Add types for #56 Missing type annotations

.gitignore

@@ -45,3 +45,8 @@ _build
 .idea
 .vscode
 *~
+
+# virtualenv
+Pipfile
+Pipfile.lock
+Makefile

.pre-commit-config.yaml

@@ -25,6 +25,7 @@ repos:
         types: [python]
         args:
           - --disable=consider-using-f-string
+          - --min-similarity-lines=14
         exclude: "^(docs/|examples/|tests/|setup.py$)"
     -   id: pylint
         name: pylint (example code)

.pylintrc

@@ -252,8 +252,7 @@ ignore-docstrings=yes
 ignore-imports=yes
 
 # Minimum lines number of a similarity.
-min-similarity-lines=4
-
+min-similarity-lines=14
 
 [BASIC]
 

adafruit_imageload/__init__.py

@@ -1,4 +1,5 @@
 # SPDX-FileCopyrightText: 2018 Scott Shawcroft for Adafruit Industries
+# SPDX-FileCopyrightText: Matt Land
 #
 # SPDX-License-Identifier: MIT
 
@@ -8,22 +9,42 @@
 
 Load pixel values (indices or colors) into a bitmap and colors into a palette.
 
-* Author(s): Scott Shawcroft
+* Author(s): Scott Shawcroft, Matt Land
 
 """
 # pylint: disable=import-outside-toplevel
 
+try:
+    from typing import (
+        Tuple,
+        Iterator,
+        Optional,
+        List,
+        Iterable,
+        Union,
+    )
+    from io import BufferedReader
+    from displayio import Palette, Bitmap
+    from .displayio_types import PaletteConstructor, BitmapConstructor
+except ImportError:
+    pass
+
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ImageLoad.git"
 
 
-def load(file_or_filename, *, bitmap=None, palette=None):
+def load(
+    file_or_filename: Union[str, BufferedReader],
+    *,
+    bitmap: Optional[BitmapConstructor] = None,
+    palette: Optional[PaletteConstructor] = None
+) -> Tuple[Bitmap, Optional[Palette]]:
     """Load pixel values (indices or colors) into a bitmap and colors into a palette.
 
     bitmap is the desired type. It must take width, height and color_depth in the constructor. It
     must also have a _load_row method to load a row's worth of pixel data.
 
-    palette is the desired pallete type. The constructor should take the number of colors and
+    palette is the desired palette type. The constructor should take the number of colors and
     support assignment to indices via [].
     """
     if not bitmap or not palette:

adafruit_imageload/bmp/__init__.py

@@ -1,4 +1,5 @@
 # SPDX-FileCopyrightText: 2018 Scott Shawcroft for Adafruit Industries
+# SPDX-FileCopyrightText: Matt Land
 #
 # SPDX-License-Identifier: MIT
 
@@ -8,16 +9,29 @@
 
 Load pixel values (indices or colors) into a bitmap and colors into a palette from a BMP file.
 
-* Author(s): Scott Shawcroft
+* Author(s): Scott Shawcroft, Matt Land
 
 """
 # pylint: disable=import-outside-toplevel
 
+try:
+    from typing import Tuple, Optional, Set, List
+    from io import BufferedReader
+    from displayio import Palette, Bitmap
+    from ..displayio_types import PaletteConstructor, BitmapConstructor
+except ImportError:
+    pass
+
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ImageLoad.git"
 
 
-def load(file, *, bitmap=None, palette=None):
+def load(
+    file: BufferedReader,
+    *,
+    bitmap: BitmapConstructor = None,
+    palette: PaletteConstructor = None
+) -> Tuple[Bitmap, Optional[Palette]]:
     """Loads a bmp image from the open ``file``.
 
     Returns tuple of bitmap object and palette object.

adafruit_imageload/bmp/indexed.py

@@ -1,4 +1,5 @@
 # SPDX-FileCopyrightText: 2018 Scott Shawcroft for Adafruit Industries
+# SPDX-FileCopyrightText: Matt Land
 #
 # SPDX-License-Identifier: MIT
 
@@ -8,33 +9,43 @@
 
 Load pixel values (indices or colors) into a bitmap and colors into a palette from an indexed BMP.
 
