resources.md

Drawable and Mipmap

Difference between drawable/ or mipmap/

• mipmap/ is for app icons.
  • https://developer.android.com/studio/write/create-app-icons
  • https://developer.android.com/training/multiscreen/screendensities#mipmap
• drawable/ is not for app icons.

  • A vector drawable is a vector graphic defined in an XML file as a set of points, lines, and curves along with its associated color information.

    • https://developer.android.com/develop/ui/views/graphics/vector-drawable-resources

  • Supported file types are PNG (preferred), JPG (acceptable), and GIF (discouraged).

    • https://developer.android.com/develop/ui/views/graphics/drawables#drawables-from-images

How to create notification icons

A notification is a message that you can display to the user outside of the normal UI of your app. Image Asset Studio places notifications icons in the proper locations in the res/drawable-density/ directories:

https://developer.android.com/studio/write/create-app-icons#notification

How to convert alpha (0.0 .. 1.0) to hexadecimal (0x00 ... 0xFF)

1. Calculate 255 * alpha (0.0 ... 1.0)
2. Convert the result to hexadecimal.

For example:

• alpha 1.0 = 255 * 1.0 = 0xFF
• alpha 0.5 = 255 * 0.5 = 0x80
• alpha 0.0 = 255 * 0.0 = 0x00

Alpha (in RGB) mapping among float, decimal, and hexadecimal

Alpha (0.0 ~ 1.0)	Alpha in decimal	Alpha in hexadecimal
0.0	0	0x00
0.1	26	0x1A
0.2	51	0x33
0.3	77	0x4D
0.4	102	0x66
0.5	128	0x80
0.6	153	0x99
0.7	179	0xB3
0.8	204	0xCC
0.9	230	0xE6
1.0	255	0xFF

<selector> / ColorStateList / DrawableStateList

• A state list, i.e. <selector>, can be used only for colors or drawables.
  • https://developer.android.com/guide/topics/resources/color-list-resource
  • https://developer.android.com/guide/topics/resources/drawable-resource#StateList
• ColorStateList
  • https://developer.android.com/reference/kotlin/android/content/res/ColorStateList
• DrawableStateList
  • https://developer.android.com/reference/kotlin/android/graphics/drawable/StateListDrawable