Added support for endless labels

For issue #2

Author: sam159

.github/workflows/docker-image.yml

@@ -2,7 +2,7 @@ name: Dockerhub Publish
 
 on:
   push:
-    branches: [ "main" ]
+    branches: [ "main", "develop" ]
     tags: [ "v*" ]
   pull_request:
     branches: [ "main" ]

CHANGELOG.md

@@ -1,3 +1,7 @@
+# next
+
+- Added support for printing endless labels
+
 # 0.3.0
 
 - Added support for using QR codes instead of Datamatrix

README.md

@@ -38,6 +38,7 @@ The label size and printer are configured via environmental variables. You can a
 | NAME_MAX_LINES     | 4                     | The maximum number of lines to use for the name                                               |
 | DUE_DATE_FONT      | NotoSerif-Regular.ttf | The file name of the font in the fonts directory                                              |
 | DUE_DATE_FONT_SIZE | 30                    | The size of that font                                                                         |
+| ENDLESS_MARGIN     | 10                    | The top & bottom margin to add when using endless labels                                      |
 
 Included fonts are `NotoSans-Regular.ttf` and `NotoSerif-Regular.ttf`
 
@@ -75,7 +76,7 @@ Its advisable to run and install in a [venv](https://docs.python.org/3/library/v
     python -m venv .venv
     source ./.venv/bin/activate
     # Install packages
-    python -m pip install -U -r requirements
+    python -m pip install -U -r requirements.txt
 
