This document provides an overview of Android resources, which include strings, layouts, colors, dimensions, images and other assets that are used in Android applications. It discusses the different types of resources and how they are defined using XML files and referenced using unique IDs in Java code. Key resource types covered include strings, colors, dimensions, layouts, drawables and styles/themes. The document also summarizes common Android views and view groups like buttons, pickers, lists and different layout managers like linear, relative and frame layouts.

1. Android Application
Fundamentals

3. Android Resources
Compiled and Uncompiled Android Resources
• XML files
• Raw files

4. String Resources
• Define strings in one or more
XML resource files.
• These XML files containing
string-resource definitions
reside in the /res/values
subdirectory.
strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">hello</string>
<string name="app_name">hello
appname</string>
</resources>
Android Resources

5. Layout Resources
• A key resource used in
Android UI programming.
public class HelloWorldActivity extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
...
}
Android Resources

6. Example main.xml Layout File
<?xml version="1.0" encoding="utf-
8"?>
<LinearLayout
xmlns:android="http://schemas.andr
oid.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
</LinearLayout>
Android Resources

7. Color Resources
<resources>
<color name="red">#f00</color>
<color
name="blue">#0000ff</color>
<color
name="green">#f0f0</color>
<color
name="main_back_ground_color">
#ffffff00</color>
</resources>
Android Resources

8. Color Resources in Java code
int mainBackGroundColor =
activity.getResources.getColor(R.color.main_back_ground_color);
Using Colors in View Definitions
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@color/red"
android:text="Sample Text to Show Red Color"/>
Android Resources

9. Dimension Resources
You can specify the dimensions in any of the following units:
px: Pixels
in: Inches
mm: Millimeters
pt: Points
dp: Density-independent pixels based on pixel density per inch
sp: Scale-independent pixels (dimensions that allow for user sizing;
helpful for use in fonts)
Android Resources

10. XML Syntax for Defining Dimension
Resources
<resources>
<dimen name="mysize_in_pixels">1px</dimen>
<dimen name="mysize_in_dp">5dp</dimen>
<dimen name="medium_size">100sp</dimen>
</resources>
Using Dimension Resources in XML
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="@dimen/medium_size"/>
Android Resources

11. Image Resources
Using Image Resources in XML
<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Dial"
android:background="@drawable/sample_image"
/>
Android Resources

12. Android Resources
package com.mycompany.android.my-root-package;
public final class R {
...other entries depending on your project and application
public static final class string
{
...other entries depending on your project and application
publicstaticfinal int hello=0x7f040000;
publicstaticfinal int app_name=0x7f040001;
...other entries depending on your project and application
}
...other entries depending on your project and application
}
• R.java with unique IDs for the
two string resources specified.
R.java

13. Resource Reference Syntax
Android resources are identified (or referenced) by their IDs in Java source code.
<TextView android:id="@+id/text">
//Success: Creates an id called "text" in the local package's R.java
In the syntax "@+id/text", the + sign has a special meaning. It tells Android that the ID
text may not already exist
Android Resources

14. Android
View and ViewGroup

15. Buttons

16. Basic Button
<Button android:id="@+id/button1"
android:text="@string/basicBtnLabel"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
……………………
ImageButton
<ImageButton android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="myClickHandler"
android:src="@drawable/icon" />
……………..
ImageButton imageButton2 =
(ImageButton)this.findViewById(R.id.imageButton2);
imageButton2.setImageResource(R.drawable.icon);
Buttons

17. ToggleButton
<ToggleButton android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Toggle Button"
android:textOn="Stop"
android:textOff="Run"/>
Button button1 = (Button)this.findViewById(R.id.button1);
button1.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Intent intent = new Intent(Intent.ACTION_VIEW,
Uri.parse("http://www.androidbook.com"));
startActivity(intent);
}
});
Buttons

18. CheckBox
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<CheckBox android:id="@+id/chickenCB"
android:text="Chicken" android:checked="true"
android:layout_width=“wrap_content"
android:layout_height="wrap_content" />
<CheckBox android:id="@+id/fishCB" android:text="Fish"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<CheckBox android:id="@+id/steakCB"
android:text="Steak" android:checked="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
CheckBox

