vcl: FontMetric now has ImplFontMetricPtr objects

ImplFontMetricPtr is a typedef to an intrusive_ptr<ImplFontMetric>.
I have ditched the manual reference counting to use Boost's smart
pointer.

Change-Id: I5e93f45d19d43c8b7253f4342c1b9ef4a4301527

3 files changed, 28 insertions, 26 deletions

diff --git a/include/vcl/metric.hxx b/include/vcl/metric.hxx
index 0cd14b1c20f8..e37b91ffac75 100644
--- a/include/vcl/metric.hxx
+++ b/include/vcl/metric.hxx
@@ -33,6 +33,7 @@ class CmapResult;
 typedef sal_uInt32 sal_UCS4;
 typedef boost::intrusive_ptr< ImplFontCharMap > ImplFontCharMapPtr;
 typedef boost::intrusive_ptr< FontCharMap > FontCharMapPtr;
+typedef boost::intrusive_ptr< ImplFontMetric > ImplFontMetricPtr;
 
 class VCL_DLLPUBLIC FontMetric : public vcl::Font
 {
@@ -72,7 +73,7 @@ public:
     bool                operator!=( const FontMetric& rMetric ) const
                             { return !operator==( rMetric ); }
 protected:
-    ImplFontMetric*     mpImplMetric;    // Implementation
+    ImplFontMetricPtr   mpImplMetric;    // Implementation
 };
 
 template< typename charT, typename traits >
diff --git a/vcl/inc/impfontmetric.hxx b/vcl/inc/impfontmetric.hxx
index 226be2edfac5..7b9413f9fe4f 100644
--- a/vcl/inc/impfontmetric.hxx
+++ b/vcl/inc/impfontmetric.hxx
@@ -20,8 +20,17 @@
 #ifndef INCLUDED_VCL_INC_IMPFONTMETRIC_HXX
 #define INCLUDED_VCL_INC_IMPFONTMETRIC_HXX
 
+#include <boost/intrusive_ptr.hpp>
+
+class ImplFontCharMap;
+typedef boost::intrusive_ptr< ImplFontCharMap > ImplFontCharMapPtr;
+
 class ImplFontMetric
 {
+    friend class FontMetric;
+    friend void intrusive_ptr_add_ref(ImplFontMetric* pImplFontMetric);
+    friend void intrusive_ptr_release(ImplFontMetric* pImplFontMetric);
+
 private:
     long                mnAscent;      // Ascent
     long                mnDescent;     // Descent
@@ -41,8 +50,6 @@ public:
     bool                operator==( const ImplFontMetric& ) const;
 
                         ImplFontMetric();
-    void                AddReference();
-    void                DeReference();
 
     long                GetAscent() const                           { return mnAscent; }
     long                GetDescent() const                          { return mnDescent; }
@@ -70,6 +77,17 @@ public:
 
 };
 
+inline void intrusive_ptr_add_ref(ImplFontMetric* pImplFontMetric)
+{
+    ++pImplFontMetric->mnRefCount;
+}
+
+inline void intrusive_ptr_release(ImplFontMetric* pImplFontMetric)
+{
+    if (--pImplFontMetric->mnRefCount == 0)
+        delete pImplFontMetric;
+}
+
 #endif // INCLUDED_VCL_INC_IMPFONTMETRIC_HXX
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/gdi/metric.cxx b/vcl/source/gdi/metric.cxx
index eb7271d4a82e..adbb45420af0 100644
--- a/vcl/source/gdi/metric.cxx
+++ b/vcl/source/gdi/metric.cxx
@@ -26,19 +26,17 @@
 #include <cstdio>
 
 FontMetric::FontMetric()
-:   mpImplMetric( new ImplFontMetric )
+:   mpImplMetric( new ImplFontMetric() )
 {}
 
 FontMetric::FontMetric( const FontMetric& rFontMetric )
-:  Font( rFontMetric )
-{
-    mpImplMetric = rFontMetric.mpImplMetric;
-    mpImplMetric->AddReference();
-}
+    : Font( rFontMetric )
+    , mpImplMetric( rFontMetric.mpImplMetric )
+{}
 
 FontMetric::~FontMetric()
 {
-    mpImplMetric->DeReference();
+    mpImplMetric = nullptr;
 }
 
 FontMetric& FontMetric::operator=( const FontMetric& rFontMetric )
@@ -47,9 +45,7 @@ FontMetric& FontMetric::operator=( const FontMetric& rFontMetric )
 
     if( mpImplMetric != rFontMetric.mpImplMetric )
     {
-        mpImplMetric->DeReference();
         mpImplMetric = rFontMetric.mpImplMetric;
-        mpImplMetric->AddReference();
     }
 
     return *this;
@@ -181,25 +177,12 @@ ImplFontMetric::ImplFontMetric()
     mnLineHeight( 0 ),
     mnSlant( 0 ),
     mnBulletOffset( 0 ),
-    mnRefCount( 1 ),
+    mnRefCount( 0 ),
     mbScalableFont( false ),
     mbFullstopCentered( false ),
     mbDevice( false )
 {}
 
-inline void ImplFontMetric::AddReference()
-{
-    // TODO: disable refcounting on the default maps?
-    ++mnRefCount;
-}
-
-inline void ImplFontMetric::DeReference()
-{
-    // TODO: disable refcounting on the default maps?
-    if( --mnRefCount <= 0 )
-        delete this;
-}
-
 bool ImplFontMetric::operator==( const ImplFontMetric& r ) const
 {
     if(    mbScalableFont     != r.mbScalableFont