Inherit cairo.Surface properties from target in cache

Lookup the target window when creating a caching surface
and inherit its properties (font, scaling which fixes #43, fallback
resolution, etc.)

pympress/scribble.py

@@ -105,7 +105,7 @@ def __init__(self, config, builder, notes_mode):
         self.scribble_color = Gdk.RGBA()
         self.scribble_color.parse(config.get('scribble', 'color'))
         self.scribble_width = config.getint('scribble', 'width')
-        self.cache.add_widget("scribble_p_da", PDF_CONTENT_PAGE if notes_mode else PDF_REGULAR, False)
+        self.cache.add_widget(self.scribble_p_da, PDF_CONTENT_PAGE if notes_mode else PDF_REGULAR, False)
 
         self.config = config
 

pympress/surfacecache.py

@@ -72,6 +72,10 @@ class SurfaceCache(object):
     #: popped from the start of the cache.
     surface_cache = {}
 
+    #: `dict` containing functions that return a :class:`~cairo.Surface` given a :class:`~cairo.Context`, width `int` and height `int`
+    #: see :func:`~cairo.Surface.create_similar`
+    surface_factory = {}
+
     #: Size of the different managed widgets, as a `dict` of tuples
     surface_size = {}
 
@@ -104,21 +108,23 @@ def __init__(self, doc, max_pages):
         self.doc_lock = threading.Lock()
 
 
-    def add_widget(self, widget_name, wtype, start_enabled = True):
+    def add_widget(self, widget, wtype, start_enabled = True):
         """ Add a widget to the list of widgets that have to be managed (for caching and prerendering).
 
         This creates new entries for ``widget_name`` in the needed internal data
         structures, and creates a new thread for prerendering pages for this widget.
 
         Args:
-            widget_name (`str`):  string used to identify a widget
+            widget (:class:`~Gtk.Widget`):  The widget for which we need to cache
             wtype (`int`):  type of document handled by the widget (see :attr:`surface_type`)
             start_enabled (`bool`):  whether this widget is initially in the list of widgets to prerender
         """
+        widget_name = widget.get_name()
         self.surface_cache[widget_name] = OrderedDict()
         self.surface_size[widget_name] = (-1, -1)
         self.surface_type[widget_name] = wtype
         self.locks[widget_name] = threading.Lock()
+        self.surface_factory[widget_name] = lambda c, w, h: widget.get_window().create_similar_surface(c, w, h)
         if start_enabled:
             self.enable_prerender(widget_name)
 
@@ -279,7 +285,7 @@ def renderer(self, widget_name, page_nb):
         # Render to a ImageSurface
         # 32 to support alpha (needed with premultiplied values?)
         # Anyway 24 uses 32-bit values with 8 unused
-        surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, ww, wh)
+        surface = self.surface_factory[widget_name](cairo.CONTENT_COLOR, ww, wh)
         context = cairo.Context(surface)
         page.render_cairo(context, ww, wh, wtype)
         del context

pympress/ui.py

@@ -243,7 +243,7 @@ def make_cwin(self):
         else:
             page_type = document.PDF_REGULAR
 
-        self.cache.add_widget("c_da", page_type)
+        self.cache.add_widget(self.c_da, page_type)
         self.c_frame.set_property("ratio", self.doc.current_page().get_aspect_ratio(page_type))
 
 
@@ -278,13 +278,13 @@ def make_pwin(self):
             self.get_object(n).set_active(init_checkstates[n])
 
         if self.notes_mode:
-            self.cache.add_widget("p_da_cur", PDF_CONTENT_PAGE)
-            self.cache.add_widget("p_da_next", PDF_CONTENT_PAGE)
-            self.cache.add_widget("p_da_notes", PDF_NOTES_PAGE)
+            self.cache.add_widget(self.p_da_cur, PDF_CONTENT_PAGE)
+            self.cache.add_widget(self.p_da_next, PDF_CONTENT_PAGE)
+            self.cache.add_widget(self.p_da_notes, PDF_NOTES_PAGE)
         else:
-            self.cache.add_widget("p_da_cur", PDF_REGULAR)
-            self.cache.add_widget("p_da_next", PDF_REGULAR)
-            self.cache.add_widget("p_da_notes", PDF_REGULAR, False)
+            self.cache.add_widget(self.p_da_cur, PDF_REGULAR)
+            self.cache.add_widget(self.p_da_next, PDF_REGULAR)
+            self.cache.add_widget(self.p_da_notes, PDF_REGULAR, False)
 
 
         # set default value