[gnome-flashback] display-config: add support for overscan compensation

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 7cd0de04d355b1cb69c311b7f32bd847ae6f1aec
Author: Tomeu Vizoso <tomeu vizoso collabora com>
Date:   Wed Apr 16 10:20:55 2014 +0200

    display-config: add support for overscan compensation
    
    Some DRM drivers have added a consistent set of properties that
    allow compensating for the overscan that some TVs do, without the
    user being able to disable.

 .../libdisplay-config/flashback-display-config.c   |    6 ++
 .../libdisplay-config/flashback-monitor-config.c   |   14 ++++-
 .../libdisplay-config/flashback-monitor-manager.c  |   59 ++++++++++++++++++++
 .../libdisplay-config/flashback-monitor-manager.h  |    2 +
 4 files changed, 78 insertions(+), 3 deletions(-)
---
diff --git a/gnome-flashback/libdisplay-config/flashback-display-config.c 
b/gnome-flashback/libdisplay-config/flashback-display-config.c
index 5161ea7..11ae7db 100644
--- a/gnome-flashback/libdisplay-config/flashback-display-config.c
+++ b/gnome-flashback/libdisplay-config/flashback-display-config.c
@@ -382,6 +382,8 @@ handle_get_resources (MetaDBusDisplayConfig *skeleton,
                              g_variant_new_boolean (output->is_presentation));
       g_variant_builder_add (&properties, "{sv}", "connector-type",
                              g_variant_new_string (get_connector_type_name (output->connector_type)));
+      g_variant_builder_add (&properties, "{sv}", "underscanning",
+                             g_variant_new_boolean (output->is_underscanning));
 
       edid = flashback_monitor_manager_read_edid (manager, output);
 
@@ -623,6 +625,7 @@ handle_apply_configuration (MetaDBusDisplayConfig *skeleton,
       MetaOutputInfo *output_info;
       gboolean primary;
       gboolean presentation;
+      gboolean underscanning;
 
       if (output_index >= manager->n_outputs)
         {
@@ -641,6 +644,9 @@ handle_apply_configuration (MetaDBusDisplayConfig *skeleton,
       if (g_variant_lookup (properties, "presentation", "b", &presentation))
         output_info->is_presentation = presentation;
 
+      if (g_variant_lookup (properties, "underscanning", "b", &underscanning))
+        output_info->is_underscanning = underscanning;
+
       g_ptr_array_add (output_infos, output_info);
     }
 
diff --git a/gnome-flashback/libdisplay-config/flashback-monitor-config.c 
b/gnome-flashback/libdisplay-config/flashback-monitor-config.c
index dc45fac..970425b 100644
--- a/gnome-flashback/libdisplay-config/flashback-monitor-config.c
+++ b/gnome-flashback/libdisplay-config/flashback-monitor-config.c
@@ -57,6 +57,7 @@ typedef struct {
 
   gboolean is_primary;
   gboolean is_presentation;
+  gboolean is_underscanning;
 } MetaOutputConfig;
 
 typedef struct {
@@ -664,6 +665,7 @@ meta_monitor_config_assign_crtcs (MetaConfiguration       *config,
                                                 &config->keys[i]);
       output_info->is_primary = output_config->is_primary;
       output_info->is_presentation = output_config->is_presentation;
+      output_info->is_underscanning = output_config->is_underscanning;
 
       g_ptr_array_add (outputs, output_info);
     }
@@ -865,7 +867,8 @@ handle_start_element (GMarkupParseContext  *context,
              strcmp (element_name, "reflect_x") == 0 ||
              strcmp (element_name, "reflect_y") == 0 ||
              strcmp (element_name, "primary") == 0 ||
-             strcmp (element_name, "presentation") == 0) && parser->unknown_count == 0)
+             strcmp (element_name, "presentation") == 0 ||
+             strcmp (element_name, "underscanning") == 0) && parser->unknown_count == 0)
           {
             parser->state = STATE_OUTPUT_FIELD;
 
@@ -1172,6 +1175,8 @@ handle_text (GMarkupParseContext *context,
           parser->output.is_primary = read_bool (text, text_len, error);
         else if (strcmp (parser->output_field, "presentation") == 0)
           parser->output.is_presentation = read_bool (text, text_len, error);
+        else if (strcmp (parser->output_field, "underscanning") == 0)
+          parser->output.is_underscanning = read_bool (text, text_len, error);
         else
           g_assert_not_reached ();
         return;
@@ -1654,6 +1659,7 @@ init_config_from_output (MetaOutputConfig *config,
   config->transform = output->crtc->transform;
   config->is_primary = output->is_primary;
   config->is_presentation = output->is_presentation;
+  config->is_underscanning = output->is_underscanning;
 }
 
 static void
@@ -1748,7 +1754,8 @@ meta_monitor_config_save (FlashbackMonitorConfig *self)
                                       "      <reflect_x>%s</reflect_x>\n"
                                       "      <reflect_y>no</reflect_y>\n"
                                       "      <primary>%s</primary>\n"
-                                      "      <presentation>%s</presentation>\n",
+                                      "      <presentation>%s</presentation>\n"
+                                      "      <underscanning>%s</underscanning>\n",
                                       output->rect.width,
                                       output->rect.height,
                                       refresh_rate,
@@ -1757,7 +1764,8 @@ meta_monitor_config_save (FlashbackMonitorConfig *self)
                                       rotation_map[output->transform & 0x3],
                                       output->transform >= META_MONITOR_TRANSFORM_FLIPPED ? "yes" : "no",
                                       output->is_primary ? "yes" : "no",
-                                      output->is_presentation ? "yes" : "no");
+                                      output->is_presentation ? "yes" : "no",
+                                      output->is_underscanning ? "yes" : "no");
             }
 
