Hylograph.Behavior

identityTransform :: ZoomTransform

The zoom transform with no scaling and no translation.

attachZoomWithTransform and attachZoomWithCallback both take a transform to restore. Pass this one when there is nothing to restore — on a first render, say — rather than writing the record out.

attachZoom :: Element -> ZoomConfig -> Effect Element

Attach zoom and pan to an element, transforming whatever the config's selector matches.

The element is typically the <svg>; the selector names the group inside it that actually moves.

_ <- attachZoom svgElem (defaultZoom (ScaleExtent 0.5 4.0) ".zoom-group")

Returns the element, for chaining.

attachZoomWithTransform :: Element -> ZoomConfig -> ZoomTransform -> Effect Element

Attach zoom and immediately apply a transform.

Use this to preserve the user's zoom across a re-render: read the transform with readZoomTransform before tearing down, hand it back here afterwards.

attachZoomWithCallback :: Element -> ZoomConfig -> ZoomTransform -> (ZoomTransform -> Effect Unit) -> Effect Element

Attach zoom, apply a transform, and run a callback on every zoom event.

The callback is for things that must track the zoom but are not inside the transformed group — annotations positioned in screen space, arrows whose stroke width should not scale, a readout of the current level.

readZoomTransform :: Element -> Effect ZoomTransform

The element's current zoom transform, or identityTransform if it has never been zoomed.

registerSimulation :: String -> Effect Unit -> Effect Unit

Make a simulation reachable by name, so that simulationDrag can find it.

simulationDrag "lesmis" in a HATS tree says which simulation a drag should reheat; this says what is under that name. The second argument is the reheat action, run whenever a drag on a registered node begins.

registerSimulation "lesmis" (Sim.reheat sim)

Names are global. Pair every call with unregisterSimulation when the visualisation is torn down, or a finalised simulation stays reachable.

unregisterSimulation :: String -> Effect Unit

Remove a simulation from the registry. Call this on teardown.

data ScrollBehavior

How a scroll should be animated.

Constructors

• Smooth
• Instant
• Auto

  Auto defers to the element's computed scroll-behavior.

Instances

• Eq ScrollBehavior
• Ord ScrollBehavior
• Show ScrollBehavior

data ScrollBlock

Where the element should come to rest in the scrollport.

Constructors

• Start
• Center
• End
• Nearest

  Nearest scrolls the least amount that brings it into view.

Instances

• Eq ScrollBlock
• Ord ScrollBlock
• Show ScrollBlock

scrollToElement :: String -> Effect Unit

Scroll the element with the given id into view: smoothly, centred.

These are the defaults you want almost always. Reach for scrollToElementWith when they are not.

scrollToElementWith :: ScrollBehavior -> ScrollBlock -> String -> Effect Unit

Scroll the element with the given id into view, choosing the animation and the resting position.

type ZoomTransform = { k :: Number, x :: Number, y :: Number }

A zoom transform: scale k, and translation x/y.

Produced by every zoom event and accepted by the attach functions in Hylograph.Behavior, which is how zoom state survives a re-render. { k: 1.0, x: 0.0, y: 0.0 } is the identity, available there as identityTransform.