1 /* 2 * Copyright (C) 2010 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 /* 32 This file contains the declaration for CppVariant, a type used by C++ classes 33 that are to be bound to JavaScript objects. 34 35 CppVariant exists primarily as an interface between C++ callers and the 36 corresponding NPVariant type. CppVariant also provides a number of 37 convenience constructors and accessors, so that the NPVariantType values 38 don't need to be exposed, and a destructor to free any memory allocated for 39 string values. 40 */ 41 42 #ifndef CppVariant_h 43 #define CppVariant_h 44 45 #include "WebBindings.h" 46 #include "webkit/support/webkit_support.h" 47 #include <string> 48 #include <wtf/Vector.h> 49 50 class CppVariant : public NPVariant { 51 public: 52 CppVariant(); 53 ~CppVariant(); 54 void setNull(); 55 void set(bool); 56 void set(int32_t); 57 void set(double); 58 59 // Note that setting a CppVariant to a string value involves copying the 60 // string data, which must be freed with a call to freeData() when the 61 // CppVariant is set to a different value or is no longer needed. Normally 62 // this is handled by the other set() methods and by the destructor. 63 void set(const char*); // Must be a null-terminated string. 64 void set(const std::string&); 65 void set(const NPString&); 66 void set(const NPVariant&); 67 68 // Note that setting a CppVariant to an NPObject involves ref-counting 69 // the actual object. freeData() should only be called if the CppVariant 70 // is no longer needed. The other set() methods handle this internally. 71 // Also, the object's NPClass is expected to be a static object: neither 72 // the NP runtime nor CppVariant will ever free it. 73 void set(NPObject*_value); 74 75 // These three methods all perform deep copies of any string data. This 76 // allows local CppVariants to be released by the destructor without 77 // corrupting their sources. In performance-critical code, or when strings 78 // are very long, avoid creating new CppVariants. 79 // In case of NPObject as the data, the copying involves ref-counting 80 // as opposed to deep-copying. The ref-counting ensures that sources don't 81 // get corrupted when the copies get destroyed. 82 void copyToNPVariant(NPVariant* result) const; 83 CppVariant& operator=(const CppVariant& original); 84 CppVariant(const CppVariant& original); 85 86 // Calls NPN_ReleaseVariantValue, which frees any string data 87 // held by the object and sets its type to null. 88 // In case of NPObject, the NPN_ReleaseVariantValue decrements 89 // the ref-count (releases when ref-count becomes 0) 90 void freeData(); 91 92 // Compares this CppVariant's type and value to another's. They must be 93 // identical in both type and value to be considered equal. For string and 94 // object types, a deep comparison is performed; that is, the contents of the 95 // strings, or the classes and refcounts of the objects, must be the same, 96 // but they need not be the same pointers. 97 bool isEqual(const CppVariant&) const; 98 99 // The value of a CppVariant may be read directly from its NPVariant (but 100 // should only be set using one of the set() methods above). Although the 101 // type of a CppVariant is likewise public, it can be accessed through these 102 // functions rather than directly if a caller wishes to avoid dependence on 103 // the NPVariantType values. 104 bool isBool() const { return (type == NPVariantType_Bool); } 105 bool isInt32() const { return (type == NPVariantType_Int32); } 106 bool isDouble() const { return (type == NPVariantType_Double); } 107 bool isNumber() const { return (isInt32() || isDouble()); } 108 bool isString() const { return (type == NPVariantType_String); } 109 bool isVoid() const { return (type == NPVariantType_Void); } 110 bool isNull() const { return (type == NPVariantType_Null); } 111 bool isEmpty() const { return (isVoid() || isNull()); } 112 bool isObject() const { return (type == NPVariantType_Object); } 113 114 // Converters. The CppVariant must be of a type convertible to these values. 115 // For example, toInt32() works only if isNumber() is true. 116 std::string toString() const; 117 int32_t toInt32() const; 118 double toDouble() const; 119 bool toBoolean() const; 120 // Returns a vector of strings for the specified argument. This is useful 121 // for converting a JavaScript array of strings into a vector of strings. 122 Vector<std::string> toStringVector() const; 123 124 // Invoke method of the given name on an object with the supplied arguments. 125 // The first argument should be the object on which the method is to be 126 // invoked. Returns whether the method was successfully invoked. If the 127 // method was invoked successfully, any return value is stored in the 128 // CppVariant specified by result. 129 bool invoke(const std::string&, const CppVariant* arguments, 130 uint32_t argumentCount, CppVariant& result) const; 131 }; 132 133 #endif // CppVariant_h 134
