OOJSMissionVariables.m

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/*
 
OOJSMissionVariables.h
 
JavaScript mission variables object.
 
 
Oolite
Copyright (C) 2004-2013 Giles C Williams and contributors
 
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
 
*/
 
#import "OOJSMissionVariables.h"
#import "OOJavaScriptEngine.h"
#import "OOIsNumberLiteral.h"
 
#import "OOJSPlayer.h"
 
 
static NSString *KeyForPropertyID(JSContext *context, jsid propID)
{
    NSCParameterAssert(JSID_IS_STRING(propID));
    
    NSString *key = OOStringFromJSString(context, JSID_TO_STRING(propID));
    if ([key hasPrefix:@"_"])  return nil;
    return [@"mission_" stringByAppendingString:key];
}
 
 
static JSBool MissionVariablesDeleteProperty(JSContext *context, JSObject *this, jsid propID, jsval *value);
static JSBool MissionVariablesGetProperty(JSContext *context, JSObject *this, jsid propID, jsval *value);
static JSBool MissionVariablesSetProperty(JSContext *context, JSObject *this, jsid propID, JSBool strict, jsval *value);
static JSBool MissionVariablesEnumerate(JSContext *context, JSObject *object, JSIterateOp enumOp, jsval *state, jsid *idp);
 
#ifndef NDEBUG
static id MissionVariablesConverter(JSContext *context, JSObject *object);
#endif
 
 
static JSClass sMissionVariablesClass =
{
    "MissionVariables",
    JSCLASS_NEW_ENUMERATE,
    
    JS_PropertyStub,
    MissionVariablesDeleteProperty,
    MissionVariablesGetProperty,
    MissionVariablesSetProperty,
    (JSEnumerateOp)MissionVariablesEnumerate,
    JS_ResolveStub,
    JS_ConvertStub,
    JS_FinalizeStub
};
 
 
void InitOOJSMissionVariables(JSContext *context, JSObject *global)
{
    JS_DefineObject(context, global, "missionVariables", &sMissionVariablesClass, NULL, OOJS_PROP_READONLY);
    
#ifndef NDEBUG
    // Allow callObjC() on missionVariables to call methods on the mission variables dictionary.
    OOJSRegisterObjectConverter(&sMissionVariablesClass, MissionVariablesConverter);
#endif
}
 
 
#ifndef NDEBUG
static id MissionVariablesConverter(JSContext *context, JSObject *object)
{
    return [PLAYER missionVariables];
}
#endif
 
 
static JSBool MissionVariablesDeleteProperty(JSContext *context, JSObject *this, jsid propID, jsval *value)
{
    OOJS_NATIVE_ENTER(context)
    
    PlayerEntity                *player = OOPlayerForScripting();
    
    if (JSID_IS_STRING(propID))
    {
        NSString *key = KeyForPropertyID(context, propID);
        [player setMissionVariable:nil forKey:key];
    }
    return YES;
    
    OOJS_NATIVE_EXIT
}
 
 
static JSBool MissionVariablesGetProperty(JSContext *context, JSObject *this, jsid propID, jsval *value)
{
    OOJS_NATIVE_ENTER(context)
    
    PlayerEntity                *player = OOPlayerForScripting();
    
    if (JSID_IS_STRING(propID))
    {
        NSString *key = KeyForPropertyID(context, propID);
        if (key == nil)  return YES;
        
        id mvar = [player missionVariableForKey:key];
        
        if ([mvar isKindOfClass:[NSString class]])  // Currently there should only be strings, but we may want to change this.
        {
            if (OOIsNumberLiteral(mvar, YES))
            {
                return JS_NewNumberValue(context, [mvar doubleValue], value);
            }
        }
        
        *value = OOJSValueFromNativeObject(context, mvar);
    }
    return YES;
    
    OOJS_NATIVE_EXIT
}
 
 
static JSBool MissionVariablesSetProperty(JSContext *context, JSObject *this, jsid propID, JSBool strict, jsval *value)
{
    OOJS_NATIVE_ENTER(context)
    
    PlayerEntity                *player = OOPlayerForScripting();
    
    if (JSID_IS_STRING(propID))
    {
        NSString *key = KeyForPropertyID(context, propID);
        if (key == nil)
        {
            OOJSReportError(context, @"Invalid mission variable name \"%@\".", [OOStringFromJSID(propID) escapedForJavaScriptLiteral]);
            return NO;
        }
        
        NSString *objValue = OOStringFromJSValue(context, *value);
        
        if ([objValue isKindOfClass:[NSNull class]])  objValue = nil;
        [player setMissionVariable:objValue forKey:key];
    }
    return YES;
    
    OOJS_NATIVE_EXIT
}
 
 
static JSBool MissionVariablesEnumerate(JSContext *context, JSObject *object, JSIterateOp enumOp, jsval *state, jsid *idp)
{
    OOJS_NATIVE_ENTER(context)
    
    NSEnumerator *enumerator = nil;
    
    switch (enumOp)
    {
        case JSENUMERATE_INIT:
        case JSENUMERATE_INIT_ALL:  // For ES5 Object.getOwnPropertyNames(). Since we have no non-enumerable properties, this is the same as _INIT.
        {
            // -allKeys implicitly makes a copy, which is good since the enumerating code might mutate.
            NSArray *mvars = [[PLAYER missionVariables] allKeys];
            enumerator = [[mvars objectEnumerator] retain];
            *state = PRIVATE_TO_JSVAL(enumerator);
            
            NSUInteger count = [mvars count];
            assert(count <= INT32_MAX);
            if (idp != NULL)  *idp = INT_TO_JSID((uint32_t)count);
            return YES;
        }
        
        case JSENUMERATE_NEXT:
        {
            enumerator = JSVAL_TO_PRIVATE(*state);
            for (;;)
            {
                NSString *next = [enumerator nextObject];
                if (next == nil)  break;
                if (![next hasPrefix:@"mission_"])  continue;   // Skip mission instructions, which aren't visible through missionVariables.
                
                next = [next substringFromIndex:8];     // Cut off "mission_".
                
                jsval val = [next oo_jsValueInContext:context];
                return JS_ValueToId(context, val, idp);
            }
            
            // If we got here, we've hit the end of the enumerator.
            *state = JSVAL_NULL;
            // Fall through.
        }
        
        case JSENUMERATE_DESTROY:
        {
            if (enumerator == nil && JSVAL_IS_DOUBLE(*state))
            {
                enumerator = JSVAL_TO_PRIVATE(*state);
            }
            [enumerator release];
            
            if (idp != NULL)  *idp = JSID_VOID;
            return YES;
        }
    }
    
    OOJS_NATIVE_EXIT
}