Android Resources Naming Convention
Resource files
Resources file names are written in lowercase_underscore.
Drawable files
Naming conventions for drawables:
| Asset Type | Prefix | Example |
|---|---|---|
| Action bar | ab_ |
ab_stacked.9.png |
| Button | btn_ |
btn_send_pressed.9.png |
| Dialog | dialog_ |
dialog_top.9.png |
| Divider | divider_ |
divider_horizontal.9.png |
| Icon | ic_ |
ic_star.png |
| Menu | menu_ |
menu_submenu_bg.9.png |
| Notification | notification_ |
notification_bg.9.png |
| Tabs | tab_ |
tab_pressed.9.png |
Naming conventions for icons (taken from Android iconography guidelines):
| Asset Type | Prefix | Example |
|---|---|---|
| Icons | ic_ |
ic_star.png |
| Launcher icons | ic_launcher |
ic_launcher_calendar.png |
| Menu icons and Action Bar icons | ic_menu |
ic_menu_archive.png |
| Status bar icons | ic_notify |
ic_notify_msg.png |
| Tab icons | ic_tab |
ic_tab_recent.png |
| Dialog icons | ic_dialog |
ic_dialog_info.png |
Naming conventions for selector states:
| State | Suffix | Example |
|---|---|---|
| Normal | _normal |
btn_order_normal.9.png |
| Pressed | _pressed |
btn_order_pressed.9.png |
| Focused | _focused |
btn_order_focused.9.png |
| Disabled | _disabled |
btn_order_disabled.9.png |
| Selected | _selected |
btn_order_selected.9.png |
Layout files
Layout files should match the name of the Android components that they are intended for but moving the top level component name to the beginning. For example, if we are creating a layout for the SignInActivity, the name of the layout file should be activity_sign_in.xml.
| Component | Prefix | Class Name | Layout Name |
|---|---|---|---|
| Activity | activity_ |
MainPageActivity | activity_main.xml |
| Fragment | fragment_ |
DetailsPageFragment | fragment_details.xml |
| Dialog | dialog_ |
NewItemPageDialogFragment | dialog_new_item.xml |
| AdapterView item | item_ |
PersonViewHolder | item_person.xml |
| Custom view layout | view_ |
ProfileAvatarView | view_profile_avatar.xml |
| Partial layout | partial_ |
--- | partial_stats_bar.xml |
A slightly different case is when we are creating a layout that is going to be inflated by an Adapter, e.g to populate a ListView. In this case, the name of the layout should start with item_.
Note that there are cases where these rules will not be possible to apply. For example, when creating layout files that are intended to be part of other layouts. In this case you should use the prefix partial_.
Menu files
Similar to layout files, menu files should match the name of the component. For example, if we are defining a menu file that is going to be used in the UserActivity, then the name of the file should be activity_user.xml
A good practice is to not include the word menu as part of the name because these files are already located in the menu directory.
Values files
Resource files in the values folder should be plural:
| File | Description |
|---|---|
strings.xml |
Strings |
colors.xml |
Colors |
dimens.xml |
Sizes |
attrs.xml |
Custom attributes |
themes.xml |
Theme & ThemeOverlay |
styles.xml |
Widget styles |
shape.xml |
ShapeAppearance |
motion.xml |
Animations styles |
IDs
Resource IDs and names are written in lowercase_underscore.
Naming pattern: @+id/<module>_<layout>_<element_name>_<element_type>
| Sample | Description |
|---|---|
@+id/activity_main_lst |
Any List data from MainPageActivity. |
@+id/fragment_details_name_txt |
EditText for Name from DetailsPageFragment. |
@+id/dialog_new_item_save_btn |
Button for Save from NewItemDialog. |
@+id/item_person_name_lbl |
TextView for Name Person from list item. |
@+id/notifications_activity_settings_camera_cb |
CheckBox for Camera from Settings page from Notifications module. |
Common controls prefix mapping:
| Prefix | Controls |
|---|---|
| btn | Button, ImageButton |
| label | TextView |
| input | EditText |
| list | ListView, RecyclerView |
| img | ImageView |
For other controls use the short form:
| Prefix | Controls |
|---|---|
| cb | CheckBox |
| ll | LinearLayout |
| rl | RelativeLayout |
| pb | ProgressBar |