Class: ThumbWheel

• Inheritance
• Description
• Related information
• Instance protocol
  • accessing
  • accessing-behavior
  • accessing-look
  • drawing
  • events
  • forced scroll
  • initialization
  • private
  • queries
• Examples

Inheritance:

   Object
   |
   +--GraphicsContext
      |
      +--DeviceGraphicsContext
         |
         +--GraphicsMedium
            |
            +--DisplaySurface
               |
               +--SimpleView
                  |
                  +--View
                     |
                     +--ThumbWheel

Package:

stx:libwidg3

Category:

Views-Interactors

Version:

rev: 1.31 date: 2006/03/20 08:37:28

user: cg

file: ThumbWheel.st directory: libwidg3

module: stx stc-classLibrary: libwidg3

Author:

Claus Gittinger

Description:

A thumbWheel is like a slider, but looks different ...
ThumbWheels are useful with 3D applications, to control
things like rotation, translation and magnification.

Related information:

    Slider
    ScrollBar
    StepSlider

Instance protocol:

 keyboardStep

return the scrollers keyboard step. If non-nil,
thats the stepping value used with cursorUp/cursorDown keys.
(not used with Scrollers, but provided for subclasses)

 keyboardStep: aNumber

set the scrollers keyboard step. If non-nil,
thats the stepping value used with cursorUp/cursorDown keys.
(not used with Scrollers, but provided for subclasses)

 start

return the wheels range minimum.

 start: aNumber

set the wheels range minimum.

 start: start stop: stop

set the wheels range minimum.

 step

return the wheels range step.

 step: aNumber

set the wheels range step.

 stop

return the wheels range end.

 stop: aNumber

set the wheels range end.

 thumbOrigin: pos

same as thumbPosition (for protocol compatibility with sliders)

 thumbPosition

sreturn the position

 thumbPosition: pos

set the wheels position; the argument should be in the start..stop
interval.

 endMoveAction

set the endMoveAction, a block which is evaluated when the wheel
stops to move (i.e. the user releases the mouse).
The default is nil (i.e. no action)

 endMoveAction: aBlock

set the endMoveAction, a block which is evaluated when the wheel
stops to move (i.e. the user releases the mouse).

 endlessRotation: aBoolean

if true, rotation wraps and endless rotation is permitted.
If false (the default), rotation ends at rangeStart/rangeEnd.

 scrollAction

return the scrollAction, a block which is evaluated when the wheel
is turned (i.e. for every change).

 scrollAction: aBlock

set the scrollAction, a block which is evaluated when the wheel
is turned (i.e. for every change).

 startMoveAction

return the startMoveAction, a block which is evaluated when the wheel
starts to turn (i.e. the user clicks on it).
The default is nil (i.e. no action)

 startMoveAction: aBlock

set the startMoveAction, a block which is evaluated when the wheel
starts to turn (i.e. the user clicks on it).

 orientation

return the wheels orientation; #horizontal or #vertical

 orientation: aSymbol

set the wheels orientation; the argument may be one of
#horizontal or #vertical

 redrawX: x y: y width: w height: h

redraw the thumbWheel.
Q: is it worth the effort - or should we simply use some bitmap ?

 buttonMotion: state x: x y: y

 buttonPress: button x: x y: y

 buttonRelease: button x: x y: y

 keyPress: key x: x y: y

 sizeChanged: how

 update: something with: aParameter from: changedObject

handle update from a model (if any)

 scrollDown: amountToScroll

compatibility with SimpleView. This allows mouse wheel actions on Scrollers
Note: this is used for horizontal scrollers, too (scrollRight)

 scrollStep: delta

step by some delta

 scrollUp: amountToScroll

compatibility with SimpleView. This allows mouse wheel actions on Scrollers
Note: this is used for horizontal scrollers, too (scrollLeft)

 initialize

initialize - setup instvars from defaults

 tellOthers

notify others of a change

 preferredExtent

return a useful default extent

 verticalScrollStep

mouse wheel: scroll step
Note: this is used for horizontal scrollers, too

Examples:

  |top wheel|

  top := StandardSystemView new.
  top extent:200@200.

