first pass at python module for handling display updates

SoundslabDisplay.py

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+import time
+from PIL import Image, ImageFont, ImageDraw
+from ST7789 import ST7789
+from glob import glob
+import struct
+import smbus
+import sys
+
+class SoundslabDisplay:
+    def __init__(self):
+        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.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, 78)
+    
+    def updateOverlay(self, current_track_number, total_track_number, battery_level_percent, track_progress_percent):
+        # 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)
+        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
+        
+        # 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 
+        battery_display = '{:02.2f}'.format(battery_level_percent) + '%'
+        overlay.text((self.screen_size[0] - 70, 0), battery_display, font=font, fill=self.fg_color)
+        
+        # add progress meter
+        overlay.rectangle([(10, self.screen_size[1] - 15), (self.screen_size[0] - 10, self.screen_size[1] - 5)], fill=(0, 0, 0, 0), outline=self.fg_color, width=1)
+        overlay.rectangle([(10, self.screen_size[1] - 15), (int((self.screen_size[0] - 20) * (track_progress_percent / 100)) + 10, self.screen_size[1] - 5)], fill=self.fg_color, outline=self.fg_color, width=1)
+        
+        self.current_overlay = im_overlay.copy()
+    
+    def updateAlbumArt(self, cover_image_file):
+        im = Image.open(cover_image_file).convert("RGBA")
+        image = im.resize(self.screen_size)
+        self.current_background = image.copy()
+        
+    def updateDisplay(self):
+        tempoutput = Image.alpha_composite(self.current_background, self.current_overlay)
+        self.st7789.display(Image.alpha_composite(tempoutput, self.current_menu))