1. Mobile Applications (Android Programming)
Semester II
Dr. Saman Mirza Abdullah

2. Class Objective The objective of this class is:
To learn how Android applications store and access important resources such as strings, graphics, and other data.
To learn how to organize Android resources within the project files.
To learn the localization and configuration of different devices.
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3. Resources Directory
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4. Resources and Codes
Good developers not put data within the source code.
Instead, data are accessed programmatically.
Storing application resources in a single place
Is a more organized approach to development,
Makes the code more readable and maintainable
Localization (adaption) of applications for different languages and devices.
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5. Resources All Android application are composed of two things:
Functionalities:
Is a code that determines the behaviors of the application, such algorithms or models for problems.
Resources:
They are data or information accessed by the source code, such as string, style and themes, dimensions, image and icons, audio files, vedios, and other data.
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6. Storing Resources
Resources are separately stored from .java class files
They are stored in XML, but still row data and graphs are accepted.
They are stored in /res directory
File names should be lowercase.
No duplicated.
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7. Resource Directories
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8. Resource Type and File Hierarchy
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9. Default VS Alternative Resources
There are many criterion for storing resources.
Default resources are those that stored automatically by the created applications.
Creating some special resources are needed in some cases:
Internationalization, when an application needed to work with multi-languages.
Localization, when there is a need to run an application smoothly on different devices and orientations.
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10. Alternative Resources: Examples
An application with different graphical size.
/res/drwable-ldpi/mylogo.png (low-density screen)
/res/drwable-mdpi/mylogo.png (medium-density screen)
/res/drwable-hdpi/mylogo.png (high-density screen)
/res/drwable-xhdpi/mylogo.png (extra high-density screen)
/res/drwable-xxhdpi/mylogo.png (extra extra high-density screen)
Application for different orientations:
/res/layout-port/main.xml (layout loaded in portiere)
/res/layout-land/main.xml (layout loaded in landscape)
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11. Access Resources
All resource files will be compiled and seen as R.Java class file and it is sub-classes.
The file will be automatically generated when any resources are added.
Through this files the content is accessed.
Example:
A String named strHello defined within the resource file called /res/values/string.mls
Can be accessed R.string.strHellow  doesn't return data.
String mystring = getResource().getString (R.String.strHello)
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12. Accessing Resource Programmatically
Using String resources programmatically:
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13. String Resources Using Bold, Italic, and underline.
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14. Working with Images
Applications often include visual elements such as icons and graphics.
Android supports several image formats.
can be directly included as resources for your application.
All resource filenames must be lowercase and simple
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15. List of Image Formats
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16. Accessing Image Resource
Image resources are simply another kind of Drawable called a BitmapDrawable.
For Accessing, mostly it needs only the resource ID of the image.
It can be accessed directly using BitmapDrawable function.
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17. Color State List
Some time it needs to color an object based on state of the object.
Could be done by special recourse called selector.
Example:
A Button control may need to by gray when disable, green when activated, and yellow when processed.
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18. Color State List
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19. Color State Defining
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20. Button State Color we define a Button and set the textColor
the state list resource file text_color.xml is defined as list of state color.
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21. Class End
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