init commit with repo structure and basic files

labeler/infra/renderer.py

@@ -0,0 +1,125 @@
+import textwrap
+from string import ascii_letters
+
+from PIL import ImageFont, ImageDraw, Image as PILImage
+
+from labeler.domain.objects import Image, LabelDefinition
+from labeler.interfaces import Renderer
+
+
+class PILRenderer(Renderer):
+    def __init__(self):
+        self.font_path = "/Library/Fonts/Arial.ttf"
+
+    def render_label(self, label_definition: LabelDefinition) -> Image:
+        if label_definition.length is None:
+            pil_image = self.__render_no_fixed_lenth(label_definition)
+        else:
+            pil_image = self.__render_fixed_length(label_definition)
+
+        return Image.from_pil(pil_image)
+
+    def __render_fixed_length(self, label_definition: LabelDefinition):
+        width = label_definition.pixel_width
+        length = label_definition.pixel_length
+        font, text = self.__get_font(
+            label_definition.text,
+            width,
+            length,
+        )
+        im = PILImage.new("1", (length, width), 1)
+        draw = ImageDraw.Draw(im)
+        draw.text(
+            (length / 2, width / 2),
+            text,
+            font=font,
+            fill=0,
+            anchor="mm",
+            align="center",
+        )
+        return im
+
+    def __render_no_fixed_lenth(self, label_definition: LabelDefinition):
+        lines_to_print = label_definition.text.count("\n") + 1
+        text = "\n".join([line.strip() for line in label_definition.text.split("\n")])
+
+        text_height = label_definition.pixel_width // lines_to_print
+
+        while text_height > 0:
+            font = ImageFont.truetype(
+                "/Library/Fonts/Arial.ttf",
+                text_height,
+            )
+            if lines_to_print > 1:
+                occupied_height = font.getsize_multiline(text)[1]
+            else:
+                occupied_height = font.getsize(text)[1]
+            if occupied_height <= label_definition.pixel_width:
+                break
+            text_height -= 1
+
+        sizes = [font.getsize(line) for line in text.split("\n")]
+
+        length = max(length for length, height in sizes)
+
+        im = PILImage.new("1", (length, label_definition.pixel_width), 1)
+        draw = ImageDraw.Draw(im)
+        draw.text(
+            (length / 2, label_definition.pixel_width / 2),
+            text,
+            font=font,
+            fill=0,
+            anchor="mm",
+            align="center",
+        )
+        return im
+
+    def __get_font(self, text: str, max_width: int, max_length: int):
+        font_size = max_width
+        step = max_width // 2
+        last_good = None
+        last_corrected = None
+        while step > 1:
+            fits, corrected = self.__will_font_fit(
+                text, self.font_path, font_size, max_width, max_length
+            )
+            if fits:
+                last_good = font_size
+                last_corrected = corrected
+                font_size += step
+            else:
+                font_size -= step
+            step //= 2
+
+        return ImageFont.truetype(self.font_path, last_good), last_corrected
+
+    def __will_font_fit(
+        self, text: str, font_path: str, font_size: int, max_width: int, max_length: int
+    ):
+        font = ImageFont.truetype(font_path, font_size)
+        if "\n" in text:
+            text_width, text_height = font.getsize_multiline(text)
+        else:
+            text_width, text_height = font.getsize(text)
+
+        if text_height > max_width:
+            return False, None
+
+        if text_width <= max_length:
+            # Now we know that the text fits. We can stop trying
+            return True, text
+
+        avg_char_width = sum(font.getsize(char)[0] for char in ascii_letters) / len(
+            ascii_letters
+        )
+        charachters_per_line = max_length // avg_char_width
+        if charachters_per_line < max(len(line) for line in text.split(" ")):
+            return False, None
+
+        wrapped = textwrap.fill(text, charachters_per_line)
+        wrapped_width, wrapped_height = font.getsize_multiline(wrapped)
+        if wrapped_height <= max_width and wrapped_width <= max_length:
+            # Now we know that the text fits. We can stop trying
+            return True, wrapped
+
+        return False, None