better centering support

--HG--
branch : pmacs2

method/__init__.py

@@ -396,7 +396,7 @@ class ToggleMargins(Method):
 class CenterView(Method):
     '''Move view to center on cursor'''
     def _execute(self, w, **vargs):
-        w.center_view()
+        w.center_view(force=True)
 class SetMark(Method):
     '''Set the mark to the current cursor location'''
     def _execute(self, w, **vargs):

window.py

@@ -221,7 +221,7 @@ class Window(object):
     def last_is_visible(self):
         return self.point_is_visible(self.buffer.get_buffer_end())
         
-    def center_view(self):
+    def center_view(self, force=False):
         (x, y) = self.logical_cursor().xy()
         counter = 0
         while counter < self.height / 2:
@@ -234,6 +234,14 @@ class Window(object):
                 (x, y) = (0, 0)
                 break
             counter += 1
+
+        # 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 - (x % self.width), y)
         self.redraw()
     def lower_view(self):
@@ -267,11 +275,13 @@ class Window(object):
         self.first = Point(x - (x % self.width), y)
         self.redraw()
     def assure_visible_cursor(self):
-        p = self.logical_cursor()
-        if self.first > p:
-            self.upper_view()
-        elif p > self.last:
-            self.lower_view()
+        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):
@@ -457,7 +467,13 @@ class Window(object):
         self.assure_visible_cursor()
     def goto_end(self, force=False):
         self.cursor = self.buffer.get_buffer_end()
-        (x, y) = self.logical_cursor().xy()
+        (x, y) = self.last_visible_coords()
+        if force or not self.cursor_is_visible():
+            self.first = Point(x - (x % self.width), y)
+            self.redraw()
+
+    def last_visible_coords(self):
+        (x, y) = self.buffer.get_buffer_end().xy()
         if x == 0:
             y -= 1
             x = len(self.buffer.lines[y])
@@ -474,10 +490,7 @@ class Window(object):
                 (x, y) = (0, 0)
                 break
             counter += 1
-        
-        if force or not self.cursor_is_visible():
-            self.first = Point(x - (x % self.width), y)
-            self.redraw()
+        return (x, y)
 
     # mark manipulation
     def set_mark_point(self, p):