The issue described in the mentioned bug is reall because
Acrobat is rendering the XFA instead of the Acroform.
The original patch just tried to workaround the issue but it
induces some regressions.
This was added in PR 14899, over a year ago, however it's still completely unused in the PDF.js library/viewer. In hindsight I think that it was a mistake to add unused functionality, and the issue should probably have been WONTFIXed instead, however we probably can't just remove it now.
Thanks to the pre-processor, we can at least exclude this code in the *built-in* Firefox PDF Viewer.
After the changes in PR 16828 the `StampEditor` can now be initialized with a File, in addition to a URL, hence it seems that the `isEmpty` method ought to take that property into account as well.
Looking at this I also noticed that the assignment in the constructor may cause the `this.#bitmapUrl`/`this.#bitmapFile` fields be `undefined` which "breaks" the comparisons in the `isEmpty` method.
We could obviously fix those specific cases, but it seemed overall safer (with future changes) to just update the `isEmpty` method to be less sensitive to exactly how these fields are initialized and reset.
Currently we're repeating virtually the same code *four times* when fetching the bitmap-data, which seems unnecessary.
Also, ensure that the `#bitmapPromise` is always `null`ed by moving that into the `StampEditor.#getBitmapDone` method.
Given that the `PDFDocumentLoadingTask.destroy()`-method is documented as being asynchronous, you thus need to await its completion before attempting to load a new PDF document when using the global `workerPort`.
If you don't await destruction as intended then a new `getDocument`-call can remain pending indefinitely, without any kind of indication of the problem, as shown in the issue.
In order to improve the current situation, without unnecessarily complicating the API-implementation, we'll now throw during the `getDocument`-call if the global `workerPort` is in the process of being destroyed.
This part of the code-base has apparently never been covered by any tests, hence the patch adds unit-tests for both the *correct* usage (awaiting destruction) as well as the specific case outlined in the issue.
The main stamp button will be used to just enter in a add/edit image mode:
- the user can add a new image in using the new button.
- the user can edit an image in resizing, moving it.
In image mode, when the user clicks outside on the page but not on an editor,
then all the selected editors will be unselected.
Given that the FieldObjects are parsed in parallel, in combination with the existing caching in the `getPage`-method and `annotations`-getter, adding additional caches for this fallback code-path doesn't seem entirely necessary.
We're adding the action in the undo/redo stack whatever the status of the
operation was. This patch aims to add the action only when the image has been
successfully added.
When several editors are selected and the window loses and then gets back its focus,
the previously focused editor is triggering its focus callback making it the only
selected one.
This patch aims to avoid triggering the focus callback called when the main window
gets its focus back.
When moving an element in the DOM, the focus is potentially lost, so we need to make sure
that the focused element before the translation will get back its focus after it.
But we must take care to not execute any focus/blur callbacks because the user didn't
do anything which should trigger such events: it's a detail of implementation. For example,
when several editors are selected and moved, then at the end the same must be selected, so
no element receive a focus event which will set it as selected.
There are 2 rotation we've to deal with: the viewer one and the editor one.
The previous implementation was a bit complex and having to deal with these
rotation would have potentially increase it.
So this patch aims to simplify the implementation and deal with all the possible
cases.
The main idea is to transform the mouse deltas according to the rotations and then
apply the resizing in the page coordinates system.
