https://bugs.kde.org/show_bug.cgi?id=409644
Bug ID: 409644 Summary: [Wayland] Panning is laggy Product: okular Version: unspecified Platform: Archlinux Packages OS: Linux Status: REPORTED Severity: normal Priority: NOR Component: PDF backend Assignee: okular-de...@kde.org Reporter: s.scalabri...@gmail.com Target Milestone: --- Okular version: 19.04.2 SUMMARY Using a 4K external display with my laptop in Wayland makes the "Browse tool" very laggy. For example, if I press the left mouse button, I move the pointer and I release the button, the viewing area of the PDF moves, but 4/5 times more slowly than the mouse pointer, i.e., it keeps moving when I release the button. If I do the same in the "Thumbnails" area, instead, it works correctly. I think this is similar to https://bugs.kde.org/show_bug.cgi?id=387567. I can experience the problem when: 1) the "Browse tool" is used in the PDF area; 2) the scrollbar of the PDF area is moved. Okular works correctly when: 1) I browse the thumbnails of the PDF; 2) I use the mouse wheel. STEPS TO REPRODUCE 1. Open a PDF Okular with a 4K external monitor connected 2. Press the left button in the PDF view area, move the pointer, release the button OBSERVED RESULT The movement is significantly slower than the pointer, the viewport keeps moving even after the mouse button is released. EXPECTED RESULT The viewport moves as fast as the mouse pointer and it stops when the left button is released. SOFTWARE/OS VERSIONS Linux/KDE Plasma: 5.1.15-arch1 (available in About System) KDE Plasma Version: 5.16.2 KDE Frameworks Version: 5.59.0 Qt Version: 5.13.0 Monitors: dual monitor, one 4K (external, scaled 2x), one 1080p (integrated in the laptop, not scaled) VGA controller: Intel Corporation UHD Graphics 630 ADDITIONAL INFORMATION This happens only in Wayland, not in X11. If I remember correctly, it doesn't happen when I don't connect the external monitor. -- You are receiving this mail because: You are watching all bug changes.