improvements to selecting multiple files to send

[Simon-Laux]

• Dropping multiple files onto deltachat now sends images as compressed images instead of uncompressed files
• Added support for selecting multiple files in the attachment file picker.
• fix compression of images when added with Image option from attachment menu

closes #4219

[WofWca]

I did not test the browser version, but the Electron one looks alright, apart from removeTempFile().

I tested it on a surface level, and looked at the code somewhat thoroughly. It appears to only affect the places where multiSelections is used, otherwise the behavior of showOpenFileDialog is the same.

In addition, I would assume we don't want to release it with 1.48?

[WofWca]

So this is copy-pasted from

deltachat-desktop/packages/frontend/src/components/message/MessageListAndComposer.tsx

Lines 168 to 190 in f0e4cc5

	openDialog(ConfirmSendingFiles, {
	sanitizedFileList,
	chatName: chat.name,
	onClick: async (isConfirmed: boolean) => {
	if (!isConfirmed) {
	return
	}
	for (const file of sanitizedFileList) {
	const path = await writeTempFileFromFile(file)
	const msgViewType: Viewtype = file.type.startsWith('image')
	? 'Image'
	: 'File'
	sendMessage(accountId, chat.id, {
	file: path,
	viewtype: msgViewType,
	}).then(() => {
	// start sending other files, don't wait until last file is sent
	runtime.removeTempFile(path)
	})
	}
	},
	})

but in that code we also do writeTempFileFromFile. Why do we have to do that there, but not here.

And, most importantly, if we decide to not create temp files, we should not runtime.removeTempFile() here. Currently in Electron this simply gives an error of "Path is outside of the temp folder". I did not check what the browser version does, but it does not look good.

I think it'd be nice to add a docstring to removeTempFile, or somehow make it safer in general.

[Simon-Laux]

but in that code we also do writeTempFileFromFile. Why do we have to do that there, but not here.

because here we get valid file paths.
everything would be cleaner if we could pass files directly to core without these temp files, but that api doesn't exist yet.

For drag and drop I needed to change it, because it was an electron specific api and also did not always work #3595.

but it does not look good.

I know, needs to be improved, I plan to move the used temp folder to a different place, I already added a todo item to #4232 - in that process we can make the path check even safer.

[WofWca]

I know, needs to be improved

I'm interested in a sense that it wouldn't work great if you pass normal, non-temporary files there 😅

[Simon-Laux]

In addition, I would assume we don't want to release it with 1.48?

works, fixes bugs and brings a usecase back that would otherwise have been removed (send multiple images files uncompressed in one action). So I would release it with 1.48, we will have a few more test releases before it anyway.

I did not test the browser version

I tested it in the browser and on electron.

[nicodh]

I missed before that this includes a bugfix - so if we skip the wrong removeTempFile line I would vote to include it in the release

[nicodh]

The line
runtime.removeTempFile(filePath)
is definitely wrong since as Simon says, filePath is the original file path

"Why do we have to do that there," ?
The reason is that drag & drop only provides DataTransfer files which have no path and we need to pass a local path as file attachement to core

[Simon-Laux]

it is needed for browser, for electron the call just failed because it can not delete non-temp files.
I put a if-clause around it to only run it in browser target.