Created attachment 189597 [details]
poster_feature

SUMMARY Add native poster printing (tiled printing) capability to Okular. This feature allows users to scale up a document and print it across multiple physical sheets of paper, which can then be assembled into a larger poster.

STEPS TO REPRODUCE

Open a document (e.g., a PDF) in Okular.
Select File -> Print (Ctrl+P).
Click on the "Options" or "Properties" button to see the Okular-specific print options.
Change the "Print Mode" from "Fit to printable area" to "Poster".
Adjust "Tile Scale" (e.g., 200%) and "Overlap" as desired.
Enable "Draw Cut Marks" and "Draw Labels" for easier assembly.
Observe the live preview on the right side of the dialog.
Click "Print".
OBSERVED RESULT Currently, Okular only supports "Fit to printable area", "Fit to full page", and "Multiple pages per sheet (N-Up)". To print a poster, users must rely on external tools or specialized printer drivers, which often lack a live preview of how the tiles will be cut.

EXPECTED RESULT Okular should provide a built-in "Poster" mode that handles the tiling logic internally, providing a live preview of the grid, mandatory/optional overlap regions, and helper marks (cut marks/labels) to facilitate the creation of large-format prints from standard desktop printers.

SOFTWARE/OS VERSIONS Windows: (Please fill if applicable) macOS: (Please fill if applicable) Linux/KDE Plasma: Linux (CachyOS/Ubuntu/Debian - please specify your distro) KDE Plasma Version: (Check in Info Center) KDE Frameworks Version: (Check in Info Center) Qt Version: (Check in Info Center)

ADDITIONAL INFORMATION This feature has been implemented with a dedicated 
PosterPrinter
 class and a 
PosterPreviewWidget
 for real-time visual feedback. The preview shows:

The page grid.
Overlap areas (shaded).
Tile coordinates (if enabled).
Example preview image: https://github.com/3ddruck12/okular/raw/work/poster-printing/okularposter.png Implementation branch: https://github.com/3ddruck12/okular/tree/work/poster-printing