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Defining view characteristics 3 – Apple Newton Programmer’s Newton 2.0 (for Newton 2.0) User Manual

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C H A P T E R 3

Views

3-8

About Views

As the grid lines are infinitely thin, so a point is infinitely small. Pixels, by contrast,
lie between the lines of the coordinate grid, not at their intersections.

This relationship gives them a definite physical extent, so that they can be seen on
the screen.

Defining View Characteristics

3

A template that describes a view is stored as a frame that has slots for view
characteristics. Here is a NewtonScript example of a template that describes a view:

{viewClass: clView,

viewBounds: RelBounds( 20, 50, 94, 142 ),

viewFlags: vNoFlags,

viewFormat:vfFillWhite+vfFrameBlack+vfPen(1),

viewJustify: vjCenterH,

viewFont: simpleFont10,

declareSelf: 'base,

debug: "dialer",

};

Briefly, the syntax for defining a frame is:

{

slotName

:

slotValue

,

slotName

:

slotValue

,

...};

where slotName is the name of a slot, and slotValue is the value of a slot. For more
details on NewtonScript syntax, refer to The NewtonScript Programming Language.

Frames serving as view templates have slots that define the following kinds of view
characteristics:

Class

The

viewClass

slot defines the class of graphic object from

which the view is constructed.

Behavior

The

viewFlags

slot defines other primary view behaviors

and controls recognition behavior.

Location, size, and alignment

The

viewBounds

and

viewJustify

slots define the

location, size, and alignment of the view and its contents.

Appearance

The

viewFormat

slot defines the frame and fill

characteristics. The

viewFillPattern

and

viewFramePattern

slots control custom patterns.

Transfer modes used in drawing the view are controlled
by the

viewTransferMode

slot.