Add warning on tab close

[JustusFT]

Ref: #80

When the user tries to navigate away during a transfer, they will be prompted with a warning that the transfer will cancel. Note that newer browser versions will not show the custom error message but instead a generic warning. See this for more information: https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event#compatibility_notes

Closing the tab or clicking a link will trigger the warning on the following screens:

• ReceiveConsentScreen
• ReceiveProgressScreen
• SendInstructionsScreen
• SendProgressScreen

[JustusFT]

Also, maybe we should do something about this link to the terms in ReceiveConsentScreen, such as having it open in a new tab or in a modal to prevent the warning from happening.

Also, a better solution later on could be that the user is allowed to view other pages during a transfer, and have a way to return to the ongoing transfer screen

[donpui]

Also, a better solution later on could be that the user is allowed to view other pages during a transfer, and have a way to return to the ongoing transfer screen

This would be nice thing. Probably we will need this when we will have dilation and multiple file transfer sending.

[donpui]

Also, maybe we should do something about this link to the terms in ReceiveConsentScreen, such as having it open in a new tab or in a modal to prevent the warning from happening.

Probably this is the case, where we need to force user open in new tab.

[donpui]

FYI: On iOS Safari/Chrome this doesn't work.. however with Android Chrome it works.

[donpui]

Copy link button doesn't work for me. @JustusFT can you verify on your side?

[donpui]

Desktop Chrome/Firefox/Safari are working

[donpui]

Check Copy link. Also Terms link make _blank to open in new tab.

[JustusFT]

@donpui Looks like the mobile clipboard issue was present for a while. I made a separate PR for the fix: #112

[donpui]

@donpui Looks like the mobile clipboard issue was present for a while. I made a separate PR for the fix: #112

This helped, thanks

[donpui]

Seems ok