Smooth scrolling. Fixes bug #445859 (Raphael Slinckx).

2007-06-10 Xavier Claessens  <xclaesse@gmail.com>

	* libempathy-gtk/gossip-chat-view.c: Smooth scrolling.
	Fixes bug #445859 (Raphael Slinckx).

svn path=/trunk/; revision=143

diff --git a/ChangeLog b/ChangeLog
index bb55d670fa2cdad9f9b59f3db480408acee1e58f..8967cce61bdd240685c44bcd2c15eca210c65b2e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-06-10 Xavier Claessens  <xclaesse@gmail.com>
+
+       * libempathy-gtk/gossip-chat-view.c: Smooth scrolling.
+       Fixes bug #445859 (Raphael Slinckx).
+
 2007-06-09 Xavier Claessens  <xclaesse@gmail.com>
 
        * libempathy/gossip-contact.c: Emit notify signal only if the property

diff --git a/libempathy-gtk/gossip-chat-view.c b/libempathy-gtk/gossip-chat-view.c
index 24770f5ded9aa11af081d44875544da7587dc190..9fea2fbf17bfdd29283efe78a54b1c4322b69c1a 100644 (file)
--- a/libempathy-gtk/gossip-chat-view.c
+++ b/libempathy-gtk/gossip-chat-view.c
@@ -57,6 +57,8 @@
 #define TIMESTAMP_INTERVAL 300
 
 #define MAX_LINES 800
+#define MAX_SCROLL_TIME 0.4 /* seconds */
+#define SCROLL_DELAY 33     /* milliseconds */
 
 #define GET_PRIV(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GOSSIP_TYPE_CHAT_VIEW, GossipChatViewPriv))
 
@@ -77,6 +79,8 @@ struct _GossipChatViewPriv {
        BlockType      last_block_type;
 
        gboolean       allow_scrolling;
+       guint          scroll_src;
+       GTimer        *scroll_time;
        gboolean       is_group_chat;
 
        GtkTextMark   *find_mark_previous;
@@ -343,6 +347,12 @@ chat_view_finalize (GObject *object)
        if (priv->last_contact) {
                g_object_unref (priv->last_contact);
        }
+       if (priv->scroll_time) {
+               g_timer_destroy (priv->scroll_time);
+       }
+       if (priv->scroll_src) {
+               g_source_remove (priv->scroll_src);
+       }
 
        G_OBJECT_CLASS (gossip_chat_view_parent_class)->finalize (object);
 }
@@ -1629,13 +1639,38 @@ gossip_chat_view_scroll (GossipChatView *view,
                      allow_scrolling ? "enabled" : "disabled");
 }
 
+/* Code stolen from pidgin/gtkimhtml.c */
+static gboolean
+chat_view_scroll_cb (GossipChatView *view)
+{
+       GossipChatViewPriv *priv;
+       GtkAdjustment      *adj;
+       gdouble             max_val;
+
+       priv = GET_PRIV (view);
+       adj = GTK_TEXT_VIEW (view)->vadjustment;
+       max_val = adj->upper - adj->page_size;
+
+       g_return_val_if_fail (priv->scroll_time != NULL, FALSE);
+
+       if (g_timer_elapsed (priv->scroll_time, NULL) > MAX_SCROLL_TIME) {
+               /* time's up. jump to the end and kill the timer */
+               gtk_adjustment_set_value (adj, max_val);
+               g_timer_destroy (priv->scroll_time);
+               priv->scroll_time = NULL;
+               priv->scroll_src = 0;
+               return FALSE;
+       }
+
+       /* scroll by 1/3rd the remaining distance */
+       gtk_adjustment_set_value (adj, gtk_adjustment_get_value (adj) + ((max_val - gtk_adjustment_get_value (adj)) / 3));
+       return TRUE;
+}
+
 void
 gossip_chat_view_scroll_down (GossipChatView *view)
 {
        GossipChatViewPriv *priv;
-       GtkTextBuffer      *buffer;
-       GtkTextIter         iter;
-       GtkTextMark        *mark;
 
        g_return_if_fail (GOSSIP_IS_CHAT_VIEW (view));
 
@@ -1647,22 +1682,17 @@ gossip_chat_view_scroll_down (GossipChatView *view)
 
        gossip_debug (DEBUG_DOMAIN, "Scrolling down");
 
-       buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
-
-       gtk_text_buffer_get_end_iter (buffer, &iter);
-       mark = gtk_text_buffer_create_mark (buffer,
-                                           NULL,
-                                           &iter,
-                                           FALSE);
-
-       gtk_text_view_scroll_to_mark (GTK_TEXT_VIEW (view),
-                                     mark,
-                                     0.0,
-                                     FALSE,
-                                     0,
-                                     0);
+       if (priv->scroll_time) {
+               g_timer_destroy (priv->scroll_time);
+       }
+       if (priv->scroll_src) {
+               g_source_remove (priv->scroll_src);
+       }
 
-       gtk_text_buffer_delete_mark (buffer, mark);
+       priv->scroll_time = g_timer_new();
+       priv->scroll_src = g_timeout_add (SCROLL_DELAY,
+                                         (GSourceFunc) chat_view_scroll_cb,
+                                         view);
 }
 
 gboolean