Add some api for the display applet.

display: Add helper functions for translating between logical and
xinerama monitor numbers.

Monitor 0 is traditionally the primary monitor. Logical monitors
don't work this way - if you change the primary, its number stays
the same. Fortunately the underlying x number is still available.

This may eventually be complicated by monitors that allow multiple
logical inputs (tiling), but I have none to test with.

Author: mtwebster

src/backends/meta-monitor-manager.c

@@ -3564,3 +3564,150 @@ meta_monitor_manager_get_vendor_name (MetaMonitorManager *manager,
 
   return gnome_pnp_ids_get_pnp_id (manager->pnp_ids, vendor);
 }
+
+#define META_MONITOR_TRANSFORM_INVALID -1
+
+MetaMonitorTransform
+xrandr_to_monitor_transform (MetaXrandrRotation rotation)
+{
+    switch (rotation)
+      {
+      case META_XRANDR_ROTATION_NORMAL:
+        return META_MONITOR_TRANSFORM_NORMAL;
+      case META_XRANDR_ROTATION_LEFT:
+        return META_MONITOR_TRANSFORM_90;
+      case META_XRANDR_ROTATION_FLIPPED:
+        return META_MONITOR_TRANSFORM_180;
+      case META_XRANDR_ROTATION_RIGHT:
+        return META_MONITOR_TRANSFORM_270;
+
+      default:
+        g_return_val_if_reached (META_MONITOR_TRANSFORM_INVALID);
+      }
+}
+
+gboolean
+meta_monitor_manager_can_apply_rotation (MetaMonitorManager *manager,
+                                         MetaXrandrRotation  rotation)
+{
+  gboolean ret = FALSE;
+
+  if (!meta_monitor_manager_get_is_builtin_display_on (manager))
+    return FALSE;
+
+  MetaOrientation orientation = xrandr_to_monitor_transform (rotation);
+
+  if (orientation == META_MONITOR_TRANSFORM_INVALID)
+    {
+      meta_warning ("Invalid orientation requested.");
+      return ret;
+    }
+
+  MetaMonitorsConfig *config = meta_monitor_config_manager_create_for_orientation (manager->config_manager, orientation);
+
+  ret = config != NULL;
+
+  g_clear_object (&config);
+
+  if (ret)
+    return TRUE;
+
+  MetaXrandrRotation current_rotation;
+  meta_monitor_manager_get_current_rotation (manager, &current_rotation);
+
+  if (current_rotation == rotation)
+    return TRUE;
+
+  return FALSE;
+}
+
+gboolean
+meta_monitor_manager_apply_temporary_rotation (MetaMonitorManager *manager,
+                                               MetaXrandrRotation  rotation)
+{
+  MetaOrientation orientation = xrandr_to_monitor_transform (rotation);
+
+  if (orientation == META_MONITOR_TRANSFORM_INVALID)
+    {
+      meta_warning ("Invalid orientation requested.");
+      return FALSE;
+    }
+
+  GError *error = NULL;
+  MetaMonitorsConfig *config = meta_monitor_config_manager_create_for_orientation (manager->config_manager, orientation);
+
+  if (!config)
+    {
+      meta_warning ("Could not create config for rotation.");
+      return FALSE;
+    }
+
+  if (!meta_monitor_manager_apply_monitors_config (manager,
+                                                   config,
+                                                   META_MONITORS_CONFIG_METHOD_TEMPORARY,
+                                                   &error))
+    {
+      g_warning ("Failed to use rotate monitor configuration: %s",
+                 error->message);
+      g_error_free (error);
+      g_object_unref (config);
+      return FALSE;
+    }
+
+  g_object_unref (config);
+
+  return TRUE;
+}
+
+MetaXrandrRotation
+monitor_transform_to_xrandr_rotation (MetaMonitorTransform transform)
+{
+    switch (transform)
+      {
+      case META_MONITOR_TRANSFORM_NORMAL:
+        return META_XRANDR_ROTATION_NORMAL;
+      case META_MONITOR_TRANSFORM_90:
+        return META_XRANDR_ROTATION_LEFT;
+      case META_MONITOR_TRANSFORM_180:
+        return META_XRANDR_ROTATION_FLIPPED;
+      case META_MONITOR_TRANSFORM_270:
+        return META_XRANDR_ROTATION_RIGHT;
+      default:
+        g_return_val_if_reached (META_XRANDR_ROTATION_NORMAL);
+      }
+}
+
+/**
+ * meta_monitor_manager_get_current_rotation:
+ * @manager: A #MetaMonitorManager object
+ * @rotation: (out): The current #MetaXrandrRotation applied to the laptop panel.
+ * 
+ * Returns %TRUE if there is a laptop panel and its current rotation
+ * can be determined, otherwise %FALSE
+ */
+gboolean
+meta_monitor_manager_get_current_rotation (MetaMonitorManager *manager,
+                                           MetaXrandrRotation *rotation)
+{
+  MetaMonitor *monitor;
+  MetaLogicalMonitor *logical_monitor;
+
+  *rotation = META_XRANDR_ROTATION_NORMAL;
+  monitor = meta_monitor_manager_get_laptop_panel (manager);
+
+  if (monitor == NULL || !meta_monitor_is_active (monitor))
+    {
+      return FALSE;
+    }
+
+  logical_monitor = meta_monitor_get_logical_monitor (monitor);
+
+  if (logical_monitor != NULL)
+    {
+      MetaMonitorTransform transform = meta_logical_monitor_get_transform (logical_monitor);
+      *rotation = monitor_transform_to_xrandr_rotation (transform);
+      return TRUE;
+    }
+
+  return FALSE;
+}