19. RadioButton
RadioButton
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RadioGroup android:id="@+id/rBtnGrp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<RadioButton android:id="@+id/chRBtn"
android:text="Chicken"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
………………………..
</RadioGroup>
</LinearLayout>

20. RadioButton
ImageView
<ImageView android:id="@+id/img"
android:layout_width="wrap_content"
android:layout_height="wrap_content“
android:src="@drawable/abc"
/>

21. DatePicker
<DatePicker android:id="@+id/datePicker"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
………………………..
DatePicker dp = (DatePicker)this.findViewById(R.id.datePicker);
dateDefault.setText("Date defaulted to " + (dp.getMonth() + 1) + "/" +
dp.getDayOfMonth() + "/" + dp.getYear());
dp.init(2008, 11, 10, null);
TimePicker
<TimePicker android:id="@+id/timePicker"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
………………………..
TimePicker tp = (TimePicker)this.findViewById(R.id.timePicker);
tp.setIs24HourView(true);
tp.setCurrentHour(new Integer(10));
tp.setCurrentMinute(new Integer(10));
Pickers

22. DigitalClock
<DigitalClock
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
AnalogClock
<AnalogClock
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
Pickers

23. ListView
<ListView android:id="@+id/list"
android:layout_width=" wrap_content "
android:layout_height=" wrap_content "
android:entries=“@array/mylist” />
List

24. Layout Manager
Layout Manager Description
LinearLayout Organizes its children either horizontally or vertically
TableLayout Organizes its children in tabular form
RelativeLayout Organizes its children relative to one another or to
the parent
FrameLayout Allows you to dynamically changethe control(s) in
the layout

25. Layout Manager
LinearLayout
<LinearLayout
xmlns:android="http://schemas.android.com/a
pk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<!—add components-->
</LinearLayout>

26. Layout Manager
RelativeLayout
<RelativeLayout …………… >
<TextView android:id="@+id/userNameLbl"
android:text="Username: “
android:layout_alignParentTop="true" />
<EditText android:id="@+id/userNameText"
android:layout_toRightOf="@id/userNameLbl" />
<TextView android:id="@+id/pwdLbl"
android:layout_below="@id/userNameText"
android:text="Password: " />
<EditText android:id="@+id/pwdText"
android:layout_toRightOf="@id/pwdLbl"
android:layout_below="@id/userNameText" />
<TextView android:id="@+id/pwdCriteria"
android:layout_below="@id/pwdText"
android:text="Password Criteria... " />
</RelativeLayout>

27. TableLayout
<TableLayout ……… >
<TableRow>
<TextView android:text="First Name:“
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<EditText android:text="Edgar“
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</TableRow>
<TableRow>
<TextView android:text="Last Name:"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<EditText android:text="Poe"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</TableRow>
</TableLayout>
Layout Manager

28. Layout Manager
FrameLayout
<FrameLayout android:id="@+id/frmLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView
android:id="@+id/oneImgView"
android:src="@drawable/one"
android:scaleType="fitCenter"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<ImageView
android:id="@+id/twoImgView"
android:src="@drawable/two"
android:scaleType="fitCenter"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:visibility="gone" />
</FrameLayout>

29. Styles
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name=“SpelError">
<item
name="android:layout_width">fill_parent</item>
<item
name="android:layout_height">wrap_content</item>
<item name="android:textColor">#FF0000</item>
<item
name="android:typeface">monospace</item>
</style>
</resources>
………………..
<TextView android:id="@+id/errorText"
style="@style/ SpelError"
android:text=“Styling”
/>
Styles

30. Themes
If you have some style elements you want applied across an entire activity, or across
the whole application, you should use a theme instead. A theme is it’s exactly like a
style. To specify a theme for an activity or an application, we would add an attribute
to the <activity>or <application>tag in the AndroidManifest.xml.
<activity android:theme="@style/MyActivityTheme">
<application android:theme="@style/MyApplicationTheme">
Themes