9
when you open the selector again, you will see that the ele-
ments have changed.
Lists
Lists have similar functionality as the selectors except that they
view multiple elements at once and take much more space
than a selector. Figure 8 shows an example of a list. Lists can
also have multiple pages as selectors do and the functionali-
ty is the same.
Note that selectors and lists are not usually sorted, since the
data is loaded directly from the databases in the order it
has been stored into the database and sorting requires more
processing power than is available in Palm. If you want to
have the subjects in alphabetical order across multiple list
2.2 Basic graphical elements
Buttons
An example button is shown in Figure 3. When you tap on a
button, some action is performed.
Selectors
Selectors are lists that have only one visible element at a time.
Figure 4 shows an example of a closed selector. When a se-
lector is tapped it opens and shows the list of elements it con-
tains. Figure 5 shows an example of an open selector. Tap-
ping on one of the list elements selects the element and closes
the selector.
Powertimer may contain more data that is possible to show in
a selector at once. For example a group of 40 subjects that
performs 10 tests results in 400 test actions (and thousands of
test results). For that purpose the selectors may contain multi-
ple pages of data. The pages speed up the loading of data
from the databases, since only one page needs to be load-
ed at a time. The downside to this is that you have to shuffle
through the pages to locate the right element. When a multi-
page selector is opened for the first time, it will look like Fig-
ure 6. If the selector is in its last page, it will only show the
Pre-
vious Page
element as shown in Figure 7. If the selector is in a
middle page it shows both the
-Previous Page
and
+Next Page
elements.
If you tap on the
+Next Page
or
-Previous Page
elements, noth-
ing seems to happen and the selector will close. However,
Figure 3
Button
Figure 5
Open selector
Figure 6
First page of a openened multipage selector
Figure 4
Closed selector
Figure 8
List
Figure 7
Last page of a opened multi-page selector
