TF-2764 Add adr for preview PDF in EmailView

docs/adr/0048-view-one-by-one-pdf-in-dart-side-in-only-web-app.md

@@ -0,0 +1,28 @@
+# 48. View one-by-one PDF in Dart side in only Web app
+
+Date: 2024-05-17
+
+## Status
+
+Accepted
+
+## Context
+
+- In EmailView when the user clicks on an attachment, we should display a PDF viewer for the user.
+- In PDF Viewer users can view full pages of the PDF file and can download or print it.
+
+## Decision
+
+- Create PDF Viewer with [pdf_render](https://github.com/linagora/flutter_pdf_render.git)
+- Viewer will stay overlay in web app tab
+- Actions supported: `Download`, `Print`, `Zoom In/Out`, `Show current/total pages` in viewer
+
+## Consequences
+
+- PDF viewer works well on all browsers (Chrome/Firefox/Edge/Safari/Opera)
+
+## Improvement
+
+- `Print name`: Some browsers (Firefox/Safari/Edge) use a random name to name the file when printing.
+- `Jump to page`: When using the standard size of PDF pages to display in the viewer, the `jumpToPage` method of `pdf_render` does not work correctly. So we will temporarily disable it.
+- `Drag the scrollbar`: Currently the pdf page is displayed in an `Interactive viewer` so does not interact with the `Scrollbar`