CHAPTER 2
Container Views
2-44 How Views Work

Scrolling Performance 2

Scrolling the contents of a view can sometimes seem slow. Here are some
techniques you can use to improve scrolling speed:
■Implement the accelerated scrolling behavior described in “Local Scroll
Arrows” on page 2-39.
■Scroll multiple lines at a time, rather than just a single line at a time, when
the user taps a scroll arrow.
■Reduce the number of child views that need to be redrawn, if possible. For
example, make a list that is implemented as several paragraphs (each a
separate view) into a single paragraph.
■Set the view fill to white. Many views need no fill color, so you may be
inclined to set the fill color to none when you create such a view.
However, it’s best to fill the view with white if you don’t need a
transparent view. This can increase the performance of your application
because when the system is redrawing the screen, it doesn’t have to
update views behind those filled with a solid color such as white.
Overview 2
In addition to scrolling, an application that deals with multiple instances of
similar information can show an overview of the information—a view of the
forest instead of the trees. From the overview a user can select a part of the
information to see in detail. Figure 2-37 shows a conceptual view of the
Notepad’s overview.

Overview Contents 2

An overview is not another view displayed on top of the current view; an
overview is the same view in a different format. Instead of showing
individual data items in full detail, an overview presents a summary list of
multiple data items.