Struct lv2_sys::LV2UI_Port_Subscribe

#[repr(C)]pub struct LV2UI_Port_Subscribe {
    pub handle: LV2UI_Feature_Handle,
    pub subscribe: Option<unsafe extern "C" fn(handle: LV2UI_Feature_Handle, port_index: u32, port_protocol: u32, features: *const *const LV2_Feature) -> u32>,
    pub unsubscribe: Option<unsafe extern "C" fn(handle: LV2UI_Feature_Handle, port_index: u32, port_protocol: u32, features: *const *const LV2_Feature) -> u32>,
}

Feature to subscribe to port updates (LV2_UI__portSubscribe).

Fields

handle: LV2UI_Feature_Handle

Pointer to opaque data which must be passed to subscribe() and unsubscribe().

subscribe: Option<unsafe extern "C" fn(handle: LV2UI_Feature_Handle, port_index: u32, port_protocol: u32, features: *const *const LV2_Feature) -> u32>

Subscribe to updates for a port.

This means that the host will call the UI's port_event() function when the port value changes (as defined by protocol).

Calling this function with the same port_index and port_protocol as an already active subscription has no effect.

@param handle The handle field of this struct. @param port_index The index of the port. @param port_protocol The URID of the ui:PortProtocol. @param features Features for this subscription. @return 0 on success.

unsubscribe: Option<unsafe extern "C" fn(handle: LV2UI_Feature_Handle, port_index: u32, port_protocol: u32, features: *const *const LV2_Feature) -> u32>

Unsubscribe from updates for a port.

This means that the host will cease calling calling port_event() when the port value changes.

Calling this function with a port_index and port_protocol that does not refer to an active port subscription has no effect.

@param handle The handle field of this struct. @param port_index The index of the port. @param port_protocol The URID of the ui:PortProtocol. @param features Features for this subscription. @return 0 on success.

Trait Implementations

impl Clone for LV2UI_Port_Subscribe

fn clone(&self) -> LV2UI_Port_Subscribe

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for LV2UI_Port_Subscribe

impl Debug for LV2UI_Port_Subscribe

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

Formats the value using the given formatter.