Ticket #3358: smooth_scrolling_patch.diff

src/conversation_textview.py

@@ -10 +10 @@
 ##
 ## This program is distributed in the hope that it will be useful,
 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
-## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ## GNU General Public License for more details.
 ##
 
 import random
 from tempfile import gettempdir
 from subprocess import Popen
+from threading import Timer # for smooth scrolling
 
 import gtk
 import pango
@@ -44 +45 @@
         path_to_file = os.path.join(gajim.DATA_DIR, 'pixmaps', 'muc_separator.png')
         FOCUS_OUT_LINE_PIXBUF = gtk.gdk.pixbuf_new_from_file(path_to_file)
 
+        # smooth scroll constants
+        MAX_SCROLL_TIME = 0.4 # seconds
+        SCROLL_DELAY = 33 # milliseconds
+
         def __init__(self, account, used_in_history_window = False):
                 '''if used_in_history_window is True, then we do not show
                 Clear menuitem in context menu'''
@@ -154 +159 @@
                 self.line_tooltip = tooltips.BaseTooltip()
                 # use it for hr too
                 self.tv.focus_out_line_pixbuf = ConversationTextview.FOCUS_OUT_LINE_PIXBUF
+                self.smooth_id = None
 
         def del_handlers(self):
                 for i in self.handlers.keys():
@@ -181 +187 @@
                         return True
                 return False
 
+        # Smooth scrolling inspired by Pidgin code
+        def smooth_scroll(self):
+                parent = self.tv.get_parent()
+                if not parent:
+                        return False
+                vadj = parent.get_vadjustment()
+                max_val = vadj.upper - vadj.page_size + 1
+                cur_val = vadj.get_value()
+                # scroll by 1/3rd of remaining distance
+                onethird = cur_val + ((max_val - cur_val) / 3.0)
+                vadj.set_value(onethird)
+                if max_val - onethird < 0.01:
+                        print "sroll finished"
+                        self.smooth_id = None
+                        self.smooth_scroll_timer.cancel()
+                        return False
+                return True                
+
+        def smooth_scroll_timeout(self):
+                print "-->smooth_scroll_timeout"
+                gobject.source_remove(self.smooth_id)
+                self.smooth_id = None
+                parent = self.tv.get_parent()
+                if parent:
+                        vadj = parent.get_vadjustment()
+                        vadj.set_value(vadj.upper - vadj.page_size + 1)
+
+        def smooth_scroll_to_end(self):
+                if None != self.smooth_id: # already scrolling
+                        return False
+                print "-->add timeout"
+                self.smooth_id = gobject.timeout_add(self.SCROLL_DELAY,
+                                                                                         self.smooth_scroll)
+                self.smooth_scroll_timer = Timer(self.MAX_SCROLL_TIME,
+                                                                                 self.smooth_scroll_timeout)
+                self.smooth_scroll_timer.start()
+                return False
+
         def scroll_to_end(self):
                 parent = self.tv.get_parent()
                 buffer = self.tv.get_buffer()
@@ -192 +236 @@
                 adjustment.set_value(0)
                 return False # when called in an idle_add, just do it once
 
-        def bring_scroll_to_end(self, diff_y = 0):
+        def bring_scroll_to_end(self, diff_y = 0,\
+                                                        use_smooth =\
+                                                        gajim.config.get('use_smooth_scrolling')):
                 ''' scrolls to the end of textview if end is not visible '''
                 buffer = self.tv.get_buffer()
                 end_iter = buffer.get_end_iter()
@@ -200 +246 @@
                 visible_rect = self.tv.get_visible_rect()
                 # scroll only if expected end is not visible
                 if end_rect.y >= (visible_rect.y + visible_rect.height + diff_y):
-                        gobject.idle_add(self.scroll_to_end_iter)
+                        if use_smooth:
+                                gobject.idle_add(self.smooth_scroll_to_end)
+                        else:
+                                gobject.idle_add(self.scroll_to_end_iter)
 
         def scroll_to_end_iter(self):
                 buffer = self.tv.get_buffer()
@@ -857 +906 @@
                 if at_the_end or kind == 'outgoing':
                         # we are at the end or we are sending something
                         # scroll to the end (via idle in case the scrollbar has appeared)
-                        gobject.idle_add(self.scroll_to_end)
+                        if gajim.config.get('use_smooth_scrolling'):
+                                gobject.idle_add(self.smooth_scroll_to_end)
+                        else:
+                                gobject.idle_add(self.scroll_to_end)
 
                 buffer.end_user_action()
 

src/common/config.py

@@ -218 +218 @@
                 'hide_groupchat_occupants_list': [opt_bool, False, _('Hides the group chat occupants list in group chat window.')],
                 'chat_merge_consecutive_nickname': [opt_bool, False, _('In a chat, show the nickname at the beginning of a line only when it\'s not the same person talking than in previous message.')],
                 'chat_merge_consecutive_nickname_indent': [opt_str, '  ', _('Indentation when using merge consecutive nickname.')],
+        'use_smooth_scrolling': [opt_bool, True, _('Smooth scroll message in conversation window')],
                 'gc_nicknames_colors': [ opt_str, '#a34526:#c000ff:#0012ff:#388a99:#045723:#7c7c7c:#ff8a00:#94452d:#244b5a:#32645a', _('List of colors that will be used to color nicknames in group chats.'), True ],
                 'ctrl_tab_go_to_next_composing': [opt_bool, True, _('Ctrl-Tab go to next composing tab when none is unread.')],
                 'confirm_metacontacts': [ opt_str, '', _('Should we show the confirm metacontacts creation dialog or not? Empty string means we never show the dialog.')],

src/chat_control.py

@@ -812 +812 @@
                                 self.msg_scrolledwindow.set_property('vscrollbar-policy', 
                                         gtk.POLICY_NEVER)
                                 self.msg_scrolledwindow.set_property('height-request', -1)
-
-                self.conv_textview.bring_scroll_to_end(diff_y - 18)
+                        # put inside "if diff_y != 0"" or it is called at each keystroke
+                        self.conv_textview.bring_scroll_to_end(diff_y - 18)
                 
                 # enable scrollbar automatic policy for horizontal scrollbar
                 # if message we have in message_textview is too big