fix: position reference footer below content to prevent overlap (Closes #25) (#28)

layout/src/main/kotlin/de/pfadfinder/songbook/layout/MeasurementEngine.kt

@@ -91,11 +91,11 @@ class MeasurementEngine(
             }
         }
 
-        // Reference book footer: reserve space for abbreviation row + page number row + separator line
+        // Reference book footer: gap + separator line + abbreviation row + page number row
         if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
             val metaLineHeight = fontMetrics.measureLineHeight(config.fonts.metadata, config.fonts.metadata.size)
+            heightMm += 4f * 0.3528f         // gap before footer (4pt converted to mm)
             heightMm += metaLineHeight * 1.4f * 2  // two rows (headers + numbers)
-            heightMm += metaLineHeight * 0.5f  // separator line gap
         }
 
         val pageCount = if (heightMm <= contentHeightMm) 1 else 2

renderer-pdf/src/main/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfBookRenderer.kt

@@ -240,12 +240,11 @@ class PdfBookRenderer : BookRenderer {
             }
         }
 
-        // Reference footer
+        // Reference footer: gap + separator line + abbreviation row + page number row
         if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
             val lineHeight = metaSize * 1.4f
+            reserved += 4f              // gap before footer
             reserved += lineHeight * 2  // two rows (headers + numbers)
-            reserved += lineHeight * 1.5f  // separator line gap
-            reserved += lineHeight * 0.5f  // bottom gap
         }
 
         return reserved
@@ -474,10 +473,10 @@ class PdfBookRenderer : BookRenderer {
 
         // Render reference book footer on the last page of the song
         if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty() && isLastPage) {
+            y -= 4f  // gap before reference footer
             renderReferenceFooter(
                 cb, fontMetrics, config, song,
-                leftMargin, contentWidth,
-                bottomMargin
+                leftMargin, y, contentWidth
             )
         }
     }
@@ -512,8 +511,9 @@ class PdfBookRenderer : BookRenderer {
     }
 
     /**
-     * Renders reference book abbreviations and page numbers as a footer row
-     * at the bottom of the song page, above the page number.
+     * Renders reference book abbreviations and page numbers as a footer
+     * on the song page, positioned below the current content at [topY].
+     * Layout (top to bottom): separator line, abbreviation row, page number row.
      */
     private fun renderReferenceFooter(
         cb: PdfContentByte,
@@ -521,40 +521,44 @@ class PdfBookRenderer : BookRenderer {
         config: BookConfig,
         song: Song,
         leftMargin: Float,
-        contentWidth: Float,
-        bottomMargin: Float
+        topY: Float,
+        contentWidth: Float
     ) {
         val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
         val metaSize = config.fonts.metadata.size
         val lineHeight = metaSize * 1.4f
 
-        // Position: just above the page number area
-        val footerY = bottomMargin + lineHeight * 0.5f
-
-        // Map book IDs to abbreviations
-        val refAbbreviations = config.referenceBooks.associate { it.id to it.abbreviation }
         val books = config.referenceBooks
 
         // Calculate column widths: evenly distribute across content width
         val colWidth = contentWidth / books.size
 
-        // Row 1: Abbreviation headers
+        // Draw a thin separator line at the top of the footer
+        val lineY = topY
+        cb.setLineWidth(0.3f)
+        cb.setColorStroke(Color.LIGHT_GRAY)
+        cb.moveTo(leftMargin, lineY)
+        cb.lineTo(leftMargin + contentWidth, lineY)
+        cb.stroke()
+
+        // Row 1: Abbreviation headers (below the separator line)
+        val abbrY = lineY - lineHeight
         for ((i, book) in books.withIndex()) {
             val x = leftMargin + i * colWidth
             val abbr = book.abbreviation
             val textWidth = metaFont.getWidthPoint(abbr, metaSize)
-            // Center text in column
             val textX = x + (colWidth - textWidth) / 2
 
             cb.beginText()
             cb.setFontAndSize(metaFont, metaSize)
             cb.setColorFill(Color.DARK_GRAY)
-            cb.setTextMatrix(textX, footerY + lineHeight)
+            cb.setTextMatrix(textX, abbrY)
             cb.showText(abbr)
             cb.endText()
         }
 
-        // Row 2: Page numbers
+        // Row 2: Page numbers (below abbreviation headers)
+        val numY = abbrY - lineHeight
         for ((i, book) in books.withIndex()) {
             val x = leftMargin + i * colWidth
             val pageNum = song.references[book.id]
@@ -566,18 +570,11 @@ class PdfBookRenderer : BookRenderer {
                 cb.beginText()
                 cb.setFontAndSize(metaFont, metaSize)
                 cb.setColorFill(Color.DARK_GRAY)
-                cb.setTextMatrix(textX, footerY)
+                cb.setTextMatrix(textX, numY)
                 cb.showText(pageText)
                 cb.endText()
             }
         }
-
-        // Draw a thin line above the footer
-        cb.setLineWidth(0.3f)
-        cb.setColorStroke(Color.LIGHT_GRAY)
-        cb.moveTo(leftMargin, footerY + lineHeight * 1.5f)
-        cb.lineTo(leftMargin + contentWidth, footerY + lineHeight * 1.5f)
-        cb.stroke()
     }
 
     private fun renderForewordPage(

songbook.yaml

@@ -37,6 +37,9 @@ reference_books:
     name: "Pfadfinderliederbuch"
     abbreviation: "PfLB"
 
+toc:
+  highlight_column: "Seite"
+
 output:
   directory: "./output"
   filename: "liederbuch.pdf"