Struct kas::widget::DragHandle

pub struct DragHandle { /* fields omitted */ }

Draggable Handle

A DragHandle is a draggable object with a given size which is restricted to a track and has an offset relative to the start of that track.

This widget is unusual in several ways:

1. Layout::size_rules does not request any size; the parent is expected to do this.
2. Layout::set_rect sets the track within which this handle may move; the parent should always call DragHandle::set_size_and_offset afterwards.
3. Layout::draw does nothing. The parent should handle all drawing.
4. Optionally, this widget can handle clicks on the track area via DragHandle::handle_press_on_track.

Methods

impl DragHandle

pub fn new() -> Self

Construct

pub fn set_size_and_offset(&mut self, size: Size, offset: Coord) -> TkAction

Set a new handle size and offset

Returns TkAction::Redraw if a redraw is required.

pub fn track(&self) -> Rect

Get the current tract Rect

pub fn offset(&self) -> Coord

Get the current handle offset

pub fn max_offset(&self) -> Coord

Get the maximum allowed offset

This depends on size of the handle and the track.

pub fn set_offset(&mut self, offset: Coord) -> (Coord, TkAction)

Set a new handle offset

Returns the new offset (after clamping input) and an action: None if the handle hasn't moved; Redraw if it has (though this widget is not directly responsible for drawing, so this may not be accurate).

pub fn handle_press_on_track(
    &mut self,
    mgr: &mut Manager,
    source: PressSource,
    coord: Coord
) -> Coord

Handle an event on the track itself

If it is desired to make the handle move when the track area is clicked, then the parent widget should call this method when receiving Event::PressStart.

This method moves the handle immediately and returns the new offset.

Trait Implementations

impl Clone for DragHandle

fn clone(&self) -> DragHandle

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DragHandle

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Default for DragHandle

fn default() -> DragHandle

Returns the "default value" for a type.

impl Handler for DragHandle

type Msg = Coord

Type of message returned by this widget

fn handle(&mut self, mgr: &mut Manager, event: Event) -> Response<Self::Msg>

Handle an event and return a user-defined message

fn activation_via_press(&self) -> bool

Generic handler: translate presses to activations

impl Layout for DragHandle

This implementation is unusual in that:

1. size_rules always returns SizeRules::EMPTY
2. set_rect sets the track within which this handle may move; the parent should call DragHandle::set_size_and_offset after set_rect (otherwise the handle's offset will not be updated)
3. draw does nothing: the parent is expected to do all drawing

fn size_rules(&mut self, _: &mut dyn SizeHandle, _: AxisInfo) -> SizeRules

Get size rules for the given axis

fn set_rect(&mut self, rect: Rect, _: AlignHints)

Apply a given rect to self

fn draw(&self, _: &mut dyn DrawHandle, _: &ManagerState, _: bool)

Draw a widget and its children

fn translation(&self, _child_index: usize) -> Coord

Get translation of a child

fn spatial_range(&self) -> (usize, usize)

Iterate through children in spatial order

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

Find a widget by coordinate

impl SendEvent for DragHandle

fn send(
    &mut self,
    mgr: &mut Manager,
    id: WidgetId,
    event: Event
) -> Response<Self::Msg>

Send an event

impl Widget for DragHandle

impl WidgetChildren for DragHandle

fn len(&self) -> usize

Get the number of child widgets

fn get(&self, _index: usize) -> Option<&dyn WidgetConfig>

Get a reference to a child widget by index, or None if the index is out of bounds.

fn get_mut(&mut self, _index: usize) -> Option<&mut dyn WidgetConfig>

Mutable variant of get

fn is_ancestor_of(&self, id: WidgetId) -> bool

Check whether id is a descendant

fn find(&self, id: WidgetId) -> Option<&dyn WidgetConfig>

Find a child widget by identifier

fn find_mut(&mut self, id: WidgetId) -> Option<&mut dyn WidgetConfig>

Find a child widget by identifier

fn walk(&self, f: &mut dyn FnMut(&dyn WidgetConfig))

Walk through all widgets, calling f once on each.

fn walk_mut(&mut self, f: &mut dyn FnMut(&mut dyn WidgetConfig))

Walk through all widgets, calling f once on each.

impl WidgetConfig for DragHandle

fn key_nav(&self) -> bool

Is this widget navigable via Tab key?

fn cursor_icon(&self) -> CursorIcon

Which cursor icon should be used on hover?

fn configure(&mut self, _: &mut Manager)

Configure widget

fn configure_recurse<'a, 'b>(&mut self, cmgr: ConfigureManager<'a, 'b>)

Configure self and children

impl WidgetCore for DragHandle

fn as_any(&self) -> &dyn Any

Get self as type Any

fn as_any_mut(&mut self) -> &mut dyn Any

Get self as type Any (mutable)

fn core_data(&self) -> &CoreData

Get direct access to the CoreData providing property storage.

fn core_data_mut(&mut self) -> &mut CoreData

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

Get the name of the widget struct

fn as_widget(&self) -> &dyn WidgetConfig

Erase type

fn as_widget_mut(&mut self) -> &mut dyn WidgetConfig

Erase type

fn id(&self) -> WidgetId

Get the widget's numeric identifier

fn is_disabled(&self) -> bool

Get whether the widget is disabled

fn set_disabled(&mut self, disabled: bool) -> TkAction

Get the disabled state of a widget

fn rect(&self) -> Rect

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

fn input_state(&self, mgr: &ManagerState, disabled: bool) -> InputState

Construct InputState