This commit is contained in:
jpirnay
2026-03-26 11:05:13 +01:00
parent ac42d5ef36
commit 1af3f81336
4 changed files with 235 additions and 2 deletions
+7
View File
@@ -22,6 +22,10 @@ struct BlockStyle {
int16_t textIndent = 0;
bool textIndentDefined = false; // true if text-indent was explicitly set in CSS
bool textAlignDefined = false; // true if text-align was explicitly set in CSS
// Set when this block was created by a <br> element. Used by startNewTextBlock to inject
// a full line-height gap when the <br> block stays empty (section-break use case).
// NOT propagated through getCombinedBlockStyle so it can't leak into sibling blocks.
bool fromBrElement = false;
// Combined horizontal insets (margin + padding)
[[nodiscard]] int16_t leftInset() const { return marginLeft + paddingLeft; }
@@ -58,6 +62,9 @@ struct BlockStyle {
combinedBlockStyle.alignment = alignment;
combinedBlockStyle.textAlignDefined = textAlignDefined;
}
// fromBrElement is never propagated — it is consumed by startNewTextBlock
// when the empty <br> block is merged with the following paragraph.
combinedBlockStyle.fromBrElement = false;
return combinedBlockStyle;
}
@@ -133,7 +133,17 @@ void ChapterHtmlSlimParser::startNewTextBlock(const BlockStyle& blockStyle) {
// Merge with existing block style to accumulate CSS styling from parent block elements.
// This handles cases like <div style="margin-bottom:2em"><h1>text</h1></div> where the
// div's margin should be preserved, even though it has no direct text content.
currentTextBlock->setBlockStyle(currentTextBlock->getBlockStyle().getCombinedBlockStyle(blockStyle));
BlockStyle incoming = blockStyle;
if (currentTextBlock->getBlockStyle().fromBrElement) {
// The empty block was created by a <br> section separator. Inject a full line of
// blank space before the following paragraph so the scene/section break is visible.
// This only fires when the <br> block stayed empty (i.e. no inline text was added).
const int16_t lineHeight = static_cast<int16_t>(renderer.getLineHeight(fontId) * lineCompression + 0.5f);
incoming.marginTop = static_cast<int16_t>(incoming.marginTop + lineHeight);
}
currentTextBlock->setBlockStyle(currentTextBlock->getBlockStyle().getCombinedBlockStyle(incoming));
if (!pendingAnchorId.empty()) {
anchorData.push_back({std::move(pendingAnchorId), static_cast<uint16_t>(completedPageCount)});
@@ -587,7 +597,13 @@ void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char*
// flush word preceding <br/> to currentTextBlock before calling startNewTextBlock
self->flushPartWordBuffer();
}
self->startNewTextBlock(self->currentTextBlock->getBlockStyle());
// Tag the new block so startNewTextBlock can inject a full line-height gap if
// the block remains empty (i.e. <br> is a section separator between paragraphs).
// If the block gets text added before the next block opens it becomes non-empty,
// goes through makePages() normally, and the flag has no effect (inline <br> case).
BlockStyle brStyle = self->currentTextBlock->getBlockStyle();
brStyle.fromBrElement = true;
self->startNewTextBlock(brStyle);
} else {
self->currentCssStyle = cssStyle;
self->startNewTextBlock(userAlignmentBlockStyle);
+210
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@@ -0,0 +1,210 @@
#!/usr/bin/env python3
"""
Generate a test EPUB for <br> section-break rendering.
Tests that a bare <br> element between paragraphs produces a visible blank-line
gap (section separator), while a <br> inside a paragraph only produces a line
break with no extra spacing.
Cases covered:
1. Standalone <br> between paragraphs (section break — must show gap).
2. <br class="..."> with a CSS class (calibre-style section break).
3. Multiple consecutive <br> elements (each adds one line of spacing).
4. Inline <br> inside a <p> (line break only — no extra gap).
5. <br> at start of chapter (no gap before first paragraph).
6. <br> following a heading.
Visual verification instructions are embedded as the first paragraph of each
chapter so a human tester can confirm the expected result on device.
"""
import os
import zipfile
from pathlib import Path
OUTPUT_DIR = Path(__file__).parent.parent / "test" / "epubs"
OUTPUT_PATH = OUTPUT_DIR / "test_br_section_break.epub"
FILLER = (
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod "
"tempor incididunt ut labore et dolore magna aliqua."
