Update

bookwyrm/activitypub/book.py

@@ -37,6 +37,7 @@ class Book(BookData):
     publishedDate: str = ""
 
     cover: Document = None
+    preview_image: Document = None
     type: str = "Book"
 
 

bookwyrm/migrations/0076_book_preview_image.py

@@ -12,10 +12,8 @@ class Migration(migrations.Migration):
 
     operations = [
         migrations.AddField(
-            model_name="edition",
-            name="preview_image",
-            field=bookwyrm.models.fields.ImageField(
-                blank=True, null=True, upload_to="previews/"
-            ),
+            model_name='book',
+            name='preview_image',
+            field=bookwyrm.models.fields.ImageField(blank=True, null=True, upload_to='cover_previews/'),
         ),
     ]

bookwyrm/models/book.py

@@ -6,7 +6,7 @@ from django.dispatch import receiver
 from model_utils.managers import InheritanceManager
 
 from bookwyrm import activitypub
-from bookwyrm.preview_images import generate_preview_image_task
+from bookwyrm.preview_images import generate_preview_image_from_edition_task
 from bookwyrm.settings import DOMAIN, DEFAULT_LANGUAGE
 from bookwyrm.tasks import app
 
@@ -85,6 +85,9 @@ class Book(BookDataModel):
     cover = fields.ImageField(
         upload_to="covers/", blank=True, null=True, alt_field="alt_text"
     )
+    preview_image = fields.ImageField(
+        upload_to="cover_previews/", blank=True, null=True, alt_field="alt_text"
+    )
     first_published_date = fields.DateTimeField(blank=True, null=True)
     published_date = fields.DateTimeField(blank=True, null=True)
 
@@ -207,9 +210,6 @@ class Edition(Book):
         activitypub_field="work",
     )
     edition_rank = fields.IntegerField(default=0)
-    preview_image = fields.ImageField(
-        upload_to="previews/", blank=True, null=True, alt_field="alt_text"
-    )
 
     activity_serializer = activitypub.Edition
     name_field = "title"
@@ -302,6 +302,7 @@ def isbn_13_to_10(isbn_13):
 
 
 @receiver(models.signals.post_save, sender=Edition)
-# pylint: disable=unused-argument
-def preview_image(instance, *args, **kwargs):
-    generate_preview_image_task(instance, *args, **kwargs)
+def preview_image(instance, **kwargs):
+    updated_fields = kwargs["update_fields"]
+
+    generate_preview_image_from_edition_task.delay(instance.id, updated_fields)

bookwyrm/preview_images.py

@@ -1,13 +1,17 @@
+import colorsys
 import math
+import os
 import textwrap
 
+from colorthief import ColorThief
 from io import BytesIO
-from PIL import Image, ImageDraw, ImageFont, ImageOps
+from PIL import Image, ImageDraw, ImageFont, ImageOps, ImageColor
 from pathlib import Path
 from uuid import uuid4
 
 from django.core.files.base import ContentFile
 from django.core.files.uploadedfile import InMemoryUploadedFile
+from django.db.models import Avg
 
 from bookwyrm import models, settings
 from bookwyrm.tasks import app
@@ -17,54 +21,64 @@ import logging
 
 IMG_WIDTH = settings.PREVIEW_IMG_WIDTH
 IMG_HEIGHT = settings.PREVIEW_IMG_HEIGHT
-BG_COLOR = (182, 186, 177)
+BG_COLOR = settings.PREVIEW_BG_COLOR
+TEXT_COLOR = settings.PREVIEW_TEXT_COLOR
+DEFAULT_COVER_COLOR = settings.PREVIEW_DEFAULT_COVER_COLOR
 TRANSPARENT_COLOR = (0, 0, 0, 0)
-TEXT_COLOR = (16, 16, 16)
 
-margin = math.ceil(IMG_HEIGHT / 10)
-gutter = math.ceil(margin / 2)
-cover_img_limits = math.ceil(IMG_HEIGHT * 0.8)
+margin = math.floor(IMG_HEIGHT / 10)
+gutter = math.floor(margin / 2)
+cover_img_limits = math.floor(IMG_HEIGHT * 0.8)
 path = Path(__file__).parent.absolute()
-font_path = path.joinpath("static/fonts/public_sans")
+font_dir = path.joinpath("static/fonts/public_sans")
+icon_font_dir = path.joinpath("static/css/fonts")
 
