ephy-embed: slightly delay delayed load requests

If the user is rapidly switching through many tabs with delayed load
requests, we shouldn't load them all. Instead, wait until the user stops
briefly on a tab before loading it.

https://bugzilla.gnome.org/show_bug.cgi?id=745260

1 files changed, 31 insertions, 5 deletions

diff --git a/embed/ephy-embed.c b/embed/ephy-embed.c
index 798bbc43a..a98824aba 100644
--- a/embed/ephy-embed.c
+++ b/embed/ephy-embed.c
@@ -70,6 +70,7 @@ struct _EphyEmbedPrivate
 
   char *title;
   WebKitURIRequest *delayed_request;
+  guint delayed_request_source_id;
 
   GSList *messages;
   GSList *keys;
@@ -365,6 +366,11 @@ ephy_embed_dispose (GObject *object)
     priv->clear_progress_source_id = 0;
   }
 
+  if (priv->delayed_request_source_id) {
+    g_source_remove (priv->delayed_request_source_id);
+    priv->delayed_request_source_id = 0;
+  }
+
   /* Do not listen to status message notifications anymore, if we try
    * to update the statusbar after dispose we might crash. */
   if (priv->status_handler_id) {
@@ -648,17 +654,19 @@ progress_update (EphyWebView *view, GParamSpec *pspec, EphyEmbed *embed)
                                  (loading || progress == 1.0) ? progress : 0.0);
 }
 
-static void
-ephy_embed_maybe_load_delayed_request (EphyEmbed *embed)
+static gboolean
+load_delayed_request_if_mapped (gpointer user_data)
 {
+  EphyEmbed *embed = EPHY_EMBED (user_data);
   EphyEmbedPrivate *priv = embed->priv;
   EphyWebView *web_view;
 
-  if (!priv->delayed_request)
-    return;
+  priv->delayed_request_source_id = 0;
 
-  web_view = ephy_embed_get_web_view (embed);
+  if (!gtk_widget_get_mapped (GTK_WIDGET (embed)))
+    return G_SOURCE_REMOVE;
 
+  web_view = ephy_embed_get_web_view (embed);
   ephy_web_view_load_request (web_view, priv->delayed_request);
   g_clear_object (&priv->delayed_request);
 
@@ -666,6 +674,24 @@ ephy_embed_maybe_load_delayed_request (EphyEmbed *embed)
    * loading as soon as possible.
    */
   g_signal_emit_by_name (web_view, "load-changed", WEBKIT_LOAD_STARTED);
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+ephy_embed_maybe_load_delayed_request (EphyEmbed *embed)
+{
+  EphyEmbedPrivate *priv = embed->priv;
+
+  if (!priv->delayed_request || priv->delayed_request_source_id != 0)
+    return;
+
+  /* Add a very small delay before loading the request, so that if the user
+   * is scrolling rapidly through a bunch of delayed tabs, we don't start
+   * loading them all.
+   */
+  priv->delayed_request_source_id = g_timeout_add (300, load_delayed_request_if_mapped, embed);
+  g_source_set_name_by_id (priv->delayed_request_source_id, "[epiphany] load_delayed_request_if_mapped");
 }
 
 static void