Mohammed Ersan discusses themes and styles in Android development. A style defines visual properties for a view, while a theme defines properties for an entire activity or application. Styles can inherit properties from parent styles and themes apply styles to all views. Key aspects of themes include material design attributes, default styles, using themes in layouts, and selectors. Themes are a powerful tool that developers should learn to use properly from the start of development.

1. Android
Themes &
Styles
By Mohammed Ersan

2. Who Am I?
Mohammed Ersan
Senior Android Developer
MTT Dublin
Github @MoshDev

3. Themes & Styles

4. Themes &
Styles
Style vs Theme
Style Basics
Inheritance
Attributes
View Constructors
Material
Theme Shared Styles
In-Layout Theme
ContextThemeWrapper
Selectors & Drawables
Hints & Tools

5. Style
A style is a collection of properties that
specify the look and format for a View or
window. A style can specify properties
such as height, padding, font color, font
size, background color, and much more. A
style is defined in an XML resource that is
separate from the XML that specifies the
layout.
Theme
A theme is a style applied to an entire
Activity or application, rather than an
individual View. When a style is applied as
a theme, every View in the Activity or
application will apply each style property
that it supports.
Style vs Theme
Source: https://developer.android.com/guide/topics/ui/themes.html

6. Style Theme
Style vs Theme

7. Xml file
res/values
Root node <resources>
<style>
Name is required
<item>
Parent is Optional
AAPT (Android Asset Packaging Tool)
Style Basics
Source: https://developer.android.com/guide/topics/ui/themes.html
http://elinux.org/Android_aapt

8. Parent
<style name="MyButtonStyle" parent="@style/Widget.AppCompat.Button">
Period (dot)
only works for styles defined by your own resources
<style name="style_vs_theme_body_text.sample">
Period + Parent
<style name="style_vs_theme_body_text.sample" parent="Widget.AppCompat.Button">
Inheritance

9. ● Format
○ Enum (only integers)
○ Boolean (true|false)
○ Color
○ Dimension
○ Flag (only integers)
○ Float
○ Fraction (only percentage %)
Attributes (Properties)
● Declare-styleable
○ R.styleable.<name>
○ R.styleable.<name>_<attribute>

10. View(Context)
View(Context, AttributeSet) **
View(Context, AttributeSet, defStyleAttr)
View(Context, AttributeSet, defStyleAttr, defStyleRes) (Api 21)
View Constructors

11. 1. colorPrimary
2. colorPrimaryDark
3. colorControlNormal
4. colorControlActivated
5. colorButtonNormal
6. textColorPrimary
7. textColorSecondary
8. textColorPrimaryDisableOnly
9. textColorTertiary
10.textColorHint
11.windowBackground
Material

12. toolbarStyle
buttonStyle
textViewStyle
checkboxStyle
…
Theme Default Styles
To change default view style
Check the <View> source code
Search Platform/AppCompat theme source code

13. In-Layout Theme
android:theme
Individual views
ViewGroup Inheritance
ContextThemeWrapper
TextView1 --> ...InLayoutThemeActivity@7d3740e
TextView2 --> android.view.ContextThemeWrapper@5c46c40
TextView3 --> android.view.ContextThemeWrapper@b0afcbe
TextView4 --> android.view.ContextThemeWrapper@b0afcbe

14. ContextThemeWrapper

15. Selectors & Drawables

16. Hints & Tools
Alpha colors

17. Hints & Tools
Extract Style

18. Conclusion
Themes are very powerful tool in Android, start using them correctly since the
beginning of development and it will end well.

19. Questions
つづく