Easily Manage Graphics in Xcode Projects

Introduction

Challenges Managing Graphic Assets

Part of the process of building an app for watchOS, iOS, or macOS is including all the image assets and app icons in your application. Each image assets or app icons requires several copies for different resolutions, different devices, and different sizes. Right now, this needs to be done by exporting all the various similar images from a major graphics application.

That means developers need to:

Multiple Images

Manually Create Multiple Sizes

Each graphic must be manually converted and resized several times for each update.

Multiple Images

Store Generated Image Files

An asset catalog image set will need a 1x, 2x, 3x of each graphic and App Icons may need as many 30 different sizes.

What If You Had…

Multiple Images Multiple Images Multiple Images Multiple Images Multiple Images Multiple Images

Care-Free Graphic Management Where…

  • Only one file is needed for each Image Set and App Icon.
  • Graphic Designers need only export a single file change each time rather than as many as serveral scaled copies.
  • Resizing and conversion is done behind the scenes based on a single source image.

What Speculid Does

Speculid links a single graphic file to an Image Set or App Icon and automatically renders different resolutions, file types, and sizes for all the image specifications required.

diagram

Multiple Images

Automate the process

Speculid automates the process so only one graphic file is needed. Add Speculid to your build process and now the conversions and resizing are automated as part of the build process. Now there is no need for anyone to manually create each size for each device every time.

Multiple Images

Tidy Your Repo

Reduce the size of your repository by including a single vector or raster image and ignore all your automated png and pdf files at compile. That means faster remote pulls, less redundancy, and complete syncronization between sizes.

Features

This means Speculid can…

Input File Types Supported

Modifiers

Output File Types Supported

Download

There are 3 ways to download Speculid: Email Signup, Homebrew, and Github Releases:

Email Signup

Email signup allows for you to get delivered updates to your email box of new features and updates…

Sign up below to get the latest version.
 

To download Speculid, enter your email address here to request access to the latest version.

Homebrew

If you are already using Homebrew, installing via the homebrew command allows for easy installation as well as staying up-to-date on new releases. To install, type:

brew cask install brightdigit/speculid/speculid

This will automatically install the terminal command for easy scripting.

Github Releases

You can directly download the application from the Github Repo releases page.

Download .zip Download .tar.gz

Documentation

Installation

Once you have downloaded the zip file (i.e Not Homebrew), go ahead and copy the application Speculid.App to the Applications folder.

A command line tool is included in the application bundle. Copy the command line tool to your /bin/ folder:

$ sudo cp /Applications/Speculid.app/Contents/SharedSupport/speculid /usr/local/bin

Fastlane Integration

Once you have the application installed, if you are using Fastlane, you can integrate with your actions, by adding the plugin after installation:

fastlane add_plugin speculid

Then in your Fastfile add speculid to your action:

default_platform(:ios)

platform :ios do
  desc "Application Build"
  lane :build do
    ...
    speculid
    ...
  end
end

Usage

Speculid only supports being called through a command line terminal for now. Once you have copied the command to your /usr/local/bin folder you should be able to access it easily.

$ speculid --process <file>
$ speculid --help
$ speculid --version

Options:
  --help     Show this screen.
  --version  Show version.

File Format and Properties

The .speculid file is a json file with the image set or app icon path, the graphic file source, and optionally basic image geometry (width or height). All paths specified in the json file could be relative to the .speculid file Assets.xcassets/Raster Image.imageset or an absolute path /Users/leo/Documents/Projects/Speculid/examples/Assets/Assets.xcassets/Raster Image.imageset.

Here are some examples of a .speculid file:

{
  "set" : "Assets.xcassets/Raster Image.imageset",
  "source" : "layers.png",
  "geometry" : "128"
}

or

{
  "set" : "Assets.xcassets/iOS AppIcon.appiconset",
  "source" : "geometry.svg",
  "background" : "#FFFFFFFF",
  "remove-alpha" : true
}

Set

set

Image Set Examples from Xcode

Set is the path to the Image Set or App Icon folder used by Xcode. For more information on Image Sets, App Icons, and Asset Catalogs, check out this article here.

Source

source

The path to the image source file. This can be either a SVG or PNG file.

