Struct VelocityDrag 

pub struct VelocityDrag { /* private fields */ }

State for velocity-based dragging

This helper manages drag state for sliders, knobs, or any parameter control that benefits from velocity-sensitive adjustment.

Example

use armas_basic::animation::{VelocityDrag, VelocityDragConfig, DragMode};

let mut drag = VelocityDrag::new(VelocityDragConfig::new().sensitivity(1.5));

// On mouse down:
drag.begin(current_value, mouse_y, use_velocity_mode);

// On mouse drag:
let delta = drag.update(mouse_y, value_range);
value += delta;

// On mouse up:
drag.end();

Implementations

impl VelocityDrag

pub const fn new(config: VelocityDragConfig) -> Self

Create a new velocity drag helper with the given configuration

pub fn with_defaults() -> Self

Create with default configuration

pub const fn mode(&self) -> DragMode

Get the current drag mode

pub fn is_dragging(&self) -> bool

Check if a drag is in progress

pub fn is_velocity_mode(&self) -> bool

Check if velocity mode is active

pub fn is_absolute_mode(&self) -> bool

Check if absolute mode is active

pub const fn begin( &mut self, current_value: f64, mouse_pos: f64, use_velocity_mode: bool, )

Begin a drag operation

• current_value: The current parameter value
• mouse_pos: Current mouse position (typically Y for vertical, X for horizontal)
• use_velocity_mode: Whether to use velocity mode (can be toggled by modifier)

pub fn begin_auto( &mut self, current_value: f64, mouse_pos: f64, modifiers: &Modifiers, default_velocity_mode: bool, )

Begin drag, automatically choosing mode based on modifier keys

If default_velocity_mode is true, velocity mode is the default and modifier keys switch to absolute. Otherwise, absolute is default.

pub fn update( &mut self, mouse_pos: f64, value_range: f64, drag_pixels: f64, ) -> f64

Update during drag and return the value delta

• mouse_pos: Current mouse position
• value_range: Total range of the parameter (max - min)
• drag_pixels: Number of pixels for full range in absolute mode

Returns the delta to add to the current value

pub fn update_tracked( &mut self, mouse_pos: f64, value_range: f64, drag_pixels: f64, ) -> f64

Update and track accumulated delta

Same as update() but also tracks the total change for absolute mode

pub const fn end(&mut self)

End the drag operation

pub const fn start_value(&self) -> f64

Get the start value when drag began

pub const fn accumulated_delta(&self) -> f64

Get the total accumulated delta since drag began

Trait Implementations

impl Clone for VelocityDrag

fn clone(&self) -> VelocityDrag

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VelocityDrag

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

Formats the value using the given formatter.