  wheel := ThumbWheel in:top.
  wheel orientation:#vertical.
  wheel level:1.

  wheel origin:0.0@0.0; extent:(wheel preferredExtent).

  top open.

  |top wheel1 wheel2|

  top := StandardSystemView new.
  top extent:200@200.

  wheel1 := ThumbWheel in:top.
  wheel1 orientation:#vertical.
  wheel1 level:1.

  wheel1 origin:0.0@0.0; extent:(wheel1 preferredExtent).

  wheel2 := ThumbWheel in:top.
  wheel2 orientation:#horizontal.
  wheel2 level:1.

  wheel2 origin:0.0@1.0; extent:(wheel2 preferredExtent).
  wheel2 topInset:(wheel2 preferredExtent y negated).
  wheel2 bottomInset:(wheel2 preferredExtent y).
  top open.

  |top wheel|

  top := StandardSystemView new.
  top extent:200@200.

  wheel := ThumbWheel in:top.
  wheel orientation:#vertical.
  wheel level:1.

  wheel origin:0.0@0.0; extent:(wheel preferredExtent).
  wheel scrollAction:[:value | Transcript showCR:value rounded].
  top open.

  |top wheel model|

  model := ValueHolder new.
  model 
      onChangeSend:#value 
      to:[Transcript show:'value now: '; showCR:model value rounded].

  top := StandardSystemView new.
  top extent:200@200.

  wheel := ThumbWheel in:top.
  wheel orientation:#vertical.
  wheel level:1.

  wheel origin:0.0@0.0; extent:(wheel preferredExtent).
  wheel model:model.
  top open.

  |top wheel model|

  model := ValueHolder new.
  model 
      onChangeSend:#value 
      to:[Transcript show:'value now: '; showCR:model value rounded].

  top := StandardSystemView new.
  top extent:200@200.

  wheel := ThumbWheel in:top.
  wheel orientation:#vertical.
  wheel level:1.
  wheel endlessRotation:true.

  wheel origin:0.0@0.0; extent:(wheel preferredExtent).
  wheel model:model.
  top open.

  |top wheel1 wheel2 image magX magY hHolder vHolder imageView|

  magX := magY := 1.

  hHolder := ValueHolder new.
  hHolder
      onChangeSend:#value 
      to:[
          magX := hHolder value * 2 / 360.
          magX = 0 ifTrue:[magX := 0.01].
          Transcript show:'magX now '; showCR:magX.
          imageView clear.
          imageView magnification:magX@magY].

  vHolder := ValueHolder new.
  vHolder
      onChangeSend:#value 
      to:[
          magY := vHolder value * 2 / 360.
          magY = 0 ifTrue:[magY := 0.01].
          Transcript show:'magY now '; showCR:magY.
          imageView clear.
          imageView magnification:magX@magY].

  top := StandardSystemView new.
  top extent:200@200.

  wheel1 := ThumbWheel in:top.
  wheel1 orientation:#vertical.
  wheel1 level:1.
  wheel1 origin:0.0@0.0; extent:(wheel1 preferredExtent).
  wheel1 model:vHolder.

  wheel2 := ThumbWheel in:top.
  wheel2 orientation:#horizontal.
  wheel2 level:1.
  wheel2 origin:0.0@1.0; extent:(wheel2 preferredExtent).
  wheel2 topInset:(wheel2 preferredExtent y negated).
  wheel2 bottomInset:(wheel2 preferredExtent y).
  wheel2 model:hHolder.

  imageView := ImageEditView in:top.
  imageView level:1.
  imageView origin:0.0@0.0 corner:1.0@1.0.
  imageView leftInset:(wheel1 preferredExtent x).
  imageView bottomInset:(wheel2 preferredExtent y).
  imageView image:(Image fromFile:'bitmaps/garfield.gif').
  top open.