monitor-manager: Add per backend capabilities

Add a private API for querying backend capabilities. For now, only
mirroring capability is reported.

https://bugzilla.gnome.org/show_bug.cgi?id=777732

src/backends/meta-monitor-manager-dummy.c

@@ -599,6 +599,12 @@ meta_monitor_manager_dummy_get_supported_scales (MetaMonitorManager *manager,
   *n_scales = G_N_ELEMENTS (supported_scales_dummy);
 }
 
+static MetaMonitorManagerCapability
+meta_monitor_manager_dummy_get_capabilities (MetaMonitorManager *manager)
+{
+  return META_MONITOR_MANAGER_CAPABILITY_MIRRORING;
+}
+
 static void
 meta_monitor_manager_dummy_class_init (MetaMonitorManagerDummyClass *klass)
 {
@@ -611,6 +617,7 @@ meta_monitor_manager_dummy_class_init (MetaMonitorManagerDummyClass *klass)
   manager_class->is_transform_handled = meta_monitor_manager_dummy_is_transform_handled;
   manager_class->calculate_monitor_mode_scale = meta_monitor_manager_dummy_calculate_monitor_mode_scale;
   manager_class->get_supported_scales = meta_monitor_manager_dummy_get_supported_scales;
+  manager_class->get_capabilities = meta_monitor_manager_dummy_get_capabilities;
 }
 
 static void

src/backends/meta-monitor-manager-private.h

@@ -68,6 +68,12 @@ typedef struct _MetaCrtcInfo MetaCrtcInfo;
 typedef struct _MetaOutputInfo MetaOutputInfo;
 typedef struct _MetaTileInfo MetaTileInfo;
 
+typedef enum _MetaMonitorManagerCapability
+{
+  META_MONITOR_MANAGER_CAPABILITY_NONE = 0,
+  META_MONITOR_MANAGER_CAPABILITY_MIRRORING = (1 << 0)
+} MetaMonitorManagerCapability;
+
 typedef enum
 {
   META_MONITOR_TRANSFORM_NORMAL,
@@ -357,6 +363,8 @@ struct _MetaMonitorManagerClass
   void (*get_supported_scales) (MetaMonitorManager *,
                                 float             **,
                                 int                *);
+
+  MetaMonitorManagerCapability (*get_capabilities) (MetaMonitorManager *);
 };
 
 void                meta_monitor_manager_rebuild (MetaMonitorManager *manager,

src/backends/native/meta-monitor-manager-kms.c

@@ -1918,6 +1918,29 @@ meta_monitor_manager_kms_get_supported_scales (MetaMonitorManager *manager,
   *n_scales = G_N_ELEMENTS (supported_scales_kms);
 }
 
+static MetaMonitorManagerCapability
+meta_monitor_manager_kms_get_capabilities (MetaMonitorManager *manager)
+{
+  MetaBackend *backend = meta_get_backend ();
+  MetaRenderer *renderer = meta_backend_get_renderer (backend);
+  MetaRendererNative *renderer_native = META_RENDERER_NATIVE (renderer);
+  MetaMonitorManagerCapability capabilities =
+    META_MONITOR_MANAGER_CAPABILITY_NONE;
+
+  switch (meta_renderer_native_get_mode (renderer_native))
+    {
+    case META_RENDERER_NATIVE_MODE_GBM:
+      capabilities |= META_MONITOR_MANAGER_CAPABILITY_MIRRORING;
+      break;
+#ifdef HAVE_EGL_DEVICE
+    case META_RENDERER_NATIVE_MODE_EGL_DEVICE:
+      break;
+#endif
+    }
+
+  return capabilities;
+}
+
 static void
 meta_monitor_manager_kms_dispose (GObject *object)
 {
@@ -1960,4 +1983,5 @@ meta_monitor_manager_kms_class_init (MetaMonitorManagerKmsClass *klass)
   manager_class->is_transform_handled = meta_monitor_manager_kms_is_transform_handled;
   manager_class->calculate_monitor_mode_scale = meta_monitor_manager_kms_calculate_monitor_mode_scale;
   manager_class->get_supported_scales = meta_monitor_manager_kms_get_supported_scales;
+  manager_class->get_capabilities = meta_monitor_manager_kms_get_capabilities;
 }

src/backends/x11/meta-monitor-manager-xrandr.c

@@ -1596,6 +1596,12 @@ meta_monitor_manager_xrandr_get_supported_scales (MetaMonitorManager *manager,
   *n_scales = G_N_ELEMENTS (supported_scales_xrandr);
 }
 
+static MetaMonitorManagerCapability
+meta_monitor_manager_xrandr_get_capabilities (MetaMonitorManager *manager)
+{
+  return META_MONITOR_MANAGER_CAPABILITY_MIRRORING;
+}
+
 static void
 meta_monitor_manager_xrandr_init (MetaMonitorManagerXrandr *manager_xrandr)
 {
@@ -1674,6 +1680,7 @@ meta_monitor_manager_xrandr_class_init (MetaMonitorManagerXrandrClass *klass)
   manager_class->is_transform_handled = meta_monitor_manager_xrandr_is_transform_handled;
   manager_class->calculate_monitor_mode_scale = meta_monitor_manager_xrandr_calculate_monitor_mode_scale;
   manager_class->get_supported_scales = meta_monitor_manager_xrandr_get_supported_scales;
+  manager_class->get_capabilities = meta_monitor_manager_xrandr_get_capabilities;
 
   quark_meta_monitor_xrandr_data =
     g_quark_from_static_string ("-meta-monitor-xrandr-data");

src/tests/meta-monitor-manager-test.c

@@ -374,6 +374,12 @@ meta_monitor_manager_test_get_supported_scales (MetaMonitorManager *manager,
   *n_scales = G_N_ELEMENTS (supported_scales_test);
 }
 
+static MetaMonitorManagerCapability
+meta_monitor_manager_test_get_capabilities (MetaMonitorManager *manager)
+{
+  return META_MONITOR_MANAGER_CAPABILITY_MIRRORING;
+}
+
 static void
 meta_monitor_manager_test_dispose (GObject *object)
 {
@@ -408,4 +414,5 @@ meta_monitor_manager_test_class_init (MetaMonitorManagerTestClass *klass)
   manager_class->is_transform_handled = meta_monitor_manager_test_is_transform_handled;
   manager_class->calculate_monitor_mode_scale = meta_monitor_manager_test_calculate_monitor_mode_scale;
   manager_class->get_supported_scales = meta_monitor_manager_test_get_supported_scales;
+  manager_class->get_capabilities = meta_monitor_manager_test_get_capabilities;
 }