Support Printing Text

.editorconfig

@@ -0,0 +1,132 @@
+# EditorConfig is awesome: http://EditorConfig.org
+
+# https://github.com/jokeyrhyme/standard-editorconfig
+
+# top-most EditorConfig file
+root = true
+
+# defaults
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+# Bazel: https://bazel.build/
+# https://github.com/bazelbuild/buildtools/blob/master/BUILD.bazel
+[*.{bazel,bzl}]
+indent_size = 4
+indent_style = space
+
+# CSS
+# https://google.github.io/styleguide/htmlcssguide.xml#General_Formatting_Rules
+# http://cssguidelin.es/#syntax-and-formatting
+[*.css]
+indent_size = 2
+indent_style = space
+trim_trailing_whitespace = true
+
+# GNU make
+# https://www.gnu.org/software/make/manual/html_node/Recipe-Syntax.html
+[Makefile]
+indent_style = tab
+
+# Go
+# https://golang.org/cmd/gofmt/
+[{go.mod,*.go}]
+indent_style = tab
+
+# GraphQL
+# https://graphql.org/learn/
+# https://prettier.io
+[*.graphql]
+indent_size = 2
+indent_style = space
+
+# HTML
+# https://google.github.io/styleguide/htmlcssguide.xml#General_Formatting_Rules
+[*.{htm,html}]
+indent_size = 2
+indent_style = space
+trim_trailing_whitespace = true
+
+# Java
+# https://google.github.io/styleguide/javaguide.html#s4.2-block-indentation
+[*.java]
+indent_size = 2
+indent_style = space
+
+# JavaScript, JSON, JSX, JavaScript Modules, TypeScript
+# https://github.com/feross/standard
+# https://prettier.io
+[*.{cjs,js,json,jsx,mjs,ts,tsx}]
+indent_size = 2
+indent_style = space
+
+# Kotlin
+# https://android.github.io/kotlin-guides/style.html#indentation
+[*.{kt,kts}]
+indent_size = 4
+indent_style = space
+
+# LESS
+# https://github.com/less/less-docs#less-standards
+[*.less]
+indent_size = 2
+indent_style = space
+
+# PHP
+# http://www.php-fig.org/psr/psr-2/
+[*.php]
+indent_size = 4
+indent_style = space
+
+# Python
+# https://www.python.org/dev/peps/pep-0008/#code-lay-out
+[*.py]
+indent_size = 4
+indent_style = space
+
+# Ruby
+# http://www.caliban.org/ruby/rubyguide.shtml#indentation
+[*.rb]
+indent_size = 2
+indent_style = space
+
+# Rust
+# https://github.com/rust-lang/rust/blob/master/src/doc/style/style/whitespace.md
+[*.rs]
+indent_size = 4
+indent_style = space
+insert_final_newline = false
+trim_trailing_whitespace = true
+
+# SASS
+# https://sass-guidelin.es/#syntax--formatting
+[*.{sass,scss}]
+indent_size = 2
+indent_style = space
+
+# Shell
+# https://google.github.io/styleguide/shell.xml#Indentation
+[*.{bash,sh,zsh}]
+indent_size = 2
+indent_style = space
+
+# Svelte
+# https://github.com/sveltejs/svelte/blob/master/.editorconfig
+[*.svelte]
+indent_size = 2
+indent_style = tab
+
+# TOML
+# https://github.com/toml-lang/toml/tree/master/examples
+[*.toml]
+indent_size = 2
+indent_style = space
+
+# YAML
+# http://yaml.org/spec/1.2/2009-07-21/spec.html#id2576668
+[*.{yaml,yml}]
+indent_size = 2
+indent_style = space