-* Author(s): Scott Shawcroft
+* Author(s): Scott Shawcroft, Matt Land
 
 """
 
-__version__ = "0.0.0-auto.0"
-__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ImageLoad.git"
 
 import sys
 
+try:
+    from typing import Tuple, Optional
+    from io import BufferedReader
+    from displayio import Palette, Bitmap
+    from ..displayio_types import PaletteConstructor, BitmapConstructor
+except ImportError:
+    pass
+
 try:
     from bitmaptools import readinto as _bitmap_readinto
 except ImportError:
-    _bitmap_readinto = None  # pylint: disable=invalid-name
+    _bitmap_readinto = None  # pylint: disable=invalid-name  # type: Callable
+
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ImageLoad.git"
 
 
 def load(
-    file,
-    width,
-    height,
-    data_start,
-    colors,
-    color_depth,
-    compression,
+    file: BufferedReader,
+    width: int,
+    height: int,
+    data_start: int,
+    colors: int,
+    color_depth: int,
+    compression: int,
     *,
-    bitmap=None,
-    palette=None
-):
+    bitmap: BitmapConstructor = None,
+    palette: PaletteConstructor = None,
+) -> Tuple[Bitmap, Optional[Palette]]:
     """Loads indexed bitmap data into bitmap and palette objects.
 
     :param file file: The open bmp file
@@ -46,7 +57,7 @@ def load(
     :param int compression: 0 - none, 1 - 8bit RLE, 2 - 4bit RLE"""
     # pylint: disable=too-many-arguments,too-many-locals,too-many-branches
     if palette:
-        palette = palette(colors)
+        palette = palette(colors)  # type: Palette
 
         file.seek(data_start - colors * 4)
         for value in range(colors):
@@ -67,7 +78,7 @@ def load(
 
             # convert unsigned int to signed int when height is negative
             height = negative_height_check(height)
-        bitmap = bitmap(width, abs(height), colors)
+        bitmap = bitmap(width, abs(height), colors)  # type: Bitmap
         file.seek(data_start)
         line_size = width // (8 // color_depth)
         if width % (8 // color_depth) != 0:
@@ -122,7 +133,13 @@ def load(
     return bitmap, palette
 
 
-def decode_rle(bitmap, file, compression, y_range, width):
+def decode_rle(
+    bitmap: Bitmap,
+    file: BufferedReader,
+    compression: int,
+    y_range: Tuple[int, int, int],
+    width: int,
+) -> None:
     """Helper to decode RLE images"""
     # pylint: disable=too-many-locals,too-many-nested-blocks,too-many-branches
 

adafruit_imageload/bmp/negative_height_check.py

@@ -1,15 +1,18 @@
 # SPDX-FileCopyrightText: 2018 Scott Shawcroft for Adafruit Industries
+# SPDX-FileCopyrightText: Matt Land
 #
 # SPDX-License-Identifier: MIT
 
 """
 Check for negative height on the BMP.
 Seperated into it's own file to support builds
 without longint.
+
+* Author(s): Tim Cocks, Matt Land
 """
 
 
-def negative_height_check(height):
+def negative_height_check(height: int) -> int:
     """Check the height return modified if negative."""
     if height > 0x7FFFFFFF:
         return height - 4294967296

adafruit_imageload/displayio_types.py

@@ -0,0 +1,26 @@
+# SPDX-FileCopyrightText: Matt Land
+#
+# SPDX-License-Identifier: MIT
+"""
+`adafruit_imageload.displayio_types`
+====================================================
+
+This is a utility file for type aliases.
+https://mypy.readthedocs.io/en/stable/kinds_of_types.html#type-aliases
+Type aliases contain compound declarations (used many places in the project) with a single
+definition readable by humans.
+
+* Author(s): Matt Land
+
+"""
+try:
+    from typing import Callable
+    from displayio import Palette, Bitmap
+
+    PaletteConstructor = Callable[[int], Palette]
+    BitmapConstructor = Callable[[int, int, int], Bitmap]
+except ImportError:
+    pass
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ImageLoad.git"

adafruit_imageload/gif.py

@@ -1,4 +1,5 @@
 # SPDX-FileCopyrightText: 2019 Radomir Dopieralski for Adafruit Industries
+# SPDX-FileCopyrightText: Matt Land
 #
 # SPDX-License-Identifier: MIT
 
@@ -9,30 +10,45 @@
 Load pixel values (indices or colors) into a bitmap and colors into a palette
 from a GIF file.
 
