Fix #10806 - No scrolling in Read

Read had implemented scrolling by page (with page up/down keys),
this patch implement scroll by steps with the keys up/down
in pdf and epub backends.

2 files changed, 30 insertions, 4 deletions

diff --git a/epubview/epubview.py b/epubview/epubview.py
index 5dccad0..b9f157c 100644
--- a/epubview/epubview.py
+++ b/epubview/epubview.py
@@ -27,7 +27,6 @@ import BeautifulSoup
 from epub import _Epub
 from jobs import _JobPaginator as _Paginator
 
-
 LOADING_HTML = '''
 <div style="width:100%;height:100%;text-align:center;padding-top:50%;">
     <h1>Loading...</h1>
@@ -249,7 +248,8 @@ class _View(gtk.HBox):
         Scrolls through the pages.
         Scrolling is horizontal if horizontal is set to True
         Valid scrolltypes are:
-        gtk.SCROLL_PAGE_BACKWARD and gtk.SCROLL_PAGE_FORWARD
+        gtk.SCROLL_PAGE_BACKWARD, gtk.SCROLL_PAGE_FORWARD,
+        gtk.SCROLL_STEP_BACKWARD and gtk.SCROLL_STEP_FORWARD
         '''
         if scrolltype == gtk.SCROLL_PAGE_BACKWARD:
             self.__going_back = True
@@ -261,6 +261,16 @@ class _View(gtk.HBox):
             self.__going_fwd = True
             if not self._do_page_transition():
                 self._view.move_cursor(gtk.MOVEMENT_PAGES, 1)
+        elif scrolltype == gtk.SCROLL_STEP_BACKWARD:
+            self.__going_fwd = False
+            self.__going_back = True
+            if not self._do_page_transition():
+                self._view.move_cursor(gtk.MOVEMENT_DISPLAY_LINES, -1)
+        elif scrolltype == gtk.SCROLL_STEP_FORWARD:
+            self.__going_fwd = True
+            self.__going_back = False
+            if not self._do_page_transition():
+                self._view.move_cursor(gtk.MOVEMENT_DISPLAY_LINES, 1)
         else:
             print ('Got unsupported scrolltype %s' % str(scrolltype))
 
diff --git a/evinceadapter.py b/evinceadapter.py
index 64b5cb7..3d3350c 100644
--- a/evinceadapter.py
+++ b/evinceadapter.py
@@ -14,7 +14,7 @@ class EvinceViewer():
         self._view = evince.View()
 
     def setup(self, activity):
-
+        self._activity = activity
         self._view.connect('selection-changed',
                             activity._view_selection_changed_cb)
 
@@ -222,14 +222,30 @@ class EvinceViewer():
         Scrolls through the pages.
         Scrolling is horizontal if horizontal is set to True
         Valid scrolltypes are:
-        gtk.SCROLL_PAGE_BACKWARD and gtk.SCROLL_PAGE_FORWARD
+        gtk.SCROLL_PAGE_BACKWARD, gtk.SCROLL_PAGE_FORWARD,
+        gtk.SCROLL_STEP_BACKWARD and gtk.SCROLL_STEP_FORWARD
         '''
+        _logger.error('scroll: %s', scrolltype)
+
         if scrolltype == gtk.SCROLL_PAGE_BACKWARD:
             self._view.scroll(gtk.SCROLL_PAGE_BACKWARD, -1)
         elif scrolltype == gtk.SCROLL_PAGE_FORWARD:
             self._view.scroll(gtk.SCROLL_PAGE_FORWARD, 1)
+        elif scrolltype == gtk.SCROLL_STEP_BACKWARD:
+            self._scroll_step(False)
+        elif scrolltype == gtk.SCROLL_STEP_FORWARD:
+            self._scroll_step(True)
         else:
             print ('Got unsupported scrolltype %s' % str(scrolltype))
 
+    def _scroll_step(self, forward):
+        v_adj = self._activity._scrolled.get_vadjustment()
+        v_value = v_adj.get_value()
+        step = v_adj.get_step_increment()
+        if forward:
+            v_adj.set_value(v_value + step)
+        else:
+            v_adj.set_value(v_value - step)
+
     def copy(self):
         self._view.copy()