Android Application Development Cookbook: 93 Recipes for Building Winning Apps

54
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ChAPter 2
using Views to design the user interFAce
for (int i = 1; i <= tag; i++) {
star = (CheckBox) rating.findViewWithTag(String.valueOf(i));
star.setChecked(true);
}
//---uncheck all remaining stars---
for (int i = tag + 1; i <= 5; i++) {
star = (CheckBox) rating.findViewWithTag(String.valueOf(i));
star.setChecked(false);
}
}
};
}
Here, you first locate all five checkboxes and listen to each checkbox’s 
onClick()
event. You locate 
the individual checkboxes using the 
findViewWithTag()
method of the 
LinearLayout
instance 
(because the checkboxes are all embedded within a 
LinearLayout
). 
When a checkbox is tapped, you check all the checkboxes up to the checkbox that was tapped and 
uncheck all the checkboxes thereafter. 
Figure 2-9 shows the star rating system in action. 
Figure 2-9 
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Recipe 2.6 using AutocompleteTextView
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55
reCiPe 2.6 
using AutoCoMPLetetextvieW
Android Versions
Level 1 and above
permissions
None
source code to download from Wrox.com
AutoComplete.zip
While you can use an 
EditText
view for entering text, it is sometimes useful to provide users 
with suggestions to automatically complete what they are typing. For example, if a user is typing 
a search string into an 
EditText
, you can offer possible suggestions to complete the search string 
while the user is typing. In this case, you can use the 
AutoCompleteTextView
to do so. This recipe 
shows you how.
solution
The 
AutoCompleteTextView
is an editable text view that shows completion suggestions while the 
user is typing. The suggestions are displayed as a drop-down menu that contains content that is sup-
plied by you. 
Assume you have the following code snippet in the 
activity_main.xml
file:
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Name of President" />
android:id="@+id/txtCountries"
android:layout_width="match_parent"
android:layout_height="wrap_content" />

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