Data ) -> Node<'a>

Erase type