some code clean-up and comment fixes

--HG--
branch : pmacs2

window.py

@@ -3,6 +3,8 @@ import color, highlight, regex
 from point import Point
 from render import RenderString
 
+CONTEXT = 2
+
 # note about the cursor: the cursor position will insert in front of the
 # character it highlights. to this end, it needs to be able to highlight behind
 # the last character on a line. thus, the x coordinate of the (logical) cursor
@@ -13,9 +15,9 @@ from render import RenderString
 # will jump in to the end of the shorter line. however, moving back up will
 # jump back out to its previous position. in these cases the cursor stores the
 # original x value, but the logical cursor function maps x to the "last
-# character on the line" for the shorter line. any line movement or actions on
-# the shorter line will "set" the cursor to its position on the shorter line.
-
+# character on the line" for the shorter line. any line movement or actions
+# which modify the x coordinate will "set" the cursor to a new position, and the
+# old x value will be forgotten.
 class Window(object):
     margins_visible = False
     def __init__(self, b, a, height=24, width=80, mode_name=None):
@@ -246,13 +248,6 @@ class Window(object):
         if x >= self.width and x == len(self.buffer.lines[y]):
             x -= self.width
 
-        # make sure we aren't "centering" on the end of the file (where half the
-        # screen is empty). that is, unless that's what the user wants
-        # (indicated by force=True).
-        #if not force:
-        #    (x2, y2) = self.last_visible_coords()
-        #    if y2 < y or x2 < x:
-        #        x, y = x2, y2
         self.first = Point(x, y)
         self.redraw()
     def lower_view(self):
@@ -288,11 +283,6 @@ class Window(object):
     def assure_visible_cursor(self):
         if not self.cursor_is_visible():
             self.center_view()
-        #p = self.logical_cursor()
-        #if self.first > p:
-        #    self.upper_view()
-        #elif p > self.last:
-        #    self.lower_view()
         
     # moving in buffer
     def forward(self):
@@ -486,14 +476,9 @@ class Window(object):
 
     def last_visible_coords(self):
         (x, y) = self.buffer.get_buffer_end().xy()
-        #if x == 0:
-        #    y -= 1
-        #    x = len(self.buffer.lines[y])
-        #else:
-        #    x -= 1
         counter = 0
-        # 3 means last line we see + 2 blank line of context
-        while counter < self.height - 3:
+        limit = self.height - 1 - CONTEXT
+        while counter < limit:
             if x > self.width:
                 d = x % self.width
                 if d: