input.fileDialogOpened + unhandledPromptBehavior:file

[sadym-chromium]

This PR implements input.fileDialogOpened event and defines unhandledPromptBehavior for file. It should be accompanied by the following changes:
HTML spec: whatwg/html#11030
WebDriver Classic spec: w3c/webdriver#1884
File system access: WICG/file-system-access#452

Open questions:

1. Should the dialogs be dismissed, or just suppressed in case of user passes "accept" / "ignore"? Current implementation cancels the dialog, which is consistent with other user prompts.
2. Should the event be merged into browsingContext.userPromptOpened? If so, there will be no way of subscribing only for input.fileDialogOpened event. Also, file dialogs are specific, as it does not support browsingContext.handleUserPrompt.

Re-imagining the #568, addressing #494.

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Preview | Diff

[OrKoN]

LGTM

[juliandescottes]

just 2 nits otherwise lgtm

[sadym-chromium]

@juliandescottes PTAL on the w3c/webdriver#1884

[whimboo]

@sadym-chromium when filling out the BiDi status spreadsheet I stumbled over this PR and the question if we actually want to have a input.dismissFileDialog command. There was such one suggested over on #535 but that PR got closed, and I cannot find any other reference.

Given that you already have input.fileDialogOpened implemented in Chrome do you think that we still need such a method? Thanks.

[sadym-chromium]

@sadym-chromium when filling out the BiDi status spreadsheet I stumbled over this PR and the question if we actually want to have a input.dismissFileDialog command. There was such one suggested over on #535 but that PR got closed, and I cannot find any other reference.

Given that you already have input.fileDialogOpened implemented in Chrome do you think that we still need such a method? Thanks.

I can be mistaken, but from what I remember, dismissing file dialogs is not possible in some OS. I think current functionality covers all the scenario we are aware of, and we don't need input.dismissFileDialog method.

[whimboo]

@sadym-chromium when filling out the BiDi status spreadsheet I stumbled over this PR > I can be mistaken, but from what I remember, dismissing file dialogs is not possible in some OS. I think current functionality covers all the scenario we are aware of, and we don't need input.dismissFileDialog method.

Hm, so we basically have the event input.fileDialogOpened, which is emitted when a file dialog is opened. Does it mean that we do not show a real file picker but just a mock? I actually cannot remember anymore what the decision actually was here.

[sadym-chromium]

@sadym-chromium when filling out the BiDi status spreadsheet I stumbled over this PR > I can be mistaken, but from what I remember, dismissing file dialogs is not possible in some OS. I think current functionality covers all the scenario we are aware of, and we don't need input.dismissFileDialog method.

Hm, so we basically have the event input.fileDialogOpened, which is emitted when a file dialog is opened. Does it mean that we do not show a real file picker but just a mock? I actually cannot remember anymore what the decision actually was here.

Showing or not the file dialog depends on the "unhandledPromptBehavior:file" capability, and the event is emitted regardless of that.

[whimboo]

Showing or not the file dialog depends on the "unhandledPromptBehavior:file" capability, and the event is emitted regardless of that.

Lets see where we end-up when we are going to implement the file open dialog support. We will reporter back then.