     # exit with ./.venv/bin/deactivate
 ```
@@ -84,7 +85,6 @@ For development you can use `flask run --debug` to run the service on port 5000.
 
 ## TODO
 
-- Endless Labels
 - Some more formatting options
 
 ### Docker
@@ -101,4 +101,4 @@ An example `docker-compose.yml` file can be found [here](docker-compose.yml).
 
 I'll try to keep on top of bugs but feature requests may go unfulfilled. Please use the issue tracking in Github.
 
-PRs welcome!
+PRs are welcome!

app/__init__.py

@@ -19,6 +19,7 @@
 NAME_MAX_LINES = int(getenv("NAME_MAX_LINES", "4"))
 DUE_DATE_FONT =  getenv("NAME_FONT", "NotoSerif-Regular.ttf")
 DUE_DATE_FONT_SIZE = int(getenv("DUE_DATE_FONT_SIZE", "30"))
+ENDLESS_MARGIN = int(getenv("ENDLESS_MARGIN", "10"))
 
 selected_backend = guess_backend(PRINTER_PATH)
 BACKEND_CLASS = backend_factory(selected_backend)['backend_class']
@@ -33,7 +34,7 @@
 
 @app.route("/")
 def home_route():
-    return "Label %s, Size %ix%i"%(label_spec.identifier, label_spec.dots_printable[0], label_spec.dots_printable[1])
+    return "Label %s, %s"%(label_spec.identifier, label_spec.name)
 
 def get_params():
     source = request.form if request.method == "POST" else request.args
@@ -57,7 +58,7 @@ def get_params():
 def print_route():
     (name, barcode, dueDate) = get_params();
 
-    label = createLabelImage(label_spec.dots_printable, name, nameFont, NAME_MAX_LINES, createBarcode(barcode, BARCODE_FORMAT), dueDate, ddFont)
+    label = createLabelImage(label_spec.dots_printable, ENDLESS_MARGIN, name, nameFont, NAME_FONT_SIZE, NAME_MAX_LINES, createBarcode(barcode, BARCODE_FORMAT), dueDate, ddFont)
 
     buf = BytesIO()
     label.save(buf, format="PNG")
@@ -70,7 +71,7 @@ def print_route():
 def test():
     (name, barcode, dueDate) = get_params();
 
-    img = createLabelImage(label_spec.dots_printable, name, nameFont, NAME_MAX_LINES, createBarcode(barcode, BARCODE_FORMAT), dueDate, ddFont)
+    img = createLabelImage(label_spec.dots_printable, ENDLESS_MARGIN, name, nameFont, NAME_FONT_SIZE, NAME_MAX_LINES, createBarcode(barcode, BARCODE_FORMAT), dueDate, ddFont)
     buf = BytesIO()
     img.save(buf, format="PNG")
     buf.seek(0)
@@ -89,4 +90,3 @@ def sendToPrinter(image : Image):
     be = BACKEND_CLASS(PRINTER_PATH)
     be.write(bql.data)
     del be
-

app/imaging.py

@@ -19,36 +19,62 @@ def createBarcode(text: str, type: str):
         case _:
             return createDatamatrix(text)
 
-def createLabelImage(labelSize : tuple, text : str, textFont : ImageFont, textMaxLines : int, barcode : Image, dueDate : str, dueDateFont : ImageFont):
+def createLabelImage(labelSize : tuple, endlessMargin : int, text : str, textFont : ImageFont, textFontSize : int, textMaxLines : int, barcode : Image, dueDate : str, dueDateFont : ImageFont):
+    (width, height) = labelSize
+    # default line spacing used by multiline_text, doesn't seem to have an effect if changed though but we need to take into account
+    lineSpacing = 4
+    # margin to use for label
+    marginTop = 0
+    marginBottom = 0
+
+    # for endless labels with a height of zero
+    if height == 0:
+        # height should be text size + spacing x max lines + margin x 2
+        height = (textFontSize + lineSpacing) * textMaxLines + endlessMargin * 2
+        # negate the empty space above the text
+        (_, tTop, _, _) = textFont.getbbox("testing")
+        marginTop = endlessMargin - tTop
+        # regular bottom margin
+        marginBottom = endlessMargin
+        # make space for the due date
+        if dueDate:
+            (_, _, _, ddBottom) = dueDateFont.getbbox(dueDate)
+            height += ddBottom
+
     # increase the size of the barcode if space permits
-    if (barcode.size[1] * 4) < labelSize[1]:
+    if (barcode.size[1] * 8) < height:
+        barcode = barcode.resize((barcode.size[0] * 8, barcode.size[1] * 8), Image.Resampling.NEAREST)
+    if (barcode.size[1] * 6) < height:
+        barcode = barcode.resize((barcode.size[0] * 6, barcode.size[1] * 6), Image.Resampling.NEAREST)
+    if (barcode.size[1] * 4) < height:
         barcode = barcode.resize((barcode.size[0] * 4, barcode.size[1] * 4), Image.Resampling.NEAREST)
-    if (barcode.size[1] * 2) < labelSize[1]:
+    if (barcode.size[1] * 2) < height:
         barcode = barcode.resize((barcode.size[0] * 2, barcode.size[1] * 2), Image.Resampling.NEAREST)
 
-    label = Image.new("RGB", labelSize, ImageColor.getrgb("#FFF"))
-    # vertically align barcode
+    label = Image.new("RGB", (width, height), ImageColor.getrgb("#FFF"))
+    # vertically align barcode (ignoring margin)
     barcode_padding = [0, (int)((label.size[1] / 2) - (barcode.size[1] / 2))]
     label.paste(barcode, barcode_padding)
 
     draw = ImageDraw.Draw(label)
 
-    (nameText, nameTextWidth) = wrapText(text, textFont, label.size[0] - barcode.size[0], textMaxLines)
-    nameMaxWidth = label.size[0] - barcode.size[0]
+    (nameText, nameTextWidth) = wrapText(text, textFont, width - barcode.size[0], textMaxLines)
+    nameMaxWidth = width - barcode.size[0]
     nameLeftMargin = (nameMaxWidth - nameTextWidth) / 2
 
     draw.multiline_text(
-        [barcode.size[0] + nameLeftMargin, 0],
+        [barcode.size[0] + nameLeftMargin, marginTop],
         nameText,
         fill = ImageColor.getrgb("#000"),
         font = textFont,
-        align = "center"
+        align = "center",
+        spacing = lineSpacing
     )
 
     if dueDate:
         (_, _, ddRight, ddBottom) = dueDateFont.getbbox(dueDate)
         draw.text(
-            [label.size[0] - ddRight, label.size[1] - ddBottom],
+            [label.size[0] - ddRight, label.size[1] - ddBottom - marginBottom],
             dueDate,
             fill = ImageColor.getrgb("#000"),
             font = dueDateFont
@@ -100,5 +126,8 @@ def wrapText(text : str, font : ImageFont, maxWidth : int, maxLines : int):
     if len(lines) > maxLines:
         lines = lines[0:maxLines]
         lines[-1] += '...'
+        lineLength = font.getlength(lines[-1])
+        if lineLength > longestLine:
+            longestLine = lineLength
 
-    return ('\n'.join(lines), longestLine)
+    return ('\n'.join(lines), longestLine)