Add wxConfig::Read(float *) overload.

This uses Read(double *) but casts the result to float after checking that it
is in the correct range.

Closes #12100.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64428 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -449,6 +449,7 @@ All:
 - Added wxResourceTranslationsLoader for loading translations from Windows
   resources.
 - Added wxMessageQueue::Clear().
+- Added wxConfig::Read(float *) overload (Terry Farnham).
 
 Unix:
 

include/wx/confbase.h

@@ -181,6 +181,10 @@ public:
   bool Read(const wxString& key, double* val) const;
   bool Read(const wxString& key, double* val, double defVal) const;
 
+    // read a float
+  bool Read(const wxString& key, float* val) const;
+  bool Read(const wxString& key, float* val, float defVal) const;
+
     // read a bool
   bool Read(const wxString& key, bool* val) const;
   bool Read(const wxString& key, bool* val, bool defVal) const;

interface/wx/config.h

@@ -589,10 +589,33 @@ public:
     */
     bool Read(const wxString& key, double* d,
                      double defaultVal) const;
+
     /**
-        Reads a bool value, returning @true if the value was found. If the
+        Reads a float value, returning @true if the value was found.
+
+        With the second overload, if the value was not found, @a defaultVal is
+        used instead.
+
+        Notice that the value is read as a double but must be in a valid range
+        for floats for the function to return @true.
+
+        @since 2.9.1
+
+        @beginWxPerlOnly
+        Not supported by wxPerl.
+        @endWxPerlOnly
+    */
+    //@{
+    bool Read(const wxString& key, float* f) const;
+    bool Read(const wxString& key, float* f, float defaultVal) const;
+    //@}
+
+    /**
+        Reads a float value, returning @true if the value was found. If the
         value was not found, @a b is not changed.
 
+        @since 2.9.1
+
         @beginWxPerlOnly
         Not supported by wxPerl.
         @endWxPerlOnly

src/common/config.cpp

@@ -43,6 +43,7 @@
 #include <stdlib.h>
 #include <ctype.h>
 #include <limits.h>     // for INT_MAX
+#include <float.h>      // for FLT_MAX
 
 // ----------------------------------------------------------------------------
 // global and class static variables
@@ -180,6 +181,36 @@ bool wxConfigBase::Read(const wxString& key, int *pi, int defVal) const
     return r;
 }
 
+// Read floats as doubles then just type cast it down.
+bool wxConfigBase::Read(const wxString& key, float* val) const
+{
+    wxCHECK_MSG( val, false, wxT("wxConfig::Read(): NULL parameter") );
+
+    double temp;
+    if ( !Read(key, &temp) )
+        return false;
+
+    wxCHECK_MSG( fabs(temp) <= FLT_MAX, false,
+                     wxT("float overflow in wxConfig::Read") );
+    wxCHECK_MSG( (temp == 0.0) || (fabs(temp) >= FLT_MIN), false,
+                     wxT("float underflow in wxConfig::Read") );
+
+    *val = static_cast<float>(temp);
+
+    return true;
+}
+
+bool wxConfigBase::Read(const wxString& key, float* val, float defVal) const
+{
+    wxCHECK_MSG( val, false, wxT("wxConfig::Read(): NULL parameter") );
+
+    if ( Read(key, val) )
+        return true;
+
+    *val = defVal;
+    return false;
+}
+
 // the DoReadXXX() for the other types have implementation in the base class
 // but can be overridden in the derived ones
 bool wxConfigBase::DoReadBool(const wxString& key, bool* val) const

tests/config/fileconf.cpp

@@ -82,6 +82,7 @@ private:
         CPPUNIT_TEST( AddToExistingRoot );
         CPPUNIT_TEST( ReadNonExistent );
         CPPUNIT_TEST( ReadEmpty );
+        CPPUNIT_TEST( ReadFloat );
     CPPUNIT_TEST_SUITE_END();
 
     void Path();
@@ -105,6 +106,7 @@ private:
     void AddToExistingRoot();
     void ReadNonExistent();
     void ReadEmpty();
+    void ReadFloat();
 
 
     static wxString ChangePath(wxFileConfig& fc, const wxChar *path)
@@ -659,5 +661,24 @@ void FileConfigTestCase::ReadEmpty()
     wxFileConfig fc(sis);
 }
 
+void FileConfigTestCase::ReadFloat()
+{
+    static const char *confTest =
+        "x=1.234\n"
+        "y=-9876.5432\n"
+        "z=2e+308\n"
+    ;
+
+    wxStringInputStream sis(confTest);
+    wxFileConfig fc(sis);
+
+    float f;
+    CPPUNIT_ASSERT( fc.Read("x", &f) );
+    CPPUNIT_ASSERT_EQUAL( 1.234f, f );
+
+    CPPUNIT_ASSERT( fc.Read("y", &f) );
+    CPPUNIT_ASSERT_EQUAL( -9876.5432f, f );
+}
+
 #endif // wxUSE_FILECONFIG