src/core/display.c

@@ -3925,4 +3925,40 @@ gboolean
 meta_display_get_desklets_above (MetaDisplay *display)
 {
     return display->desklets_above;
+}
+
+gint
+meta_display_xinerama_index_to_logical_index (MetaDisplay *display,
+                                              gint         x_index)
+{
+    MetaLogicalMonitor *monitor;
+
+    monitor = meta_x11_display_xinerama_index_to_logical_monitor (display->x11_display, x_index);
+
+    if (monitor == NULL)
+      {
+        return 0;
+      }
+
+    return monitor->number;
+}
+
+gint
+meta_display_logical_index_to_xinerama_index (MetaDisplay *display,
+                                              gint         log_index)
+{
+    MetaBackend *backend = meta_get_backend ();
+    MetaMonitorManager *manager;
+    MetaLogicalMonitor *monitor;
+
+    manager = meta_backend_get_monitor_manager (backend);
+    monitor = meta_monitor_manager_get_logical_monitor_from_number (manager, log_index);
+
+    if (monitor == NULL)
+      {
+        return 0;
+      }
+
+    return meta_x11_display_logical_monitor_to_xinerama_index (display->x11_display, monitor);
+
 }

src/meta/display.h

@@ -289,6 +289,14 @@ META_EXPORT
 void meta_display_focus_default_window (MetaDisplay *display,
                                         guint32      timestamp);
 
+META_EXPORT
+gint meta_display_xinerama_index_to_logical_index (MetaDisplay *display,
+                                                   gint         x_index);
+
+META_EXPORT
+gint meta_display_logical_index_to_xinerama_index (MetaDisplay *display,
+                                                   gint         log_index);
+
 /**
  * MetaDisplayCorner:
  * @META_DISPLAY_TOPLEFT: top-left corner

src/meta/meta-monitor-manager.h

@@ -33,6 +33,14 @@ typedef enum
   META_MONITOR_SWITCH_CONFIG_UNKNOWN,
 } MetaMonitorSwitchConfigType;
 
+typedef enum
+{
+  META_XRANDR_ROTATION_NORMAL,
+  META_XRANDR_ROTATION_LEFT,
+  META_XRANDR_ROTATION_FLIPPED,
+  META_XRANDR_ROTATION_RIGHT
+} MetaXrandrRotation;
+
 typedef struct _MetaMonitorManagerClass    MetaMonitorManagerClass;
 typedef struct _MetaMonitorManager         MetaMonitorManager;
 
@@ -62,4 +70,12 @@ MetaMonitorSwitchConfigType meta_monitor_manager_get_switch_config (MetaMonitorM
 META_EXPORT
 gint meta_monitor_manager_get_display_configuration_timeout (void);
 
+META_EXPORT
+gboolean meta_monitor_manager_can_apply_rotation (MetaMonitorManager *manager, MetaXrandrRotation rotation);
+
+META_EXPORT
+gboolean meta_monitor_manager_apply_temporary_rotation (MetaMonitorManager *manager, MetaXrandrRotation rotation);
+
+META_EXPORT
+gboolean meta_monitor_manager_get_current_rotation (MetaMonitorManager *manager, MetaXrandrRotation *rotation);
 #endif /* META_MONITOR_MANAGER_H */