Drivers UI: Added name validation/linting for Driver Variables

When attempting to change a driver variable name to an "invalid" name,
an indicator will now be shown beside the offending variable name.
Clicking on this icon will show a popup which provides more information
about why the variable name cannot be used.

Reasons that it knows about are:
1) Starts with number
2) Has a dot
3) Has a space
4) Starts with or contains a special character
5) Starts with an underscore (Python does allow this, but it's bad practice,
   and makes checking security of drivers harder)
6) Is a reserved Python keyword

1 files changed, 39 insertions, 5 deletions

diff --git a/source/blender/makesdna/DNA_anim_types.h b/source/blender/makesdna/DNA_anim_types.h
index d80b50945df..fc32bbd1e99 100644
--- a/source/blender/makesdna/DNA_anim_types.h
+++ b/source/blender/makesdna/DNA_anim_types.h
@@ -327,13 +327,15 @@ typedef enum eDriverTarget_TransformChannels {
  */
 typedef struct DriverVar {
 	struct DriverVar *next, *prev;
-
+	
 	char name[64];              /* name of the variable to use in py-expression (must be valid python identifier) - MAX_ID_NAME-2 */
-
+	
 	DriverTarget targets[8];    /* MAX_DRIVER_TARGETS, target slots */
-	short num_targets;          /* number of targets actually used by this variable */
-
-	short type;                 /* type of driver target (eDriverTarget_Types) */
+	
+	char num_targets;           /* number of targets actually used by this variable */
+	char type;                  /* type of driver variable (eDriverVar_Types) */
+	
+	short flag;                 /* validation tags, etc. (eDriverVar_Flags) */
 	float curval;               /* result of previous evaluation */
 } DriverVar;
 
@@ -355,6 +357,38 @@ typedef enum eDriverVar_Types {
 	MAX_DVAR_TYPES
 } eDriverVar_Types;
 
+/* Driver Variable Flags */
+typedef enum eDriverVar_Flags {
+	/* variable is not set up correctly */
+	DVAR_FLAG_ERROR               = (1 << 0),
+	
+	/* variable name doesn't pass the validation tests */
+	DVAR_FLAG_INVALID_NAME        = (1 << 1),
+	/* name starts with a number */
+	DVAR_FLAG_INVALID_START_NUM   = (1 << 2),
+	/* name starts with a special character (!, $, @, #, _, etc.) */
+	DVAR_FLAG_INVALID_START_CHAR  = (1 << 3),
+	/* name contains a space */
+	DVAR_FLAG_INVALID_HAS_SPACE   = (1 << 4),
+	/* name contains a dot */
+	DVAR_FLAG_INVALID_HAS_DOT     = (1 << 5),
+	/* name contains invalid chars */
+	DVAR_FLAG_INVALID_HAS_SPECIAL = (1 << 6),
+	/* name is a reserved keyword */
+	DVAR_FLAG_INVALID_PY_KEYWORD  = (1 << 7),
+} eDriverVar_Flags;
+
+/* All invalid dvar name flags */
+#define DVAR_ALL_INVALID_FLAGS (   \
+	DVAR_FLAG_INVALID_NAME |       \
+	DVAR_FLAG_INVALID_START_NUM | \
+	DVAR_FLAG_INVALID_START_CHAR | \
+	DVAR_FLAG_INVALID_HAS_SPACE |  \
+	DVAR_FLAG_INVALID_HAS_DOT |    \
+	DVAR_FLAG_INVALID_HAS_SPECIAL |  \
+	DVAR_FLAG_INVALID_PY_KEYWORD  \
+)
+
 /* --- */
 
 /* Channel Driver (i.e. Drivers / Expressions) (driver)