Added typing and missing CP7 functions

[hackapet/Adafruit_Blinka_Displayio.git] / displayio / _palette.py

diff --git a/displayio/_palette.py b/displayio/_palette.py
new file mode 100644 (file)
index 0000000..8579bcb
--- /dev/null
+++ b/displayio/_palette.py
@@ -0,0 +1,122 @@
+# SPDX-FileCopyrightText: 2020 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+"""
+`displayio.palette`
+================================================================================
+
+displayio for Blinka
+
+**Software and Dependencies:**
+
+* Adafruit Blinka:
+  https://github.com/adafruit/Adafruit_Blinka/releases
+
+* Author(s): Melissa LeBlanc-Williams
+
+"""
+
+from typing import Optional, Union, Tuple
+import _typing
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_Blinka_displayio.git"
+
+
+class Palette:
+    """Map a pixel palette_index to a full color. Colors are transformed to the display’s
+    format internally to save memory.
+    """
+
+    def __init__(self, color_count: int):
+        """Create a Palette object to store a set number of colors."""
+        self._needs_refresh = False
+
+        self._colors = []
+        for _ in range(color_count):
+            self._colors.append(self._make_color(0))
+            self._update_rgba(len(self._colors) - 1)
+
+    def _update_rgba(self, index):
+        color = self._colors[index]["rgb888"]
+        transparent = self._colors[index]["transparent"]
+        self._colors[index]["rgba"] = (
+            color >> 16,
+            (color >> 8) & 0xFF,
+            color & 0xFF,
+            0 if transparent else 0xFF,
+        )
+
+    def _make_color(self, value, transparent=False):
+        color = {
+            "transparent": transparent,
+            "rgb888": 0,
+            "rgba": (0, 0, 0, 255),
+        }
+        if isinstance(value, (tuple, list, bytes, bytearray)):
+            value = (value[0] & 0xFF) << 16 | (value[1] & 0xFF) << 8 | value[2] & 0xFF
+        elif isinstance(value, int):
+            if not 0 <= value <= 0xFFFFFF:
+                raise ValueError("Color must be between 0x000000 and 0xFFFFFF")
+        else:
+            raise TypeError("Color buffer must be a buffer, tuple, list, or int")
+        color["rgb888"] = value
+        self._needs_refresh = True
+
+        return color
+
+    def __len__(self) -> int:
+        """Returns the number of colors in a Palette"""
+        return len(self._colors)
+
+    def __setitem__(
+        self,
+        index: int,
+        value: Union[int, _typing.ReadableBuffer, Tuple[int, int, int]],
+    ) -> None:
+        """Sets the pixel color at the given index. The index should be
+        an integer in the range 0 to color_count-1.
+
+        The value argument represents a color, and can be from 0x000000 to 0xFFFFFF
+        (to represent an RGB value). Value can be an int, bytes (3 bytes (RGB) or
+        4 bytes (RGB + pad byte)), bytearray, or a tuple or list of 3 integers.
+        """
+        if self._colors[index]["rgb888"] != value:
+            self._colors[index] = self._make_color(value)
+            self._update_rgba(index)
+
+    def __getitem__(self, index: int) -> Optional[int]:
+        if not 0 <= index < len(self._colors):
+            raise ValueError("Palette index out of range")
+        return self._colors[index]["rgb888"]
+
+    def make_transparent(self, palette_index: int) -> None:
+        """Set the palette index to be a transparent color"""
+        self._colors[palette_index]["transparent"] = True
+        self._update_rgba(palette_index)
+
+    def make_opaque(self, palette_index: int) -> None:
+        """Set the palette index to be an opaque color"""
+        self._colors[palette_index]["transparent"] = False
+        self._update_rgba(palette_index)
+
+    def _get_palette(self):
+        """Generate a palette for use with PIL"""
+        palette = []
+        for color in self._colors:
+            palette += color["rgba"][0:3]
+        return palette
+
+    def _get_alpha_palette(self):
+        """Generate an alpha channel palette with white being
+        opaque and black being transparent"""
+        palette = []
+        for color in self._colors:
+            for _ in range(3):
+                palette += [0 if color["transparent"] else 255]
+        return palette
+
+    def is_transparent(self, palette_index: int) -> bool:
+        """Returns True if the palette index is transparent. Returns False if opaque."""
+        return self._colors[palette_index]["transparent"]