From 86c3df5572be06c9131b961eb0447d26cbdf7c6b Mon Sep 17 00:00:00 2001
From: Marc Prud'hommeaux <marc@skip.tools>
Date: Sat, 4 Jan 2025 15:47:28 -0500
Subject: [PATCH] Android support

---
 .github/workflows/android.yml | 20 ++++++++++++++++++++
 Sources/PNG/System.swift      | 22 +++++++++++++++++++---
 2 files changed, 39 insertions(+), 3 deletions(-)
 create mode 100644 .github/workflows/android.yml

diff --git a/.github/workflows/android.yml b/.github/workflows/android.yml
new file mode 100644
index 00000000..f4eb58cb
--- /dev/null
+++ b/.github/workflows/android.yml
@@ -0,0 +1,20 @@
+name: Android
+
+on:
+    push:
+        branches: [ master ]
+    pull_request:
+        branches: [ master ]
+
+jobs:
+    android:
+        runs-on: ubuntu-24.04
+        name: Android
+
+        steps:
+            -   name: Checkout repository
+                uses: actions/checkout@v4
+            -   name: Build for Android
+                uses: skiptools/swift-android-action@v2
+                with:
+                    run-tests: false
diff --git a/Sources/PNG/System.swift b/Sources/PNG/System.swift
index 69672259..f7e0d682 100644
--- a/Sources/PNG/System.swift
+++ b/Sources/PNG/System.swift
@@ -6,6 +6,8 @@
     import Darwin
 #elseif canImport(Glibc)
     import Glibc
+#elseif canImport(Android)
+    import Android
 #elseif canImport(Musl)
     import Musl
 #elseif os(Windows)
@@ -15,7 +17,7 @@
     #warning("unsupported or untested platform (please open an issue at https://github.com/tayloraswift/swift-png/issues)")
 #endif
 
-#if canImport(Darwin) || canImport(Glibc) || canImport(Musl) || os(Windows)
+#if canImport(Darwin) || canImport(Glibc) || canImport(Android) || canImport(Musl) || os(Windows)
 
 /// A namespace for platform-dependent functionality.
 ///
@@ -28,7 +30,11 @@ enum System
     public
     enum File
     {
+        #if os(Android)
+        typealias Descriptor = OpaquePointer
+        #else
         typealias Descriptor = UnsafeMutablePointer<FILE>
+        #endif
 
         /// A type for reading data from files on disk.
         public
@@ -100,7 +106,12 @@ extension System.File.Source
         {
             (buffer:inout UnsafeMutableBufferPointer<UInt8>, count:inout Int) in
 
-            count = fread(buffer.baseAddress, MemoryLayout<UInt8>.stride,
+            #if os(Android)
+            let baseAddress = buffer.baseAddress!
+            #else
+            let baseAddress = buffer.baseAddress
+            #endif
+            count = fread(baseAddress, MemoryLayout<UInt8>.stride,
                 capacity, self.descriptor)
         }
 
@@ -213,7 +224,12 @@ extension System.File.Destination
     {
         let count:Int = buffer.withUnsafeBufferPointer
         {
-            fwrite($0.baseAddress, MemoryLayout<UInt8>.stride,
+            #if os(Android)
+            let baseAddress = $0.baseAddress!
+            #else
+            let baseAddress = $0.baseAddress
+            #endif
+            return fwrite(baseAddress, MemoryLayout<UInt8>.stride,
                 $0.count, self.descriptor)
         }