PDF and images

.pdf files open in a native viewer (Qt6::Pdf, no heavy dependencies), rendered on the CPU and without WebEngine. Images open in the image view; animated GIFs play in the animated view.

The tab toolbar offers six side panels, one at a time: Outline (the table of contents stored in the file itself — when the PDF has none, the button is disabled and says so), Thumbnails (the pages at a glance, rendered as you scroll), Search, Links, Properties (title, author, dates, page and file size) and Highlights (the passages you highlighted, in reading order).

Search (Ctrl+F) looks through the whole document: matches are highlighted on the pages and listed with their surrounding text, and F3 / Shift+F3 step between them. The scan is progressive, so the list grows as the document is walked through.

The page field accepts the number or the printed label: in a document whose front matter is numbered in roman numerals, typing 1 goes to the printed page "1", not to the first sheet. The page mode button switches between continuous scrolling and one page at a time.

A password protected PDF asks for the password when opened (up to three tries); cancelling simply leaves the tab unopened. Within the same LightNote run the password is not asked again — the app reopens the tab by itself when it releases it for being idle, and it would be the app creating the annoyance. Ticking "Remember this file's password" in the prompt makes it last across runs too: it is protected by Windows (only for you, only on this machine), never goes to Git or to the cloud, and is not carried by the settings export. To erase them all: Settings → Features → Protected file passwords. A protected PDF is not reopened on startup — instead of queueing password prompts before showing the window, it waits for you to open it.

From the toolbar action menu: copy the page text, export the whole document's text, copy or save the page as an image, and send the page to today's note. The Links panel exists because Qt's PDF component follows internal links on its own but ignores external ones — that is where a web address is opened, with a confirmation.

Highlighting. The Highlight button turns on the marker pen: drag over the page's text and the passage is highlighted; the arrow beside it picks the colour. The highlight attaches to the text, not to a rectangle — that is why it follows zoom and page mode without drifting, and why it does not work on a scanned PDF, which has no text layer (the app says so instead of doing nothing). In the Highlights panel, clicking jumps to the page and the context menu adds a note, copies the passage or deletes it. In the toolbar's action menu, Copy the highlights and Save the highlights as a note… write the reading notes in Markdown: each passage as a quote and, per page, a link that opens the PDF there (paper.pdf#page=12). The price: highlights are saved in a file beside the PDF (paper.pdf.highlights.json, readable text you can version with Git) and not inside it — so they show up in LightNote and not in another PDF reader. If the file is replaced by a different version, a highlight that lost its place is marked as such instead of being painted over the wrong sentence.

Limitation: outside the marker pen there is no mouse text selection, because Qt's PDF component does not provide it. To take the content with you, use "copy this page's text", the document export or the highlight itself.