Screen Base Class

This base class defines the required screen API. The API includes all the functions that the sensor needs to render on a display, including text and geometry operations.

class firmware.screen_base.ScreenBase

Bases: object

This class defines the screen API, which is uniform among all displays that can be passed to the sensor code. This defines methods for drawing text and shapes on a surface, whether real or emulated.

BLACK = 0

Black color definition that should be overridden in derived class implementations

BLUE = 0

Blue color definition that should be overridden in derived class implementations

GRAY = 0

Gray color definition that should be overridden in derived class implementations

GREEN = 0

Green color definition that should be overridden in derived class implementations

RED = 0

Red color definition that should be overridden in derived class implementations

WHITE = 0

White color definition that should be overridden in derived class implementations

YELLOW = 0

Yellow color definition that should be overridden in derived class implementations

circle(point: tuple, radius: int, color: int) → None

This function draws a hollow circle at the given point and radius, with the given color

Parameters:

  • point – Center point of the circle

  • radius – Radius of the circle

  • color – Color of the circle

Returns:

Nothing

draw_qr(y_offset: int, qr_bits: list, scale: int = 3) → None

This function can render a set of bits as black and white, such as a QR code.

Parameters:

  • y_offset – The top margin above the rendered bits

  • qr_bits – The bits to render, as a list of lists of ones and zeroes

  • scale – The render scale to make it show up easier on the screen

Returns:

Nothing

fill(color: int) → None

This function fills the draw surface with the provided color.

Parameters:

color – The color to fill

Returns:

Nothing

fillrect(point: tuple, size: tuple, color: int) → None

This function draws a filled rectangle at the given point and size, with the given color

Parameters:

  • point – Top left point of the rectangle

  • size – The size (width, height) of the rectangle box

  • color – The rectangle fill color

Returns:

Nothing

hline(point: tuple, length: int, color: int) → None

This function draws a horizontal line at the given point, with the given length and color

Parameters:

  • point – Left point of the horizontal line

  • length – Length of the line to draw

  • color – Line color

Returns:

Nothing

rect(point: tuple, size: tuple, color: int) → None

This function draws a hollow rectangle at the given point and size, with the given color

Parameters:

  • point – Top left point of the rectangle

  • size – The size (width, height) of the rectangle box

  • color – The rectangle outline color

Returns:

Nothing

text(point: tuple, text: str, color: int, size: int = 1, nowrap: bool = True) → None

This function renders text at the given point with the given color and size

Parameters:

  • point – Top left point of the text string

  • text – The text string to render

  • color – The text color

  • size – The size of the font

  • nowrap – A flag to determine whether to not wrap text

Returns:

Nothing

vline(point: tuple, length: int, color: int) → None

This function draws a vertical line at the given point, with the given length and color

Parameters:

  • point – Top point of the horizontal line

  • length – Length of the line to draw

  • color – Line color

Returns:

Nothing