Fl_Quartz_Graphics_Driver: separate CoreText- and ATSU-based code using new, derived classes.

FLTK for the Mac OS platform draws text using 2 distinct system APIs depending on the 
version of the running OS. Classes Fl_CoreText_Graphics_Driver and Fl_ATSU_Graphics_Driver are defined
and implement the same virtual functions of class Fl_Quartz_Graphics_Driver using
CoreText and ATSU, respectively. The app allocates an object of one of these derived
classes according to the running OS version.



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11967 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

src/drivers/Quartz/Fl_Quartz_Copy_Surface_Driver.cxx

@@ -30,7 +30,7 @@ Fl_Copy_Surface_Driver *Fl_Copy_Surface_Driver::newCopySurfaceDriver(int w, int
 }
 
 Fl_Quartz_Copy_Surface_Driver::Fl_Quartz_Copy_Surface_Driver(int w, int h) : Fl_Copy_Surface_Driver(w, h) {
-  driver(new Fl_Quartz_Graphics_Driver);
+  driver(Fl_Graphics_Driver::newMainGraphicsDriver());
   prepare_copy_pdf_and_tiff(w, h);
 }
 

src/drivers/Quartz/Fl_Quartz_Graphics_Driver.H

@@ -25,9 +25,15 @@
 #ifndef FL_QUARTZ_GRAPHICS_DRIVER_H
 #define FL_QUARTZ_GRAPHICS_DRIVER_H
 
+#include <FL/x.H>
 #include <FL/Fl_Graphics_Driver.H>
 #include <ApplicationServices/ApplicationServices.h>
 
+// condition for the ATSU API to be available at compile time
+#define HAS_ATSU (!defined(__LP64__) || !__LP64__) && MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_11
+
+struct Fl_Fontdesc;
+
 /**
  \brief The Mac OS X-specific graphics class.
  *
@@ -40,10 +46,12 @@ protected:
   typedef struct { float x; float y; } XPOINT;
   XPOINT *p;
   bool high_resolution_;
-public:
+// protected constructor to ensure only derived classes are allocated
   Fl_Quartz_Graphics_Driver() : Fl_Graphics_Driver(), gc_(NULL), p_size(0), p(NULL) {
     high_resolution_ = false;
   }
+public:
+  static const int CoreText_threshold; // min Mac OS version for CoreText
   virtual ~Fl_Quartz_Graphics_Driver() { if (p) free(p); }
   virtual int has_feature(driver_feature mask) { return mask & NATIVE; }
   virtual void gc(void *ctxt) {if (ctxt != gc_) global_gc(); gc_ = (CGContextRef)ctxt; }
@@ -128,13 +136,45 @@ protected:
   void font(Fl_Font face, Fl_Fontsize fsize);
   double width(const char *str, int n);
   double width(unsigned int c);
-  void text_extents(const char*, int n, int& dx, int& dy, int& w, int& h);
   int height();
   int descent();
   virtual bool high_resolution() { return high_resolution_; }
   virtual void global_gc();
+  // Next group of virtual functions have at least one alternative
+  // CoreText- or ATSU-based implementation.
+  virtual void draw_float(float x, float y, const char *str, int n) {}
+  virtual double width(const UniChar* txt, int n, Fl_Font_Descriptor *fl_fontsize) {return 0;}
+public:
+  virtual Fl_Font set_fonts(const char* xstarname) {return 0;}
+  virtual Fl_Fontdesc* calc_fl_fonts(void) {return NULL;}
+  virtual void set_fontname_in_fontdesc(Fl_Fontdesc *f);
+  virtual void descriptor_init(const char* name, Fl_Fontsize Size, Fl_Font_Descriptor *d) {}
+  // end of function group
 };
 
+#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
+class Fl_CoreText_Graphics_Driver : public Fl_Quartz_Graphics_Driver {
+  void text_extents(const char*, int n, int& dx, int& dy, int& w, int& h);
+  virtual void draw_float(float x, float y, const char *str, int n);
+  virtual double width(const UniChar* txt, int n, Fl_Font_Descriptor *fl_fontsize);
+  Fl_Font set_fonts(const char* xstarname);
+  virtual Fl_Fontdesc* calc_fl_fonts(void);
+  virtual void set_fontname_in_fontdesc(Fl_Fontdesc *f);
+  virtual void descriptor_init(const char* name, Fl_Fontsize Size, Fl_Font_Descriptor *d);
+};
+#endif
+
+#ifdef HAS_ATSU
+class Fl_ATSU_Graphics_Driver : public Fl_Quartz_Graphics_Driver {
+  void text_extents(const char*, int n, int& dx, int& dy, int& w, int& h);
+  virtual void draw_float(float x, float y, const char *str, int n);
+  virtual double width(const UniChar* txt, int n, Fl_Font_Descriptor *fl_fontsize);
+  Fl_Font set_fonts(const char* xstarname);
+  virtual Fl_Fontdesc* calc_fl_fonts(void);
+  virtual void descriptor_init(const char* name, Fl_Fontsize Size, Fl_Font_Descriptor *d);
+};
+#endif
+
 extern float fl_quartz_line_width_;
 
 #endif // FL_QUARTZ_GRAPHICS_DRIVER_H

src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx

@@ -19,6 +19,7 @@
 
 #include "../../config_lib.h"
 #include "Fl_Quartz_Graphics_Driver.H"
+#include "../Darwin/Fl_Darwin_System_Driver.H"
 #include <FL/x.H>
 
 /*
@@ -27,7 +28,20 @@
  */
 Fl_Graphics_Driver *Fl_Graphics_Driver::newMainGraphicsDriver()
 {
-  return new Fl_Quartz_Graphics_Driver();
+#if HAS_ATSU
+  static int option = 0; // 0: not initialized, 1: use CoreText, 2: use ATSU
+  if (!option) {
+    option = 2;
+    if (Fl_Darwin_System_Driver::calc_mac_os_version() >= Fl_Quartz_Graphics_Driver::CoreText_threshold) {
+      option = 1;
+    }
+  }
+  if (option == 2) return new Fl_ATSU_Graphics_Driver();
+#endif // HAS_ATSU
+#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
+  return new Fl_CoreText_Graphics_Driver();
+#endif
+  return NULL; // should not happen
 }
 
 char Fl_Quartz_Graphics_Driver::can_do_alpha_blending() {

src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.cxx

@@ -53,7 +53,7 @@ Fl_Quartz_Image_Surface_Driver::Fl_Quartz_Image_Surface_Driver(int w, int h, int
   CGColorSpaceRef lut = CGColorSpaceCreateDeviceRGB();
   offscreen = CGBitmapContextCreate(calloc(W*H,4), W, H, 8, W*4, lut, kCGImageAlphaPremultipliedLast);
   CGColorSpaceRelease(lut);
-  driver(new Fl_Quartz_Graphics_Driver);
+  driver(Fl_Graphics_Driver::newMainGraphicsDriver());
   CGContextTranslateCTM(offscreen, 0.5, -0.5); // as when drawing to a window
   if (high_res) {
     CGContextScaleCTM(offscreen, 2, 2);