+def get_font(font_name, size=28):
+    if font_name == "light":
+        font_path = "%s/PublicSans-Light.ttf" % font_dir
+    if font_name == "regular":
+        font_path = "%s/PublicSans-Regular.ttf" % font_dir
+    elif font_name == "bold":
+        font_path = "%s/PublicSans-Bold.ttf" % font_dir
+    elif font_name == "icomoon":
+        font_path = "%s/icomoon.ttf" % icon_font_dir
 
-def generate_texts_layer(edition, text_x):
     try:
-        font_title = ImageFont.truetype("%s/PublicSans-Bold.ttf" % font_path, 48)
-        font_authors = ImageFont.truetype("%s/PublicSans-Regular.ttf" % font_path, 40)
+        font = ImageFont.truetype(font_path, size)
     except OSError:
-        font_title = ImageFont.load_default()
-        font_authors = ImageFont.load_default()
+        font = ImageFont.load_default()
 
-    text_layer = Image.new("RGBA", (IMG_WIDTH, IMG_HEIGHT), color=TRANSPARENT_COLOR)
+    return font
+
+
+def generate_texts_layer(book, content_width):
+    font_title = get_font("bold", size=48)
+    font_authors = get_font("regular", size=40)
+
+    text_layer = Image.new("RGBA", (content_width, IMG_HEIGHT), color=TRANSPARENT_COLOR)
     text_layer_draw = ImageDraw.Draw(text_layer)
 
     text_y = 0
 
-    text_y = text_y + 6
-
     # title
-    title = textwrap.fill(edition.title, width=28)
+    title = textwrap.fill(book.title, width=28)
     text_layer_draw.multiline_text((0, text_y), title, font=font_title, fill=TEXT_COLOR)
 
     text_y = text_y + font_title.getsize_multiline(title)[1] + 16
 
     # subtitle
-    authors_text = ", ".join(a.name for a in edition.authors.all())
+    authors_text = book.author_text
     authors = textwrap.fill(authors_text, width=36)
     text_layer_draw.multiline_text(
         (0, text_y), authors, font=font_authors, fill=TEXT_COLOR
     )
 
-    imageBox = text_layer.getbbox()
-    return text_layer.crop(imageBox)
+    text_layer_box = text_layer.getbbox()
+    return text_layer.crop(text_layer_box)
 
 
-def generate_site_layer(text_x):
-    try:
-        font_instance = ImageFont.truetype("%s/PublicSans-Light.ttf" % font_path, 28)
-    except OSError:
-        font_instance = ImageFont.load_default()
+def generate_instance_layer(content_width):
+    font_instance = get_font("light", size=28)
 
     site = models.SiteSettings.objects.get()
 
@@ -74,42 +88,157 @@ def generate_site_layer(text_x):
         static_path = path.joinpath("static/images/logo-small.png")
         logo_img = Image.open(static_path)
 
-    site_layer = Image.new("RGBA", (IMG_WIDTH - text_x - margin, 50), color=BG_COLOR)
+    instance_layer = Image.new("RGBA", (content_width, 62), color=TRANSPARENT_COLOR)
 
     logo_img.thumbnail((50, 50), Image.ANTIALIAS)
 
-    site_layer.paste(logo_img, (0, 0))
+    instance_layer.paste(logo_img, (0, 0))
 
-    site_layer_draw = ImageDraw.Draw(site_layer)
-    site_layer_draw.text((60, 10), site.name, font=font_instance, fill=TEXT_COLOR)
+    instance_layer_draw = ImageDraw.Draw(instance_layer)
+    instance_layer_draw.text((60, 10), site.name, font=font_instance, fill=TEXT_COLOR)
 
-    return site_layer
+    line_width = 50 + 10 + font_instance.getsize(site.name)[0]
+
+    line_layer = Image.new("RGBA", (line_width, 2), color=(*(ImageColor.getrgb(TEXT_COLOR)), 50))
+    instance_layer.alpha_composite(line_layer, (0, 60))
+
+    return instance_layer
 
 
-def generate_preview_image(edition):
-    img = Image.new("RGBA", (IMG_WIDTH, IMG_HEIGHT), color=BG_COLOR)
+def generate_rating_layer(rating, content_width):
+    font_icons = get_font("icomoon", size=60)
 
-    cover_img_layer = Image.open(edition.cover)
+    icon_star_full = Image.open(path.joinpath("static/images/icons/star-full.png"))
+    icon_star_empty = Image.open(path.joinpath("static/images/icons/star-empty.png"))
+    icon_star_half = Image.open(path.joinpath("static/images/icons/star-half.png"))
+
+    icon_size = 64
+    icon_margin = 10
+
+    rating_layer_base = Image.new("RGBA", (content_width, icon_size), color=TRANSPARENT_COLOR)
+    rating_layer_color = Image.new("RGBA", (content_width, icon_size), color=TEXT_COLOR)
+    rating_layer_mask = Image.new("RGBA", (content_width, icon_size), color=TRANSPARENT_COLOR)
+
+    position_x = 0
+
+    for r in range(math.floor(rating)):
+        rating_layer_mask.alpha_composite(icon_star_full, (position_x, 0))
+        position_x = position_x + icon_size + icon_margin
+
+    if math.floor(rating) != math.ceil(rating):
+        rating_layer_mask.alpha_composite(icon_star_half, (position_x, 0))
+        position_x = position_x + icon_size + icon_margin
+
+    for r in range(5 - math.ceil(rating)):
+        rating_layer_mask.alpha_composite(icon_star_empty, (position_x, 0))
+        position_x = position_x + icon_size + icon_margin
+
+    rating_layer_mask = rating_layer_mask.getchannel("A")
+    rating_layer_mask = ImageOps.invert(rating_layer_mask)
+
+    rating_layer_composite = Image.composite(rating_layer_base, rating_layer_color, rating_layer_mask)
+
+    return rating_layer_composite
+
+
+def generate_default_cover():
+    font_cover = get_font("light", size=28)
+
+    cover_width = math.floor(cover_img_limits * .7)
+    default_cover = Image.new("RGB", (cover_width, cover_img_limits), color=DEFAULT_COVER_COLOR)
+    default_cover_draw = ImageDraw.Draw(default_cover)
+
+    text = "no cover :("
+    text_dimensions = font_cover.getsize(text)
+    text_coords = (math.floor((cover_width - text_dimensions[0]) / 2),
+                   math.floor((cover_img_limits - text_dimensions[1]) / 2))
+    default_cover_draw.text(text_coords, text, font=font_cover, fill='white')
+
+    return default_cover
+
+
+def generate_preview_image(book_id, rating=None):
+    book = models.Book.objects.select_subclasses().get(id=book_id)
+
+    rating = models.Review.objects.filter(
+        privacy="public",
+        deleted=False,
+        book__in=[book_id],
+    ).aggregate(Avg("rating"))["rating__avg"]
+
+    # Cover
+    try:
+      cover_img_layer = Image.open(book.cover)
       cover_img_layer.thumbnail((cover_img_limits, cover_img_limits), Image.ANTIALIAS)
+      color_thief = ColorThief(book.cover)
+      dominant_color = color_thief.get_color(quality=1)
+    except:
+      cover_img_layer = generate_default_cover()
+      dominant_color = ImageColor.getrgb(DEFAULT_COVER_COLOR)
 
-    text_x = margin + cover_img_layer.width + gutter
+    # Color
+    if BG_COLOR == 'use_dominant_color':
+        image_bg_color = "rgb(%s, %s, %s)" % dominant_color
+        # Lighten color
+        image_bg_color_rgb = [x/255.0 for x in ImageColor.getrgb(image_bg_color)]
+        image_bg_color_hls = colorsys.rgb_to_hls(*image_bg_color_rgb)
+        image_bg_color_hls = (image_bg_color_hls[0], 0.9, image_bg_color_hls[1])
+        image_bg_color = tuple([math.ceil(x * 255) for x in colorsys.hls_to_rgb(*image_bg_color_hls)])
+    else:
+        image_bg_color = BG_COLOR
 
-    texts_layer = generate_texts_layer(edition, text_x)
-    text_y = IMG_HEIGHT - margin - texts_layer.height
+    # Background (using the color)
+    img = Image.new("RGBA", (IMG_WIDTH, IMG_HEIGHT), color=image_bg_color)
 
-    site_layer = generate_site_layer(text_x)
+    # Contents
+    content_x = margin + cover_img_layer.width + gutter
+    content_width = IMG_WIDTH - content_x - margin
 
-    # Composite all layers
-    img.paste(cover_img_layer, (margin, margin))
-    img.alpha_composite(texts_layer, (text_x, text_y))
-    img.alpha_composite(site_layer, (text_x, margin))
+    instance_layer = generate_instance_layer(content_width)
+    texts_layer = generate_texts_layer(book, content_width)
+
+    contents_layer = Image.new("RGBA", (content_width, IMG_HEIGHT), color=TRANSPARENT_COLOR)
+    contents_composite_y = 0
+    contents_layer.alpha_composite(instance_layer, (0, contents_composite_y))
+    contents_composite_y = contents_composite_y + instance_layer.height + gutter
+    contents_layer.alpha_composite(texts_layer, (0, contents_composite_y))
+    contents_composite_y = contents_composite_y + texts_layer.height + 30
+
+    if rating:
+        # Add some more margin
+        contents_composite_y = contents_composite_y + 30
+        rating_layer = generate_rating_layer(rating, content_width)
+        contents_layer.alpha_composite(rating_layer, (0, contents_composite_y))
+        contents_composite_y = contents_composite_y + rating_layer.height + 30
+
+    contents_layer_box = contents_layer.getbbox()
+    contents_layer_height = contents_layer_box[3] - contents_layer_box[1]
+
+    contents_y = math.floor((IMG_HEIGHT - contents_layer_height) / 2)
+    # Remove Instance Layer from centering calculations
+    contents_y = contents_y - math.floor((instance_layer.height + gutter) / 2)
+    
+    if contents_y < margin:
+        contents_y = margin
+
+    cover_y = math.floor((IMG_HEIGHT - cover_img_layer.height) / 2)
+
+    # Composite layers
+    img.paste(cover_img_layer, (margin, cover_y))
+    img.alpha_composite(contents_layer, (content_x, contents_y))
 
     file_name = "%s.png" % str(uuid4())
 
     image_buffer = BytesIO()
     try:
+        try:
+            old_path = book.preview_image.path
+        except ValueError:
+            old_path = ''
+
+        # Save
         img.save(image_buffer, format="png")
-        edition.preview_image = InMemoryUploadedFile(
+        book.preview_image = InMemoryUploadedFile(
             ContentFile(image_buffer.getvalue()),
             "preview_image",
             file_name,
@@ -117,17 +246,17 @@ def generate_preview_image(edition):
             image_buffer.tell(),
             None,
         )
+        book.save(update_fields=["preview_image"])
 
-        edition.save(update_fields=["preview_image"])
+        # Clean up old file after saving
+        if os.path.exists(old_path):
+            os.remove(old_path)
     finally:
         image_buffer.close()
 
 
 @app.task
-def generate_preview_image_task(instance, *args, **kwargs):
+def generate_preview_image_from_edition_task(book_id, updated_fields=None):
     """generate preview_image after save"""
-    updated_fields = kwargs["update_fields"]
-
     if not updated_fields or "preview_image" not in updated_fields:
-        logging.warn("image name to delete", instance.preview_image.name)
-        generate_preview_image(edition=instance)
+        generate_preview_image(book_id=book_id)

bookwyrm/settings.py

@@ -37,10 +37,14 @@ LOCALE_PATHS = [
 
 DEFAULT_AUTO_FIELD = "django.db.models.AutoField"
 
-# preview image
+# Preview image
 
+# Specify RGB tuple or RGB hex strings, or 'use_dominant_color'
+PREVIEW_BG_COLOR = 'use_dominant_color'
 PREVIEW_IMG_WIDTH = 1200
 PREVIEW_IMG_HEIGHT = 630
+PREVIEW_TEXT_COLOR = '#363636'
+PREVIEW_DEFAULT_COVER_COLOR = '#002549'
 
 # Quick-start development settings - unsuitable for production
 # See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/

requirements.txt

@@ -1,4 +1,5 @@
 celery==4.4.2
+colorthief==0.2.1
 Django==3.2.0
 django-model-utils==4.0.0
 environs==7.2.0