Add new QPDFObjectHandle::Integer and QPDFObjectHandle::asInteger

Implement all existing integer accessors in terms of asInteger.

include/qpdf/QPDFObjectHandle.hh

@@ -23,6 +23,7 @@
 #define QPDFOBJECTHANDLE_HH
 
 #include <qpdf/QPDFObjectHandle_core.hh>
+#include <qpdf/QPDFObjectHandle_typed.hh>
 
 // See qpdf/QPDFObjectHandle_core.hh for the definition of QPDFObjectHandle.
 

include/qpdf/QPDFObjectHandle_core.hh

@@ -66,6 +66,8 @@ class QPDFObjectHandle
     friend class QPDFParser;
 
   public:
+    class Typed;
+    class Integer;
     // This class is used by replaceStreamData.  It provides an alternative way of associating
     // stream data with a stream.  See comments on replaceStreamData and newStream for additional
     // details.
@@ -647,6 +649,8 @@ class QPDFObjectHandle
     // return type may be returned. For example, on a system with 32-bit int, a numeric object with
     // a value of 2^40 (or anything too big for 32 bits) will be returned as INT_MAX.
     QPDF_DLL
+    QPDFObjectHandle::Integer asInteger(bool optional = false);
+    QPDF_DLL
     long long getIntValue();
     QPDF_DLL
     bool getValueAsInt(long long&);
@@ -1367,7 +1371,6 @@ class QPDFObjectHandle
     QPDF_Bool* asBool();
     QPDF_Dictionary* asDictionary();
     QPDF_InlineImage* asInlineImage();
-    QPDF_Integer* asInteger();
     QPDF_Name* asName();
     QPDF_Null* asNull();
     QPDF_Operator* asOperator();

include/qpdf/QPDFObjectHandle_typed.hh

@@ -0,0 +1,138 @@
+// Copyright (c) 2005-2024 Jay Berkenbilt
+//
+// This file is part of qpdf.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Versions of qpdf prior to version 7 were released under the terms
+// of version 2.0 of the Artistic License. At your option, you may
+// continue to consider qpdf to be licensed under those terms. Please
+// see the manual for additional information.
+
+#ifndef QPDFOBJECTHANDLE_TYPED_HH
+#define QPDFOBJECTHANDLE_TYPED_HH
+
+#include <bitset>
+
+class QPDFObjectHandle::Typed
+{
+  public:
+    operator QPDFObjectHandle() const
+    {
+        return oh;
+    }
+
+    QPDF_DLL
+    operator bool() noexcept
+    {
+        return flags.test(fl_valid);
+    }
+
+    QPDF_DLL
+    operator bool() const noexcept
+    {
+        return flags.test(fl_valid);
+    }
+
+    QPDF_DLL
+    bool
+    null() const noexcept
+    {
+        return flags.test(fl_null);
+    }
+
+    QPDF_DLL
+    QPDFObjGen
+    getObjGen() const
+    {
+        return oh.getObjGen();
+    }
+
+    // ... and all the other methods applicable to all object types.
+
+  protected:
+    using Flags = std::bitset<3>;
+
+    enum flags { fl_valid, fl_null, fl_no_type_check };
+
+    Typed() = default;
+    Typed(QPDFObjectHandle const& oh, Flags flags) :
+        oh(oh),
+        flags(flags)
+    {
+    }
+
+    Typed(QPDFObjectHandle&& oh, Flags flags) :
+        oh(std::move(oh)),
+        flags(flags)
+    {
+    }
+
+    Typed(Typed const&) = default;
+    Typed(Typed&&) = default;
+    Typed& operator=(Typed const&) = default;
+    Typed& operator=(Typed&&) = default;
+    ~Typed() = default;
+
+    QPDFObjectHandle oh;
+    Flags flags{};
+};
+
+class QPDFObjectHandle::Integer: public QPDFObjectHandle::Typed
+{
+    friend class QPDFObjectHandle;
+
+  public:
+    QPDF_DLL
+    operator long long();
+
+    QPDF_DLL
+    operator int();
+
+    QPDF_DLL
+    operator unsigned long long();
+
+    QPDF_DLL
+    operator unsigned int();
+
+    QPDF_DLL
+    long long
+    value()
+    {
+        return *this;
+    }
+
+    template <typename T>
+    bool
+    assign_to(T& var)
+    {
+        if (flags.test(0)) {
+            var = *this;
+            return true;
+        }
+        return false;
+    }
+
+  private:
+    Integer() = default;
+    Integer(QPDFObjectHandle const& oh, Flags flags) :
+        QPDFObjectHandle::Typed(oh, flags)
+    {
+    }
+    Integer(QPDFObjectHandle&& oh, QPDF_Integer* ptr, Flags flags) :
+        QPDFObjectHandle::Typed(std::move(oh), flags)
+    {
+    }
+};
+
+#endif // QPDFOBJECTHANDLE_TYPED_HH

libqpdf/QPDFObjectHandle.cc

@@ -273,12 +273,6 @@ QPDFObjectHandle::asInlineImage()
     return dereference() ? obj->as<QPDF_InlineImage>() : nullptr;
 }
 
-QPDF_Integer*
-QPDFObjectHandle::asInteger()
-{
-    return dereference() ? obj->as<QPDF_Integer>() : nullptr;
-}
-
 QPDF_Name*
 QPDFObjectHandle::asName()
 {
@@ -499,110 +493,123 @@ QPDFObjectHandle::getValueAsBool(bool& value)
 