README.md

@@ -18,39 +18,32 @@ $ pip install -r requirements.txt
 
 # Usage
 ```bash
-$ ./print.py --help
-usage: print.py [-h] [-l {debug,info,warn,error}]
-                [-b {mean-threshold,floyd-steinberg,halftone,none}] [-s]
-                [-d DEVICE] [-t]
-                filename
+$ python print.py --help
+usage: print.py [-h] [--filename FILENAME] [--text TEXT] [--log-level {debug,info,warn,error}]
+                [--img-binarization-algo {mean-threshold,floyd-steinberg,halftone,none}] [--show-preview]
+                [--devicename DEVICENAME] [--darker]
 
 prints an image on your cat thermal printer
 
-positional arguments:
-  filename
-
-optional arguments:
+options:
   -h, --help            show this help message and exit
-  -l {debug,info,warn,error}, --log-level {debug,info,warn,error}
-  -b {mean-threshold,floyd-steinberg,halftone,none}, --img-binarization-algo {mean-threshold,floyd-steinberg,halftone,none}
-                        Which image binarization algorithm to use. If 'none'
-                        is used, no binarization will be used. In this case
-                        the image has to have a width of 384 px.
-  -s, --show-preview    If set, displays the final image and asks the user for
-                        confirmation before printing.
-  -d DEVICE, --device DEVICE
-                        The printer's Bluetooth Low Energy (BLE) address (MAC
-                        address on Linux; UUID on macOS) or advertisement name
-                        (e.g.: "GT01", "GB02", "GB03"). If omitted, the the
-                        script will try to auto discover the printer based on
-                        its advertised BLE services.
-  -t, --darker          Print the image in text mode. This leads to more
-                        contrast, but slower speed.
+  --filename FILENAME   Path to image file to print.
+  --text TEXT           Prints provided text messages. Either --filename or --text should be provided, but not both.
+  --log-level {debug,info,warn,error}
+  --img-binarization-algo {mean-threshold,floyd-steinberg,halftone,none}
+                        Which image binarization algorithm to use. If 'none' is used, no binarization will be used. In this
+                        case the image has to have a width of 384 px.
+  --show-preview        If set, displays the final image and asks the user for confirmation before printing.
+  --devicename DEVICENAME
+                        Specify the Bluetooth Low Energy (BLE) device name to search for. If not specified, the script will
+                        try to auto discover the printer based on its advertised BLE service UUIDs. Common names are similar
+                        to "GT01", "GB02", "GB03".
+  --darker              Print the image in text mode. This leads to more contrast, but slower speed.
 ```
 
