E-book viewer: When in flow mode, handle swiping on the touchscreen differently. Swiping now scrolls line by line in flow mode instead of page by page. If you wish to scroll page by page in flow mode, tap instead of swiping.

src/calibre/gui2/viewer/gestures.py

@@ -62,7 +62,8 @@ class Help(QDialog):  # {{{
 
             <dt>Swipe</dt>
             <dd>Swipe to the left to go to the next page and to the right to go to the previous page.
-            This mimics turning pages in a paper book.</dd>
+            This mimics turning pages in a paper book. When the viewer is not in paged mode, swiping
+            scrolls the text line by line instead of page by page.</dd>
 
             <dt>Pinch</dt>
             <dd>Pinch in or out to decrease or increase the font size</dd>
@@ -115,6 +116,12 @@ class TouchPoint(object):
         axis = (Left, Right) if xabs > yabs else (Up, Down)
         return axis[0 if d < 0 else 1]
 
+    @property
+    def swipe_live(self):
+        x_movement = self.current_screen_position.x() - self.previous_screen_position.x()
+        y_movement = self.current_screen_position.y() - self.previous_screen_position.y()
+        return (x_movement, y_movement)
+
 def get_pinch(p1, p2):
     starts = [p1.start_screen_position, p2.start_screen_position]
     ends = [p1.current_screen_position, p2.current_screen_position]
@@ -132,6 +139,7 @@ class State(QObject):
 
     tapped = pyqtSignal(object)
     swiped = pyqtSignal(object)
+    swiping = pyqtSignal(object, object)
     pinched = pyqtSignal(object)
     tap_hold_started = pyqtSignal(object)
     tap_hold_updated = pyqtSignal(object)
@@ -175,6 +183,9 @@ class State(QObject):
             self.clear()
         else:
             self.check_for_holds()
+            if {Swipe, SwipeAndHold} & self.possible_gestures:
+                tp = next(self.touch_points.itervalues())
+                self.swiping.emit(*tp.swipe_live)
 
     def check_for_holds(self):
         if not {SwipeAndHold, TapAndHold} & self.possible_gestures:
@@ -247,6 +258,7 @@ class GestureHandler(QObject):
         self.last_swipe_hold_update = None
         self.state.swiped.connect(self.handle_swipe)
         self.state.tapped.connect(self.handle_tap)
+        self.state.swiping.connect(self.handle_swiping)
         self.state.tap_hold_started.connect(partial(self.handle_tap_hold, 'start'))
         self.state.tap_hold_updated.connect(partial(self.handle_tap_hold, 'update'))
         self.state.tap_hold_finished.connect(partial(self.handle_tap_hold, 'end'))
@@ -314,9 +326,29 @@ class GestureHandler(QObject):
         if self.close_open_menu():
             return
         view = self.parent()
+        if not view.document.in_paged_mode:
+            return
         func = {Left:'next_page', Right: 'previous_page', Up:'goto_previous_section', Down:'goto_next_section'}[direction]
         getattr(view, func)()
 
+    def handle_swiping(self, x, y):
+        if max(abs(x), abs(y)) < 1:
+            return
+        view = self.parent()
+        if view.document.in_paged_mode:
+            return
+        ydirection = Up if y < 0 else Down
+        if view.manager is not None and abs(y) > 0:
+            if ydirection is Up and view.document.at_bottom:
+                view.manager.next_document()
+                return
+            elif ydirection is Down and view.document.at_top:
+                view.manager.previous_document()
+                return
+        view.scroll_by(x=-x, y=-y)
+        if view.manager is not None:
+            view.manager.scrolled(view.scroll_fraction)
+
     def current_position(self, tp):
         return self.parent().mapFromGlobal(tp.current_screen_position.toPoint())
 
@@ -346,6 +378,8 @@ class GestureHandler(QObject):
 
     def handle_swipe_hold(self, action, direction):
         view = self.parent()
+        if not view.document.in_paged_mode:
+            return
         if action == 'start':
             self.last_swipe_hold_update = time.time()
             try: