SwiftCairo

A Swift wrapper around cairo-1.x that is largely auto-generated from gobject-introspection. For up to date (auto-generated) reference documentation, see https://rhx.github.io/SwiftCairo/

macOS 11 build macOS 10.15 build Ubuntu 20.04 build Ubuntu 18.04 build

What is new?

Version 15 of gir2swift provides a Package Manager Plugin. This requires Swift 5.6 or higher.

Prerequisites

Swift 5.6 or higher

To build, download Swift from https://swift.org/download/ – if you are using macOS, make sure you have the command line tools installed as well). Test that your compiler works using swift --version, which should give you something like

$ swift --version
swift-driver version: 1.45.2 Apple Swift version 5.6 (swiftlang-5.6.0.323.62 clang-1316.0.20.8)
Target: x86_64-apple-darwin20.3.0

on macOS, or on Linux you should get something like:

$ swift --version
Swift version 5.6.0 (swift-5.6.0-RELEASE)
Target: x86_64-unknown-linux-gnu

GLib 2.56 and Cairo 1.14.10 or higher

These Swift wrappers have been tested with glib-2.56, 2.58, 2.60, 2.62, 2.64, 2.66, 2.68, 2.70, and 2.72. They should work with higher versions, but YMMV. Also make sure you have gobject-introspection and its .gir files installed.

Linux

Ubuntu

On Ubuntu 18.04, and 20.04 you can use the glib that comes with the distribution. Just install with the apt package manager:

sudo apt update
sudo apt install libcairo2-dev libcairo-gobject2 gobject-introspection libgirepository1.0-dev libxml2-dev
Fedora

On Fedora 29, you can use the gtk that comes with the distribution. Just install with the dnf package manager:

sudo dnf install cairo-devel cairo-gobject-devel glib2-devel gobject-introspection-devel libxml2-devel

macOS

On macOS, you can install glib and Cairo using HomeBrew (for setup instructions, see http://brew.sh). Once you have a running HomeBrew installation, you can use it to install a native version of cairo:

brew update
brew install cairo glib glib-networking gobject-introspection pkg-config

Usage

Normally, you don’t build this package directly (but for testing you can - see ‘Building’ below). Instead you need to embed SwiftCairo into your own project using the Swift Package Manager. After installing the prerequisites (see ‘Prerequisites’ below), add SwiftCairo as a dependency to your Package.swift file, e.g.:

// swift-tools-version:5.6

import PackageDescription

let package = Package(name: "MyPackage",
    dependencies: [
        .package(url: "https://github.com/rhx/gir2swift.git", branch: "main"),
        .package(url: "https://github.com/rhx/SwiftCairo.git",  branch: "main"),
    ],
    targets: [
        .target(name: "MyPackage",
                dependencies: [
                    .product(name: "Cairo", package: "SwiftCairo")
                ]
        )
    ]
)

Building

Normally, you don’t build this package directly, but you embed it into your own project (see ‘Usage’ above). However, you can build and test this module separately to ensure that everything works. Make sure you have all the prerequisites installed (see above). After that, you can simply clone this repository and build the command line executable (be patient, this will download all the required dependencies and take a while to compile) using

git clone https://github.com/rhx/SwiftCairo.git
cd SwiftCairo
swift build
swift test

Documentation

You can find reference documentation inside the docs folder. This was generated using the jazzy tool. If you want to generate your own documentation, matching your local installation, you can use the generate-documentation.sh script in the repository. Make sure you have sourcekitten and jazzy installed, e.g. on macOS:

brew install sourcekitten
sudo gem install jazzy
./generate-documentation.sh

Troubleshooting

Here are some common errors you might encounter and how to fix them.

Missing .gir Files

If you get an error such as

Girs located at
Cannot open '/GLib-2.0.gir': No such file or directory

Make sure that you have the relevant gobject-introspection packages installed (as per the Pre-requisites section), including their .gir and .pc files.

Old Swift toolchain or Xcode

If, when you run swift build, you get a Segmentation fault (core dumped) or circular dependency error such as

warning: circular dependency detected while parsing pangocairo: harfbuzz -> freetype2 -> harfbuzz

this probably means that your Swift toolchain is too old, particularly on Linux (at the time of this writing, some Linux distributions require at least Swift 5.5). Make sure the latest toolchain is the one that is found when you run the Swift compiler (see above).

If you get an older version, make sure that the right version of the swift compiler is found first in your PATH. On macOS, use xcode-select to select and install the latest version, e.g.:

sudo xcode-select -s /Applications/Xcode.app
xcode-select --install

Known Issues

  • When building, a lot of warnings appear. This is largely an issue with automatic RawRepresentable conformance in the Swift Standard library. As a workaround, you can turn this off by passing the -Xswiftc -suppress-warnings parameter when building.

  • The current build system does not support directory paths with spaces (e.g. the My Drive directory used by Google Drive File Stream).

  • BUILD_DIR is not supported in the current build system.

As a workaround, you can use the old build scripts, e.g. ./build.sh (instead of run-gir2swift.sh and swift build) to build a package.