New settings definitions and validators.

Will be used by a new settings.py parser.  In progress

overviewer_core/settingsValidators.py

@@ -0,0 +1,61 @@
+# see settingsDefinition.py
+import os
+import os.path
+
+class ValidationException(Exception):
+    pass
+
+def validatePath(path):
+    if not os.path.exists(path):
+        raise ValidationException("%r does not exist" % path)
+    if not os.path.isdir(path):
+        raise ValidationException("%r is not a directory" % path)
+    return os.abspath(path)
+
+def validateRenderMode(mode):
+    # TODO get list of valid rendermodes
+    raise NotImplementedError("validateRenderMode")
+
+def validateNorthDirection(direction):
+    # normalize to integers
+    intdir = 0 #default
+    if type(direction) == int:
+        intdir = direction
+    else:
+        if direction == "upper-left": intdir = 0
+        if direction == "upper-right": intdir = 1
+        if direction == "lower-right": intdir = 2
+        if direction == "lower-left": intdir = 3
+    if intdir < o or intdir > 3:
+        raise ValidationException("%r is not a valid north direction" % direction)
+    return intdir
+
+def validateRenderRange(r):
+    raise NotImplementedError("render range")
+
+def validateStochastic(s):
+    val = float(s)
+    if val < 0 or val > 1:
+        raise ValidationException("%r is not a valid stochastic value.  Should be between 0.0 and 1.0" % s)
+    return val
+
+def validateImgFormat(fmt):
+    if fmt not in ("png", "jpg", "jpeg"):
+        raise ValidationException("%r is not a valid image format" % fmt)
+    if fmt == "jpeg": fmt = "jpg"
+    return fmt
+
+def validateImgQuality(qual):
+    intqual = int(qual)
+    if (intqual < 0 or intqual > 100):
+        raise ValidationException("%r is not a valid image quality" % intqual)
+    return intqual
+
+def validateBGColor(color):
+    raise NotImplementedError("bg color")
+
+def validateOptImg(opt):
+    return bool(opt)
+
+
+