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fix: add bounds checking and content splitting for multi-page songs (Closes #17) (#20)

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This commit was merged in pull request #20.
This commit is contained in:
shahondin1624
2026-03-17 14:18:07 +01:00
parent 0fb2771279
commit a69d14033d
3 changed files with 536 additions and 32 deletions
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250
renderer-pdf/src/main/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfBookRenderer.kt
View File

@@ -63,7 +63,7 @@ class PdfBookRenderer : BookRenderer {
renderSongPage(
cb, chordLyricRenderer, fontMetrics, config,
pageContent.song, pageContent.pageIndex,
contentTop, leftMargin, contentWidth
contentTop, leftMargin, contentWidth, marginBottom
)
}
is PageContent.FillerImage -> {
@@ -91,6 +91,166 @@ class PdfBookRenderer : BookRenderer {
document.close()
}
/**
* Computes the index of the first section that should be rendered on page 1.
* All sections before this index render on page 0; sections from this index
* onward render on page 1.
*
* If all sections fit on page 0, returns song.sections.size (i.e., nothing on page 1).
*/
private fun computeSplitIndex(
song: Song,
fontMetrics: PdfFontMetrics,
config: BookConfig,
contentWidth: Float,
availableHeightOnPage0: Float
): Int {
var consumed = 0f
// Header: title
consumed += config.fonts.title.size * 1.5f
// Top metadata
val renderMetaAtBottom = config.layout.metadataPosition == "bottom"
if (!renderMetaAtBottom) {
val metaParts = buildMetadataLines(song, config)
if (metaParts.isNotEmpty()) {
consumed += config.fonts.metadata.size * 1.8f * metaParts.size
}
}
// Key/capo
if (song.key != null || song.capo != null) {
consumed += config.fonts.metadata.size * 1.8f
}
consumed += 4f // gap before sections
for ((index, section) in song.sections.withIndex()) {
val sectionHeight = calculateSectionHeight(section, fontMetrics, config, contentWidth)
if (consumed + sectionHeight > availableHeightOnPage0) {
// This section doesn't fit on page 0
return index
}
consumed += sectionHeight
// Add verse spacing
consumed += config.layout.verseSpacing / 0.3528f
}
return song.sections.size
}
/**
* Calculates the height in PDF points that a section will consume when rendered.
*/
private fun calculateSectionHeight(
section: SongSection,
fontMetrics: PdfFontMetrics,
config: BookConfig,
contentWidth: Float
): Float {
var height = 0f
val metaSize = config.fonts.metadata.size
// Section label
if (section.label != null || section.type == SectionType.CHORUS) {
val labelText = section.label ?: when (section.type) {
SectionType.CHORUS -> "Refrain"
SectionType.REPEAT -> "Wiederholung"
else -> null
}
if (labelText != null) {
height += metaSize * 1.5f
}
}
// Empty chorus (reference)
if (section.type == SectionType.CHORUS && section.lines.isEmpty()) {
height += metaSize * 1.8f
return height
}
// Repeat start marker (contributes no extra height - drawn at current y)
// Lines
val chordSize = config.fonts.chords.size
val lyricSize = config.fonts.lyrics.size
val chordLineHeight = chordSize * 1.2f
val lyricLineHeight = lyricSize * 1.2f
val chordLyricGap = config.layout.chordLineSpacing / 0.3528f
for (line in section.lines) {
if (line.imagePath != null) {
// Inline image: 40mm max height + gaps
val maxImageHeight = 40f / 0.3528f
height += maxImageHeight + 6f
} else {
val hasChords = line.segments.any { it.chord != null }
var lineHeight = lyricLineHeight
if (hasChords) {
lineHeight += chordLineHeight + chordLyricGap
}
height += lineHeight + 1f // 1pt gap between lines
}
}
// Repeat end marker
if (section.type == SectionType.REPEAT) {
height += metaSize * 1.5f
}
return height
}
/**
* Calculates the space (in PDF points) that must be reserved at the bottom of
* the last page of a song for notes, bottom-position metadata, and reference footer.
