[Feature]: Remember Last Zoom #20545
Description
Is the feature relevant to the Firefox PDF Viewer?
No
Feature description
Feature: Remember last zoom level across sessions
What it does: Adds a user-toggle in the Tools (secondary) menu, “Remember zoom,” that, when enabled, stores the last zoom level used in the viewer. On reopening a PDF (with no overriding per-document history), the viewer applies that stored zoom automatically instead of the default scale.
Why: Users frequently prefer a consistent zoom level; this removes the need to reselect their preferred zoom on each open.
Scope: Generic web viewer. Preference persisted via viewer prefs/localStorage; integrates with existing toolbar UI and event bus.
User flow
Open the viewer.
Open Tools menu → toggle “Remember zoom” on.
Set a zoom (e.g., 175% or Page Width).
Reload and reopen a PDF; zoom should restore to the remembered value unless a document-specific view history overrides it.
Toggle off to revert to normal default/history behavior.
Behavior details
Preference flag: rememberLastZoom (boolean) with stored value rememberLastZoomValue (string).
Remembered zoom is updated on zoom change when the toggle is enabled.
On load: uses defaultZoomValue first; if absent and remember-last-zoom is enabled and has a stored value, applies that (unless view history supplies its own zoom when viewOnLoad isn’t INITIAL).
Acceptance criteria
Toggle appears in Tools menu with proper label/tooltip and reflects state.
With toggle on, changing zoom and reloading restores that zoom on next open (when no overriding history).
With toggle off, remembered zoom is not applied; defaults/history continue to work.
Preference persists across reloads; no console errors.
Other PDF viewers
No response