soundslab/SoundslabDisplay.py

import time
from PIL import Image, ImageFont, ImageDraw
from ST7789 import ST7789
from glob import glob
import struct
import smbus
import sys
import musicpd
from math import floor

class SoundslabDisplay:
    def __init__(self, player_client):
        self.screen_size = 240, 240
        self.spi_speed_mhz = 80
        self.st7789 = ST7789(
                rotation=90,
                port=0,
                cs=1,
                dc=9,
                backlight=13,
                spi_speed_hz=self.spi_speed_mhz * 1000 * 1000
        )
        self.displayOn = True
        self.current_background = Image.new("RGBA", self.screen_size, (0, 0, 255, 255))
        self.current_overlay    = Image.new("RGBA", self.screen_size, (0, 0, 0, 0))
        self.current_menu       = Image.new("RGBA", self.screen_size, (0, 0, 0, 0))
        self.fg_color = (255, 255, 255, 211)
        self.bg_color = (0, 0, 0, 127)
        
        # the connection to mpd passed in
        self.player_client = player_client

        # track battery voltage over time so we can figure out if we're charging the battery or not
        self.previous_voltage = 0.0
        # track currently playing song's art path to eliminate unnecessary reloads of the same image file
        self.current_art_path = None

    def _displayOff(self):
        self.st7789.set_backlight(0) # turn off the backlight
        self.st7789.command(0x28)    # turn off the display itself
        self.displayOn = False

    def _displayOn(self):
        self.st7789.command(0x29)    # turn on the display itself
        self.st7789.set_backlight(1) # turn on the backlight
        self.displayOn = True

    def toggleDisplayOnOff(self):
        if self.displayOn:
            self._displayOff()
        else:
            self._displayOn()

    def getBatteryState(self):
        bus = smbus.SMBus(1)

        address = 0x36

        read = bus.read_word_data(address, 2)
        swapped = struct.unpack("<H", struct.pack(">H", read))[0]
        voltage = swapped * 78.125 / 1000000

        read = bus.read_word_data(address, 4)
        swapped = struct.unpack("<H", struct.pack(">H", read))[0]
        capacity = swapped / 256

        self.previous_voltage = voltage

        return (voltage, capacity)

    
    def updateOverlay(self):
        # initialize overlay
        im_overlay = Image.new("RGBA", self.screen_size, (0, 0, 0, 0))
        font = ImageFont.truetype(font='/usr/share/fonts/truetype/hack/Hack-Bold.ttf', size=18)
        small_font = ImageFont.truetype(font='/usr/share/fonts/truetype/hack/Hack-Regular.ttf', size=14)
        overlay = ImageDraw.Draw(im_overlay)

        # draw four rects on edges of screen_size
        overlay.rectangle([(0, 0), (self.screen_size[0], 20)], self.bg_color) # top bar
        overlay.rectangle([(0, self.screen_size[1] - 20), (self.screen_size[0], self.screen_size[1])], self.bg_color) # bottom bar
        overlay.rectangle([(0, 20), (20, self.screen_size[1] - 20)], self.bg_color) # left bar
        overlay.rectangle([(self.screen_size[0] - 20, 20), (self.screen_size[0], self.screen_size[1] - 20)], self.bg_color) # right bar
        
        # get status from mpd
        current_status = self.player_client.status()
        current_track_number   = int(current_status['song']) + 1
        total_track_number     = current_status['playlistlength']
        track_progress_percent = float(current_status['elapsed']) / float(current_status['duration'])
        print("track progress:" + str(track_progress_percent))
        # add track # / total # 
        track_and_queue = str(current_track_number) + " of " + str(total_track_number)
        overlay.text((10, 0), track_and_queue, font=font, fill=self.fg_color)
        
        # add battery level 
        previous_voltage = self.previous_voltage
        (voltage, capacity) = self.getBatteryState()
        battery_display = '{:02.2f}'.format(capacity) + '%'
        battery_display_offset = 80
        print("Battery: voltage: " + str(voltage) + " prev voltage: " + str(previous_voltage) + " capacity: " + str(capacity))
        # below method doesn't work - very inaccurate!
        # should probably track over a longer period of time, which will mean
        # it's harder to come up with a valid "charging or not" decision
        # if voltage > previous_voltage:
        #     # we're probably charging!
        #     battery_display = 'Chrg ' + battery_display
        #     battery_display_offset = 130
        overlay.text((self.screen_size[0] - battery_display_offset, 0), battery_display, font=font, fill=self.fg_color)
        
        # add progress meter
        overlay.rectangle([(70, self.screen_size[1] - 15), (self.screen_size[0] - 70, self.screen_size[1] - 5)], fill=(0, 0, 0, 0), outline=self.fg_color, width=1)
        overlay.rectangle([(70, self.screen_size[1] - 15), (int((self.screen_size[0] - 140) * track_progress_percent) + 70, self.screen_size[1] - 5)], fill=self.fg_color, outline=self.fg_color, width=1)

        # add playhead position and song duration displays at beginning and end of progress meter
        (time_width, time_height) = overlay.textsize(text='00:00', font=small_font)
        playhead = str(floor(float(current_status['elapsed']) / 60)) + ":" + "{:02d}".format(floor(float(current_status['elapsed']) % 60))
        duration = str(floor(float(current_status['duration']) / 60)) + ":" + "{:02d}".format(floor(float(current_status['duration']) % 60))
        overlay.text((5, self.screen_size[1] - 20 + floor(time_height / 2)), playhead, font=small_font, fill=self.fg_color)
        overlay.text((self.screen_size[0] - 5 - time_width, self.screen_size[1] - 20 + floor(time_height / 2)), duration, font=small_font, fill=self.fg_color)
        
        self.current_overlay = im_overlay.copy()
    
    def updateAlbumArt(self):
        current_status = self.player_client.status()
        song_data = self.player_client.playlistid(current_status['songid'])
        path_info = song_data[0]['file'].split('/')
        cover_image_file = '/media/usb0/' + path_info[0] + '/' + path_info[1] + '/cover.jpg'
        if cover_image_file != self.current_art_path:
            self.current_art_path = cover_image_file
            im = Image.open(cover_image_file).convert("RGBA")
            image = im.resize((200, 200))
            # get dominant color from album art
            #test_image = im.convert("RGB")
            #test_image.resize((1, 1), resample=0)
            #dominant_color = test_image.getpixel((0, 0))
            # get top left pixel color instead and use that!
            dominant_color = image.getpixel((0, 0))
            backing = Image.new("RGBA", self.screen_size, dominant_color)
            backing.paste(image, (20, 20))
            self.current_background = backing.copy()
        
    def updateDisplay(self):
        tempoutput = Image.alpha_composite(self.current_background, self.current_overlay)
        self.st7789.display(Image.alpha_composite(tempoutput, self.current_menu))