calculate dpi

2 files changed, 7 insertions, 24 deletions

diff --git a/RulerActivity.py b/RulerActivity.py
index f536c09..b3b012b 100644
--- a/RulerActivity.py
+++ b/RulerActivity.py
@@ -55,7 +55,7 @@ _logger = logging.getLogger("ruler-activity")
 
 from gettext import gettext as _
 
-from util import get_hardware
+from util import get_hardware, calc_dpi
 import show_rulers
 import show_grids
 import show_checkers
@@ -70,7 +70,7 @@ class MyCanvas(gtk.DrawingArea):
         self._draw_ruler = False
         self._object = None
         self.connect('expose-event', self.__expose_event_cb)
-        self.dpi = 200
+        self._dpi = 96
 
     def __expose_event_cb(self, drawing_area, event):
         cr = self.window.cairo_create()
@@ -120,21 +120,8 @@ class RulerActivity(activity.Activity):
         width = gtk.gdk.screen_width()
         height = gtk.gdk.screen_height() - GRID_CELL_SIZE
 
-        # Read the dpi from the Journal
-        if get_hardware()[0:2] == 'xo':
-            if width == 1024:
-                self._canvas.set_dpi(160)  # OLPC XO 3.0
-            else:
-                self._canvas.set_dpi(200)  # other OLPC XO
-            self.known_dpi = True
-        else:
-            self.known_dpi = False
-            try:
-                dpi = self.metadata['dpi']
-                _logger.debug("Read dpi: " + str(dpi))
-                self._canvas.set_dpi(int(dpi))
-            except KeyError:
-                self._canvas.set_dpi(96)  # Just a guess
+        dpi, self.known_dpi = calc_dpi()
+        self._canvas.set_dpi(dpi)
 
         # Create instances of our graphics
         self._r = show_rulers.ScreenOfRulers(font, font_bold, width, height)
@@ -194,10 +181,10 @@ class RulerActivity(activity.Activity):
             toolbar_box.toolbar.insert(self.checker, -1)
 
             if not self.known_dpi:
+                print self.known_dpi
                 separator = gtk.SeparatorToolItem()
                 separator.show()
                 toolbar_box.toolbar.insert(separator, -1)
-
                 dpi = self._canvas.get_dpi()
                 self._dpi_spin_adj = gtk.Adjustment(dpi, 72, 200, 2, 32, 0)
                 self._dpi_spin = gtk.SpinButton(self._dpi_spin_adj, 0, 0)
diff --git a/util.py b/util.py
index a043adf..4f9e76f 100644
--- a/util.py
+++ b/util.py
@@ -78,10 +78,6 @@ def dimensions_mm(dpi, w, h):
     return int(w * 25.40 / dpi), int(h * 25.40 / dpi)
 
 
-def calc_dpmm():
-    return 1.0*gtk.gdk.screen_width()/gtk.gdk.screen_width_mm()
-
-
 def calc_dpi():
     '''Looking for 'dimensions' line in xdpyinfo
        dimensions:    1280x800 pixels (339x212 millimeters)'''
@@ -90,10 +86,10 @@ def calc_dpi():
         strings = output[find(output, 'dimensions:'):].split()
         w = int(strings[1].split('x')[0]) # e.g., 1280x800
         mm = int(strings[3][1:].split('x')[0])  # e.g., (339x212)
-        return int(w * 25.4 / w)
+        return int((w * 25.4 / mm) + 0.5), True
     else:
         # just in case the above fails
-        return 96
+        return 96, False
 
 #
 # Cairo-related utilities