Bug 200558 – [Win][WebKit2] Can't prevent input events by canceling keydown events

• Component: WebKit2
• Status: RESOLVED DUPLICATE

[Fujii Hironori]

[Win][WebKit2] Can't prevent input events by canceling keydown events

You can test it by using
https://javascript.info/keyboard-events

In old Windows WK2, this issue was fixed in

Bug 56020 – WebKit2: Pressing Tab in Web Inspector's console does not cycle through completion options
r83633

In Windows WK1, WM_CHAR event is removed if WM_DOWN is consumed.

WebView::keyDown
::PeekMessage(&msg, m_viewWindow, WM_CHAR, WM_CHAR, PM_REMOVE);
https://trac.webkit.org/browser/webkit/trunk/Source/WebKitLegacy/win/WebView.cpp?rev=248454#L2393

r23462
r25377
r28620 (Bug 13916)

[Fujii Hironori]

Test cases testing preventing a keydown event.

fast/events/inputText-never-fired-on-keydown-cancel.html
fast/events/keydown-keypress-preventDefault.html

[Fujii Hironori]

In old WebKit2 approach, TranslateMessage was called if a keydown
event isn't comsumed.

This has two problems:
1. This method can't be used in applications which is using TranslateMessage normally.
   For example and particularly, MiniBrowser can't use it because it supports WK1 and WK2 windows.
2. keypress event could be dispatched after keyup event unexpectedly.
   For example, if I type VK_A and VK_B quickly. Following native key events are queued:

     WM_KEYDOWN (VK_A)
     WM_KEYUP (VK_A)
     WM_KEYDOWN (VK_B)
     WM_KEYUP (VK_B)

   The first WM_KEYDOWN is sent to web process, and remaining events are queued in m_keyEventQueue.
   In didNotHandleKeyEvent of the first event, WM_CHAR (a) is posted by TranslateMessage.
   This is too late.

[Fujii Hironori]

Created attachment 380184 [details]
WIP patch

This WIP patch removed queued WebEvent::Char events if WebEvent::RawKeyDown is handled.

This WIP patch works fine for MiniBrowser, but for WebKitTestRunner
because WebKitTestRunner processes IPC messages synchronously.

[Fujii Hironori]

Created attachment 380185 [details]
Patch

[Fujii Hironori]

Created attachment 380186 [details]
Patch

[Fujii Hironori]

(In reply to Fujii Hironori from comment #2)
> In old WebKit2 approach, TranslateMessage was called if a keydown
> event isn't comsumed.
> 
> This has two problems:
> 1. This method can't be used in applications which is using TranslateMessage
>    normally.
>    For example and particularly, MiniBrowser can't use it because it
>    supports WK1 and WK2 windows.

This might be possible by checking the target window is WK1.

>    while (PeekMessage(&msg, 0, 0, 0, PM_REMOVE)) {
>        if (isWebKit1BrowserWindow(msg.hwnd))
>            TranslateMessage(&msg);
>        DispatchMessage(&msg);
>    }

[Fujii Hironori]

Comment on attachment 380186 [details]
Patch

This approach doesn't seem good for Bug 202183. Cleared r? flag.

[Fujii Hironori]

Fixed in r252976.

*** This bug has been marked as a duplicate of bug 204694 ***