[balsa] Handle a clicked link that requires a new window

[Peter Bloomfield <PeterB src gnome org>]

commit a037f554afb25e35f7d61072eb6b9e29b4a1a5d8
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Fri Oct 30 09:35:49 2009 -0400

    Handle a clicked link that requires a new window

 ChangeLog       |    7 +++++
 libbalsa/html.c |   73 +++++++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 72 insertions(+), 8 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 17b6d68..2178e39 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2009-10-30  Peter Bloomfield
+
+	* libbalsa/html.c (lbh_navigation_policy_decision_requested_cb,
+	lbh_web_view_ready_idle, lbh_web_view_ready_cb,
+	lbh_create_web_view_cb, libbalsa_html_new): handle a clicked
+	link that requires a new window.
+
 2009-10-28  Peter Bloomfield
 
 	* src/balsa-mime-widget.c (balsa_mime_widget_destroy): unref
diff --git a/libbalsa/html.c b/libbalsa/html.c
index f6d86d7..5ebad07 100644
--- a/libbalsa/html.c
+++ b/libbalsa/html.c
@@ -110,21 +110,75 @@ lbh_size_request_cb(GtkWidget      * widget,
     requisition->height = gtk_adjustment_get_upper(info->vadj);
 }
 
-static WebKitNavigationResponse
-lbh_navigation_requested_cb(WebKitWebView        * web_view,
-                            WebKitWebFrame       * frame,
-                            WebKitNetworkRequest * request,
-                            gpointer               data)
+static gboolean
+lbh_navigation_policy_decision_requested_cb(WebKitWebView             * web_view,
+                                            WebKitWebFrame            * frame,
+                                            WebKitNetworkRequest      * request,
+                                            WebKitWebNavigationAction * action,
+                                            WebKitWebPolicyDecision   * decision,
+                                            gpointer                    data)
 {
     LibBalsaWebKitInfo *info = data;
     const gchar *uri = webkit_network_request_get_uri(request);
 
     g_print("%s %s\n", __func__, uri);
     (*info->clicked_cb)(uri);
+    webkit_web_policy_decision_ignore(decision);
+
+    return TRUE;
+}
+
+/*
+ * To handle a clicked link that is supposed to open in a new window
+ * (specifically, has the attribute 'target="_blank"'), we must allow
+ * WebKit to open one, but we destroy it after it has emitted the
+ * "navigation-policy-decision-requested" signal.
+ */
+
+/*
+ * Idle handler to actually unref it.
+ */
+static gboolean
+lbh_web_view_ready_idle(WebKitWebView * web_view)
+{
+    g_object_unref(g_object_ref_sink(web_view));
+
+    return FALSE;
+}
+
+/*
+ * Window is ready, now we destroy it.
+ */
+static gboolean
+lbh_web_view_ready_cb(WebKitWebView * web_view,
+                      gpointer        data)
+{
+    g_idle_add((GSourceFunc) lbh_web_view_ready_idle, web_view);
+
+    return TRUE;
+}
+
+/*
+ * WebKit wants a new window.
+ */
+static WebKitWebView *
+lbh_create_web_view_cb(WebKitWebView  * web_view,
+                       WebKitWebFrame * frame,
+                       gpointer         data)
+{
+    GtkWidget *widget;
 
-    return WEBKIT_NAVIGATION_RESPONSE_IGNORE;
+    widget = webkit_web_view_new();
+    g_signal_connect(widget, "navigation-policy-decision-requested",
+                     G_CALLBACK
+                     (lbh_navigation_policy_decision_requested_cb), data);
+    g_signal_connect(widget, "web-view-ready", G_CALLBACK(lbh_web_view_ready_cb),
+                     NULL);
+
+    return WEBKIT_WEB_VIEW(widget);
 }
 
+
 /* Create a new WebKitWebView widget:
  * text			the HTML source;
  * len			length of text;
@@ -172,8 +226,11 @@ libbalsa_html_new(const gchar * text, size_t len,
                      G_CALLBACK(lbh_hovering_over_link_cb), info);
 
     info->clicked_cb = clicked_cb;
-    g_signal_connect(web_view, "navigation-requested",
-                     G_CALLBACK(lbh_navigation_requested_cb), info);
+    g_signal_connect(web_view, "navigation-policy-decision-requested",
+                     G_CALLBACK
+                     (lbh_navigation_policy_decision_requested_cb), info);
+    g_signal_connect(web_view, "create-web-view",
+                     G_CALLBACK(lbh_create_web_view_cb), info);
 
     g_signal_connect(web_view, "load-progress-changed",
                      G_CALLBACK(gtk_widget_queue_resize), NULL);