Enum freya::events::Force

pub enum Force {
    Calibrated {
        force: f64,
        max_possible_force: f64,
        altitude_angle: Option<f64>,
    },
    Normalized(f64),
}

Describes the force of a touch event

Variants

Calibrated

On iOS, the force is calibrated so that the same number corresponds to roughly the same amount of pressure on the screen regardless of the device.

Fields

force: f64

The force of the touch, where a value of 1.0 represents the force of an average touch (predetermined by the system, not user-specific).

The force reported by Apple Pencil is measured along the axis of the pencil. If you want a force perpendicular to the device, you need to calculate this value using the altitude_angle value.

max_possible_force: f64

The maximum possible force for a touch.

The value of this field is sufficiently high to provide a wide dynamic range for values of the force field.

altitude_angle: Option<f64>

The altitude (in radians) of the stylus.

A value of 0 radians indicates that the stylus is parallel to the surface. The value of this property is Pi/2 when the stylus is perpendicular to the surface.

Normalized(f64)

If the platform reports the force as normalized, we have no way of knowing how much pressure 1.0 corresponds to – we know it’s the maximum amount of force, but as to how much force, you might either have to press really really hard, or not hard at all, depending on the device.

Implementations

impl Force

pub fn normalized(&self) -> f64

Returns the force normalized to the range between 0.0 and 1.0 inclusive.

Instead of normalizing the force, you should prefer to handle Force::Calibrated so that the amount of force the user has to apply is consistent across devices.

Trait Implementations

impl Clone for Force

fn clone(&self) -> Force

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Force

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

Formats the value using the given formatter.

impl PartialEq for Force

fn eq(&self, other: &Force) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Force

impl StructuralPartialEq for Force