Apple Newton Utilities User's Guide download pdf (Page 273)

100

101

CHAPTER 7

Controls and Other Protos

Gauge and Slider Protos 7-13

■ The clGaugeView class is used to display objects that look like analog bar

gauges. Although the

clGaugeView class is available, you should use the

protoGauge to display bar gauges. purpose as is the protoGauge proto. For

more information about the slots and methods for the

protoGauge proto, see

“protoGauge” (page 6-35) in Newton Programmer’s Reference.

Figure 7-20 A clGaugeView view

Implementing a Simple Slider 7

The clGaugeView class and the slider protos all have several slots to deﬁne the

appearance and range of the slider:

■ The viewBounds slot speciﬁes the size and location of the slider.

■ The viewValue slot speciﬁes the current value of the slider.

■ The minValue slot speciﬁes the minimum value of the slider, with a default

value of

■ The maxValue slot speciﬁes the maximum value of the slider, with a default

value of

100.

You can specify the initial value of a slider in the

viewValue slot. However, you

often need to look up the initial value; when this is the case, set the initial value of

the slider in the ViewSetupFormScript method.

To implement a slider, deﬁne your template with the proto that you want to use,

specify the appearance and range slots, and (optionally) assign an initial value in

the

ViewSetupFormScript method of the proto. For some protos, you need to

deﬁne additional methods that respond to the user modifying the slider.

The following example is a template that uses

protoSlider to allow adjustment

of the current system volume:

SoundSetter := {...

_proto: protoSlider,

viewBounds: RelBounds( 12, -21, 65, 9),

viewJustify: vjParentBottomV,

maxValue: 4,

ViewSetupFormScript: func()

self.viewValue := GetUserConfig('soundVolume);

Knob

1 2 ... 268 269 270 271 272 273 274 275 276 277 278 ... 941 942

Comments to this Manuals

No comments

Apple Newton Utilities User's Guide Page 273

Comments to this Manuals

Related products and manuals for Software Apple Newton Utilities