           g_string_append (buffer, "    </output>\n");
diff --git a/gnome-flashback/libdisplay-config/flashback-monitor-manager.c 
b/gnome-flashback/libdisplay-config/flashback-monitor-manager.c
index e662ab0..22c41cd 100644
--- a/gnome-flashback/libdisplay-config/flashback-monitor-manager.c
+++ b/gnome-flashback/libdisplay-config/flashback-monitor-manager.c
@@ -320,6 +320,38 @@ output_set_presentation_xrandr (FlashbackMonitorManagerPrivate *priv,
                            (unsigned char*) &value, 1);
 }
 
+static gboolean
+output_get_underscanning_xrandr (FlashbackMonitorManagerPrivate *priv,
+                                 MetaOutput                     *output)
+{
+  gboolean value = FALSE;
+  Atom atom, actual_type;
+  int actual_format;
+  unsigned long nitems, bytes_after;
+  unsigned char *buffer;
+  char *str;
+
+  atom = XInternAtom (priv->xdisplay, "underscan", False);
+  XRRGetOutputProperty (priv->xdisplay,
+                        (XID)output->winsys_id,
+                        atom,
+                        0, G_MAXLONG, False, False, XA_ATOM,
+                        &actual_type, &actual_format,
+                        &nitems, &bytes_after, &buffer);
+
+  if (actual_type != XA_ATOM || actual_format != 32 ||
+      nitems < 1)
+    goto out;
+
+  str = XGetAtomName (priv->xdisplay, *(Atom *)buffer);
+  value = !strcmp(str, "on");
+  XFree (str);
+
+out:
+  XFree (buffer);
+  return value;
+}
+
 static int
 normalize_backlight (MetaOutput *output,
                      int         hw_value)
@@ -1001,6 +1033,7 @@ read_current_config (FlashbackMonitorManager *manager)
 
           meta_output->is_primary = ((XID)meta_output->winsys_id == primary_output);
           meta_output->is_presentation = output_get_presentation_xrandr (priv, meta_output);
+          meta_output->is_underscanning = output_get_underscanning_xrandr (priv, meta_output);
           output_get_backlight_limits_xrandr (priv, meta_output);
 
         if (!(meta_output->backlight_min == 0 && meta_output->backlight_max == 0))
@@ -1192,6 +1225,27 @@ flashback_monitor_manager_new (MetaDBusDisplayConfig *display_config)
                        NULL);
 }
 
+static void
+output_set_underscanning_xrandr (FlashbackMonitorManagerPrivate *priv,
+                                 MetaOutput                     *output,
+                                 gboolean                        underscanning)
+{
+  Atom prop, valueatom;
+  const char *value;
+
+  prop = XInternAtom (priv->xdisplay, "underscan", False);
+
+  /* XXX: Also implement underscan border */
+  value = underscanning ? "on" : "off";
+  valueatom = XInternAtom (priv->xdisplay, value, False);
+
+  XRRChangeOutputProperty (priv->xdisplay,
+                           (XID)output->winsys_id,
+                           prop,
+                           XA_ATOM, 32, PropModeReplace,
+                           (unsigned char*) &valueatom, 1);
+}
+
 void
 flashback_monitor_manager_apply_configuration (FlashbackMonitorManager  *manager,
                                                MetaCRTCInfo            **crtcs,
@@ -1392,8 +1446,13 @@ flashback_monitor_manager_apply_configuration (FlashbackMonitorManager  *manager
                                       output_info->output,
                                       output_info->is_presentation);
 
+      output_set_underscanning_xrandr (priv,
+                                       output_info->output,
+                                       output_info->is_underscanning);
+
       output->is_primary = output_info->is_primary;
       output->is_presentation = output_info->is_presentation;
+      output->is_underscanning = output_info->is_underscanning;
     }
 
   /* Disable outputs not mentioned in the list */
diff --git a/gnome-flashback/libdisplay-config/flashback-monitor-manager.h 
b/gnome-flashback/libdisplay-config/flashback-monitor-manager.h
index 4ea3db0..0300180 100644
--- a/gnome-flashback/libdisplay-config/flashback-monitor-manager.h
+++ b/gnome-flashback/libdisplay-config/flashback-monitor-manager.h
@@ -112,6 +112,7 @@ struct _MetaOutput
   */
   gboolean            is_primary;
   gboolean            is_presentation;
+  gboolean            is_underscanning;
 
   gpointer            driver_private;
   GDestroyNotify      driver_notify;
@@ -210,6 +211,7 @@ struct _MetaOutputInfo
   MetaOutput *output;
   gboolean    is_primary;
   gboolean    is_presentation;
+  gboolean    is_underscanning;
 };
 
 #define FLASHBACK_TYPE_MONITOR_MANAGER flashback_monitor_manager_get_type ()