From 6a6b2a6f58285c5a5757f1c24280d9568b1c7b67 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 16 Dec 2010 10:05:42 -0700
Subject: [PATCH] ...

---
 src/calibre/gui2/viewer/documentview.py | 35 ++++++++-----------------
 src/calibre/gui2/viewer/flip.py         | 18 +++++++++++++
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/src/calibre/gui2/viewer/documentview.py b/src/calibre/gui2/viewer/documentview.py
index e63568ce74..f131dd522d 100644
--- a/src/calibre/gui2/viewer/documentview.py
+++ b/src/calibre/gui2/viewer/documentview.py
@@ -468,7 +468,6 @@ class DocumentView(QWebView):
         QWebView.__init__(self, *args)
         self.flipper = SlideFlip(self)
         self.is_auto_repeat_event = False
-        self.load_flip_direction = None
         self.debug_javascript = False
         self.shortcuts =  Shortcuts(SHORTCUTS, 'shortcuts/viewer')
         self.self_closing_pat = re.compile(r'<([a-z1-6]+)\s+([^>]+)/>',
@@ -647,10 +646,6 @@ class DocumentView(QWebView):
         return '<%s %s></%s>'%(match.group(1), match.group(2), match.group(1))
 
     def load_path(self, path, pos=0.0):
-        if self.load_flip_direction is not None:
-            self.flipper.initialize(self.current_page_image(),
-                    self.load_flip_direction=='next')
-            self.load_flip_direction = None
         self.initial_pos = pos
         mt = getattr(path, 'mime_type', None)
         if mt is None:
@@ -763,11 +758,9 @@ class DocumentView(QWebView):
         if self.document.at_top:
             if self.manager is not None:
                 self.to_bottom = True
-                self.load_flip_direction = 'previous' if epf else None
-                try:
+                if epf:
+                    self.flipper.initialize(self.current_page_image(), False)
                     self.manager.previous_document()
-                finally:
-                    self.load_flip_direction = None
         else:
             opos = self.document.ypos
             upper_limit = opos - delta_y
@@ -800,11 +793,9 @@ class DocumentView(QWebView):
         delta_y = window_height - 25
         if self.document.at_bottom or ddelta <= 0:
             if self.manager is not None:
-                self.load_flip_direction = 'next' if epf else None
-                try:
-                    self.manager.next_document()
-                finally:
-                    self.load_flip_direction = None
+                if epf:
+                    self.flipper.initialize(self.current_page_image())
+                self.manager.next_document()
         elif ddelta < 25:
             self.scroll_by(y=ddelta)
             return
@@ -816,11 +807,9 @@ class DocumentView(QWebView):
             #print 'After set padding=0:', self.document.ypos
             if opos < oopos:
                 if self.manager is not None:
-                    self.load_flip_direction = 'next' if epf else None
-                    try:
-                        self.manager.next_document()
-                    finally:
-                        self.load_flip_direction = None
+                    if epf:
+                        self.flipper.initialize(self.current_page_image())
+                    self.manager.next_document()
                 return
             lower_limit = opos + delta_y # Max value of top y co-ord after scrolling
             max_y = self.document.height - window_height # The maximum possible top y co-ord
@@ -828,11 +817,9 @@ class DocumentView(QWebView):
                 padding = lower_limit - max_y
                 if padding == window_height:
                     if self.manager is not None:
-                        self.load_flip_direction = 'next' if epf else None
-                        try:
-                            self.manager.next_document()
-                        finally:
-                            self.load_flip_direction = 'next'
+                        if epf:
+                            self.flipper.initialize(self.current_page_image())
+                        self.manager.next_document()
                     return
                 #print 'Setting padding to:', lower_limit - max_y
                 self.document.set_bottom_padding(lower_limit - max_y)
diff --git a/src/calibre/gui2/viewer/flip.py b/src/calibre/gui2/viewer/flip.py
index 4be0657ee9..5432909b2b 100644
--- a/src/calibre/gui2/viewer/flip.py
+++ b/src/calibre/gui2/viewer/flip.py
@@ -12,6 +12,8 @@ class SlideFlip(QWidget):
 
     # API {{{
 
+    # In addition the isVisible() and setVisible() methods must be present
+
     def __init__(self, parent):
         QWidget.__init__(self, parent)
 
@@ -27,9 +29,19 @@ class SlideFlip(QWidget):
 
     @property
     def running(self):
+        'True iff animation is currently running'
         return self.animation.state() == self.animation.Running
 
     def initialize(self, image, forwards=True):
+        '''
+        Initialize the flipper, causes the flipper to show itself displaying
+        the full `image`.
+
+        :param image: The image to display as background
+        :param forwards: If True flipper will flip forwards, otherwise
+                         backwards
+
+        '''
         self.flip_forwards = forwards
         self.before_image = QPixmap.fromImage(image)
         self.after_image = None
@@ -37,6 +49,12 @@ class SlideFlip(QWidget):
         self.setVisible(True)
 
     def __call__(self, image, duration=0.5):
+        '''
+        Start the animation. You must have called :meth:`initialize` first.
+
+        :param duration: Animation duration in seconds.
+
+        '''
         if self.running:
             return
         self.after_image = QPixmap.fromImage(image)