Support units in modal numinput

Summary:
This completly changes the way modal numinput is handled. Now, edited expression is a string, which then gets unit- and py-evaluated to get a float value.

We gain many power and flexibility, but lose a few "shortcuts" like '-' to negate, or '/' to inverse (if they are really needed, we still can add them with modifiers, like e.g. ctrl-/ or so).

Features:
- units (cm, ", deg, etc.).
- basic operations from python/BKE_unit (+, *, **, etc.), and math constants and functions (pi, sin, etc.).
- you can navigate in edited value (left/right key, ctrl to move by block) and insert/delete chars, e.g. to fix a typo without having to rewrite everything.
- you can go to next/previous value with (ctrl-)TAB key.
- As before, hitting backspace after having deleted all leading chars will first reset the edited value to init state, and on second press, the whole "modal numinput" editing will be cancelled, going back to usual transform with mouse.

Notes:
- Did not touch to how values are shown in header when modal numinput is not enabled (would do that in another commit), so this is still quite inconsistent.
- Added back radian support in BKE_unit.
- Added arcminute/arcsecond to BKE_unit.
(those unit changes affect all angle UI controls, btw, so you can now enter radians or longitude/latitude values when in degrees units).

Related to T37600.

Reviewers: brecht, campbellbarton, carter2422

Reviewed By: brecht, campbellbarton, carter2422
Thanks everybody!

Differential Revision: http://developer.blender.org/D61

1 files changed, 21 insertions, 22 deletions

diff --git a/source/blender/blenkernel/intern/unit.c b/source/blender/blenkernel/intern/unit.c
index 17aad7a5a2c..632ac6234b2 100644
--- a/source/blender/blenkernel/intern/unit.c
+++ b/source/blender/blenkernel/intern/unit.c
@@ -260,9 +260,12 @@ static struct bUnitCollection buNaturalTimeCollection = {buNaturalTimeDef, 3, 0,
 
 
 static struct bUnitDef buNaturalRotDef[] = {
-	{"degree", "degrees",			"°", NULL, "Degrees",		M_PI / 180.0, 0.0,	B_UNIT_DEF_NONE},
-//	{"radian", "radians",			"r", NULL, "Radians",		1.0, 0.0,			B_UNIT_DEF_NONE},
-//	{"turn", "turns",				"t", NULL, "Turns",			1.0/(M_PI*2.0), 0.0,B_UNIT_DEF_NONE},
+	{"degree",    "degrees",     "°",  "d",   "Degrees",     M_PI / 180.0,             0.0,  B_UNIT_DEF_NONE},
+	/* arcminutes/arcseconds are used in Astronomy/Navigation areas... */
+	{"arcminute", "arcminutes",  "'",  NULL,  "Arcminutes",  (M_PI / 180.0) / 60.0,    0.0,  B_UNIT_DEF_SUPPRESS},
+	{"arcsecond", "arcseconds",  "\"", NULL,  "Arcseconds",  (M_PI / 180.0) / 3600.0,  0.0,  B_UNIT_DEF_SUPPRESS},
+	{"radian",    "radians",     "r",  NULL,  "Radians",     1.0,                      0.0,  B_UNIT_DEF_NONE},
+//	{"turn",      "turns",       "t",  NULL,  "Turns",       1.0 / (M_PI * 2.0),       0.0,  B_UNIT_DEF_NONE},
 	{NULL, NULL, NULL, NULL, NULL, 0.0, 0.0}
 };
 static struct bUnitCollection buNaturalRotCollection = {buNaturalRotDef, 0, 0, sizeof(buNaturalRotDef) / sizeof(bUnitDef)};
@@ -340,12 +343,12 @@ static void unit_dual_convert(double value, bUnitCollection *usys, bUnitDef **un
 	*unit_b = unit_best_fit(*value_b, usys, *unit_a, 1);
 }
 
-static int unit_as_string(char *str, int len_max, double value, int prec, bUnitCollection *usys,
-                          /* non exposed options */
-                          bUnitDef *unit, char pad)
+static size_t unit_as_string(char *str, int len_max, double value, int prec, bUnitCollection *usys,
+                             /* non exposed options */
+                             bUnitDef *unit, char pad)
 {
 	double value_conv;
-	int len, i;
+	size_t len, i;
 
 	if (unit) {
 		/* use unit without finding the best one */
@@ -413,8 +416,10 @@ static int unit_as_string(char *str, int len_max, double value, int prec, bUnitC
 	return i;
 }
 
-/* Used for drawing number buttons, try keep fast */
-void bUnit_AsString(char *str, int len_max, double value, int prec, int system, int type, int split, int pad)
+/* Used for drawing number buttons, try keep fast.
+ * Return the length of the generated string.
+ */
+size_t bUnit_AsString(char *str, int len_max, double value, int prec, int system, int type, int split, int pad)
 {
 	bUnitCollection *usys = unit_get_system(system, type);
 
@@ -430,20 +435,21 @@ void bUnit_AsString(char *str, int len_max, double value, int prec, int system,
 
 		/* check the 2 is a smaller unit */
 		if (unit_b > unit_a) {
-			int i = unit_as_string(str, len_max, value_a, prec, usys, unit_a, '\0');
+			size_t i;
+			i = unit_as_string(str, len_max, value_a, prec, usys, unit_a, '\0');
 
 			/* is there enough space for at least 1 char of the next unit? */
 			if (i + 2 < len_max) {
 				str[i++] = ' ';
 
 				/* use low precision since this is a smaller unit */
-				unit_as_string(str + i, len_max - i, value_b, prec ? 1 : 0, usys, unit_b, '\0');
+				i += unit_as_string(str + i, len_max - i, value_b, prec ? 1 : 0, usys, unit_b, '\0');
 			}
-			return;
+			return i;
 		}
 	}
 
-	unit_as_string(str, len_max, value, prec, usys, NULL, pad ? ' ' : '\0');
+	return unit_as_string(str, len_max, value, prec, usys, NULL, pad ? ' ' : '\0');
 }
 
 BLI_INLINE int isalpha_or_utf8(const int ch)
@@ -606,15 +612,8 @@ int bUnit_ReplaceString(char *str, int len_max, const char *str_prev, double sca
 		return 0;
 	}
 
-	{ /* make lowercase */
-		int i;
-		char *ch = str;
-
-		for (i = 0; (i < len_max) && (*ch != '\0'); i++, ch++) {
-			if ((*ch >= 'A') && (*ch <= 'Z'))
-				*ch += ('a' - 'A');
-		}
-	}
+	/* make lowercase */
+	BLI_ascii_strtolower(str, len_max);
 
 	for (unit = usys->units; unit->name; unit++) {
 		/* in case there are multiple instances */