Struct gdk4::ScrollEvent[][src]

#[repr(transparent)]
pub struct ScrollEvent(_);
Expand description

An event related to a scrolling motion.

Implementations

Extracts the scroll deltas of a scroll event.

The deltas will be zero unless the scroll direction is ScrollDirection::Smooth.

Returns
delta_x

return location for x scroll delta

delta_y

return location for y scroll delta

Extracts the direction of a scroll event.

Returns

the scroll direction of @self

Check whether a scroll event is a stop scroll event.

Scroll sequences with smooth scroll information may provide a stop scroll event once the interaction with the device finishes, e.g. by lifting a finger. This stop scroll event is the signal that a widget may trigger kinetic scrolling based on the current velocity.

Stop scroll events always have a delta of 0/0.

Returns

true if the event is a scroll stop event

Methods from Deref<Target = Event>

Returns a DeviceTool representing the tool that caused the event.

If the was not generated by a device that supports different tools (such as a tablet), this function will return None.

Note: the DeviceTool will be constant during the application lifetime, if settings must be stored persistently across runs, see DeviceTool::serial().

Returns

The current device tool

Retuns the event sequence to which the event belongs.

Related touch events are connected in a sequence. Other events typically don’t have event sequence information.

Returns

the event sequence that the event belongs to

Extracts all axis values from an event.

Returns

true on success, otherwise false

axes

the array of values for all axes

Extract the axis value for a particular axis use from an event structure.

axis_use

the axis use to look for

Returns

true if the specified axis was found, otherwise false

value

location to store the value found

Returns the device of an event.

Returns

a Device

Retrieves the display associated to the @self.

Returns

a Display

Retrieves the type of the event.

Returns

a EventType

Retrieves the history of the device that @self is for, as a list of time and coordinates.

The history includes positions that are not delivered as separate events to the application because they occurred in the same frame as @self.

Note that only motion and scroll events record history, and motion events do it only if one of the mouse buttons is down.

Returns

an array of time and coordinates

Returns the modifier state field of an event.

Returns

the modifier state of @self

Returns whether this event is an ‘emulated’ pointer event.

Emulated pointer events typically originate from a touch events.

Returns

true if this event is emulated

Extract the event surface relative x/y coordinates from an event.

Returns
x

location to put event surface x coordinate

y

location to put event surface y coordinate

Returns the seat that originated the event.

Returns

a Seat.

Extracts the surface associated with an event.

Returns

The Surface associated with the event

Returns the timestamp of @self.

Not all events have timestamps. In that case, this function returns GDK_CURRENT_TIME.

Returns

timestamp field from @self

Returns whether a Event should trigger a context menu, according to platform conventions.

The right mouse button typically triggers context menus.

This function should always be used instead of simply checking for event->button == GDK_BUTTON_SECONDARY.

Returns

true if the event should trigger a context menu.

Trait Implementations

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The resulting type after dereferencing.

Dereferences the value.

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Returns the type identifier of Self.

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