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