VFader

Create a vertical fader the user can drag up and down.

Faders are drawn between a starting point (x1, y1) and an ending point (x2, y2).

There are two types of faders, a horizontal fader (HFader) and a vertical fader (VFader).

Creating a VFader

You can create a VFader using the following functions:

VFader(x1, y1, x2, y2)

VFader(x1, y1, x2, y2, minValue, maxValue, startValue, action, foregroundColor, backgroundColor, outlineColor, thickness, rotation, visibility)

Parameter	Type	Default	Description
x1	int or float	required	The horizontal position of the top-left corner, in pixels.
y1	int or float	required	The vertical position of the top-left corner, in pixels.
x2	int or float	required	The horizontal position of the bottom-right corner, in pixels.
y2	int or float	required	The vertical position of the bottom-right corner, in pixels.
minValue	int	0	The smallest value the fader can take.
maxValue	int	999	The largest value the fader can take.
startValue	int or float	None	The fader's starting value. Defaults to halfway between minValue and maxValue.
action	function	None	The function to call when the fader moves; it receives the new value.
foregroundColor	Color	Color.RED	The color of the filled level.
backgroundColor	Color	Color.BLACK	The color behind the level.
outlineColor	Color	Color.BLACK	The outline color.
thickness	int	3	The outline thickness, in pixels.
rotation	int or float	0	How far to turn the fader, in degrees, counter-clockwise.
visibility	int	100	How visible the fader is, from 0 (invisible) to 100 (fully visible).

For example,

simpleFader.py

# simpleFader.py
# Creates a VFader and prints its value when it changes.

from gui import *

d = Display()

# function to specify what happens when fader is moved
def printValue(value):
   print(value)   # replace this with whatever action needs to happen

fader = VFader(25, 5, 45, 80, 0, 100, 50, printValue)
d.add(fader)

Once created, you can add it to a Display using the Display's add() function.

Functions

Once a VFader vfader has been created, the following functions are available:

Function	Description
vfader.setValue(newValue)	Set the object's value.
vfader.getValue()	Return the object's current value.

Position

Function	Description
vfader.getPosition()	Return the object's position, the top-left corner of its bounding box.
vfader.getX()	Return the object's horizontal position.
vfader.getY()	Return the object's vertical position.
vfader.getCenter()	Return the object's center point.
vfader.getCenterX()	Return the object's horizontal center.
vfader.getCenterY()	Return the object's vertical center.
vfader.setPosition(x, y)	Move the object so the top-left corner of its bounding box sits at the given point.
vfader.setX(x)	Set the object's horizontal position.
vfader.setY(y)	Set the object's vertical position.
vfader.setCenter(x, y)	Move the object so its center sits at the given point.
vfader.setCenterX(x)	Set the object's horizontal center.
vfader.setCenterY(y)	Set the object's vertical center.
vfader.move(x, y)	Move the object to a new position.

Size

Function	Description
vfader.getSize()	Return the object's width and height.
vfader.getWidth()	Return the object's width.
vfader.getHeight()	Return the object's height.
vfader.setSize(width, height)	Set the object's width and height.
vfader.setWidth(width)	Set the object's width.
vfader.setHeight(height)	Set the object's height.

Rotation

Function	Description
vfader.getRotation()	Return how far the object is turned.
vfader.setRotation(rotation)	Turn the object to a given angle.
vfader.rotate(angle)	Turn the object by an additional angle.

Visibility

Function	Description
vfader.getVisibility()	Return how visible the object is.
vfader.setVisibility(visibility)	Set how visible the object is.

Information

Function	Description
vfader.getEndpoints()	Return the object's four corners.
vfader.getBoundingBox()	Return the smallest upright box that surrounds the object.
vfader.getGroup()	Return the Group this object belongs to.
vfader.getDisplay()	Return the Display this object is on.
vfader.setToolTipText()	Set the hover text shown over the object.

Hit Testing

Function	Description
vfader.contains(x, y)	Report whether a point lies inside the object.
vfader.intersects(other)	Report whether this object overlaps another.
vfader.encloses(other)	Report whether this object completely contains another.

Events

Function	Description
vfader.onMouseClick(action)	Set up a function to call when the mouse is clicked on this object.
vfader.onMouseDown(action)	Set up a function to call when the mouse vfader is pressed on this object.
vfader.onMouseUp(action)	Set up a function to call when the mouse vfader is released over this object.
vfader.onMouseMove(action)	Set up a function to call when the mouse moves over this object.
vfader.onMouseDrag(action)	Set up a function to call when the mouse is dragged over this object.
vfader.onMouseEnter(action)	Set up a function to call when the mouse moves onto this object.
vfader.onMouseExit(action)	Set up a function to call when the mouse moves off this object.
vfader.onKeyType(action)	Set up a function to call when a key is typed (pressed and released).
vfader.onKeyDown(action)	Set up a function to call when a key is pressed down.
vfader.onKeyUp(action)	Set up a function to call when a key is released.