Geometry optional

geometry

The destination geometry of image if needed (i.e. image set). It must be in the format of:

You can only specify the height or the width. The other dimension is automatically calculated based on the aspect ratio of the image.

Background optional

background

App Icons are required to exclude any alpha channels. In order to remove a transparency from a source PNG or SVG file, you can specify to remove the alpha channel and add a background color.

The background color can be set in a standard rgb, rgba, or hex code format (#RRGGBB or #AARRGGBB). If no alpha is specified an alpha of 1.0 is assumed.

Remove Alpha optional

remove-alpha

To specifically remove the alpha channel, a true boolean value must be specified. This will remove the alpha channel from the file. Make sure to specify an opaque background color when removing the alpha channel.

Exporting SVGs for Speculid

Sketch

Sketch iOS App Icon Template Window

  1. Open Sketch and create a new document using the iOS App Icon Template. If you are using an existing project, you can skip to step 3.

    Sketch Slice Panel

  2. Once you are in the template, duplicate one of the icon size slices on the left side.

    Sketch Present Format

  3. On the right size, change the preset format to SVG.

    Sketch Export Menu

  4. In the top menu, select File > Export.

    Sketch Export Window

  5. Select your duplicated slice and select Export.

  6. Select the destination for your SVG file and Save.

Photoshop

Photoshop Export Menu

  1. Open your Photoshop document and select File > Export > Export As….

    Photoshop Export Format

  2. Under the File Settings on the right, change the format to SVG.

    Photoshop Save Dialog

  3. Select Export All and choose the destination for your SVG file and Save.

Illustrator

Illustrator Export Menu

  1. Open your Illustrator document, select FileExportExport for Screens….

    Illustrator Export Format

  2. Under Formats, update the format to SVG.

  3. Select Export Artboard and choose the destination for your SVG file and Save.

Xcode Integration and Automation

With Speculid, the process of building image assets can be automated in Xcode. Here is how to setup your project the first time:

  1. Create the speculid file and add it to your project folder, along with your source graphic files.

    Xcode Target Membership

    • Note: you don’t need to add these files to any target membership
  2. In the speculid file, Add the property for the source - the path to the SVG or PNG file.
      {
     "source" : "geometry.svg",
     ...
      }
    
  3. In the speculid file, Add the property for the set - the path to the Image Set or App Icon folder.
      {
     "set" : "Assets.xcassets/iOS AppIcon.appiconset",
     ...
      }
    
  4. optional In the speculid file, Add the property for the geometry - if this a conversion from a vector graphic (SVG) to an Image Set, you may want to supply the 1x size.
      {
     "set" : "Assets.xcassets/Raster Image.imageset",
     "source" : "layers.png",
     "geometry" : "128"
      }
    

    If you specify 128 in the geometry property, that means the width for the 1x image will be 128 pixels, the width for the 2x image will be 256 pixels, and the width for the 3x image will be 384 pixels. Heights will be calculated based on the aspect ratio of the SVG file.

    Vector images in an image set will be converted to a iOS compatible PDF file.

  5. optional In the speculid file, Add the properties for the background color and alpha removal - if this a conversion to an App Icon, you should remove any background transparency and add a background color.
      {
     "set" : "Assets.xcassets/iOS AppIcon.appiconset",
     "source" : "geometry.svg",
     "background" : "#FFFFFFFF",
     "remove-alpha" : true
      }
    

    See the file format section for more details.

  6. Add the Run Script Build Phase to the top of your project with the following code:

     find "${SRCROOT}" -name "*.speculid" -print0 |
     while IFS= read -r -d $'\0' line; do
     speculid --process "$line" &
     done
     wait
    

    Xcode Build Phase Run Script

    If you are using fastlane to build your application. You can use the plugin to build every .speculid file in your directory.

  7. Build the application. This will create the graphics which you will use in your asset image set or app icon.

    Xcode Unorganized Assets

  8. After the first build, drag the images to the correct asset slot. Each rendered image file is suffixed denoting its slot.

    (source file base name).(size)@(scale)~(idiom).(extension)

    Examples

  9. Build, Run, and Done!

Speculid ©2019, BrightDigit, LLC.