LetterAvatarSimple
Generate letter image avatars based on user initials.
Usage
LetterAvatarSimple.generate("foobar")
# => #<StringIO:0x000055b3804948a8>
We can do multiple letters:
LetterAvatarSimple.generate("Dallas Smith")
# => #<StringIO:0x000055b380e6a058>
We can save to a file:
LetterAvatarSimple.generate_file("Dallas Smith")
# => #<File:/tmp/x20190527-19344-79m629.png>
LetterAvatarSimple.generate_file("Dallas Smith", filename: "/tmp/dallas.png")
# => #<File:/tmp/dallas.png>We can specify the initials using LetterAvatarSimple::Identity:
i = LetterAvatarSimple::Identity.new("ZZ", "Dallas Smith")
LetterAvatarSimple.generate(i)
Image color is chosen from a palette based on username, so the same initials will (most likely) not share the same color:
i = LetterAvatarSimple::Identity.new("ZZ", "foobar")
LetterAvatarSimple.generate(i)
The default palette is based on Google Inbox. You can change palettes:
LetterAvatarSimple.generate("foobar", palette: :i_want_hue)
Or skip the palette feature and provide the desired color directly, in RGB tuple format:
LetterAvatarSimple.generate("foobar", color: [255,0,0])
Other options that can be provided to customize image generation:
LetterAvatarSimple.generate(
"foobar",
size: 256, # => default 1024
palette: :i_want_hue, # => default :google
# warning: this bypasses the palette's color selection
color: [255, 0, 0] # => default nil
pointsize: 150, # => default 600
font: "/tmp/path/to/font/file", # => default is path to included Roboto font
weight: 500, # => default 300
fill_color: "rgba(255, 255, 255, 1)", # => default "rgba(255, 255, 255, 0.65)"
annotate_position: "-0+10", # => default "-0+5"
filename: "/tmp/foo.png", # => default is randomly generated tempfile path
)About
Forked from letter_avatar, which was in turn extracted from Discourse.
Compared to letter_avatar, this gem:
- Outputs
StringIObinary data by default (but can write to files too!) instead of always writing files to thepublicdirectory. This way you can use image upload gems like shrine much easier - Supports keyword arguments for generating each image (don't need to edit global config or constants)
- Simplifies custom palette loading and supports multiple custom palettes
- Uses minimagick instead of homegrown ImageMagick shell execution
- Does not come with model, view, or controller helpers (you should be using shrine)
- Does not do caching (you should be using shrine)
Installation
gem "letter_avatar_simple"System requirements
ImageMagick or GraphicsMagick - see MiniMagick requirements
Color palettes
Two color palettes are provided by default: :google and :i_want_hue
Both palettes use an MD5 digest of the username to select the color, so it's likely that two different usernames that share the same initial(s) will render with different colors.
If you need the same initials to always render with the same color, simply
provide a custom palette using a customized letter_color method. See below
for an example.
:google - Google Inbox palette
:i_want_hue - iWantHue palette
Custom palettes
You can add your own custom palette:
LetterAvatarSimple.palettes[:my_palette] = LetterAvatarSimple::Palette.new([
[120, 132, 205],
[91, 149, 249],
[72, 194, 249],
[69, 208, 226],
])
# The default method of selecting the color is by MD5 digest of the username. You
# can change this behavior by providing a letter_color method.
LetterAvatarSimple.palettes[:my_palette].tap do |p|
def p.letter_color(identity)
if identity.id == "admin"
[255, 0, 0] # red
elsif identity.id == "bozo"
@palette.sample # random
else
# same initials = same color
digest = Digest::MD5.hexdigest(identity.letters.to_s)
@palette[digest[0...15].to_i(16) % @palette.length]
end
end
end
LetterAvatarSimple.generate_file("foobar", palette: :my_palette)Configuration
The same options that can be passed to generate can be set as global defaults:
LetterAvatarSimple.config do |config|
config.size = 256
config.palette = :i_want_hue
config.color = [255, 0, 0]
config.pointsize = 150
config.font = "/tmp/path/to/font/file"
config.weight = 500
config.fill_color = "rgba(255, 255, 255, 1)"
config.annotate_position = "-0+10"
end
