dannote · May 11, 2015 18:40 · May 11, 2015
diff --git a/JavaScriptCore.lua b/JavaScriptCore.lua
@@ -0,0 +1,146 @@
+local ffi = require "ffi"
+local lgi = require "lgi"
+local WebKit = lgi.WebKit
+
+ffi.cdef [[
+typedef struct OpaqueJSValue* JSObjectRef;
+typedef struct OpaqueJSValue* JSValueRef;
+typedef struct OpaqueJSString* JSStringRef;
+typedef struct OpaqueJSClass* JSClassRef;
+typedef struct OpaqueJSContext* JSContextRef;
+typedef struct OpaqueJSContext* JSGlobalContextRef;
+
+typedef enum {
+  kJSTypeUndefined,
+  kJSTypeNull,
+  kJSTypeBoolean,
+  kJSTypeNumber,
+  kJSTypeString,
+  kJSTypeObject
+} JSType;
+]]
+
+local Context = {}
+Context.__index = Context
+
+ffi.cdef [[
+typedef struct GObjectInternal WebKitWebFrame;
+JSGlobalContextRef webkit_web_frame_get_global_context(WebKitWebFrame *frame);
+]]
+function Context:new(web_view)
+  local instance = {}
+  instance.context = ffi.C.webkit_web_frame_get_global_context(web_view:get_main_frame()._native)
+  setmetatable(instance, self)
+  return instance
+end
+
+ffi.cdef [[
+JSValueRef JSEvaluateScript(JSContextRef ctx, JSStringRef script, JSObjectRef thisObject,
+  JSStringRef sourceURL, int startingLineNumber, JSValueRef* exception)
+]]
+function Context:eval(script, url, line)
+  local script = Context.make_string(script)
+  local url = url and Context.make_string(url)
+  local line  = line or 0
+  local exception = ffi.new("JSValueRef[1]")
+
+  local result = self:get_value(ffi.C.JSEvaluateScript(self.context, script, nil, url, line, exception))
+
+  if exception[0] ~= nil then
+    return result, self:get_value(exception[0])
+  end
+
+  return result
+end
+
+ffi.cdef "JSStringRef JSStringCreateWithUTF8CString(const char* string)"
+function Context.make_string(str)
+  return ffi.gc(ffi.C.JSStringCreateWithUTF8CString(str), ffi.C.JSStringRelease)
+end
+
+ffi.cdef [[
+JSValueRef JSValueMakeNull(JSContextRef ctx);
+JSValueRef JSValueMakeBoolean(JSContextRef ctx, bool value);
+JSValueRef JSValueMakeNumber(JSContextRef ctx, double value);
+JSValueRef JSValueMakeString(JSContextRef ctx, JSStringRef string);
+]]
+function Context:make_value(obj)
+  if type(obj) == "nil" then
+    return ffi.C.JSValueMakeNull(self.context)
+  elseif type(obj) == "boolean" then
+    return ffi.C.JSValueMakeBoolean(self.context, obj)
+  elseif type(obj) == "number" then
+    return ffi.C.JSValueMakeNumber(self.context, obj)
+  elseif type(obj) == "string" then
+    return ffi.C.JSValueMakeNumber(self.context, Context.make_string(obj))
+  end
+  -- table is not supported
+end
+
+ffi.cdef "JSValueRef JSValueMakeFromJSONString(JSContextRef ctx, JSStringRef string)"
+function Context:make_object(json)
+  return ffi.C.JSValueMakeFromJSONString(self.context, Context.make_string(json))
+end
+
+ffi.cdef "JSType JSValueGetType(JSContextRef ctx, JSValueRef value)"
+function Context:value_type(value)
+  local type = ffi.C.JSValueGetType(self.context, value)
+  if type == ffi.C.kJSTypeUndefined then
+    return "undefined"
+  elseif type == ffi.C.kJSTypeNull then
+    return "nil"
+  elseif type == ffi.C.kJSTypeBoolean then
+    return "boolean"
+  elseif type == ffi.C.kJSTypeNumber then
+    return "number"
+  elseif type == ffi.C.kJSTypeString then
+    return "string"
+  elseif type == ffi.C.kJSTypeObject then
+    return "object"
+  end
+end
+
+ffi.cdef [[
+size_t JSStringGetMaximumUTF8CStringSize(JSStringRef string);
+size_t JSStringGetUTF8CString(JSStringRef string, char* buffer, size_t bufferSize);
+void JSStringRelease(JSStringRef string);
+]]
+function Context.get_string(jsstr)
+  local len = ffi.C.JSStringGetMaximumUTF8CStringSize(jsstr)
+  local str = ffi.new("char[?]", len)
+  ffi.C.JSStringGetUTF8CString(jsstr, str, len)
+  return ffi.string(str, len)
+end
+
+ffi.cdef [[
+bool JSValueToBoolean(JSContextRef ctx, JSValueRef value);
+double JSValueToNumber(JSContextRef ctx, JSValueRef value, JSValueRef* exception);
+JSStringRef JSValueToStringCopy(JSContextRef ctx, JSValueRef value, JSValueRef* exception);
+]]
+function Context:get_value(value)
+  local type = ffi.C.JSValueGetType(self.context, value)
+  local exception = ffi.new("JSValueRef[1]")
+  local result
+
+  if type == ffi.C.kJSTypeUndefined or type == ffi.C.kJSTypeNull then
+    result = nil
+  elseif type == ffi.C.kJSTypeBoolean then
+    result = ffi.C.JSValueToBoolean(self.context, value)
+  elseif type == ffi.C.kJSTypeNumber then
+    result = ffi.C.JSValueToNumber(self.context, value, exception)
+  elseif type == ffi.C.kJSTypeString or type == ffi.C.kJSTypeObject then
+    local jsstr = ffi.gc(ffi.C.JSValueToStringCopy(self.context, value, exception),
+      ffi.C.JSStringRelease)
+    result = Context.get_string(jsstr)
+  end
+
+  if exception[0] ~= nil then
+    return result, self:get_value(exception[0])
+  end
+
+  return result
+end
+
+local jscore = {}
+jscore.Context = Context
+return jscore