*/
private fun calculateFooterReservation(
song: Song,
fontMetrics: PdfFontMetrics,
config: BookConfig,
contentWidth: Float
): Float {
var reserved = 0f
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
// Notes
if (song.notes.isNotEmpty()) {
reserved += 4f // gap before notes
val noteLineHeight = metaSize * 1.5f
for ((idx, note) in song.notes.withIndex()) {
val wrappedLines = wrapText(note, metaFont, metaSize, contentWidth)
reserved += noteLineHeight * wrappedLines.size
if (idx < song.notes.size - 1) {
reserved += noteLineHeight * 0.3f
}
}
}
// Bottom metadata
if (config.layout.metadataPosition == "bottom") {
val metaParts = buildMetadataLines(song, config)
if (metaParts.isNotEmpty()) {
reserved += 4f
for (metaLine in metaParts) {
val wrappedLines = wrapText(metaLine, metaFont, metaSize, contentWidth)
reserved += metaSize * 1.5f * wrappedLines.size
}
}
}
// Reference footer
if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
val lineHeight = metaSize * 1.4f
reserved += lineHeight * 2 // two rows (headers + numbers)
reserved += lineHeight * 1.5f // separator line gap
reserved += lineHeight * 0.5f // bottom gap
}
return reserved
}
private fun renderSongPage(
cb: PdfContentByte,
chordLyricRenderer: ChordLyricRenderer,
@@ -100,12 +260,28 @@ class PdfBookRenderer : BookRenderer {
pageIndex: Int, // 0 for first page, 1 for second page of 2-page songs
contentTop: Float,
leftMargin: Float,
contentWidth: Float
contentWidth: Float,
bottomMargin: Float
) {
var y = contentTop
val renderMetaAtBottom = config.layout.metadataPosition == "bottom"
// Calculate the footer reservation for the last page
val footerReservation = calculateFooterReservation(song, fontMetrics, config, contentWidth)
// Compute the split index to determine which sections go on which page.
// Page 0 gets sections 0..<splitIndex, page 1 gets sections splitIndex..<size.
// Footer space is reserved on the last page only.
val availableOnPage0 = contentTop - bottomMargin -
(if (song.sections.size > 0) footerReservation else 0f)
val splitIndex = computeSplitIndex(song, fontMetrics, config, contentWidth, availableOnPage0)
val isTwoPageSong = splitIndex < song.sections.size
val isLastPage = if (isTwoPageSong) pageIndex == 1 else pageIndex == 0
// Bottom boundary for content on this page
val yMin = bottomMargin + (if (isLastPage) footerReservation else 0f)
if (pageIndex == 0) {
// Render title
val titleFont = fontMetrics.getBaseFont(config.fonts.title)
@@ -125,6 +301,7 @@ class PdfBookRenderer : BookRenderer {
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
for (metaLine in metaParts) {
if (y - metaSize * 1.8f < yMin) break
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.GRAY)
@@ -143,24 +320,31 @@ class PdfBookRenderer : BookRenderer {
if (infoParts.isNotEmpty()) {
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.GRAY)
cb.setTextMatrix(leftMargin, y - metaSize)
cb.showText(infoParts.joinToString(" | "))
cb.endText()
y -= metaSize * 1.8f
if (y - metaSize * 1.8f >= yMin) {
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.GRAY)
cb.setTextMatrix(leftMargin, y - metaSize)
cb.showText(infoParts.joinToString(" | "))
cb.endText()
y -= metaSize * 1.8f
}
}
y -= 4f // gap before sections
}
// Determine which sections to render on this page
// For simplicity in this implementation, render all sections on pageIndex 0
// A more sophisticated implementation would split sections across pages
val sections = if (pageIndex == 0) song.sections else emptyList()
val sections = if (pageIndex == 0) {
song.sections.subList(0, splitIndex)
} else {
song.sections.subList(splitIndex, song.sections.size)
}