)
CSS = """\
body { margin: 0; padding: 0; }
p { margin-top: 1pt; margin-bottom: 0; text-indent: 1em; text-align: justify; }
h1 { text-align: center; margin-top: 0.5em; margin-bottom: 0.5em; }
h2 { text-align: center; margin-top: 0.5em; margin-bottom: 0.5em; }
.section-br { display: block; }
"""
def xhtml(title, body):
return f"""\
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>{title}</title>
<link rel="stylesheet" type="text/css" href="styles/test.css"/>
</head>
<body>
{body}
</body>
</html>"""
# ---------------------------------------------------------------------------
# Chapter 1 — standalone <br> between paragraphs
# ---------------------------------------------------------------------------
ch1 = xhtml("Ch1: Standalone br", f"""
<h1>Ch 1: Standalone &lt;br&gt; Section Break</h1>
<p>PASS: A visible blank-line gap should appear between the two sections below.</p>
<p>{FILLER}</p>
<br/>
<p>{FILLER}</p>
<p>PASS: The gap above should be roughly one line tall (same as a blank line).</p>
""")
# ---------------------------------------------------------------------------
# Chapter 2 — <br class="..."> CSS-classed section break (calibre style)
# ---------------------------------------------------------------------------
ch2 = xhtml("Ch2: Classed br", f"""
<h1>Ch 2: &lt;br class="section-br"/&gt;</h1>
<p>PASS: A blank-line gap should appear between the two sections below, identical
to Ch 1, even though the &lt;br&gt; carries a CSS class.</p>
<p>{FILLER}</p>
<br class="section-br"/>
<p>{FILLER}</p>
""")
# ---------------------------------------------------------------------------
# Chapter 3 — multiple consecutive <br> elements
# ---------------------------------------------------------------------------
ch3 = xhtml("Ch3: Multiple br", f"""
<h1>Ch 3: Multiple Consecutive &lt;br&gt; Elements</h1>
<p>PASS: Two blank lines should appear between the sections (one per &lt;br&gt;).</p>
<p>{FILLER}</p>
<br/>
<br/>
<p>{FILLER}</p>
<p>PASS: Three blank lines should appear below.</p>
<p>{FILLER}</p>
<br/>
<br/>
<br/>
<p>{FILLER}</p>
""")
# ---------------------------------------------------------------------------
# Chapter 4 — inline <br> inside a paragraph (line break, NOT a gap)
# ---------------------------------------------------------------------------
ch4 = xhtml("Ch4: Inline br", """
<h1>Ch 4: Inline &lt;br&gt; Inside a Paragraph</h1>
<p>PASS: The two lines below should be adjacent with NO extra gap between them.
The &lt;br&gt; is inside the paragraph and must only break the line.</p>
<p>First line of the paragraph.<br/>Second line of the paragraph — directly below, no gap.</p>
<p>PASS: Above should look like two closely-spaced lines, not like two paragraphs
separated by a blank line.</p>
""")
# ---------------------------------------------------------------------------
# Chapter 5 — <br> following a heading
# ---------------------------------------------------------------------------
ch5 = xhtml("Ch5: br after heading", f"""
<h1>Ch 5: &lt;br&gt; After a Heading</h1>
<br/>
<p>PASS: There should be a blank-line gap between the heading above and this paragraph.</p>
<p>{FILLER}</p>
<h2>Section heading</h2>
<br/>
<p>PASS: There should be a blank-line gap between the section heading and this paragraph.</p>
""")
# ---------------------------------------------------------------------------
# Chapter 6 — <br> at very start of chapter (no spurious leading gap)
# ---------------------------------------------------------------------------
ch6 = xhtml("Ch6: br at chapter start", f"""<br/>
<h1>Ch 6: &lt;br&gt; at Chapter Start</h1>
<p>PASS: This heading should appear near the top of the page with no large blank
area above it despite the &lt;br&gt; being the very first element.</p>
<p>{FILLER}</p>
""")
CHAPTERS = [
("ch1", "chapter1.xhtml", "Chapter 1: Standalone br", ch1),
("ch2", "chapter2.xhtml", "Chapter 2: Classed br", ch2),
("ch3", "chapter3.xhtml", "Chapter 3: Multiple br", ch3),
("ch4", "chapter4.xhtml", "Chapter 4: Inline br", ch4),
("ch5", "chapter5.xhtml", "Chapter 5: br after heading", ch5),
("ch6", "chapter6.xhtml", "Chapter 6: br at start", ch6),
]
def build_epub(path):
os.makedirs(os.path.dirname(path), exist_ok=True)
with zipfile.ZipFile(path, "w", zipfile.ZIP_DEFLATED) as epub:
# mimetype must be first and uncompressed
epub.writestr("mimetype", "application/epub+zip",
compress_type=zipfile.ZIP_STORED)
epub.writestr("META-INF/container.xml", """\
<?xml version="1.0" encoding="UTF-8"?>
<container xmlns="urn:oasis:names:tc:opendocument:xmlns:container" version="1.0">
<rootfiles>
<rootfile full-path="OEBPS/content.opf"
media-type="application/oebps-package+xml"/>
</rootfiles>
</container>""")
epub.writestr("OEBPS/styles/test.css", CSS)
manifest_items = []
spine_items = []
nav_items = []
for (chid, chfile, chtitle, chcontent) in CHAPTERS:
epub.writestr(f"OEBPS/{chfile}", chcontent)
manifest_items.append(
f' <item id="{chid}" href="{chfile}" media-type="application/xhtml+xml"/>')
spine_items.append(f' <itemref idref="{chid}"/>')
nav_items.append(f' <li><a href="{chfile}">{chtitle}</a></li>')
manifest_items.append(
' <item id="nav" href="nav.xhtml" '
'media-type="application/xhtml+xml" properties="nav"/>')
content_opf = f"""\
<?xml version="1.0" encoding="UTF-8"?>
<package xmlns="http://www.idpf.org/2007/opf" version="3.0" unique-identifier="uid">
<metadata xmlns:dc="http://purl.org/dc/elements/1.1/">
<dc:identifier id="uid">test-epub-br-section-break</dc:identifier>
<dc:title>Test: br Section Break</dc:title>
<dc:language>en</dc:language>
</metadata>
<manifest>
{chr(10).join(manifest_items)}
</manifest>
<spine>
{chr(10).join(spine_items)}
</spine>
</package>"""
epub.writestr("OEBPS/content.opf", content_opf)
nav_xhtml = f"""\
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops">
<head><title>Table of Contents</title></head>
<body>
<nav epub:type="toc">
<ol>
{chr(10).join(nav_items)}
</ol>
</nav>
</body>
</html>"""
epub.writestr("OEBPS/nav.xhtml", nav_xhtml)
print(f"Generated: {path}")
if __name__ == "__main__":
build_epub(OUTPUT_PATH)
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