From fcacd42efa5b9179a07c5794e1c0da2d7f9eee5e Mon Sep 17 00:00:00 2001
From: Fabio Erculiani <lxnay@sabayon.org>
Date: Tue, 3 May 2011 14:50:48 +0200
Subject: [PATCH] [sulfur] improve CellRendererStars rendering speed
 dramatically

---
 sulfur/src/sulfur/widgets.py | 110 +++++++++++++++++++++--------------
 1 file changed, 66 insertions(+), 44 deletions(-)

diff --git a/sulfur/src/sulfur/widgets.py b/sulfur/src/sulfur/widgets.py
index 38181d53d..71639b7e7 100644
--- a/sulfur/src/sulfur/widgets.py
+++ b/sulfur/src/sulfur/widgets.py
@@ -34,6 +34,7 @@ class CellRendererStars(gtk.GenericCellRenderer):
         self.__gobject_init__()
         self.value = -1
         self.value_voted = 0.0
+        self.__cache = {}
 
     def do_set_property(self, pspec, value):
         setattr(self, pspec.name, value)
@@ -44,6 +45,9 @@ class CellRendererStars(gtk.GenericCellRenderer):
     def on_render(self, window, widget, background_area, cell_area,
             expose_area, flags):
 
+        if self.value == -1:
+            return
+
         (x_offset, y_offset, width, height) = self.on_get_size(widget,
             cell_area)
         if isinstance(window, gtk.gdk.Window):
@@ -54,55 +58,73 @@ class CellRendererStars(gtk.GenericCellRenderer):
                                 cell_area.x+x_offset,
                                 cell_area.y+y_offset,
                                 width, height)
-        if ((self.value > -1) and (self.value < 6)) or (self.value_voted > 0):
 
-            xt = widget.style.xthickness
-            empty = gtk.Image()
-            empty.set_from_file(const.empty_background)
-            try:
-                empty_buf = empty.get_pixbuf()
-            except ValueError:
-                return
+        xt = widget.style.xthickness
 
-            if self.value_voted:
-                star = gtk.Image()
-                star.set_from_file(const.star_selected_pixmap)
+        ## caching
+        cache_id = self.value
+        int_part = int(cache_id) # truncate
+        float_part = cache_id - int_part
+        if float_part < 0.6:
+            cache_id = float(int_part) + 0.5
+        else:
+            cache_id = float(int_part) + 1.0
+
+        pixbuf = self.__cache.get((cache_id, self.value_voted))
+        if pixbuf is not None:
+            window.draw_pixbuf(None, pixbuf, 0, 0,
+                cell_area.x+x_offset+xt, cell_area.y+y_offset+xt, -1, -1)
+            return
+
+        empty = gtk.Image()
+        empty.set_from_file(const.empty_background)
+        try:
+            empty_buf = empty.get_pixbuf()
+        except ValueError:
+            return
+
+        if self.value_voted:
+            star = gtk.Image()
+            star.set_from_file(const.star_selected_pixmap)
+        else:
+            star = gtk.Image()
+            star.set_from_file(const.star_normal_pixmap)
+
+        star_empty = gtk.Image()
+        star_empty.set_from_file(const.star_empty_pixmap)
+
+        star_half = gtk.Image()
+        star_half.set_from_file(const.star_half_pixmap)
+
+        star_buf = star.get_pixbuf()
+        star_empty_buf = star_empty.get_pixbuf()
+        star_half_buf = star_half.get_pixbuf()
+
+        w, h = star_buf.get_width(), star_buf.get_height()
+        myval = self.value
+        if self.value_voted:
+            myval = self.value_voted
+        empty_buf = empty_buf.scale_simple(w*5, h+12, gtk.gdk.INTERP_BILINEAR)
+        myvals = [0, w, w*2, w*3, w*4]
+        cnt = 0
+        while myval > 0:
+            if (myval < 0.6):
+                star_half_buf.copy_area(0, 0, w, h, empty_buf, myvals[cnt],
+                    6)
             else:
-                star = gtk.Image()
-                star.set_from_file(const.star_normal_pixmap)
+                star_buf.copy_area(0, 0, w, h, empty_buf, myvals[cnt], 6)
+            myval -= 1
+            cnt += 1
 
-            star_empty = gtk.Image()
-            star_empty.set_from_file(const.star_empty_pixmap)
+        myval = 5 - cnt
+        while myval > 0:
+            star_empty_buf.copy_area(0, 0, w, h, empty_buf, myvals[cnt], 6)
+            myval -= 1
+            cnt += 1
 
-            star_half = gtk.Image()
-            star_half.set_from_file(const.star_half_pixmap)
-
-            star_buf = star.get_pixbuf()
-            star_empty_buf = star_empty.get_pixbuf()
-            star_half_buf = star_half.get_pixbuf()
-
-            w, h = star_buf.get_width(), star_buf.get_height()
-            myval = self.value
-            if self.value_voted:
-                myval = self.value_voted
-            empty_buf = empty_buf.scale_simple(w*5, h+12, gtk.gdk.INTERP_BILINEAR)
-            myvals = [0, w, w*2, w*3, w*4]
-            cnt = 0
-            while myval > 0:
-                if (myval < 0.6):
-                    star_half_buf.copy_area(0, 0, w, h, empty_buf, myvals[cnt],
-                        6)
-                else:
-                    star_buf.copy_area(0, 0, w, h, empty_buf, myvals[cnt], 6)
-                myval -= 1
-                cnt += 1
-            myval = 5 - cnt
-            while myval > 0:
-                star_empty_buf.copy_area(0, 0, w, h, empty_buf, myvals[cnt], 6)
-                myval -= 1
-                cnt += 1
-
-            if empty_buf: window.draw_pixbuf(None, empty_buf, 0, 0,
+        if empty_buf:
+            self.__cache[(cache_id, self.value_voted)] = empty_buf
+            window.draw_pixbuf(None, empty_buf, 0, 0,
                 cell_area.x+x_offset+xt, cell_area.y+y_offset+xt, -1, -1)