1 # Lint check for hardcoded colors 2 3 ## What is this lint check for 4 5 This check detects whether hardcoded colors have been added in a CL. 6 7 Starting in Android O, multiple device themes will exist on devices, enabling 8 changing the look and feel of all system UI. In order to make that effort 9 possible, colors in component that uses this check must be specified using 10 theme attributes, rather than hardcoded colors. Otherwise, when the theme 11 changes, this UI will not update properly. 12 13 ## Examples of hardcoded colors 14 15 ### Color files 16 17 ```xml 18 <!-- File: res/values/colors.xml --> 19 <?xml version="1.0" encoding="utf-8"?> 20 <resources> 21 <color name="hardcoded_color">#FFFFFF</color> 22 </resources> 23 ``` 24 25 ### Layout files 26 27 ```xml 28 <!-- File: res/layout/my_layout.xml --> 29 <?xml version="1.0" encoding="utf-8"?> 30 <TextView 31 android:textColor="#FF000000" /> 32 ``` 33 34 Or 35 36 ```xml 37 <!-- File: res/layout/my_layout.xml --> 38 <?xml version="1.0" encoding="utf-8"?> 39 <TextView 40 android:textColor="@color/hardcoded_color" /> 41 ``` 42 43 ### Style files 44 45 ```xml 46 <!-- File: res/values/styles.xml --> 47 <style name="MyStyle"> 48 <item name="android:textColor">#ff3c3c3c</item> 49 </style> 50 ``` 51 52 ## How to fix it 53 54 ### Use attributes in theming as much as possible 55 56 Here are some tips to choose the colors. 57 58 #### Choose colors for text 59 60 Use color attributes specified in the theme. Some examples: 61 62 1. `textColorPrimary` 63 2. `textColorSecondary` 64 3. `colorAccent` 65 66 #### Choose colors for icon 67 68 For `vector drawable`, please use full opacity color as `fillColor` and `tint` 69 it with theme attribute. 70 [example](https://googleplex-android-review.git.corp.google.com/#/c/1606392/2/packages/SettingsLib/res/drawable/ic_menu.xml) 71 72 #### Others 73 74 Please check the following table for more available options. 75 76 | Attribute | Description | 77 |---|---| 78 | colorAccent | Bright complement to the primary branding color. By default, this is the color applied to framework controls (via colorControlActivated). | 79 | colorForeground | Color for foreground imagery. Most text and image colors will be based on some alpha of colorForeground. | 80 | colorBackground | Color of background imagery, ex. full-screen windows. | 81 | colorBackgroundFloating | Color of background imagery for floating components, ex. dialogs, popups, and cards. | 82 | colorPrimary | The primary branding color for the app. This is the color applied to the action bar background. | 83 | colorPrimaryDark | Dark variant of the primary branding color. By default, this is the color applied to the status bar (via statusBarColor) and navigation bar (via navigationBarColor). | 84 | colorError | Color used for error states and things that need to be drawn to the users attention. | 85 | textColorPrimary (colorPrimaryText) | Is now constructed out of colorForeground and primaryContentAlpha. | 86 | textColorSecondary (colorSecondaryText) | Is now constructed out of colorForeground and primaryContentAlpha. | 87 88 ## How to bypass it 89 90 **We strongly discourage bypassing color lint check**. 91 92 However, if you need to bypass the check, please update the `baseline.xml` by running following 93 command in package root folder(i.e. package/app/Settings/) 94 95 ``` 96 export ANDROID_LINT_JARS=$(gettop)/prebuilts/checkcolor/checkcolor.jar 97 lint --check HardCodedColor --xml color-check-baseline.xml . 98 ``` 99 100 After update the `baseline.xml`, your hardcoded color will be ignored in check. Please submit the 101 new `baseline.xml` within your cl. 102 103 ## Contact us 104 105 1. For help to remove hardcoded colors or report issue in color check, please contact 106 jackqdyulei (a] google.com 107 108
