Improve error checking to Matrix parameters (#131)

Author: mutesplash

buildhat/devices.py

@@ -74,13 +74,10 @@ def _setup(device="/dev/serial0"):
 
     def __del__(self):
         if hasattr(self, "port") and Device._used[self.port]:
-            if Device._device_names[self._typeid][0] == "Matrix":
-                self.clear()  # noqa: PLE1101
             Device._used[self.port] = False
             self._conn.callit = None
             self.deselect()
-            if Device._device_names[self._typeid][0] != "Matrix":
-                self.off()
+            self.off()
 
     @staticmethod
     def name_for_id(typeid):

buildhat/matrix.py

@@ -14,20 +14,22 @@ def __init__(self, port):
         self.mode(2)
         self._matrix = [[(0, 0) for x in range(3)] for y in range(3)]
 
-    def set_pixels(self, matrix):
+    def set_pixels(self, matrix, display=True):
         """Write pixel data to LED matrix
 
         :param pixels: 3x3 list of tuples, with colour (0–10) and brightness (0–10) (see example for more detail)
+        :param display: Whether to update matrix or not
         """
+        if len(matrix) != 3:
+            raise MatrixError("Incorrect matrix height")
         for x in range(3):
+            if len(matrix[x]) != 3:
+                raise MatrixError("Incorrect matrix width")
             for y in range(3):
-                color, brightness = matrix[x][y]
-                if not (brightness >= 0 and brightness <= 10):
-                    raise MatrixError("Invalid brightness specified")
-                if not (color >= 0 and color <= 10):
-                    raise MatrixError("Invalid pixel specified")
+                matrix[x][y] = Matrix.normalize_pixel(matrix[x][y])  # pylint: disable=too-many-function-args
         self._matrix = matrix
-        self._output()
+        if display:
+            self._output()
 
     def _output(self):
         out = [0xc2]
@@ -38,7 +40,14 @@ def _output(self):
         self._write1(out)
         self.deselect()
 
-    def strtocolor(self, colorstr):
+    @staticmethod
+    def strtocolor(colorstr):
+        """Return the BuldHAT's integer representation of a color string
+
+        :param colorstr: str of a valid color
+        :return: (0-10) representing the color
+        :rtype: int
+        """
         if colorstr == "pink":
             return 1
         elif colorstr == "lilac":
@@ -63,6 +72,43 @@ def strtocolor(self, colorstr):
             return 0
         raise MatrixError("Invalid color specified")
 
+    @staticmethod
+    def normalize_pixel(pixel):
+        """Validate a pixel tuple (color, brightness) and convert string colors to integers
+
+        :param pixel: tuple of colour (0–10) or string (ie:"red") and brightness (0–10)
+        :return: (color, brightness) integers
+        :rtype: tuple
+        """
+        if isinstance(pixel, tuple):
+            c, brightness = pixel  # pylint: disable=unpacking-non-sequence
+            if isinstance(c, str):
+                c = Matrix.strtocolor(c)  # pylint: disable=too-many-function-args
+            if not (isinstance(brightness, int) and isinstance(c, int)):
+                raise MatrixError("Invalid pixel specified")
+            if not (brightness >= 0 and brightness <= 10):
+                raise MatrixError("Invalid brightness value specified")
+            if not (c >= 0 and c <= 10):
+                raise MatrixError("Invalid pixel color specified")
+            return (c, brightness)
+        else:
+            raise MatrixError("Invalid pixel specified")
+
+    @staticmethod
+    def validate_coordinate(coord):
+        """"Validate an x,y coordinate for the 3x3 Matrix
+
+        :param coord: tuple of 0-2 for the X coordinate and 0-2 for the Y coordinate
+        """
+        # pylint: disable=unsubscriptable-object
+        if isinstance(coord, tuple):
+            if not (isinstance(coord[0], int) and isinstance(coord[1], int)):
+                raise MatrixError("Invalid coord specified")
+            elif coord[0] > 2 or coord[0] < 0 or coord[1] > 2 or coord[1] < 0:
+                raise MatrixError("Invalid coord specified")
+        else:
+            raise MatrixError("Invalid coord specified")
+
     def clear(self, pixel=None):
         """Clear matrix or set all as the same pixel
 
@@ -71,21 +117,15 @@ def clear(self, pixel=None):
         if pixel is None:
             self._matrix = [[(0, 0) for x in range(3)] for y in range(3)]
         else:
-            color = ()
-            if isinstance(pixel, tuple):
-                c, brightness = pixel
-                if isinstance(c, str):
-                    c = self.strtocolor(c)
-                if not (brightness >= 0 and brightness <= 10):
-                    raise MatrixError("Invalid brightness specified")
-                if not (c >= 0 and c <= 10):
-                    raise MatrixError("Invalid pixel specified")
-                color = (c, brightness)
-            else:
-                raise MatrixError("Invalid pixel specified")
+            color = Matrix.normalize_pixel(pixel)  # pylint: disable=too-many-function-args
             self._matrix = [[color for x in range(3)] for y in range(3)]
         self._output()
 
+    def off(self):
+        # Never send the "off" command to the port a Matrix is connected to
+        # Instead, just turn all the pixels off
+        self.clear()
+
     def level(self, level):
         """Use the matrix as a "level" meter from 0-9
         (The level meter is expressed in green which seems to be unchangeable)
@@ -143,22 +183,8 @@ def set_pixel(self, coord, pixel, display=True):
         :param pixel: tuple of colour (0–10) or string and brightness (0–10)
         :param display: Whether to update matrix or not
         """
-        if isinstance(pixel, tuple):
-            c, brightness = pixel
-            if isinstance(c, str):
-                c = self.strtocolor(c)
-            if not (brightness >= 0 and brightness <= 10):
-                raise MatrixError("Invalid brightness specified")
-            if not (c >= 0 and c <= 10):
-                raise MatrixError("Invalid pixel specified")
-            color = (c, brightness)
-        else:
-            raise MatrixError("Invalid pixel specified")
-        if isinstance(coord, tuple):
-            if not (isinstance(coord[0], int) and isinstance(coord[1], int)):
-                raise MatrixError("Invalid coord specified")
-        else:
-            raise MatrixError("Invalid coord specified")
+        color = Matrix.normalize_pixel(pixel)  # pylint: disable=too-many-function-args
+        Matrix.validate_coordinate(coord)   # pylint: disable=too-many-function-args
         x, y = coord
         self._matrix[x][y] = color
         if display: