I had a bit of a frustrating time getting this working so I wanted to add some future searchable assistance.
I recently got an oled screen from adafruit and today I wanted to throw up a custom image. I used the open source software inkscape to create the image.
download the Adafruit_GFX_library and make sure it has the folder img2code
i'm running osx 10.13.1 with homebrew, i recommend getting homebrew up and going if you have not done this yet. make sure you have java 8 running, 9 will not work.
terminal commands:
brew cask uninstall java
brew tap caskroom/versions
brew cask install java8
Just running ./gradlew in the proper space like is instructed in the img2code github page did not open the "editor". I believe you do have to run that in terminal once to build dependencies though so cd into img2code and run it. If the app did not open like it did not for me Click on image2code.jar in Arduino/libraries/Adafruit_GFX_Library/Img2Code/build/libs to open up the app.
BOOM now you can upload your image by selecting choose file and copy the bitmap code for the gfx library.
all holes in this post should be answered by this youtube video.
