gi-gtk-3.0.36: Gtk bindings
CopyrightWill Thompson Iñaki García Etxebarria and Jonas Platte
LicenseLGPL-2.1
MaintainerIñaki García Etxebarria
Safe HaskellNone
LanguageHaskell2010

GI.Gtk.Objects.GestureZoom

Description

GestureZoom is a Gesture implementation able to recognize pinch/zoom gestures, whenever the distance between both tracked sequences changes, the scaleChanged signal is emitted to report the scale factor.

Synopsis

Exported types

class (GObject o, IsDescendantOf GestureZoom o) => IsGestureZoom o Source #

Type class for types which can be safely cast to GestureZoom, for instance with toGestureZoom.

Instances

Instances details
(GObject o, IsDescendantOf GestureZoom o) => IsGestureZoom o Source # 
Instance details

Defined in GI.Gtk.Objects.GestureZoom

toGestureZoom :: (MonadIO m, IsGestureZoom o) => o -> m GestureZoom Source #

Cast to GestureZoom, for types for which this is known to be safe. For general casts, use castTo.

Methods

Overloaded methods

getScaleDelta

gestureZoomGetScaleDelta Source #

Arguments

:: (HasCallStack, MonadIO m, IsGestureZoom a) 
=> a

gesture: a GestureZoom

-> m Double

Returns: the scale delta

If gesture is active, this function returns the zooming difference since the gesture was recognized (hence the starting point is considered 1:1). If gesture is not active, 1 is returned.

Since: 3.14

new

gestureZoomNew Source #

Arguments

:: (HasCallStack, MonadIO m, IsWidget a) 
=> a

widget: a Widget

-> m GestureZoom

Returns: a newly created GestureZoom

Returns a newly created Gesture that recognizes zoom in/out gestures (usually known as pinch/zoom).

Since: 3.14

Signals

scaleChanged

type C_GestureZoomScaleChangedCallback = Ptr () -> CDouble -> Ptr () -> IO () Source #

Type for the callback on the (unwrapped) C side.

type GestureZoomScaleChangedCallback Source #

Arguments

 = Double

scale: Scale delta, taking the initial state as 1:1

-> IO () 

This signal is emitted whenever the distance between both tracked sequences changes.

Since: 3.14

afterGestureZoomScaleChanged :: (IsGestureZoom a, MonadIO m) => a -> GestureZoomScaleChangedCallback -> m SignalHandlerId Source #

Connect a signal handler for the scaleChanged signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gestureZoom #scaleChanged callback

onGestureZoomScaleChanged :: (IsGestureZoom a, MonadIO m) => a -> GestureZoomScaleChangedCallback -> m SignalHandlerId Source #

Connect a signal handler for the scaleChanged signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gestureZoom #scaleChanged callback