Nova Launcher is the highly customizable launcher for Android. Part of this customization comes from developers such as yourself.
This document covers the theme format for Nova Launcher.
Most launchers, including Nova Launcher, support a superset of the theme format from Go Launcher.
However this document and project is specific to Nova Launcher. This document will try to note things which are not supported by other launchers.
This project is a sample theme for Nova Launcher that can covers:
- AndroidManifest
- Automatic App Icon Theming
- Manual App Icon Theming
- Dock Background Theming
- Wallpapers
Nova Launcher identifies themes by searching for activities that can respond to the com.novalauncher.THEME intent.
This is done by adding the following below an tag in your AndroidManifest.xml
<intent-filter>
<action android:name="com.novalauncher.THEME" />
</intent-filter>
Applying an icon theme (Nova Settings > Look and Feel > Icon Theme) will replace app icons with the icons specified in the theme. Optionally, new app icons can be automatically generated using a background, foreground, scale and mask.
Configuration for this is done in the theme's res/xml/appfilter.xml .
Replacing a specific app icon with a custom drawable included in your theme is done via:
<item component="ComponentInfo{com.android.chrome/com.google.android.apps.chrome.Main}" drawable="ic_browser_green" />
With system apps, different devices or roms may use different component names for various components. For example The dialer app on Nexus devices is com.android.contacts/.activities.DialtactsActivity but on HTC devices it is com.android.htccontacts/.DialerTabActivity. Nova includes an internal databases of these for most devices, allowing the theme to apply an icon to the system's phone app by specifying a single keyword rather than each individual activity for every device.
Note Only non-Play Store system apps are included in this, third-party apps, or Play Store apps such as Chrome, will not be included and must be themed manually.
The keywords supported are:
:BROWSER:CALCULATOR:CALENDAR:CAMERA:CLOCK:CONTACTS:EMAIL:GALLERY:PHONE:SMS
Additionally Nova's app drawer icon can be themed with :LAUNCHER_ACTION_APP_DRAWER and :LAUNCHER_ACTION_APP_DRAWER_NIGHT. The night version is used when in night mode and the user has Night mode > Drawer icon enabled in Nova Settings.
A full example is:
<item component=":SMS" drawable="ic_sms_green" />
Note Other launchers do not support these system app keywords and will ignore them.
Nova Launcher includes an option to export a full set of activity names and their original icons. This can serve as a starting point for your theme. You can find this at Nova Settings > Long-press Volume down for Labs > Debug > Export Icons
A zip will be created at /sdcard/novaIconExport.zip which contains a complete res/xml/appfilter.xml file as well as the original icons at the highest density they are available (in the appropriate drawable directory).
Nova also has an option to help find individual component names. Enable Nova Settings > Long-press volume down for Labs > Debug > Show Component in Edit dialog. Then either drag an app from the drawer to the Edit option, or long-press on a desktop icon and select Edit. The component name will be listed at the bottom of the dialog.
For apps that do not have a drawable replacement one can be generated by specifying parameters in the appfilter.xml
The four parameters are:
The background to be drawn behind the original icon. If multiple images are specified (as above img1, img2 and img3) then one will be chosen randomly.
The foreground to be drawn on top of the original icon. If multiple images are specified then one will be chosen randomly.
A mask to apply to the original icon, allowing reshaping it. Black opaque pixels in the mask will be erased while transparent pixels be unchanged. If multiple images are specified then one will be chosen randomly.
The scale the original icon should be drawn at.
Nova Launcher allows users to manually select a replacement icon, for an app, shortcut, or folder. To allow users to select one of your icons for this specify them in the res/xml/drawable.xml. Each icon is as follows
<item drawable="ic_jellybean" />
The order you list the icons in will be the order that they appear in the icon picker.
You may optionally break the icons into categories by adding dividers:
<category title="Games" />
Nova Launcher supports resource identifiers, for example for localization or compile-time error checking:
<item drawable="@drawable/ic_jellybean" />
<category title="@string/games" />
Other launchers do not support category dividers or resource identifiers
Nova Launcher allows the user to build a custom dock background based on an image picked from a theme. There is no fixed size for a dock background as Nova Launcher supports devices of many different screen sizes and aspect ratios. Additionally, there are different orientations on the same device. Instead of trying to stretched an image to fit patterns are used to fill the appropriate amount of space on any configuration.
Patterns are specified in res/xml/theme_patterns.xml and point to a drawable that is designed to be repeated.
These patterns can either be full color, or grayscale and allow the user to specify a color by setting canColor="true".
Otherwise the format is identical to res/xml/drawables.xml
<item drawable="@drawable/pattern_checkerboard" canColor="true" />
<item drawable="@drawable/pattern_colors" canColor="false" />
Note Other launchers do not support patterns for dock backgrounds and instead stretch and distort images for the dock background. It is a poor user experience, especially on tablets, but Nova Launcher is backwards compatible with this backwards approach. Legacy dock backgrounds can be specified in an string-array named dock_backgroundlist , which is also used by other launchers.
To add your wallpapers to Nova Launcher's wallpaper picker specify them in res/xml/theme_wallpapers.xml . The format is identical to res/xml/drawables.xml .
<item drawable="@drawable/wallpaper_red" />