libcore/asobj/Global_as.h

   1 //
   2 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Free Software
   3 //   Foundation, Inc
   4 //
   5 // This program is free software; you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation; either version 3 of the License, or
   8 // (at your option) any later version.
   9
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software
  17 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18 //
  19
  20 #ifndef GNASH_GLOBAL_H
  21 #define GNASH_GLOBAL_H
  22
  23 #include <string>
  24 #include <boost/preprocessor/arithmetic/inc.hpp>
  25 #include <boost/preprocessor/repetition/enum_params.hpp>
  26 #include <boost/preprocessor/repetition/repeat.hpp>
  27 #include <boost/preprocessor/repetition/repeat_from_to.hpp>
  28 #include <boost/preprocessor/seq/for_each.hpp>
  29 #include <boost/scoped_ptr.hpp>
  30
  31 #include "as_object.h"
  32 #include "fn_call.h"
  33 #include "log.h"
  34 #include "ClassHierarchy.h"
  35
  36 // Forward declarations
  37 namespace gnash {
  38     class builtin_function;
  39     class as_value;
  40     class VM;
  41     class Extension;
  42 }
  43
  44 namespace gnash {
  45
  46 /// The Global object ultimately contains all objects in an ActionScript run
  47 //
  48 /// An ActionScript run is a single version (AS1/2 or AS3) and includes all
  49 /// resources parsed from the SWF, created dynamically, loaded, or imported
  50 /// that are available to ActionScript code.
  51 //
  52 /// Each VM (VM for AS1/2, Machine for AS3) has different resources in its
  53 /// Global object. The two objects should be entirely separate.
  54 class Global_as : public as_object
  55 {
  56 public:
  57
  58     typedef as_value(*ASFunction)(const fn_call& fn);
  59     typedef void(*Properties)(as_object&);
  60
  61         explicit Global_as(VM& vm);
  62         virtual ~Global_as();
  63
  64     void registerClasses();
  65
  66     as_object* createArray();
  67
  68     VM& getVM() const {
  69         return vm();
  70     }
  71
  72     /// Create an ActionScript function
  73     builtin_function* createFunction(Global_as::ASFunction function);
  74
  75     /// Create an ActionScript class
  76     //
  77     /// An AS2 class is generally a function (the constructor) with a
  78     /// prototype.
  79     as_object* createClass(Global_as::ASFunction ctor,
  80             as_object* prototype);
  81
  82     void makeObject(as_object& o) const;
  83
  84 protected:
  85
  86     virtual void markReachableResources() const;
  87
  88 private:
  89
  90     void loadExtensions();
  91     boost::scoped_ptr<Extension> _et;
  92
  93     ClassHierarchy _classes;
  94
  95     as_object* _objectProto;
  96
  97 };
  98
  99 as_object* createObject(const Global_as& gl);
 100
 101
 102 /// Register a built-in object
 103 //
 104 /// This is used for simple objects that are part of the player API.
 105 //
 106 /// In the reference player these objects are always constructed in
 107 /// ActionScript, though their functions may be native.
 108 //
 109 /// They include (AS2) Mouse, Selection and Stage, and (AS3) all constant
 110 /// enumeration objects.
 111 //
 112 /// @param p        a pointer to a function that will attach properties to the
 113 ///                 object
 114 /// @param where    the object to which the created object will be attached
 115 /// @param uri      an ObjectURI describing the name and namespace of the
 116 ///                 created object.
 117 /// @return         the built-in object with properties attached.
 118 inline as_object*
 119 registerBuiltinObject(as_object& where, Global_as::Properties p,
 120         const ObjectURI& uri)
 121 {
 122
 123     // This is going to be the global Mouse "class"/"function"
 124     Global_as& gl = getGlobal(where);
 125     as_object* obj = createObject(gl);
 126     if (p) p(*obj);
 127
 128     where.init_member(uri, obj, as_object::DefaultFlags);
 129
 130     return obj;
 131 }
 132
 133 /// Register a built-in class
 134 //
 135 /// This is used for classes that are part of the player API.
 136 //
 137 /// In the reference player these classes are always constructed in
 138 /// ActionScript, though their functions may be native, and the constructor
 139 /// may also call native functions.
 140 //
 141 /// @param c        a pointer to a function that will attach properties to the
 142 ///                 class itself. These are known as static properties.
 143 /// @param p        a pointer to a function that will attach properties to the
 144 ///                 class prototype. These are instance properties.