for (section in sections) {
// Safety check: stop rendering if we've gone below the boundary
if (y < yMin) break
// Section label
if (section.label != null || section.type == SectionType.CHORUS) {
val labelText = section.label ?: when (section.type) {
@@ -171,6 +355,7 @@ class PdfBookRenderer : BookRenderer {
if (labelText != null) {
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
if (y - metaSize * 1.5f < yMin) break
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.DARK_GRAY)
@@ -185,6 +370,7 @@ class PdfBookRenderer : BookRenderer {
if (section.type == SectionType.CHORUS && section.lines.isEmpty()) {
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
if (y - metaSize * 1.8f < yMin) break
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.DARK_GRAY)
@@ -209,6 +395,7 @@ class PdfBookRenderer : BookRenderer {
// Render lines
for (line in section.lines) {
if (y < yMin) break
val imgPath = line.imagePath
if (imgPath != null) {
// Render inline image
@@ -223,21 +410,23 @@ class PdfBookRenderer : BookRenderer {
if (section.type == SectionType.REPEAT) {
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.DARK_GRAY)
cb.setTextMatrix(leftMargin, y - metaSize)
cb.showText(":\u2502")
cb.endText()
y -= metaSize * 1.5f
if (y - metaSize * 1.5f >= yMin) {
cb.beginText()
cb.setFontAndSize(metaFont, metaSize)
cb.setColorFill(Color.DARK_GRAY)
cb.setTextMatrix(leftMargin, y - metaSize)
cb.showText(":\u2502")
cb.endText()
y -= metaSize * 1.5f
}
}
// Verse spacing
y -= config.layout.verseSpacing / 0.3528f
}
// Render notes at the bottom (with word-wrap for multi-paragraph notes)
if (pageIndex == 0 && song.notes.isNotEmpty()) {
// Render notes on the last page
if (isLastPage && song.notes.isNotEmpty()) {
y -= 4f
val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
val metaSize = config.fonts.metadata.size
@@ -261,8 +450,8 @@ class PdfBookRenderer : BookRenderer {
}
}
// Render metadata at bottom of song page (if configured)
if (renderMetaAtBottom && pageIndex == 0) {
// Render metadata at bottom of song page (if configured) - on the last page only
if (renderMetaAtBottom && isLastPage) {
val metaParts = buildMetadataLines(song, config)
if (metaParts.isNotEmpty()) {
y -= 4f
@@ -284,15 +473,12 @@ class PdfBookRenderer : BookRenderer {
}
// Render reference book footer on the last page of the song
if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
val isLastPage = (pageIndex == 0) // For now, all content renders on page 0
if (isLastPage) {
renderReferenceFooter(
cb, fontMetrics, config, song,
leftMargin, contentWidth,
config.layout.margins.bottom / 0.3528f
)
}
if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty() && isLastPage) {
renderReferenceFooter(
cb, fontMetrics, config, song,
leftMargin, contentWidth,
bottomMargin
)
}
}

209
renderer-pdf/src/test/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfBookRendererTest.kt
View File

@@ -417,4 +417,213 @@ class PdfBookRendererTest {
baos.size() shouldBeGreaterThan 0
}
// --- Content splitting tests ---
private fun createLongSong(title: String = "Long Song"): Song {
// Create a song with many sections that will exceed one A5 page
val sections = (1..20).map { i ->
SongSection(
type = SectionType.VERSE,
label = "Verse $i",
lines = (1..4).map {
SongLine(
listOf(
LineSegment(chord = "Am", text = "Some text with chords "),
LineSegment(chord = "G", text = "and more text here")
)
)
}
)
}
return Song(title = title, sections = sections)
}
@Test
fun `render splits content across pages for two-page song`() {
val song = createLongSong()
val layout = LayoutResult(
tocPages = 0,
pages = listOf(
PageContent.SongPage(song, 0),
