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C H A P T E R 3
Views
3-38
Using Views
Each of the three return values contains three elements:
Element 0: the subview that is highlighted. This subview is usually
a
clParagraphView
, but you need to check to make sure. A
clPolygonView
is not returned here even if
HiliteOwner
returns a
clEditView
when a
clPolygonView
child is highlighted.
Element 1: the start position of the text found in the text slot of a
clParagraphView
.
Element 2: the end position of the text found in the text slot of a
clParagraphView
.
To verify that your view is a
clParagraphView
, check the
viewClass
slot of
the view. The value returned (dynamically) sometimes has a high bit set so you
need to take it into consideration using a mask constant,
vcClassMask
:
theviews.viewClass=clParagraphView OR
theView.viewClass - vcClassMask=clParagraphView
BAnd(thViews.viewClass, BNot(vcClassMask))=clParagraphView
If a graphic is highlighted and
HiliteOwner
returns a
clEditView
, check its
view children for non-
nil
values of the '
hilites
slot (the '
hilites
slot is for
use in any view but its contents are private).
Complex View Effects
3
If you have an application that uses
ViewQuitScript
in numerous places, your
view may close immediately, but to the user the Newton may appear to be hung
during the long calculations. A way to avoid this is to have the view appear open
until the close completes.
You can accomplish this effect in one of two ways. First, put your code in
ViewHideScript
instead of
ViewCloseScript
. Second, remove the view's
ViewEffect
and manually force the effect at the end of
ViewQuitScript
using the
Effect
method.
Making Modal Views
3
A modal view is one that primarily restricts the user to interacting with that view.
All taps outside the modal view are ignored while the modal view is open.
In the interest of good user interface design, you should avoid using modal views
unless they are absolutely necessary. However, there are occasions when you may
need one.
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