Bug 169111 - Writer (and Draw) form checkbox: tick does not scale at small sizes (e.g., 0.25 cm), not visible in PDF export
Summary: Writer (and Draw) form checkbox: tick does not scale at small sizes (e.g., 0....
Status: RESOLVED DUPLICATE of bug 87949
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
unspecified
Hardware: All All
: medium minor
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-10-28 13:02 UTC by chris.seiferth
Modified: 2025-11-17 18:51 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:


Attachments
screenshot of the checkbox's rendering (6.49 KB, image/png)
2025-11-16 20:34 UTC, chris.seiferth
Details

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Description chris.seiferth 2025-10-28 13:02:59 UTC
Description:
When creating a form in Writer and resizing a checkbox form control to very small dimensions (e.g., 0.25 cm × 0.25 cm), the checkmark (tick) seems so large, that only a small part of it is visable. The issue persists when exporting to PDF; the checkmark there is not visible at all in the resulting PDF, making compact form designs unusable.

Steps to Reproduce:
1. Writer / Draw → View > Toolbars > Form Controls → enable Design Mode.
2. Insert a Check Box control.
3. Set its size to 0.25 cm × 0.25 cm (Properties > Position and Size).
4. Exit Design Mode and click to check it.
5. File > Export As > Export as PDF (default settings) and open the PDF in a standard reader.

Actual Results:
- On screen: the tick is too large for the control, clipped or not visible.
- In PDF: the tick is not visible.


Expected Results:
The tick should scale proportionally to the control size so it remains fully visible on screen and in exported PDF, even at 0.25 cm × 0.25 cm.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
Version: 25.2.3.2 (X86_64) / LibreOffice Community
Build ID: 520(Build:2)
CPU threads: 8; OS: Linux 6.12; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: de-DE
Debian package version: 4:25.2.3-2+deb13u2
Calc: threaded
Comment 1 chris.seiferth 2025-10-28 13:09:09 UTC
This also happens with option fields

Proposed Solution:
1. Scalable Vector Rendering 
- Render checkbox marks as vector paths (not bitmaps) to scale proportionally with control size. 
- Use identical rendering path for on-screen display, print preview, and PDF export. 

2. Configurable Mark Styles 
- Add `Mark Style` property (dropdown: ✓ Check, X Cross, • Dot, Custom). 
- For font-based marks: Support Unicode glyph selection (e.g., U+2713 for ✓). 
- For vector marks: Provide predefined scalable paths per style. 

3. Scaling Controls 
- Add `Mark Scale` property (Auto, 50%, 75%, 100%, Custom %). 
- Add `Mark Line Width` property (e.g., 0.5 pt, 1.0 pt) to ensure legibility at small sizes. 

4. Reliability Safeguards 
- Enforce minimum mark visibility (e.g., auto-adjust `Mark Scale` if control height < 0.3 cm). 
- Trigger validation warning when mark may render invisibly (e.g., "Mark size too small for reliable output").
Comment 2 tkakar 2025-11-14 04:51:03 UTC
Unable to reproduce. The checkmark scales correctly. However, while it shows as a checkmark in LibreOffice, exporting as PDF converts it into an X mark. Since the original is about scaling (which worked for me), and not about symbol conversion, I'm marking as NEEDINFO. 

Tested in:

Version: 25.8.2.2 (X86_64)
Build ID: d401f2107ccab8f924a8e2df40f573aab7605b6f
CPU threads: 16; OS: Windows 11 X86_64 (build 26200); UI render: Skia/Vulkan; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL threaded

Version: 26.2.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 620(Build:0)
CPU threads: 16; OS: Windows 11 X86_64 (build 26200); UI render: Skia/Vulkan; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL threaded
Comment 3 chris.seiferth 2025-11-16 20:34:06 UTC
Created attachment 204029 [details]
screenshot of the checkbox's rendering
Comment 4 chris.seiferth 2025-11-17 12:36:03 UTC
I also have installed fonts-opensymbol
Comment 5 Buovjaga 2025-11-17 18:51:27 UTC
The issue with invisible checked state in exported PDFs is bug 160285

*** This bug has been marked as a duplicate of bug 87949 ***