[Themes] Rough but working code

Sources/VendettaTweak/Themes.x.swift

@@ -23,9 +23,50 @@ struct Theme: Codable {
   let data: ThemeData
 }
 
-func swizzleDCDThemeColor() {
+func hexToUIColor(_ hex: String) -> UIColor? {
+  let r: CGFloat
+  let g: CGFloat
+  let b: CGFloat
+  let a: CGFloat
+
+  if hex.hasPrefix("#") {
+    let start = hex.index(hex.startIndex, offsetBy: 1)
+    var hexColor = String(hex[start...])
+
+    if hexColor.count == 6 {
+      hexColor.append("ff")
+    }
+
+    if hexColor.count == 8 {
+      let scanner = Scanner(string: hexColor)
+      var hexNumber: UInt64 = 0
+
+      if scanner.scanHexInt64(&hexNumber) {
+        r = CGFloat((hexNumber & 0xff00_0000) >> 24) / 255
+        g = CGFloat((hexNumber & 0x00ff_0000) >> 16) / 255
+        b = CGFloat((hexNumber & 0x0000_ff00) >> 8) / 255
+        a = CGFloat(hexNumber & 0x0000_00ff) / 255
+
+        return UIColor(red: r, green: g, blue: b, alpha: a)
+      }
+    }
+  }
+
+  return nil
+}
+
+func swizzleDCDThemeColor(_ semanticColors: [String: [String]]) {
   os_log("Swizzling DCDThemeColor", log: vendettaLog, type: .info)
 
+  let DCDTheme = NSClassFromString("DCDTheme")!
+  let dcdThemeTarget: AnyClass = object_getClass(DCDTheme)!
+
+  let themeIndexSelector = NSSelectorFromString("themeIndex")
+  let themeIndexMethod = class_getClassMethod(dcdThemeTarget, themeIndexSelector)!
+  let themeIndexImpl = method_getImplementation(themeIndexMethod)
+  typealias ThemeIndexType = @convention(c) (AnyObject, Selector) -> Int
+  let themeIndex: ThemeIndexType = unsafeBitCast(themeIndexImpl, to: ThemeIndexType.self)
+
   let DCDThemeColor: AnyClass = NSClassFromString("DCDThemeColor")!
   os_log("Found instance of DCDThemeColor", log: vendettaLog, type: .debug)
   let target: AnyClass = object_getClass(DCDThemeColor)!
@@ -38,9 +79,74 @@ func swizzleDCDThemeColor() {
   os_log("DCDThemeColor has %{public}d methods", log: vendettaLog, type: .debug, methodCount)
 
   for i in 0..<Int(methodCount) {
-    let unwrapped = methods![i]
-    let methodName = NSStringFromSelector(method_getName(unwrapped))
+    let method = methods![i]
+    let selector = method_getName(method)
+    let methodName = NSStringFromSelector(selector)
     os_log(
       "Found method %{public}@", log: vendettaLog, type: .debug, methodName)
+    if let semanticColor = semanticColors[methodName] {
+      os_log(
+        "Swizzling %{public}@", log: vendettaLog, type: .debug, methodName)
+
+      let originalImpl = method_getImplementation(method)
+      typealias OriginalType = @convention(c) (AnyObject, Selector) -> UIColor
+      let original = unsafeBitCast(originalImpl, to: OriginalType.self)
+      let semanticColorBlock: @convention(block) (AnyObject) -> UIColor = {
+        (self: AnyObject) -> UIColor in
+        let themeIndexVal = themeIndex(dcdThemeTarget, themeIndexSelector)
+        if semanticColor.count - 1 >= themeIndexVal {
+          if let semanticUIColor = hexToUIColor(
+            semanticColor[themeIndexVal])
+          {
+            return semanticUIColor
           }
         }
+
+        return original(target, selector)
+      }
+      let semanticColorImplementation = imp_implementationWithBlock(
+        unsafeBitCast(semanticColorBlock, to: AnyObject.self))
+      method_setImplementation(
+        method, semanticColorImplementation)
+
+    }
+  }
+  free(methods)
+}
+
+func swizzleUIColor(_ rawColors: [String: String]) {
+  os_log("Swizzling UIColor", log: vendettaLog, type: .info)
+
+  let UIColor: AnyClass = NSClassFromString("UIColor")!
+  os_log("Found instance of UIColor", log: vendettaLog, type: .debug)
+  let target: AnyClass = object_getClass(UIColor)!
+
+  os_log("Found UIColor", log: vendettaLog, type: .debug)
+
+  var methodCount: UInt32 = 0
+  let methods = class_copyMethodList(target, &methodCount)
+
+  os_log("UIColor has %{public}d methods", log: vendettaLog, type: .debug, methodCount)
+
+  for i in 0..<Int(methodCount) {
+    let method = methods![i]
+    let selector = method_getName(method)
+    let methodName = NSStringFromSelector(selector)
+    os_log(
+      "Found method %{public}@", log: vendettaLog, type: .debug, methodName)
+    if let rawColor = rawColors[methodName] {
+      os_log(
+        "Swizzling %{public}@", log: vendettaLog, type: .debug, methodName)
+      let rawColorBlock: @convention(block) (AnyObject) -> UIColor = {
+        (self: AnyObject) -> UIColor in
+        return hexToUIColor(rawColor)!
+      }
+      let rawColorImplementation = imp_implementationWithBlock(
+        unsafeBitCast(rawColorBlock, to: AnyObject.self))
+      method_setImplementation(
+        method, rawColorImplementation)
+
+    }
+  }
+  free(methods)
+}

Sources/VendettaTweak/Tweak.x.swift

@@ -87,7 +87,10 @@ class LoadHook: ClassHook<RCTCxxBridge> {
     {
       orig.executeApplicationScript(
         "this.__vendetta_theme=\(themeString)".data(using: .utf8)!, url: source, async: false)
-        swizzleDCDThemeColor()
+      let theme = try? JSONDecoder().decode(Theme.self, from: themeString.data(using: .utf8)!)
+      if let semanticColors = theme?.data.semanticColors { swizzleDCDThemeColor(semanticColors) }
+      if let rawColors = theme?.data.rawColors { swizzleUIColor(rawColors) }
+
     }
 
     if vendetta != nil {