 145 /// @param ctor     the constructor function for the new class.
 146 /// @param where    the object to which the created object will be attached
 147 /// @param uri      an ObjectURI describing the name and namespace of the
 148 ///                 created object.
 149 /// @return         the built-in class with prototype and properties attached.
 150 inline as_object*
 151 registerBuiltinClass(as_object& where, Global_as::ASFunction ctor,
 152         Global_as::Properties p, Global_as::Properties c, const ObjectURI& uri)
 153 {
 154     Global_as& gl = getGlobal(where);
 155     as_object* proto = createObject(gl);
 156     as_object* cl = gl.createClass(ctor, proto);
 157
 158     // Attach class properties to class
 159     if (c) c(*cl);
 160
 161     // Attach prototype properties to prototype
 162     if (p) p(*proto);
 163
 164     // Register class with specified object.
 165     where.init_member(uri, cl, as_object::DefaultFlags);
 166     return cl;
 167 }
 168
 169 /// Call an as_value on an as_object.
 170 //
 171 /// The call will fail harmlessly if the as_value is not callable.
 172 inline DSOEXPORT as_value
 173 invoke(const as_value& method, const as_environment& env, as_object* this_ptr,
 174         fn_call::Args& args, as_object* super = 0,
 175         const movie_definition* callerDef = 0)
 176 {
 177
 178         as_value val;
 179         fn_call call(this_ptr, env, args);
 180         call.super = super;
 181     call.callerDef = callerDef;
 182
 183         try {
 184                 if (as_object* func = toObject(method, getVM(env))) {
 185             // Call function.
 186                     val = func->call(call);
 187                 }
 188                 else {
 189             IF_VERBOSE_ASCODING_ERRORS(
 190                 log_aserror("Attempt to call a value which is not "
 191                     "a function (%s)", method);
 192             );
 193             return val;
 194                 }
 195         }
 196         catch (ActionTypeError& e) {
 197                 assert(val.is_undefined());
 198                 IF_VERBOSE_ASCODING_ERRORS(
 199             log_aserror("%s", e.what());
 200                 );
 201         }
 202         return val;
 203 }
 204
 205 /// Helper macro for callMethod arguments.
 206 #define VALUE_ARG(z, n, t) BOOST_PP_COMMA_IF(n) t arg##n
 207
 208 /// Call a member function of this object in an AS-compatible way
 209 //
 210 /// This is a macro to cope with a varying number of arguments. The function
 211 /// signature is as follows:
 212 //
 213 /// as_value callMethod(as_object* obj, const ObjectURI& uri,
 214 ///     const as_value& arg1, ..., const as_value& argN);
 215 //
 216 /// If the member function exists and is a function, invoke() is called on
 217 /// the member with the object as the this pointer.
 218 //
 219 /// @param obj          The object to call the method on. This may be null, in
 220 ///                     which case the call is a no-op. This is because calling
 221 ///                     methods on null or non-objects in AS is harmless.
 222 /// @param name         The name of the method.
 223 ///
 224 /// @param arg0..argN   The arguments to pass
 225 ///
 226 /// @return             The return value of the call (possibly undefined).
 227 #define CALL_METHOD(x, n, t) \
 228 inline as_value \
 229 callMethod(as_object* obj, const ObjectURI& uri BOOST_PP_COMMA_IF(n)\
 230         BOOST_PP_REPEAT(n, VALUE_ARG, const as_value&)) {\
 231     if (!obj) return as_value();\
 232     as_value func;\
 233     if (!obj->get_member(uri, &func)) return as_value();\
 234     fn_call::Args args;\
 235     BOOST_PP_EXPR_IF(n, (args += BOOST_PP_REPEAT(n, VALUE_ARG, ));)\
 236     return invoke(func, as_environment(getVM(*obj)), obj, args);\
 237 }
 238
 239 /// The maximum number of as_value arguments allowed in callMethod functions.
 240 #define MAX_ARGS 4
 241 BOOST_PP_REPEAT(BOOST_PP_INC(MAX_ARGS), CALL_METHOD, )
 242
 243 /// Convenience function for finding a class constructor.
 244 //
 245 /// Only currently useful in AS2.
 246 inline as_function*
 247 getClassConstructor(const fn_call& fn, const std::string& s)
 248 {
 249     const as_value ctor(findObject(fn.env(), s));
 250     return ctor.to_function();
 251 }
 252
 253 } // namespace gnash
 254
 255 #endif