monitor-manager: Expose a few helpers to clear structs

These are useful for child classes to unwind cleanly when constructing
their structures.

https://bugzilla.gnome.org/show_bug.cgi?id=756796

2 files changed, 44 insertions, 22 deletions

diff --git a/src/backends/meta-monitor-manager-private.h b/src/backends/meta-monitor-manager-private.h
index c30e8d7b0..1b80299d1 100644
--- a/src/backends/meta-monitor-manager-private.h
+++ b/src/backends/meta-monitor-manager-private.h
@@ -414,6 +414,10 @@ gint               meta_monitor_manager_get_monitor_at_point (MetaMonitorManager
                                                               gfloat              x,
                                                               gfloat              y);
 
+void meta_monitor_manager_clear_output (MetaOutput *output);
+void meta_monitor_manager_clear_mode (MetaMonitorMode *mode);
+void meta_monitor_manager_clear_crtc (MetaCRTC *crtc);
+
 /* Returns true if transform causes width and height to be inverted
    This is true for the odd transforms in the enum */
 static inline gboolean
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index a15673e64..38ccc7261 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -346,6 +346,23 @@ meta_monitor_manager_constructed (GObject *object)
   manager->in_init = FALSE;
 }
 
+void
+meta_monitor_manager_clear_output (MetaOutput *output)
+{
+  g_free (output->name);
+  g_free (output->vendor);
+  g_free (output->product);
+  g_free (output->serial);
+  g_free (output->modes);
+  g_free (output->possible_crtcs);
+  g_free (output->possible_clones);
+
+  if (output->driver_notify)
+    output->driver_notify (output);
+
+  memset (output, 0, sizeof (*output));
+}
+
 static void
 meta_monitor_manager_free_output_array (MetaOutput *old_outputs,
                                         int         n_old_outputs)
@@ -353,22 +370,22 @@ meta_monitor_manager_free_output_array (MetaOutput *old_outputs,
   int i;
 
   for (i = 0; i < n_old_outputs; i++)
-    {
-      g_free (old_outputs[i].name);
-      g_free (old_outputs[i].vendor);
-      g_free (old_outputs[i].product);
-      g_free (old_outputs[i].serial);
-      g_free (old_outputs[i].modes);
-      g_free (old_outputs[i].possible_crtcs);
-      g_free (old_outputs[i].possible_clones);
-
-      if (old_outputs[i].driver_notify)
-        old_outputs[i].driver_notify (&old_outputs[i]);
-    }
+    meta_monitor_manager_clear_output (&old_outputs[i]);
 
   g_free (old_outputs);
 }
 
+void
+meta_monitor_manager_clear_mode (MetaMonitorMode *mode)
+{
+  g_free (mode->name);
+
+  if (mode->driver_notify)
+    mode->driver_notify (mode);
+
+  memset (mode, 0, sizeof (*mode));
+}
+
 static void
 meta_monitor_manager_free_mode_array (MetaMonitorMode *old_modes,
                                       int              n_old_modes)
@@ -376,16 +393,20 @@ meta_monitor_manager_free_mode_array (MetaMonitorMode *old_modes,
   int i;
 
   for (i = 0; i < n_old_modes; i++)
-    {
-      g_free (old_modes[i].name);
-
-      if (old_modes[i].driver_notify)
-        old_modes[i].driver_notify (&old_modes[i]);
-    }
+    meta_monitor_manager_clear_mode (&old_modes[i]);
 
   g_free (old_modes);
 }
 
+void
+meta_monitor_manager_clear_crtc (MetaCRTC *crtc)
+{
+  if (crtc->driver_notify)
+    crtc->driver_notify (crtc);
+
+  memset (crtc, 0, sizeof (*crtc));
+}
+
 static void
 meta_monitor_manager_free_crtc_array (MetaCRTC *old_crtcs,
                                       int       n_old_crtcs)
@@ -393,10 +414,7 @@ meta_monitor_manager_free_crtc_array (MetaCRTC *old_crtcs,
   int i;
 
   for (i = 0; i < n_old_crtcs; i++)
-    {
-      if (old_crtcs[i].driver_notify)
-        old_crtcs[i].driver_notify (&old_crtcs[i]);
-    }
+    meta_monitor_manager_clear_crtc (&old_crtcs[i]);
 
   g_free (old_crtcs);
 }