Control that allows the selection of a value with a knob that slides
through the section of an Arc.
Uses an Arc as anchor, which defines
the position where the control is drawn.
angleDistance defines the
section of the anchor arc which is available for user interaction.
Within this section the user can slide the control knob to select a
value.
Constructor
new ArcControl(rac, value, angleDistance)
Creates a new ArcControl instance with the starting value and the
interactive angleDistance.
Parameters:
| Name | Type | Description |
|---|---|---|
rac |
Rac
|
Instance to use for drawing and creating other objects |
value |
Number
|
The initial value of the control, in the [0,1] range |
angleDistance |
Rac.Angle
|
The angleDistance of the |
Extends
Members
(nullable) anchor :Rac.Arc
Arc to which the control will be anchored. Defines the location
where the control is drawn.
Along with angleDistance
defines the section available for user interaction.
The control cannot be drawn or selected until this property is set.
- Default Value:
-
null
-
angleDistance :Number
Angle distance of the anchor arc available for user interaction.
endLimit :Number
Maximum value that can be selected through user interaction.
- Overrides:
- Default Value:
-
1
-
markers :Array.<number>
Collection of values at which visual markers are drawn.
- Overrides:
- Default Value:
-
[]
-
projectionEnd :Number
Projected value to use when
value is 1.
- Overrides:
- Default Value:
-
1
-
projectionStart :Number
Projected value to use when
value is 0.
- Overrides:
- Default Value:
-
0
-
rac :Rac
Instance of Rac used for drawing and passed along to any created
object.
- Overrides:
startLimit :Number
Minimum value that can be selected through user interaction.
- Overrides:
- Default Value:
-
0
-
style :Rac.Stroke|Rac.Fill|Rac.StyleContainer
Style to apply when drawing. This style gets applied after
rac.controller.controlStyle.
- Overrides:
- Default Value:
-
null
-
value :Number
Current selected value, in the range [0,1].
May be further constrained to [startLimit,endLimit].
- Overrides:
Methods
addMarkerAtCurrentValue()
Adds a marker at the current value.
- Overrides:
affixAnchor() → {Rac.Arc}
Returns a new Arc produced with the anchor arc with
angleDistance, to be persisted during user interaction.
An error is thrown if anchor is not set.
- Overrides:
distance() → {Rac.Angle}
Returns the angle distance between the
anchor arc start and the control knob.
The turn of the returned Angle is equivalent to the control value
projected to the range [0,angleDistance.turn].
drawSelection(pointerCenter, fixedAnchor, pointerToKnobOffset)
Draws the selection state along with pointer interaction visuals.
- Overrides:
Parameters:
| Name | Type | Description |
|---|---|---|
pointerCenter |
Rac.Point
|
The position of the user pointer |
fixedAnchor |
Rac.Arc
|
|
pointerToKnobOffset |
Rac.Segment
|
A |
isSelected() → {Boolean}
Returns true when this control is the currently selected control.
- Overrides:
knob() → (nullable) {Rac.Point}
Returns a Point at the center of the control knob.
When anchor is not set, returns null instead.
- Overrides:
projectedValue() → {Number}
Returns value projected into the range
[projectionStart,projectionEnd].
By default the projection range is [0,1], in which case value and
projectedValue() are equal.
Projection ranges with a negative direction (E.g. [50,30], when
projectionStart is greater that projectionEnd) are supported. As
value increases, the projection returned decreases from
projectionStart until reaching projectionEnd.
- Overrides:
Examples
For a control with a projection range of [100,200]
control.setProjectionRange(100, 200)
control.value = 0; control.projectionValue() // returns 100
control.value = 0.5; control.projectionValue() // returns 150
control.value = 1; control.projectionValue() // returns 200For a control with a projection range of [50,30]
control.setProjectionRange(30, 50)
control.value = 0; control.projectionValue() // returns 50
control.value = 0.5; control.projectionValue() // returns 40
control.value = 1; control.projectionValue() // returns 30setLimitsWithAngleDistanceInsets(startInset, endInset)
Sets both startLimit and endLimit with the given insets from 0
and angleDistance.turn, correspondingly, both projected in the
[0, angleDistance.turn] range.
Parameters:
| Name | Type | Description |
|---|---|---|
startInset |
Rac.Angle
|
Number
|
The inset from |
endInset |
Rac.Angle
|
Number
|
The inset from |
Example
For an ArcControl with angleDistance of 0.5 turn
let control = new Rac.ArcControl(rac, 0, rac.Angle(0.5))
// sets startLimit as 0.1, since 0 + 0.2 * 0.5 = 0.1
// sets endLimit as 0.3, since 0.5 - 0.4 * 0.5 = 0.3
control.setLimitsWithAngleDistanceInsets(0.2, 0.4)setLimitsWithInsets(startInset, endInset)
Sets both startLimit and endLimit with the given insets from 0
and 1, correspondingly.
- Overrides:
Parameters:
| Name | Type | Description |
|---|---|---|
startInset |
Number
|
The inset from |
endInset |
Number
|
The inset from |
Example
control.setLimitsWithInsets(0.1, 0.2)
// returns 0.1, since 0 + 0.1 = 0.1
control.startLimit
// returns 0.8, since 1 - 0.2 = 0.8
control.endLimitsetValueWithAngleDistance(valueAngleDistance)
Sets value using the projection of valueAngleDistance.turn in the
[0,angleLength.turn] range.
Parameters:
| Name | Type | Description |
|---|---|---|
valueAngleDistance |
Rac.Angle
|
Number
|
The angle distance at which to set the current value |
updateWithPointer(pointerKnobCenter, fixedAnchor)
Updates value using pointerKnobCenter in relation to fixedAnchor.
value is always updated by this method to be within [0,1] and
[startLimit,endLimit].
- Overrides:
Parameters:
| Name | Type | Description |
|---|---|---|
pointerKnobCenter |
Rac.Point
|
The position of the knob center as interacted by the user pointer |
fixedAnchor |
Rac.Arc
|
Anchor produced with |