[gnome-boxes] wizard: Introduce download_media ()

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit eb9f11aa313cacc9fae311a49ec5c5cc642cb0e4
Author: Lasse Schuirmann <lasse schuirmann gmail com>
Date:   Mon Jul 14 17:48:02 2014 +0200

    wizard: Introduce download_media ()
    
    This adds a function to download media via HTTP or HTTPS protocol from
    the internet. Functions of other objects used here were gradually
    introduced with the parent commits of this.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=729026

 src/wizard.vala |   29 +++++++++++++++++++++++++++++
 1 files changed, 29 insertions(+), 0 deletions(-)
---
diff --git a/src/wizard.vala b/src/wizard.vala
index 8531784..53cd7ad 100644
--- a/src/wizard.vala
+++ b/src/wizard.vala
@@ -12,6 +12,8 @@ private enum Boxes.WizardPage {
 
 [GtkTemplate (ui = "/org/gnome/Boxes/ui/wizard.ui")]
 private class Boxes.Wizard: Gtk.Stack, Boxes.UI {
+    private const double DOWNLOAD_PROGRESS_SCALE = 0.95;
+    private const double PREPARE_PROGRESS_SCALE = 0.05;
     private const string[] page_names = { "introduction", "source", "preparation", "setup", "review" };
 
     public UIState previous_ui_state { get; protected set; }
@@ -562,6 +564,33 @@ private class Boxes.Wizard: Gtk.Stack, Boxes.UI {
         return false;
     }
 
+    private async void download_media (string uri, ActivityProgress progress) {
+        var download_progress = progress.add_child_activity (DOWNLOAD_PROGRESS_SCALE);
+        prep_status_label.label = _("Downloading media...");
+
+        try {
+            var cache_path = yield Downloader.fetch_media (uri, download_progress, prepare_cancellable);
+            prepare_downloaded_media (cache_path, progress);
+        } catch (GLib.IOError.CANCELLED e) {
+            debug ("Cancelled downloading media '%s'!", uri);
+            page = WizardPage.SOURCE;
+        } catch (GLib.Error e) {
+            warning ("Failed downloading media '%s'! %s", uri, e.message);
+            App.window.notificationbar.display_error (_("Download failed."));
+            page = WizardPage.SOURCE;
+        } finally {
+            prepare_cancellable = null;
+        }
+    }
+
+    private void prepare_downloaded_media (string cache_path, ActivityProgress progress) {
+        cleanup ();
+
+        // Relaunch prepare with local URI
+        wizard_source.uri = "file://" + cache_path;
+        prepare (progress);
+    }
+
     public void setup_ui () {
         cancel_button = App.window.topbar.wizard_toolbar.cancel_btn;
         cancel_button.clicked.connect (() => {