 # Example
 ```bash
-% ./print.py --show-preview test.png
+% python print.py --show-preview --filename test.png
 ⏳ Applying Floyd-Steinberg dithering to image...
 ✅ Done.
 ℹ️ Displaying preview.

catprinter/cmds.py

@@ -1,6 +1,8 @@
 
 PRINT_WIDTH = 384
 
+# How much extra paper to feed in order to clear the catprinter's enclosure.
+POST_PRINT_FEED_LENGTH = 25
 
 def to_unsigned_byte(val):
     '''Converts a byte in signed representation to unsigned. Assumes val is encoded in two's
@@ -167,9 +169,11 @@ def cmd_print_row(img_row):
     return b_arr
 
 
-def cmds_print_img(img, dark_mode=False):
+def cmds_print_img(img: bytes, dark_mode: bool=False) -> bytearray:
+    """Given the `img` this wraps it in a payload the catprinter understands."""
 
-    PRINTER_MODE = CMD_PRINT_TEXT if dark_mode else CMD_PRINT_IMG
+    # Not sure what the intent was, but commenting out as its not used.
+    # PRINTER_MODE = CMD_PRINT_TEXT if dark_mode else CMD_PRINT_IMG
 
     data = \
         CMD_GET_DEV_STATE + \

catprinter/img.py

@@ -1,5 +1,7 @@
-import cv2
+import io
 from math import ceil
+
+import cv2
 import numpy as np
 
 from catprinter import logger
@@ -90,11 +92,15 @@ def square_avg_value(square):
 
 
 def read_img(
-    filename,
-    print_width,
-    img_binarization_algo,
-):
-    im = cv2.imread(filename, cv2.IMREAD_GRAYSCALE)
+        file: io.BytesIO,
+        print_width,
+        logger,
+        img_binarization_algo,
+    ):
+    """Takes `file` and rescales/converts image to be just right for the
+    catprinter. This returns `bytes`, ready to transmit to the printer."""
+    img_as_array = np.asarray(file, dtype="uint8")
+    im = cv2.imdecode(img_as_array, cv2.IMREAD_GRAYSCALE)
     height = im.shape[0]
     width = im.shape[1]
     factor = print_width / width

catprinter/txt.py

@@ -0,0 +1,25 @@
+import tempfile
+
+from PIL import Image, ImageDraw, ImageFont
+
+
+def text_to_image(text):
+    # Fix newline characters that argparse escaped
+    text = text.replace("\\n", "\n")
+    font_path = "fonts/Roboto-Regular.ttf"
+    font_size = 72
+    width_scalar = 0.25
+
+    font = ImageFont.truetype(font_path, font_size, encoding="utf-8")
+    w, h = font.getsize_multiline(text)
+    image = Image.new("L", (w, int(h+h*width_scalar)), 255)
+    draw = ImageDraw.Draw(image)
+    draw.text((0,0), text, fill="black", font=font)
+
+    bits = None
+    with tempfile.TemporaryFile() as fp:
+        image.save(fp, "PNG")
+        fp.seek(0)
+        bits = fp.read()
+
+    return bits

print.py

@@ -1,30 +1,27 @@
 #!/usr/bin/env python
 import argparse
 import asyncio
+import io
 import logging
-import sys
 import os
+import sys
 
-from catprinter import logger
-from catprinter.cmds import PRINT_WIDTH, cmds_print_img
-from catprinter.ble import run_ble
-from catprinter.img import read_img, show_preview
+from catprinter import ble, cmds, img, logger, txt
 
 
 def parse_args():
     args = argparse.ArgumentParser(
         description='prints an image on your cat thermal printer')
-    args.add_argument('filename', type=str)
+    args.add_argument('--filename', type=str, default="", help="Path to image file to print.")
+    args.add_argument('--text', type=str, help="Prints provided text messages. Linebreaks can be added with a newline character \\n Either --filename or --text should be provided, but not both.")
     args.add_argument('-l', '--log-level', type=str,
                       choices=['debug', 'info', 'warn', 'error'], default='info')
     args.add_argument('-b', '--img-binarization-algo', type=str,
                       choices=['mean-threshold',
                                'floyd-steinberg', 'halftone', 'none'],
                       default='floyd-steinberg',
-                      help=f'Which image binarization algorithm to use. If \'none\'  \
-                             is used, no binarization will be used. In this case the \
-                             image has to have a width of {PRINT_WIDTH} px.')
-    args.add_argument('-s', '--show-preview', action='store_true',
+                      help=f'Which image binarization algorithm to use. If \'none\' is used, no binarization will be used. In this case the image has to have a width of {cmds.PRINT_WIDTH} px.')
+    args.add_argument('--show-preview', action='store_true',
                       help='If set, displays the final image and asks the user for \
                           confirmation before printing.')
     args.add_argument('-d', '--device', type=str, default='',
@@ -55,28 +52,48 @@ def main():
     configure_logger(log_level)
 
     filename = args.filename
-    if not os.path.exists(filename):
+    text = args.text
+
+    if not filename and not text:
+        logger.info('🛑 Both a filename and text are missing. Please provide one of these parameters. Exiting')
+        return
+
+    if filename and text:
+        logger.info('🛑 Both a filename and text were provided, only one of these parameters is allowed at a time. Exiting')
+        return
+
+    if not text and not os.path.exists(filename):
         logger.info('🛑 File not found. Exiting.')
         return
 
     try:
-        bin_img = read_img(
-            args.filename,
-            PRINT_WIDTH,
-            args.img_binarization_algo,
-        )
+        bin_img = None
+        if filename:
+            with open(filename, "rb") as f:
+                img_arr = bytearray(f.read())
+                bin_img = img.read_img(img_arr, cmds.PRINT_WIDTH,
+                            logger, args.img_binarization_algo,)
+        elif text:
+            txt_arr = bytearray(txt.text_to_image(text))
+            bin_img = img.read_img(txt_arr, cmds.PRINT_WIDTH,
+                        logger, args.img_binarization_algo,)
+
+        if bin_img is None:
+            logger.info(f'🛑 No image generated. Exiting.')
+            return
+
         if args.show_preview:
-            show_preview(bin_img)
+            img.show_preview(bin_img)
     except RuntimeError as e:
         logger.error(f'🛑 {e}')
         return
 
     logger.info(f'✅ Read image: {bin_img.shape} (h, w) pixels')
-    data = cmds_print_img(bin_img, dark_mode=args.darker)
+    data = cmds.cmds_print_img(bin_img, dark_mode=args.darker)
     logger.info(f'✅ Generated BLE commands: {len(data)} bytes')
 
     # Try to autodiscover a printer if --device is not specified.
-    asyncio.run(run_ble(data, device=args.device))
+    asyncio.run(ble.run_ble(data, device=args.device))
 
 
 if __name__ == '__main__':

requirements.txt

@@ -1,3 +1,4 @@
 bleak~=0.14.2
 numpy<2.0
-opencv-python<5.0
+opencv-python<5.0
+Pillow==9.1.0