Bob Dahlberg Dark Mode 

Dark Mode 

The reasons Looks nice Less disturbing Battery saver Digital Eye Strain Melatonin 

Structure 

<style 
 name="BaseTheme" parent=“Theme.Appcompat.DayNight"> Base Theme Structure 

Dark mode is a uiMode configuration change. Structure Base Theme Configuration Change 

Only use styled attributes, no hard coded color- references and definitely no hard coded colors. Structure Base Theme Configuration Change Styled attributes 

Only use styled attributes, no hard coded color- references and definitely no hard coded colors. 
 " Structure Base Theme Configuration Change Styled attributes 

Only use styled attributes, no hard coded color- references and definitely no hard coded colors. 
 " Structure Base Theme Configuration Change Styled attributes 

Base theme for margins, styles, sizes etc. <item name=“snackBarStyle”>@style/snack"</item> ! One theme for each flavor/dynamic theme <item name=“themeHeader”>@color/mode_header"</item> ! Structure Base Theme Configuration Change Styled attributes Theme 

Base theme for margins, styles, sizes etc. <item name=“snackBarStyle”>@style/snack"</item> ! One theme for each flavor/dynamic theme <item name=“themeHeader”>@color/mode_header"</item> ! <item name=“themeHeader”>@color/mode_gt_header"</item> ! Structure Base Theme Configuration Change Styled attributes Theme 

values/palette.xml #212121" #606060" #AFAFAF" #E6E6E6" #FAFAFA" " Structure Base Theme Configuration Change Styled attributes Theme 
 Colors 

Structure Base Theme Configuration Change Styled attributes Theme 
 Colors values/scheme.xml @color/c5" @color/c1" " values-night/scheme.xml @color/c1" @color/c5" " values/palette.xml #212121" #606060" #AFAFAF" #E6E6E6" #FAFAFA" " 

view.xml view.xml view.xml view.xml AppTheme attrs.xml view.xml palette.xml BaseTheme scheme.xml night/scheme.xml 

view.xml view.xml view.xml view.xml AppTheme attrs.xml view.xml scheme.xml night/scheme.xml 

view.xml view.xml view.xml view.xml AppTheme attrs.xml view.xml palette.xml BaseTheme KvpTheme GtTheme SportTheme DpTheme scheme.xml night/scheme.xml scheme_kvp.xml night/scheme_kvp.xml scheme_gt.xml night/scheme_gt.xml scheme_sport.xml night/scheme_sport.xml scheme_dp.xml night/scheme_dp.xml kvp/scheme.xml kvp-night/scheme.xml 

Quirks 

Themes are on Activity level Themes needs to be set before super.onCreate() The theme reference is held by context Creating Fragments uses that context Quirks Themes 

If using the night qualifier only, make sure you target rather specific. It might be used by smart-phones with their own android OS… Either battery saving or custom theming or flags. Use values-night-v29 to be sure. Quirks Themes Night-Qualifier 

Let the user choose 
 AppCompatDelegate.setDefaultNightMode(MODE_NIGHT_YES) For the session, not persistent It recreates all Activites started. Even those on the back stack when brought back Quirks Themes Night-Qualifier AppCompatDelegate 

Remember this? Quirks Themes Night-Qualifier AppCompatDelegate uiMode 

Remember this? Don’t do it! Quirks Themes Night-Qualifier AppCompatDelegate uiMode 

If you’re using the splash screen when booting the application it will follow the system. Quirks Themes Night-Qualifier AppCompatDelegate uiMode Splash screen 

Last tip Throw the colors way off! 

Last tip Throw the colors way off! 

Kotlin Conf: - ASYNCHRONOUS DATA STREAMS 
 WITH KOTLIN FLOW
 - MIGRATING FROM RXJAVA TO FLOW
 - INTRO TO CHANNELS AND FLOW Questions? Thank you! Bob Dahlberg medium.com/dahlbergbob @mr_bob