-* Author(s): Radomir Dopieralski
+* Author(s): Radomir Dopieralski, Matt Land
 
 """
 
 import struct
 
+try:
+    from typing import Tuple, Iterator, Optional, List
+    from io import BufferedReader
+    from displayio import Palette, Bitmap
+    from .displayio_types import PaletteConstructor, BitmapConstructor
+except ImportError:
+    pass
 
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ImageLoad.git"
 
 
-def load(file, *, bitmap=None, palette=None):
+def load(
+    file: BufferedReader,
+    *,
+    bitmap: BitmapConstructor,
+    palette: PaletteConstructor = None
+) -> Tuple[Bitmap, Optional[Palette]]:
     """Loads a GIF image from the open ``file``.
 
     Returns tuple of bitmap object and palette object.
 
+    :param BufferedReader file: The *.gif file being loaded
     :param object bitmap: Type to store bitmap data. Must have API similar to `displayio.Bitmap`.
       Will be skipped if None
     :param object palette: Type to store the palette. Must have API similar to
       `displayio.Palette`. Will be skipped if None"""
     header = file.read(6)
     if header not in {b"GIF87a", b"GIF89a"}:
         raise ValueError("Not a GIF file")
-    width, height, flags, _, _ = struct.unpack("<HHBBB", file.read(7))
+    width, height, flags, _, _ = struct.unpack(  # pylint: disable=no-member
+        "<HHBBB", file.read(7)
+    )
     if (flags & 0x80) != 0:
         palette_size = 1 << ((flags & 0x07) + 1)
         palette_obj = palette(palette_size)
@@ -57,9 +73,11 @@ def load(file, *, bitmap=None, palette=None):
     return bitmap_obj, palette_obj
 
 
-def _read_frame(file, bitmap):
-    """Read a signle frame and apply it to the bitmap."""
-    ddx, ddy, width, _, flags = struct.unpack("<HHHHB", file.read(9))
+def _read_frame(file: BufferedReader, bitmap: Bitmap) -> None:
+    """Read a single frame and apply it to the bitmap."""
+    ddx, ddy, width, _, flags = struct.unpack(  # pylint: disable=no-member
+        "<HHHHB", file.read(9)
+    )
     if (flags & 0x40) != 0:
         raise NotImplementedError("Interlacing not supported")
     if (flags & 0x80) != 0:
@@ -78,7 +96,7 @@ def _read_frame(file, bitmap):
                 y += 1
 
 
-def _read_blockstream(file):
+def _read_blockstream(file: BufferedReader) -> Iterator[int]:
     """Read a block from a file."""
     while True:
         size = file.read(1)[0]
@@ -95,21 +113,21 @@ class EndOfData(Exception):
 class LZWDict:
     """A dictionary of LZW codes."""
 
-    def __init__(self, code_size):
+    def __init__(self, code_size: int) -> None:
         self.code_size = code_size
         self.clear_code = 1 << code_size
         self.end_code = self.clear_code + 1
-        self.codes = []
-        self.last = None
+        self.codes = []  # type: List[bytes]
+        self.last = b""
         self.clear()
 
-    def clear(self):
+    def clear(self) -> None:
         """Reset the dictionary to default codes."""
         self.last = b""
         self.code_len = self.code_size + 1
         self.codes[:] = []
 
-    def decode(self, code):
+    def decode(self, code: int) -> bytes:
         """Decode a code."""
         if code == self.clear_code:
             self.clear()
@@ -133,7 +151,7 @@ def decode(self, code):
         return value
 
 
-def lzw_decode(data, code_size):
+def lzw_decode(data: Iterator[int], code_size: int) -> Iterator[bytes]:
     """Decode LZW-compressed data."""
     dictionary = LZWDict(code_size)
     bit = 0