Fix page overflow: add bounds checking and content splitting for multi-page songs #17

New Issue

shahondin1624 · 2026-03-17T14:08:33+01:00

shahondin1624 commented

2026-03-17 14:08:33 +01:00

Description

The PDF renderer (PdfBookRenderer) has no bounds checking when placing content on pages. The y coordinate decreases as content is added, but nothing prevents it from going below the bottom margin, causing text and images to render outside the visible page area.

Additionally, 2-page songs currently render all content on page 0 and leave page 1 blank (see comment at PdfBookRenderer.kt:160). There is no content splitting across pages.

The measurement engine's height estimates are also approximate (line height = 1.2 × fontSize), so even songs classified as 1-page may overflow if the estimate diverges from actual rendering.

Root Causes

No bounds checking: renderSongPage() never checks if y has gone below the bottom margin
No content splitting: 2-page songs put everything on page 0; page 1 is blank
Approximate measurement: PdfFontMetrics estimates may diverge from actual rendered sizes

Acceptance Criteria

The renderer tracks the current y position against the bottom margin during song page rendering
For 2-page songs, content is split across pages when it exceeds the available space on page 0 — remaining sections continue on page 1
Content that would be rendered below the bottom margin (minus space reserved for bottom metadata/references) is moved to the next page
If metadata is configured for "bottom" position, sufficient space is reserved at the bottom of the last page before rendering content
No text or images are rendered outside the printable page area
Existing tests continue to pass
New tests verify that content splitting works correctly for songs that exceed one page

Implementation Hints

In PdfBookRenderer.renderSongPage(), track y and compare against a yMin (bottom margin + reserved footer space)
When y would drop below yMin on page 0 of a 2-page song, stop rendering on page 0 and continue remaining sections on page 1
Consider splitting at section boundaries (between verses/choruses) rather than mid-section for cleaner page breaks
The measurement engine may also need adjustment if the split logic reveals measurement inaccuracies

## Description The PDF renderer (`PdfBookRenderer`) has no bounds checking when placing content on pages. The `y` coordinate decreases as content is added, but nothing prevents it from going below the bottom margin, causing text and images to render outside the visible page area. Additionally, 2-page songs currently render **all content on page 0** and leave page 1 blank (see comment at `PdfBookRenderer.kt:160`). There is no content splitting across pages. The measurement engine's height estimates are also approximate (line height = `1.2 × fontSize`), so even songs classified as 1-page may overflow if the estimate diverges from actual rendering. ## Root Causes 1. **No bounds checking**: `renderSongPage()` never checks if `y` has gone below the bottom margin 2. **No content splitting**: 2-page songs put everything on page 0; page 1 is blank 3. **Approximate measurement**: `PdfFontMetrics` estimates may diverge from actual rendered sizes ## Acceptance Criteria - [ ] The renderer tracks the current `y` position against the bottom margin during song page rendering - [ ] For 2-page songs, content is split across pages when it exceeds the available space on page 0 — remaining sections continue on page 1 - [ ] Content that would be rendered below the bottom margin (minus space reserved for bottom metadata/references) is moved to the next page - [ ] If metadata is configured for "bottom" position, sufficient space is reserved at the bottom of the last page before rendering content - [ ] No text or images are rendered outside the printable page area - [ ] Existing tests continue to pass - [ ] New tests verify that content splitting works correctly for songs that exceed one page ## Implementation Hints - In `PdfBookRenderer.renderSongPage()`, track `y` and compare against a `yMin` (bottom margin + reserved footer space) - When `y` would drop below `yMin` on page 0 of a 2-page song, stop rendering on page 0 and continue remaining sections on page 1 - Consider splitting at section boundaries (between verses/choruses) rather than mid-section for cleaner page breaks - The measurement engine may also need adjustment if the split logic reveals measurement inaccuracies

shahondin1624 referenced this issue from a commit

2026-03-17 14:17:52 +01:00

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

shahondin1624 referenced a pull request that will close this issue

2026-03-17 14:18:01 +01:00

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

shahondin1624 closed this issue

2026-03-17 14:18:07 +01:00

shahondin1624 referenced this issue from a commit

2026-03-17 14:18:09 +01:00

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

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