app: add alternative "Check for updates" button in the About dialog.

When an update is available, a big frame is visible, proposing to go to
the download page. Now a button is also available to explicitly request
for an update check in other cases (bypassing the wait delay for a
future startup).

(cherry picked from commit 827473fd88)

app/app.c

@@ -287,7 +287,7 @@ app_run (const gchar         *full_prog_name,
    * Thus we have to add a special flag when we make an update
    * check so that the timestamp is saved.
    */
-  save_gimprc_at_exit = gimp_update_check (gimp->config);
+  save_gimprc_at_exit = gimp_update_auto_check (gimp->config);
 
   /* Initialize the error handling after creating/migrating the config
    * directory because it will create some folders for backup and crash

app/dialogs/about-dialog.c

@@ -40,6 +40,7 @@
 
 #include "about-dialog.h"
 #include "authors.h"
+#include "gimp-update.h"
 
 #include "gimp-intl.h"
 
@@ -55,6 +56,8 @@ typedef struct
 {
   GtkWidget   *dialog;
 
+  GtkWidget   *update_frame;
+
   GtkWidget   *anim_area;
   PangoLayout *layout;
 
@@ -81,9 +84,8 @@ static void        about_dialog_add_animation (GtkWidget       *vbox,
 static gboolean    about_dialog_anim_expose   (GtkWidget       *widget,
                                                GdkEventExpose  *event,
                                                GimpAboutDialog *dialog);
-static void        about_dialog_add_update    (GtkWidget       *vbox,
+static void        about_dialog_add_update    (GimpAboutDialog *dialog,
-                                               GimpCoreConfig  *config,
+                                               GimpCoreConfig  *config);
-                                               GimpAboutDialog *dialog);
 static void        about_dialog_reshuffle     (GimpAboutDialog *dialog);
 static gboolean    about_dialog_timer         (gpointer         data);
 
@@ -92,6 +94,10 @@ static void        about_dialog_add_unstable_message
                                               (GtkWidget       *vbox);
 #endif /* GIMP_UNSTABLE */
 
+static void        about_dialog_last_release_changed
+                                              (GimpCoreConfig   *config,
+                                               const GParamSpec *pspec,
+                                               GimpAboutDialog  *dialog);
 
 GtkWidget *
 about_dialog_create (GimpCoreConfig *config)
@@ -161,12 +167,11 @@ about_dialog_create (GimpCoreConfig *config)
 
       if (GTK_IS_BOX (children->data))
         {
-          about_dialog_add_update (children->data,
-                                   config, &dialog);
           about_dialog_add_animation (children->data, &dialog);
 #ifdef GIMP_UNSTABLE
           about_dialog_add_unstable_message (children->data);
 #endif /* GIMP_UNSTABLE */
+          about_dialog_add_update (&dialog, config);
         }
       else
         g_warning ("%s: ooops, no box in this container?", G_STRLOC);
@@ -259,16 +264,13 @@ about_dialog_add_animation (GtkWidget       *vbox,
 }
 
 static void
-about_dialog_add_update (GtkWidget       *vbox,
+about_dialog_add_update (GimpAboutDialog *dialog,
-                         GimpCoreConfig  *config,
+                         GimpCoreConfig  *config)
-                         GimpAboutDialog *dialog)
 {
-  if (config->last_known_release != NULL)
+  GtkWidget *container;
-    {
+  GList     *children;
-      /* There is a newer version. */
+  GtkWidget *vbox;
-      GtkWidget *link;
+
-      GtkWidget *box2;
-      GtkWidget *image;
   GtkWidget *frame;
   GtkWidget *box;
   GtkWidget *label;
@@ -276,17 +278,30 @@ about_dialog_add_update (GtkWidget       *vbox,
   gchar     *date;
   gchar     *text;
 
+  /* Get the dialog vbox. */
+  container = gtk_dialog_get_content_area (GTK_DIALOG (dialog->dialog));
+  children = gtk_container_get_children (GTK_CONTAINER (container));
+  g_return_if_fail (GTK_IS_BOX (children->data));
+  vbox = children->data;
+  g_list_free (children);
+
+  /* The preferred localized date representation without the time. */
+  datetime = g_date_time_new_from_unix_local (config->check_update_timestamp);
+  date = g_date_time_format (datetime, "%x");
+  g_date_time_unref (datetime);
+
   /* The update frame. */
   frame = gtk_frame_new (NULL);
   gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 2);
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   gtk_container_add (GTK_CONTAINER (frame), box);
-
+  if (config->last_known_release != NULL)
-      /* The preferred localized date representation without the time. */
+    {
-      datetime = g_date_time_new_from_unix_local (config->check_update_timestamp);
+      /* There is a newer version. */
-      date = g_date_time_format (datetime, "%x");
+      GtkWidget *link;
-      g_date_time_unref (datetime);
+      GtkWidget *box2;
+      GtkWidget *image;
 
