X11 platform: cleaner implementation of changing the active drawing surface and maintaining clip regions.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12396 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/Fl_Graphics_Driver.H

@@ -90,6 +90,9 @@ class FL_EXPORT Fl_Graphics_Driver {
   friend FL_EXPORT void gl_start();
   friend FL_EXPORT Fl_Bitmask fl_create_bitmask(int w, int h, const uchar *array);
   friend FL_EXPORT void fl_delete_bitmask(Fl_Bitmask);
+private:
+  // some platforms may need to reimplement this
+  virtual void set_current_();
 public:
   // The following functions create the various graphics drivers that are required
   // for core operations. They must be implemented as members of Fl_Graphics_Driver,

src/Fl_Device.cxx

@@ -54,6 +54,7 @@ void Fl_Surface_Device::set_current(void)
   fl_graphics_driver = pGraphicsDriver;
   surface_ = this;
   pGraphicsDriver->global_gc();
+  driver()->set_current_();
 }
 
 Fl_Surface_Device* Fl_Surface_Device::surface_; // the current target surface of graphics operations

src/Fl_Graphics_Driver.cxx

@@ -184,6 +184,10 @@ void Fl_Graphics_Driver::uncache_pixmap(fl_uintptr_t p) {
 }
 
 
+void Fl_Graphics_Driver::set_current_() {
+}
+
+
 #ifndef FL_DOXYGEN
 Fl_Scalable_Graphics_Driver::Fl_Scalable_Graphics_Driver() : Fl_Graphics_Driver() {
   scale_ = 1;

src/drivers/Xlib/Fl_Xlib_Graphics_Driver.H

@@ -58,6 +58,7 @@ private:
   unsigned depth_; // depth of translation stack
   int stack_x_[20], stack_y_[20]; // translation stack allowing cumulative translations
   int line_delta_;
+  virtual void set_current_();
 protected:
   virtual void draw_unscaled(Fl_Pixmap *pxm, float s, int XP, int YP, int WP, int HP, int cx, int cy);
   virtual void draw_unscaled(Fl_Bitmap *pxm, float s, int XP, int YP, int WP, int HP, int cx, int cy);

src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx

@@ -273,6 +273,10 @@ void Fl_Xlib_Graphics_Driver::untranslate_all() { // undoes previous translate_a
   pop_matrix();
 }
 
+void Fl_Xlib_Graphics_Driver::set_current_() {
+  restore_clip();
+}
+
 //
 // End of "$Id$".
 //

src/drivers/Xlib/Fl_Xlib_Image_Surface_Driver.cxx

@@ -68,7 +68,6 @@ void Fl_Xlib_Image_Surface_Driver::set_current() {
   Fl_Surface_Device::set_current();
   pre_window = fl_window;
   fl_window = offscreen;
-  fl_push_no_clip();
 }
 
 void Fl_Xlib_Image_Surface_Driver::translate(int x, int y) {
@@ -87,8 +86,6 @@ Fl_RGB_Image* Fl_Xlib_Image_Surface_Driver::image()
 
 void Fl_Xlib_Image_Surface_Driver::end_current_(Fl_Surface_Device *next_current)
 {
-  fl_pop_clip();
-  next_current->driver()->restore_clip();
   fl_window = pre_window;
 }