Information hiding.

1 files changed, 43 insertions, 45 deletions

diff --git a/xgpsspeed b/xgpsspeed
index 1cbf3881..fcaca783 100755
--- a/xgpsspeed
+++ b/xgpsspeed
@@ -245,23 +245,10 @@ class Speedometer(gtk.DrawingArea):
     def get_radius(self, width, height):
         return min(width / 2.0, height / 2.0) - 20
 
-HEADING_SAT_GAP = 0.8
-GPS_PRNMAX = 32  # Above this number are SBAS satellites
-SAT_SIZE = 10  # radius of the satellite circle in skyview
-
-
-def polar2xy(radius, angle, polex, poley):
-    '''convert Polar coordinate to Cartesian coordinate system
-    the y axis in pygtk points downward
-    Args:
-       radius:
-       angle: azimuth from from Polar coordinate system, in radian
-       polex and poley are the Cartesian coordinate of the pole
-    return a tuple contains (x, y)'''
-    return (polex + cos(angle) * radius, poley - sin(angle) * radius)
-
-
 class SpeedAndTrack(gtk.DrawingArea):
+    HEADING_SAT_GAP = 0.8
+    GPS_PRNMAX = 32  # Above this number are SBAS satellites
+    SAT_SIZE = 10  # radius of the satellite circle in skyview
     def __init__(self, speed_unit=None, maxspeed=100):
         gtk.DrawingArea.__init__(self)
         self.connect('expose_event', self.expose_event)
@@ -288,6 +275,17 @@ class SpeedAndTrack(gtk.DrawingArea):
                     '%s is not a valid speed unit'
                     % (repr(speed_unit)))
 
+    @staticmethod
+    def polar2xy(radius, angle, polex, poley):
+        '''convert Polar coordinate to Cartesian coordinate system
+        the y axis in pygtk points downward
+        Args:
+           radius:
+           angle: azimuth from from Polar coordinate system, in radian
+           polex and poley are the Cartesian coordinate of the pole
+        return a tuple contains (x, y)'''
+        return (polex + cos(angle) * radius, poley - sin(angle) * radius)
+
     def expose_event(self, unused, event, empty=None):
         self.cr = self.window.cairo_create()
         self.cr.rectangle(
@@ -304,7 +302,7 @@ class SpeedAndTrack(gtk.DrawingArea):
         self.draw_arc_and_ticks(width, height, radius, x, y)
         self.draw_heading(20, self.last_heading, radius, x, y)
         for sat in self.satellites:
-            self.draw_sat(sat, radius * HEADING_SAT_GAP, x, y)
+            self.draw_sat(sat, radius * SpeedAndTrack.HEADING_SAT_GAP, x, y)
         self.draw_speed(radius, x, y)
 
     def draw_text(self, x, y, text, fontsize=10):
@@ -343,12 +341,12 @@ class SpeedAndTrack(gtk.DrawingArea):
         for i in xrange(11):
             #draw the large ticks
             alpha = (8 - i) * pi / 6
-            self.cr.move_to(*polar2xy(rspeed, alpha, x, y))
+            self.cr.move_to(*SpeedAndTrack.polar2xy(rspeed, alpha, x, y))
             self.cr.set_line_width(radius / 100)
-            self.cr.line_to(*polar2xy(rspeed - s_long, alpha, x, y))
+            self.cr.line_to(*SpeedAndTrack.polar2xy(rspeed - s_long, alpha, x, y))
             self.cr.stroke()
             self.cr.set_line_width(radius / 200)
-            xf, yf = polar2xy(rspeed + 10, alpha, x, y)
+            xf, yf = SpeedAndTrack.polar2xy(rspeed + 10, alpha, x, y)
             stxt = (self.maxspeed / 10) * i
             self.draw_text(xf, yf, stxt, fontsize=radius / 15)
 
@@ -356,14 +354,14 @@ class SpeedAndTrack(gtk.DrawingArea):
             # middle tick
             alpha = (8 - i) * pi / 6
             beta = (17 - 2 * i) * pi / 12
-            self.cr.move_to(*polar2xy(rspeed, beta, x, y))
-            self.cr.line_to(*polar2xy(rspeed - s_middle, beta, x, y))
+            self.cr.move_to(*SpeedAndTrack.polar2xy(rspeed, beta, x, y))
+            self.cr.line_to(*SpeedAndTrack.polar2xy(rspeed - s_middle, beta, x, y))
 
             #  short tick
             for n in xrange(10):
                 gamma = alpha + n * pi / 60
-                self.cr.move_to(*polar2xy(rspeed, gamma, x, y))
-                self.cr.line_to(*polar2xy(rspeed - s_short, gamma, x, y))
+                self.cr.move_to(*SpeedAndTrack.polar2xy(rspeed, gamma, x, y))
+                self.cr.line_to(*SpeedAndTrack.polar2xy(rspeed - s_short, gamma, x, y))
 
         #draw the heading arc
         self.cr.new_sub_path()
@@ -378,15 +376,15 @@ class SpeedAndTrack(gtk.DrawingArea):
         for n in xrange(0, 4):
             label = str(n * 90)
             #self.cr.set_source_rgba(0, 1, 0)
-                #radius * (1 + HEADING_SAT_GAP),
-            tbox_x, tbox_y = polar2xy(radius * 0.88,
+            #radius * (1 + SpeedAndTrack.HEADING_SAT_GAP),
+            tbox_x, tbox_y = SpeedAndTrack.polar2xy(radius * 0.88,
                                     (1 - n) * pi / 2,
                                     x, y)
             self.draw_text(tbox_x, tbox_y,
                            label, fontsize=radius / 20)
 
