Freepan View or Quickchange Margin View.

[vu205]

Can you help me add function quick change margin of view to corner of view can stay in middle of screen pdf ?
I work in technical drawing so I need read drawing pdf comfortable when view in midlle of screen.
I am using changing margin in setting but I have problem when I set margin to 800 .

[GitHubRulesOK]

A PDF "page" is normally not adjusted by a "viewer" so you need to be more descriptive about the requirement.
That setting is intended as a SMALL value between pages and the window frame so not what you seem to be attempting

WindowMargin = 2 4 2 4

You can change the outer viewer position and area easily by alter its screen location and viewport
OR you can crop a page to only show parts but that is an EDIT of the PDF internally
If you set all 4 values the same like 100 it just means the view will look like this and is not sensible to use high values

[GitHubRulesOK]

@kjk this seems to be a similar request to #6164

The concept seems to be to move all media viewport to upper right quartile but that is unusual ?

[vu205]

Currently, the drawing is always snapped/aligned to the corner of the view. Unlike standard text/word documents where content sits comfortably in the middle, technical drawing PDFs fill the entire sheet. Because of this corner-alignment, my eye position is forced to constantly look at the very edge/corner of the screen, which is quite uncomfortable. Is there a way to unbind/center the drawing and allow free panning with extra canvas space/padding around the view?

[GitHubRulesOK]

@vu205
Although PDF is similar to a Computer Aided Design / Graphics Format (charting not word processing) and Adobe Design software uses a less confined viewing model. They set the standard for PDF writing and viewing such a to constrain the viewing as if page CROP area only.

That does not mean SumatraPDF has to follow that model. However your request is less conventional behaviour compared to other PDF Page viewers. The main difference is that MuPDF is the core rendering in SumatraPDF and that is in part tied to a page treated as image co-ordinate system of top down and right units.

The developer (KJK) would have to add "padding" to all 4 sides of a page as a screen image when in "single page" mode as a minimum..
However the complexity is keeping that padding when zooming in and out and dragging.
Thus the simplest soloution is add false media size based on -1/2 w and - 1/2 Y something like this but unseen mathematics.

[kjk]

I've added Toggle Free Pan (CmdToggleFreePan, in the command palette).

When it's on, the view can go past the page edges by half a window in every direction, so any part of a page, including a corner, can be dragged or scrolled to the center of the screen. Fit Page / Fit Width and where a page lands when you navigate to it are unchanged; it only adds scroll room. The state is remembered per document.

It has no default shortcut. To bind it to F, add this to advanced settings:

Shortcuts [
    [
        Cmd = CmdToggleFreePan
        Key = f
    ]
]

(f is Toggle Fullscreen by default; this replaces it, F11 still toggles fullscreen.)

It'll be in the next pre-release build.