Add half-page scrolling (C-u / C-d)

3 files changed, 32 insertions, 0 deletions

diff --git a/doc/en/keys.txt b/doc/en/keys.txt
index 616468f5..64f5dbbd 100644
--- a/doc/en/keys.txt
+++ b/doc/en/keys.txt
@@ -86,6 +86,10 @@ height of the conversation window - 1.
 
 *Ctrl-f*:: Go one line down in the buffer.
 
+*Ctrl-u*:: Go half a screen up in the buffer.
+
+*Ctrl-d*:: Go half a screen down in the buffer.
+
 *Alt-/*:: Complete what you’re typing using the "recent" words from the
  current conversation, if any.
 
diff --git a/src/core.py b/src/core.py
index 91f69813..f9ae4198 100644
--- a/src/core.py
+++ b/src/core.py
@@ -158,6 +158,8 @@ class Core(object):
             "KEY_NPAGE": self.scroll_page_down,
             "^B": self.scroll_line_up,
             "^F": self.scroll_line_down,
+            "^D": self.scroll_half_down,
+            "^U": self.scroll_half_up,
             "KEY_F(5)": self.rotate_rooms_left,
             "^P": self.rotate_rooms_left,
             'kLFT3': self.rotate_rooms_left,
@@ -1140,6 +1142,14 @@ class Core(object):
         self.current_tab().on_line_down()
         self.refresh_window()
 
+    def scroll_half_up(self, args=None):
+        self.current_tab().on_half_scroll_up()
+        self.refresh_window()
+
+    def scroll_half_down(self, args=None):
+        self.current_tab().on_half_scroll_down()
+        self.refresh_window()
+
     def get_error_message_from_error_stanza(self, stanza):
         """
         Takes a stanza of the form <message type='error'><error/></message>
diff --git a/src/tabs.py b/src/tabs.py
index f9032b6e..55e3154c 100644
--- a/src/tabs.py
+++ b/src/tabs.py
@@ -324,6 +324,18 @@ class Tab(object):
         """
         pass
 
+    def on_half_scroll_down(self):
+        """
+        Defines what happens when we scroll half a screen down
+        """
+        pass
+
+    def on_half_scroll_up(self):
+        """
+        Defines what happens when we scroll half a screen up
+        """
+        pass
+
     def on_info_win_size_changed(self):
         """
         Called when the window with the informations is resized
@@ -529,6 +541,12 @@ class ChatTab(Tab):
     def on_scroll_down(self):
         self.text_win.scroll_down(self.text_win.height-1)
 
+    def on_half_scroll_up(self):
+        self.text_win.scroll_up((self.text_win.height-1) // 2)
+
+    def on_half_scroll_down(self):
+        self.text_win.scroll_down((self.text_win.height-1) // 2)
+
 
 class MucTab(ChatTab):
     """