         # draw the satellite arcs
-        skyradius = radius * HEADING_SAT_GAP
+        skyradius = radius * SpeedAndTrack.HEADING_SAT_GAP
         self.cr.set_line_width(radius / 200)
         self.cr.set_source_rgba(0, 0, 0)
         self.cr.arc(x, y, skyradius, 0, 2 * pi)
@@ -412,22 +410,22 @@ class SpeedAndTrack(gtk.DrawingArea):
         #draw the large ticks
         for i in xrange(12):
             agllong = i * pi / 6
-            self.cr.move_to(*polar2xy(radius - long_inset, agllong, x, y))
-            self.cr.line_to(*polar2xy(radius, agllong, x, y))
+            self.cr.move_to(*SpeedAndTrack.polar2xy(radius - long_inset, agllong, x, y))
+            self.cr.line_to(*SpeedAndTrack.polar2xy(radius, agllong, x, y))
             self.cr.set_line_width(radius / 100)
             self.cr.stroke()
             self.cr.set_line_width(radius / 200)
 
             # middle tick
             aglmid = (i + 0.5) * pi / 6
-            self.cr.move_to(*polar2xy(radius - mid_inset, aglmid, x, y))
-            self.cr.line_to(*polar2xy(radius, aglmid, x, y))
+            self.cr.move_to(*SpeedAndTrack.polar2xy(radius - mid_inset, aglmid, x, y))
+            self.cr.line_to(*SpeedAndTrack.polar2xy(radius, aglmid, x, y))
 
             #  short tick
             for n in xrange(1, 10):
                 aglshrt = agllong + n * pi / 60
-                self.cr.move_to(*polar2xy(radius - short_inset, aglshrt, x, y))
-                self.cr.line_to(*polar2xy(radius, aglshrt, x, y))
+                self.cr.move_to(*SpeedAndTrack.polar2xy(radius - short_inset, aglshrt, x, y))
+                self.cr.line_to(*SpeedAndTrack.polar2xy(radius, aglshrt, x, y))
             self.cr.stroke()
 
     def draw_heading(self, trig_height, heading, radius, x, y):
@@ -455,16 +453,16 @@ class SpeedAndTrack(gtk.DrawingArea):
         self.cr.stroke()
 
         # heading text
-        (tbox_x, tbox_y) = polar2xy(radius * 1.1, h, x, y)
+        (tbox_x, tbox_y) = SpeedAndTrack.polar2xy(radius * 1.1, h, x, y)
         self.draw_text(tbox_x, tbox_y, int(heading), fontsize=radius / 15)
 
         # the ship shape, based on test and try
-        shiplen = radius * HEADING_SAT_GAP / 4
-        xh, yh = polar2xy(shiplen * 2.3, h, x, y)
-        xa, ya = polar2xy(shiplen * 2.2, h + pi - 0.3, x, y)
-        xb, yb = polar2xy(shiplen * 2.2, h + pi + 0.3, x, y)
-        xc, yc = polar2xy(shiplen * 1.4, h - pi / 5, x, y)
-        xd, yd = polar2xy(shiplen * 1.4, h + pi / 5, x, y)
+        shiplen = radius * SpeedAndTrack.HEADING_SAT_GAP / 4
+        xh, yh = SpeedAndTrack.polar2xy(shiplen * 2.3, h, x, y)
+        xa, ya = SpeedAndTrack.polar2xy(shiplen * 2.2, h + pi - 0.3, x, y)
+        xb, yb = SpeedAndTrack.polar2xy(shiplen * 2.2, h + pi + 0.3, x, y)
+        xc, yc = SpeedAndTrack.polar2xy(shiplen * 1.4, h - pi / 5, x, y)
+        xd, yd = SpeedAndTrack.polar2xy(shiplen * 1.4, h + pi / 5, x, y)
 
         self.cr.set_source_rgba(0, 0.3, 0.2, 0.5)
         self.cr.move_to(xa, ya)
@@ -493,14 +491,14 @@ class SpeedAndTrack(gtk.DrawingArea):
         self.cr.set_line_width(2)
         self.cr.set_source_rgb(0, 0, 0)
 
-        x0, y0 = polar2xy(radius * (90 - satsoup['el']) / 90, h, x, y)
+        x0, y0 = SpeedAndTrack.polar2xy(radius * (90 - satsoup['el']) / 90, h, x, y)
 
         self.cr.new_sub_path()
-        if satsoup['PRN'] > GPS_PRNMAX:
-            self.cr.rectangle(x0 - SAT_SIZE, y0 - SAT_SIZE,
-                              SAT_SIZE * 2, SAT_SIZE * 2)
+        if satsoup['PRN'] > SpeedAndTrack.GPS_PRNMAX:
+            self.cr.rectangle(x0 - SpeedAndTrack.SAT_SIZE, y0 - SpeedAndTrack.SAT_SIZE,
+                              SpeedAndTrack.SAT_SIZE * 2, SpeedAndTrack.SAT_SIZE * 2)
         else:
-            self.cr.arc(x0, y0, SAT_SIZE, 0, pi * 2.0)
+            self.cr.arc(x0, y0, SpeedAndTrack.SAT_SIZE, 0, pi * 2.0)
 
         if satsoup['ss'] < 10:
             self.set_color('Gray')