fix: prevent drop files overlay from appearing when dragging text sel…

[JorgeEscire]

References

• Fixes Dragging text selection over submission form triggers "drop files" message #1268

Description

Prevent the "drop files" overlay from appearing when dragging text selections in Firefox on submission pages.

Instructions for Reviewers

Problem

In Firefox, dragging text selections on submission pages (new submission or edit workspace item) triggers the "Drop files to attach them to the item" overlay. This happens because the window:dragover event handlers in UploaderComponent and FileDropzoneNoUploaderComponent don't distinguish between file drags and text selection drags. Sometimes the overlay stays visible until the page is refreshed.

Chrome doesn't have this issue because it doesn't support dragging text selections in the same way.

Fix

Added a check on event.dataTransfer.types to verify it contains 'Files' before showing the document drop zone overlay. When dragging text, dataTransfer.types only contains text/plain and/or text/html, not Files.

List of changes in this PR:

• Added dataTransfer.types.includes('Files') guard in UploaderComponent.onDragOver() (uploader.component.ts)
• Added the same guard in FileDropzoneNoUploaderComponent.onDragOver() (file-dropzone-no-uploader.component.ts)

How to test

1. Open the application in Firefox
2. Navigate to a new submission or edit a workspace item
3. Select some text on the page
4. Drag the text selection around the page
5. Expected: The "Drop files" overlay should NOT appear
6. Now drag an actual file from your file explorer onto the page
7. Expected: The "Drop files" overlay should appear as normal

Checklist

• My PR is created against the main branch of code (unless it is a backport or is fixing an issue specific to an older branch).
• My PR is small in size (e.g. less than 1,000 lines of code, not including comments & specs/tests), or I have provided reasons as to why that's not possible.
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• My PR includes TypeDoc comments for all new (or modified) public methods and classes. It also includes TypeDoc for large or complex private methods.
• My PR passes all specs/tests and includes new/updated specs or tests based on the Code Testing Guide.
• My PR aligns with Accessibility guidelines if it makes changes to the user interface.
• My PR uses i18n (internationalization) keys instead of hardcoded English text, to allow for translations.
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• If my PR includes new libraries/dependencies (in package.json), I've made sure their licenses align with the DSpace BSD License based on the Licensing of Contributions documentation.
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[lgeggleston]

Thank you for the fix @JorgeEscire! You may have already seen, but just to note looks like this is currently failing one of the e2e tests.