[Spice-devel] [spice-gtk PATCHv2] usb: Add info message when USB dialog is empty

[Christophe Fergeau]

>From rh bug #804187:
« The redirection dialog can feel a bit strange when there is no device to
redirect.

It could be useful to provide a help message indicating that there is no
device to redirect yet, and that the user can insert a USB device to
redirect, and some related guidance. »

This commit adds a "No USB devices detected" infobar in the USB
dialog below the 'Select USB devices to redirect" label.
Content could probably be improved, but this is a step in the right
direction ;)

This can be tested with
diff --git a/gtk/usb-device-widget.c b/gtk/usb-device-widget.c
index b1bf090..660ea03 100644
--- a/gtk/usb-device-widget.c
+++ b/gtk/usb-device-widget.c
@@ -220,6 +220,11 @@ static GObject *spice_usb_device_widget_constructor(
                      G_CALLBACK(device_error_cb), self);

     devices = spice_usb_device_manager_get_devices(priv->manager);
+    if (devices) {
+        g_ptr_array_unref(devices);
+        devices = NULL;
+    }
+
     if (!devices)
         goto end;
---

Changes in v2:
- the 'no usb device' logic has been moved to spice_usb_device_widget_update_status
  as suggested by Hans
- removed debugging code
- instead of adding a device_count member to SpiceUsbDeviceWidget, I've
  done this through a local variable



 gtk/usb-device-widget.c | 41 +++++++++++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 10 deletions(-)

diff --git a/gtk/usb-device-widget.c b/gtk/usb-device-widget.c
index 3ed81e4..1e0df33 100644
--- a/gtk/usb-device-widget.c
+++ b/gtk/usb-device-widget.c
@@ -47,6 +47,7 @@ static void device_removed_cb(SpiceUsbDeviceManager *manager,
     SpiceUsbDevice *device, gpointer user_data);
 static void device_error_cb(SpiceUsbDeviceManager *manager,
     SpiceUsbDevice *device, GError *err, gpointer user_data);
+static gboolean spice_usb_device_widget_update_status(gpointer user_data);
 
 /* ------------------------------------------------------------------ */
 /* gobject glue                                                       */
@@ -228,6 +229,8 @@ static GObject *spice_usb_device_widget_constructor(
     g_ptr_array_unref(devices);
 
 end:
+    spice_usb_device_widget_update_status(self);
+
     return obj;
 }
 
@@ -351,21 +354,17 @@ static SpiceUsbDevice *get_usb_device(GtkWidget *widget)
     return g_object_get_data(G_OBJECT(widget), "usb-device");
 }
 
-static void check_can_redirect(GtkWidget *widget, gpointer user_data)
+static gboolean
+check_can_redirect(SpiceUsbDeviceWidget *self, SpiceUsbDevice *device)
 {
-    SpiceUsbDeviceWidget *self = SPICE_USB_DEVICE_WIDGET(user_data);
     SpiceUsbDeviceWidgetPrivate *priv = self->priv;
-    SpiceUsbDevice *device;
     gboolean can_redirect;
     GError *err = NULL;
 
-    device = get_usb_device(widget);
-    if (!device)
-        return; /* Non device widget, ie the info_bar */
+    g_return_val_if_fail(device != NULL, FALSE);
 
     can_redirect = spice_usb_device_manager_can_redirect_device(priv->manager,
                                                                 device, &err);
-    gtk_widget_set_sensitive(widget, can_redirect);
 
     /* If we can not redirect this device, append the error message to
        err_msg, but only if it is *not* already there! */
@@ -384,14 +383,32 @@ static void check_can_redirect(GtkWidget *widget, gpointer user_data)
     }
 
     g_clear_error(&err);
+
+    return can_redirect;
 }
 
 static gboolean spice_usb_device_widget_update_status(gpointer user_data)
 {
     SpiceUsbDeviceWidget *self = SPICE_USB_DEVICE_WIDGET(user_data);
     SpiceUsbDeviceWidgetPrivate *priv = self->priv;
-
-    gtk_container_foreach(GTK_CONTAINER(self), check_can_redirect, self);
+    GList *children;
+    GList *it;
+    gsize device_count;
+
+    device_count = 0;
+    children = gtk_container_get_children(GTK_CONTAINER(self));
+    for (it = children; it != NULL; it = it->next) {
+        SpiceUsbDevice *device;
+        gboolean can_redirect;
+
+        device = get_usb_device(GTK_WIDGET(it->data));
+        if (!device)
+            continue; /* Non device widget, ie the info_bar */
+        can_redirect = check_can_redirect(self, device);
+        gtk_widget_set_sensitive(GTK_WIDGET(it->data), can_redirect);
+        device_count++;
+    }
+    g_list_free(children);
 
     if (priv->err_msg) {
         spice_usb_device_widget_show_info_bar(self, priv->err_msg,
@@ -402,6 +419,11 @@ static gboolean spice_usb_device_widget_update_status(gpointer user_data)
     } else {
         spice_usb_device_widget_hide_info_bar(self);
     }
+
+    if (device_count == 0)
+        spice_usb_device_widget_show_info_bar(self, _("No USB devices detected"),
+                                              GTK_MESSAGE_INFO,
+                                              GTK_STOCK_DIALOG_INFO);
     return FALSE;
 }
 
@@ -515,7 +537,6 @@ static void device_removed_cb(SpiceUsbDeviceManager *manager,
 
     gtk_container_foreach(GTK_CONTAINER(self),
                           destroy_widget_by_usb_device, device);
-
     spice_usb_device_widget_update_status(self);
 }
 
-- 
1.7.11.4