       /* We want the frame to stand out. */
       label = gtk_label_new (NULL);
@@ -298,7 +313,7 @@ about_dialog_add_update (GtkWidget       *vbox,
       gtk_frame_set_label_widget (GTK_FRAME (frame), label);
       gtk_frame_set_label_align (GTK_FRAME (frame), 0.5, 0.5);
       gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_ETCHED_OUT);
-      gtk_box_reorder_child (GTK_BOX (vbox), frame, 2);
+      gtk_box_reorder_child (GTK_BOX (vbox), frame, 3);
 
       /* Explanation text with update image. */
       box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
@@ -314,7 +329,6 @@ about_dialog_add_update (GtkWidget       *vbox,
                                 "It is recommended to update."),
                               config->last_known_release, date);
       label = gtk_label_new (text);
-      g_free (date);
       g_free (text);
 
       gtk_box_pack_start (GTK_BOX (box2), label, FALSE, FALSE, 0);
@@ -325,10 +339,43 @@ about_dialog_add_update (GtkWidget       *vbox,
                                              _("Go to download page"));
       gtk_box_pack_start (GTK_BOX (box), link, FALSE, FALSE, 0);
       gtk_widget_show (link);
+    }
+  else
+    {
+      /* Show a check update version. */
+      GtkWidget *button;
+      gchar     *text2;
+
+      gtk_box_reorder_child (GTK_BOX (vbox), frame, 4);
+
+      text2 = g_strdup_printf (_("Last checked on %s"), date);
+      text = g_strdup_printf ("%s\n<i>%s</i>",
+                              _("Check for updates"), text2);
+
+      label = gtk_label_new (NULL);
+      gtk_label_set_markup (GTK_LABEL (label), text);
+      gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_CENTER);
+      g_free (text);
+      g_free (text2);
+
+      button = gtk_button_new ();
+      gtk_container_add (GTK_CONTAINER (button), label);
+      gtk_widget_show (label);
+
+      g_signal_connect (config, "notify::last-known-release",
+                        (GCallback) about_dialog_last_release_changed,
+                        dialog);
+      g_signal_connect_swapped (button, "clicked",
+                                (GCallback) gimp_update_check, config);
+      gtk_box_pack_start (GTK_BOX (box), button, FALSE, FALSE, 0);
+      gtk_widget_show (button);
+    }
+  g_free (date);
 
   gtk_widget_show (box);
   gtk_widget_show (frame);
-    }
+
+  dialog->update_frame = frame;
 }
 
 static void
@@ -698,3 +745,20 @@ about_dialog_add_unstable_message (GtkWidget *vbox)
 }
 
 #endif /* GIMP_UNSTABLE */
+
+static void
+about_dialog_last_release_changed (GimpCoreConfig   *config,
+                                   const GParamSpec *pspec,
+                                   GimpAboutDialog  *dialog)
+{
+  g_signal_handlers_disconnect_by_func (config,
+                                        (GCallback) about_dialog_last_release_changed,
+                                        dialog);
+  if (dialog->update_frame)
+    {
+      gtk_widget_destroy (dialog->update_frame);
+      dialog->update_frame = NULL;
+    }
+
+  about_dialog_add_update (dialog, config);
+}

app/gimp-update.c

@@ -162,10 +162,15 @@ gimp_check_updates_callback (GObject      *source,
     }
 }
 
+/*
+ * gimp_update_auto_check:
+ * @config:
+ *
+ * Run the check for newer versions of GIMP if conditions are right.
+ */
 gboolean
-gimp_update_check (GimpCoreConfig *config)
+gimp_update_auto_check (GimpCoreConfig *config)
 {
-  GFile *gimp_versions;
   gint64 prev_update_timestamp;
   gint64 current_timestamp;
 
@@ -187,6 +192,20 @@ gimp_update_check (GimpCoreConfig *config)
     return FALSE;
 #endif
 
+  return gimp_update_check (config);
+}
+
+/*
+ * gimp_update_check:
+ * @config:
+ *
+ * Run the check for newer versions of GIMP inconditionnally.
+ */
+gboolean
+gimp_update_check (GimpCoreConfig *config)
+{
+  GFile *gimp_versions;
+
 #ifdef GIMP_UNSTABLE
   if (g_getenv ("GIMP_DEV_VERSIONS_JSON"))
     gimp_versions = g_file_new_for_path (g_getenv ("GIMP_DEV_VERSIONS_JSON"));

app/gimp-update.h

@@ -22,6 +22,7 @@
 #define __APP_GIMP_UPDATE_H__
 
 
+gboolean gimp_update_auto_check (GimpCoreConfig *config);
 gboolean gimp_update_check      (GimpCoreConfig *config);