[cairo] [PATCH 20/43] drm: add helper for typecasting from abstract device to drm device type

[Enrico Weigelt, metux IT consult]

Signed-off-by: Enrico Weigelt, metux IT consult <enrico.weigelt at gr13.net>
---
 src/drm/cairo-drm-private.h |  9 +++++++++
 src/drm/cairo-drm.c         | 12 ++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/drm/cairo-drm-private.h b/src/drm/cairo-drm-private.h
index 5e8d639..e6d9196 100644
--- a/src/drm/cairo-drm-private.h
+++ b/src/drm/cairo-drm-private.h
@@ -128,6 +128,15 @@ struct _cairo_drm_device {
     cairo_drm_device_t *next, *prev;
 };
 
+static inline cairo_drm_device_t*
+cairo_abstract_device_cast_drm(cairo_device_t* dev)
+{
+    return cairo_container_of(
+	dev,
+	cairo_drm_device_t,
+	base);
+}
+
 typedef struct _cairo_drm_surface {
     cairo_surface_t base;
 
diff --git a/src/drm/cairo-drm.c b/src/drm/cairo-drm.c
index 661e181..47741a3 100644
--- a/src/drm/cairo-drm.c
+++ b/src/drm/cairo-drm.c
@@ -63,7 +63,7 @@ get_udev_property(struct udev_device *device, const char *name)
 static void
 _device_flush (void *abstract_device)
 {
-    cairo_drm_device_t *device = abstract_device;
+    cairo_drm_device_t *device = cairo_abstract_device_cast_drm(abstract_device);
 
     device->device.flush (device);
 }
@@ -71,7 +71,7 @@ _device_flush (void *abstract_device)
 static void
 _device_finish (void *abstract_device)
 {
-    cairo_drm_device_t *device = abstract_device;
+    cairo_drm_device_t *device = cairo_abstract_device_cast_drm(abstract_device);
 
     CAIRO_MUTEX_LOCK (_cairo_drm_device_mutex);
     if (device->prev != NULL)
@@ -93,7 +93,7 @@ _device_finish (void *abstract_device)
 static void
 _device_destroy (void *abstract_device)
 {
-    cairo_drm_device_t *device = abstract_device;
+    cairo_drm_device_t *device = cairo_abstract_device_cast_drm(abstract_device);
 
     device->device.destroy (device);
 }
@@ -344,7 +344,7 @@ _cairo_drm_device_reset_static_data (void)
 int
 cairo_drm_device_get_fd (cairo_device_t *abstract_device)
 {
-    cairo_drm_device_t *device = (cairo_drm_device_t *) abstract_device;
+    cairo_drm_device_t *device = cairo_abstract_device_cast_drm(abstract_device);
 
     if (device->base.status)
 	return -1;
@@ -362,7 +362,7 @@ _cairo_drm_device_fini (cairo_drm_device_t *device)
 void
 cairo_drm_device_throttle (cairo_device_t *abstract_device)
 {
-    cairo_drm_device_t *device = (cairo_drm_device_t *) abstract_device;
+    cairo_drm_device_t *device = cairo_abstract_device_cast_drm(abstract_device);
     cairo_status_t status;
 
     if (unlikely (device->base.status))
@@ -380,7 +380,7 @@ cairo_bool_t
 _cairo_drm_size_is_valid (cairo_device_t *abstract_device,
 			  int width, int height)
 {
-    cairo_drm_device_t *device = (cairo_drm_device_t *) abstract_device;
+    cairo_drm_device_t *device = cairo_abstract_device_cast_drm(abstract_device);
 
     if (unlikely (device->base.status))
 	return FALSE;
-- 
2.6.4.442.g545299f