PageContent.SongPage(song, 1)
),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, BookConfig(), baos)
baos.size() shouldBeGreaterThan 0
val bytes = baos.toByteArray()
val header = String(bytes.sliceArray(0..4))
header shouldBe "%PDF-"
}
@Test
fun `render does not overflow below bottom margin for very long song`() {
// Create an extremely long song
val sections = (1..40).map { i ->
SongSection(
type = SectionType.VERSE,
label = "Verse $i",
lines = (1..6).map {
SongLine(
listOf(
LineSegment(chord = "C", text = "A long line of text that should be rendered properly "),
LineSegment(chord = "G", text = "with chords above each segment")
)
)
}
)
}
val song = Song(title = "Very Long Song", sections = sections)
val layout = LayoutResult(
tocPages = 0,
pages = listOf(
PageContent.SongPage(song, 0),
PageContent.SongPage(song, 1)
),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, BookConfig(), baos)
baos.size() shouldBeGreaterThan 0
}
@Test
fun `render places metadata at bottom of last page for two-page song`() {
val config = BookConfig(
layout = LayoutConfig(metadataPosition = "bottom")
)
val song = createLongSong().copy(
composer = "Bach",
lyricist = "Goethe"
)
val layout = LayoutResult(
tocPages = 0,
pages = listOf(
PageContent.SongPage(song, 0),
PageContent.SongPage(song, 1)
),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, config, baos)
baos.size() shouldBeGreaterThan 0
}
@Test
fun `render places notes on last page of two-page song`() {
val song = createLongSong().copy(
notes = listOf("This is a note that should appear on the last page")
)
val layout = LayoutResult(
tocPages = 0,
pages = listOf(
PageContent.SongPage(song, 0),
PageContent.SongPage(song, 1)
),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, BookConfig(), baos)
baos.size() shouldBeGreaterThan 0
}
@Test
fun `render places reference footer on last page of two-page song`() {
val config = BookConfig(
referenceBooks = listOf(
ReferenceBook(id = "mo", name = "Mundorgel", abbreviation = "MO"),
ReferenceBook(id = "pl", name = "Pfadfinderlied", abbreviation = "PL")
)
)
val song = createLongSong().copy(
references = mapOf("mo" to 42, "pl" to 17)
)
val layout = LayoutResult(
tocPages = 0,
pages = listOf(
PageContent.SongPage(song, 0),
PageContent.SongPage(song, 1)
),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, config, baos)
baos.size() shouldBeGreaterThan 0
}
@Test
fun `render handles short song that fits on one page without splitting`() {
// A simple short song should still work correctly after split logic is added
val song = Song(
title = "Short Song",
sections = listOf(
SongSection(
type = SectionType.VERSE,
lines = listOf(
SongLine(listOf(LineSegment(chord = "Am", text = "One line")))
)
)
)
)
val layout = LayoutResult(
tocPages = 0,
pages = listOf(PageContent.SongPage(song, 0)),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, BookConfig(), baos)
baos.size() shouldBeGreaterThan 0
}
@Test
fun `render two-page song with bottom metadata and references`() {
val config = BookConfig(
layout = LayoutConfig(
metadataPosition = "bottom",
metadataLabels = "german"
),
referenceBooks = listOf(
ReferenceBook(id = "mo", name = "Mundorgel", abbreviation = "MO")
)
)
val song = createLongSong().copy(
composer = "Bach",
lyricist = "Goethe",
notes = listOf("Play softly", "Repeat last verse"),
references = mapOf("mo" to 55)
)
val layout = LayoutResult(
tocPages = 0,
pages = listOf(
PageContent.SongPage(song, 0),
PageContent.SongPage(song, 1)
),
tocEntries = emptyList()
)
val baos = ByteArrayOutputStream()
renderer.render(layout, config, baos)
baos.size() shouldBeGreaterThan 0
}
}