 // Integer accessors
 
+QPDFObjectHandle::Integer
+QPDFObjectHandle::asInteger(bool optional)
+{
+    if (isInteger()) {
+        return {*this, 1U};
+    }
+    if (isNull()) {
+        return {*this, optional ? 3U : 2U};
+    }
+    return {*this, 0U};
+}
+
+QPDFObjectHandle::Integer::operator long long()
+{
+    if (flags == 1U) {
+        if (auto ptr = oh.obj ? oh.obj->as<QPDF_Integer>() : nullptr) {
+            return ptr->getVal();
+        } else {
+            throw std::logic_error("object changed");
+        }
+    }
+    if (!flags.test(fl_valid)) {
+        oh.typeWarning("integer", "returning 0");
+    }
+    QTC::TC("qpdf", "QPDFObjectHandle integer returning 0");
+    return 0;
+}
+
+QPDFObjectHandle::Integer::operator int()
+{
+    auto value = operator long long();
+    if (value < INT_MIN) {
+        QTC::TC("qpdf", "QPDFObjectHandle int returning INT_MIN");
+        oh.warnIfPossible("requested value of integer is too small; returning INT_MIN");
+        return INT_MIN;
+    }
+    if (value > INT_MAX) {
+        QTC::TC("qpdf", "QPDFObjectHandle int returning INT_MAX");
+        oh.warnIfPossible("requested value of integer is too big; returning INT_MAX");
+        return INT_MAX;
+    }
+    return static_cast<int>(value);
+}
+
+QPDFObjectHandle::Integer::operator unsigned long long()
+{
+    auto value = operator long long();
+    if (value < 0) {
+        QTC::TC("qpdf", "QPDFObjectHandle uint returning 0");
+        oh.warnIfPossible("unsigned value request for negative number; returning 0");
+        return 0;
+    }
+    return static_cast<unsigned long long>(value);
+}
+
+QPDFObjectHandle::Integer::operator unsigned int()
+{
+    auto value = operator long long();
+    if (value < 0) {
+        QTC::TC("qpdf", "QPDFObjectHandle uint uint returning 0");
+        oh.warnIfPossible("unsigned integer value request for negative number; returning 0");
+        return 0;
+    }
+    if (value > UINT_MAX) {
+        QTC::TC("qpdf", "QPDFObjectHandle uint returning UINT_MAX");
+        oh.warnIfPossible("requested value of unsigned integer is too big; returning UINT_MAX");
+        return UINT_MAX;
+    }
+    return static_cast<unsigned int>(value);
+}
+
 long long
 QPDFObjectHandle::getIntValue()
 {
-    auto integer = asInteger();
-    if (integer) {
-        return integer->getVal();
-    } else {
-        typeWarning("integer", "returning 0");
-        QTC::TC("qpdf", "QPDFObjectHandle integer returning 0");
-        return 0;
-    }
+    return asInteger();
 }
 
 bool
 QPDFObjectHandle::getValueAsInt(long long& value)
 {
-    auto integer = asInteger();
-    if (integer == nullptr) {
-        return false;
-    }
-    value = integer->getVal();
-    return true;
+    return asInteger().assign_to(value);
 }
 
 int
 QPDFObjectHandle::getIntValueAsInt()
 {
-    int result = 0;
-    long long v = getIntValue();
-    if (v < INT_MIN) {
-        QTC::TC("qpdf", "QPDFObjectHandle int returning INT_MIN");
-        warnIfPossible("requested value of integer is too small; returning INT_MIN");
-        result = INT_MIN;
-    } else if (v > INT_MAX) {
-        QTC::TC("qpdf", "QPDFObjectHandle int returning INT_MAX");
-        warnIfPossible("requested value of integer is too big; returning INT_MAX");
-        result = INT_MAX;
-    } else {
-        result = static_cast<int>(v);
-    }
-    return result;
+    return asInteger();
 }
 
 bool
 QPDFObjectHandle::getValueAsInt(int& value)
 {
-    if (!isInteger()) {
-        return false;
-    }
-    value = getIntValueAsInt();
-    return true;
+    return asInteger().assign_to(value);
 }
 
 unsigned long long
 QPDFObjectHandle::getUIntValue()
 {
-    unsigned long long result = 0;
-    long long v = getIntValue();
-    if (v < 0) {
-        QTC::TC("qpdf", "QPDFObjectHandle uint returning 0");
-        warnIfPossible("unsigned value request for negative number; returning 0");
-    } else {
-        result = static_cast<unsigned long long>(v);
-    }
-    return result;
+    return asInteger();
 }
 
 bool
 QPDFObjectHandle::getValueAsUInt(unsigned long long& value)
 {
-    if (!isInteger()) {
-        return false;
-    }
-    value = getUIntValue();
-    return true;
+    return asInteger().assign_to(value);
 }
 
 unsigned int
 QPDFObjectHandle::getUIntValueAsUInt()
 {
-    unsigned int result = 0;
-    long long v = getIntValue();
-    if (v < 0) {
-        QTC::TC("qpdf", "QPDFObjectHandle uint uint returning 0");
-        warnIfPossible("unsigned integer value request for negative number; returning 0");
-        result = 0;
-    } else if (v > UINT_MAX) {
-        QTC::TC("qpdf", "QPDFObjectHandle uint returning UINT_MAX");
-        warnIfPossible("requested value of unsigned integer is too big; returning UINT_MAX");
-        result = UINT_MAX;
-    } else {
-        result = static_cast<unsigned int>(v);
-    }
-    return result;
+    return asInteger();
 }
 
 bool
 QPDFObjectHandle::getValueAsUInt(unsigned int& value)
 {
-    if (!isInteger()) {
-        return false;
-    }
-    value = getUIntValueAsUInt();
-    return true;
+    return asInteger().assign_to(value);
 }
 
 // Real accessors