This is a script to present "slides" (text files) on a [Badger 2040](https://shop.pimoroni.com/products/badger-2040?variant=39752959852627)

1.txt

image
images/podia-logo.bin

2.txt

qr
https://twitter.com/ideasasylum
Twitter
@ideasasylum

3.txt

text
# Jamie Lawrence
CTO, Podia
jamie@podia.com

main.py

import time
import qrcode
import badger2040
import badger_os

# Global Constants
WIDTH = badger2040.WIDTH
HEIGHT = badger2040.HEIGHT

IMAGE_WIDTH = 104

HEADING_HEIGHT = 30
TEXT_HEIGHT = 20

#NAME_HEIGHT = HEIGHT - COMPANY_HEIGHT - (DETAILS_HEIGHT * 2) - 2
TEXT_WIDTH = WIDTH
QR_TITLE_WIDTH = WIDTH - 140

HEADING_SIZE = 0.7
TEXT_SIZE = 0.5

LEFT_PADDING = 5
NAME_PADDING = 20
DETAIL_SPACING = 10

# ------------------------------
#      Utility functions
# ------------------------------

# Reduce the size of a string until it fits within a given width
def truncatestring(text, text_size, width):
    while True:
        length = display.measure_text(text, text_size)
        if length > 0 and length > width:
            text = text[:-1]
        else:
            text += ""
            return text


# ------------------------------
#      Drawing functions
# ------------------------------
def blank_canvas():
    display.pen(0)
    display.clear()
    display.pen(15)
    display.rectangle(0, 0, WIDTH, HEIGHT)

def render_slide():
    # Open the badge file
    slide = open(str(slide_number())+".txt", "r")
        
    slide_template = slide.readline()[:-1] # "image" or "text" (removing \n)
    
    if slide_template == "image":
        render_image(slide)
    elif slide_template == "text":
        render_text(slide)
    elif slide_template == "qr":
        render_qr(slide)
    else:
        error_and_reset("No slide template for" + slide_template)

def error_and_reset(message):
    badger_os.warning(display, message)
    time.sleep(4)
    update_slide_number(1)
    render_slide()

def measure_qr_code(size, code):
    w, h = code.get_size()
    module_size = int(size / w)
    return module_size * w, module_size

def draw_qr_code(ox, oy, size, code):
    size, module_size = measure_qr_code(size, code)
    display.pen(15)
    display.rectangle(ox, oy, size, size)
    display.pen(0)
    for x in range(size):
        for y in range(size):
            if code.get_module(x, y):
                display.rectangle(ox + x * module_size, oy + y * module_size, module_size, module_size)

def render_qr(slide):
    url = slide.readline()
    code = qrcode.QRCode()
    
    blank_canvas()

    display.pen(0)
    code.set_text(url)
    size, _ = measure_qr_code(128, code)
    left = top = int((badger2040.HEIGHT / 2) - (size / 2))
    draw_qr_code(WIDTH-128, 0, 128, code)
    
    title = slide.readline()
    display.pen(0)
    display.rectangle(0, 0, QR_TITLE_WIDTH, HEADING_HEIGHT)
    display.pen(15)  # Change this to 0 if a white background is used
    display.font("sans")
    display.thickness(3)
    line = truncatestring(title, TEXT_SIZE, QR_TITLE_WIDTH)
    display.text(line, LEFT_PADDING, (HEADING_HEIGHT // 2) + 1, HEADING_SIZE)

    detail = slide.readline()
    display.pen(0)
    display.font("sans")
    display.thickness(2)
    line = truncatestring(detail, TEXT_SIZE, QR_TITLE_WIDTH)
    display.text(line, LEFT_PADDING, HEADING_HEIGHT + (HEADING_HEIGHT // 2) + 1, HEADING_SIZE)

def render_image(slide):
    image_filename = slide.readline()
    buffer = bytearray(int(WIDTH * HEIGHT / 8))
    open(image_filename, "rb").readinto(buffer)

    blank_canvas()
    display.image(buffer, WIDTH, HEIGHT, 0, 0)


def render_text(slide):
    blank_canvas()
    
    line_number = 0
    line = slide.readline()
    
    while len(line) > 1:
        line_number += 1
        
        if line[0:2] == "# ":
            mode = "heading"
            line = line[2:]
        elif line[0:2] == "- ":
            mode = "list"
            line = line[2:]
        else:
            mode = "text"
            
        LINE_Y = HEADING_HEIGHT * (line_number - 1)

        if mode == "heading":
            # Uncomment this if a white background is wanted behind the company
            display.pen(0)
            display.rectangle(0, LINE_Y, TEXT_WIDTH, HEADING_HEIGHT)
            display.pen(15)  # Change this to 0 if a white background is used
            display.font("sans")
            display.thickness(3)
        elif mode == "text":
            display.pen(15)
            display.rectangle(0, LINE_Y, TEXT_WIDTH, HEADING_HEIGHT)
            display.pen(0)  # Change this to 0 if a white background is used
            display.font("sans")
            display.thickness(2)
        
        line = truncatestring(line, TEXT_SIZE, WIDTH)
        display.text(line, LEFT_PADDING, LINE_Y + (HEADING_HEIGHT // 2) + 1, HEADING_SIZE)
        line = slide.readline() 

# ------------------------------
#        Program setup
# ------------------------------

# Create a new Badger and set it to update NORMAL
display = badger2040.Badger2040()
display.led(128)
display.update_speed(badger2040.UPDATE_MEDIUM)

state = {"slide_number": 1}
badger_os.state_load("jamie", state)

def update_slide_number(num):
    state["slide_number"] = num
    badger_os.state_modify("jamie", state)

def slide_number():
    return state["slide_number"]

# ------------------------------
#       Main program
# ------------------------------

while True:
    if display.pressed(badger2040.BUTTON_A):
        # Reset to the start
        update_slide_number(1)
    if display.pressed(badger2040.BUTTON_B):
        update_slide_number(1)
    if display.pressed(badger2040.BUTTON_C):
        update_slide_number(1)
    if display.pressed(badger2040.BUTTON_UP):
        # Scroll up
        update_slide_number(slide_number()-1)
    if display.pressed(badger2040.BUTTON_DOWN):
        # Scroll down
        update_slide_number(slide_number()+1)
    
    try:    
        render_slide()
        display.update()
    except OSError:
        message = "No file found for slide number "+str(slide_number)
        badger_os.warning(display, message)
        time.sleep(4)
        update_slide_number(1)
        render_slide()
        display.update()

    # If on battery, halt the Badger to save power, it will wake up if any of the front buttons are pressed
    display.halt()