From 6fe03c5a522a95633e1e60c8ff2996c67d418add Mon Sep 17 00:00:00 2001
From: Gergely Polonkai <gergely@polonkai.eu>
Date: Sun, 21 Sep 2014 13:13:36 +0200
Subject: [PATCH 1/2] Add function ag_window_is_usable()

This function can decide if a given window is usable for opening a
new chart.
---
 src/ag-window.c | 17 +++++++++++++++++
 src/ag-window.h |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/src/ag-window.c b/src/ag-window.c
index 33e7d55..f184f44 100644
--- a/src/ag-window.c
+++ b/src/ag-window.c
@@ -2767,3 +2767,20 @@ ag_window_load_chart_list(AgWindow *window)
 
     return TRUE;
 }
+
+/**
+ * ag_window_is_usable:
+ * @window: an #AgWindow to test
+ *
+ * Checks if the given window is usable for new charts. Usability is
+ * currently means that it has no charts open.
+ *
+ * Returns: TRUE if @window is usable, FALSE otherwise
+ */
+gboolean
+ag_window_is_usable(AgWindow *window)
+{
+    AgWindowPrivate *priv = ag_window_get_instance_private(window);
+
+    return (priv->current_tab == priv->tab_list);
+}
diff --git a/src/ag-window.h b/src/ag-window.h
index 0475451..8bf51bf 100644
--- a/src/ag-window.h
+++ b/src/ag-window.h
@@ -59,6 +59,8 @@ void ag_window_change_tab(AgWindow *window, const gchar *tab_name);
 
 gboolean ag_window_load_chart_list(AgWindow *window);
 
+gboolean ag_window_is_usable(AgWindow *window);
+
 #define AG_WINDOW_ERROR (ag_window_error_quark())
 
 GQuark ag_window_error_quark(void);

From 86e6b7e4e5596623cd7b0329ea6ebb7a886ad89c Mon Sep 17 00:00:00 2001
From: Gergely Polonkai <gergely@polonkai.eu>
Date: Sun, 21 Sep 2014 13:23:19 +0200
Subject: [PATCH 2/2] Prevent AgApp for opening a new window for imports unless
 necessary

It checks the current window, then all the other windows if there is a
usable among them. Only if there is none, it will create a new window.
---
 src/ag-app.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/ag-app.c b/src/ag-app.c
index 9a2a5bc..1f30506 100644
--- a/src/ag-app.c
+++ b/src/ag-app.c
@@ -60,6 +60,36 @@ ag_app_create_window(AgApp *app)
     return window;
 }
 
+static GtkWidget *
+ag_app_get_usable_window(AgApp *app)
+{
+    GtkWidget *window;
+    GList     *l;
+
+    // Favour current window
+    window = GTK_WIDGET(gtk_application_get_active_window(GTK_APPLICATION(app)));
+
+    if (AG_IS_WINDOW(window) && ag_window_is_usable(AG_WINDOW(window))) {
+        return window;
+    }
+
+    // Otherwise, let’s use the first existing, usable window
+    for (
+                l = gtk_application_get_windows(GTK_APPLICATION(app));
+                l;
+                l = g_list_next(l)
+            ) {
+        if (AG_IS_WINDOW(l->data) && ag_window_is_usable(AG_WINDOW(l->data))) {
+            return l->data;
+        }
+    }
+
+    // If we are still here, no usable windows were found. Let’s create one
+    window = ag_app_create_window(app);
+
+    return window;
+}
+
 static void
 new_window_cb(GSimpleAction *action, GVariant *parameter, gpointer user_data)
 {
@@ -165,11 +195,12 @@ ag_app_import_file(AgApp *app, GFile *file, AgAppImportType type)
         return;
     }
 
-    window = ag_app_create_window(app);
+    window = ag_app_get_usable_window(app);
     ag_window_set_chart(AG_WINDOW(window), chart);
     ag_window_update_from_chart(AG_WINDOW(window));
     g_action_group_activate_action(G_ACTION_GROUP(window), "save", NULL);
     ag_window_change_tab(AG_WINDOW(window), "chart");
+    gtk_window_present(GTK_WINDOW(window));
 }
 
 static void