Thanks for the responses,

LGTM1

Thanks,
Vlad

On Wed, Mar 4, 2026 at 11:21 AM 'Gaston Rodriguez' via blink-dev <
[email protected]> wrote:

> Hi Vlad,
> *> Can you elaborate on the exact change this feature is introducing? It
> sounds like there is no change on Android since all of the required events
> are firing. Which additional events are now fired on other platforms when
> drag starts (and which events were already firing)?  *
> *> Are there any events that we are now _not_ firing as a result of this?*
>
> You're right that there's no change in Android since it was already
> satisfying the requirements. I removed the Android 147 ship tag. With this
> change, we now fire three additional events to the drag source on drag
> start:  `pointercancel`, `pointerout` and `pointerleave`, there are no
> events that have been removed. I updated the summary by adding the
> following paragraph:
> *> Practically, this means that after a drag has started the drag source
> will now receive the `pointercancel`, `pointerout` and `pointerleave`
> events to indicate that the current event stream has finished.*
>
> *> It seems to be passing right now, is that expected?*
>
> Yes, I had added the flag as experimental and assumed that the WPT
> platform wouldn't run with that flag enabled, TIL. Removed the disclaimer.
>
> Thanks!
>
> On Thursday, February 26, 2026 at 11:21:24 AM UTC-8 Vladimir Levin wrote:
>
>> Hi,
>>
>> Some comments below:
>>
>> On Wed, Feb 25, 2026 at 2:49 PM Chromestatus <
>> [email protected]> wrote:
>>
>>> *Contact emails*
>>> [email protected]
>>>
>>> *Specification*
>>>
>>> https://html.spec.whatwg.org/multipage/dnd.html#drag-and-drop-processing-model:~:text=Fire%20a%20pointer%20event%20at%20the%20source%20node%20named%20pointercancel%2C%20and%20fire%20any%20other%20follow%2Dup%20events%20as%20required%20by%20Pointer%20Events.%20%5BPOINTEREVENTS%5D
>>>
>>> *Summary*
>>> According to the HTML spec, when a drag starts the user agent should
>>> send the appropriate events to the drag source to indicate that the pointer
>>> event stream has ended, and that it shouldn't expect any more events from
>>> this pointer [1]. This code had been partially implemented for mouse events
>>> and fully implemented for touch drags on Android. With the work in this
>>> feature, we aim to fully satisfy this spec requirement on all other
>>> platforms. [1] Pointer event spec definition of pointer stream suppression:
>>> https://w3c.github.io/pointerevents/#suppressing-a-pointer-event-stream
>>>
>>> *Blink component*
>>> Blink>DataTransfer
>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EDataTransfer%22>
>>>
>>> *Web Feature ID*
>>> draganddrop <https://webstatus.dev/features/draganddrop>
>>>
>>> *Motivation*
>>> Chromium is currently out of spec when starting drag-and-drop
>>> operations. According to the specification, the user agent must notify the
>>> drag source that it will no longer receive pointer events from the same
>>> input source by firing the corresponding drag-* events. This behavior is
>>> fully implemented only on Android; on other platforms, Chromium does not
>>> fire all of the required events.
>>
>>
>> Can you elaborate on the exact change this feature is introducing? It
>> sounds like there is no change on Android since all of the required events
>> are firing. Which additional events are now fired on other platforms when
>> drag starts (and which events were already firing)?
>>
>> Are there any events that we are now _not_ firing as a result of this?
>>
>>
>>>
>>> *Initial public proposal*
>>> *No information provided*
>>>
>>> *TAG review*
>>> *No information provided*
>>>
>>> *TAG review status*
>>> Not applicable
>>>
>>> *Risks*
>>>
>>>
>>> *Interoperability and Compatibility*
>>> Other browsers also fall out of spec in this particular point and don't
>>> send the appropriate events when a drag starts, which means that Chromium
>>> will be the only browser that implements this behavior.
>>>
>>> *Gecko*: Neutral (https://bugzilla.mozilla.org/show_bug.cgi?id=1994552) A
>>> bug has been filed and has received interest from Firefox developers.
>>>
>>> *WebKit*: No signal (
>>> https://github.com/WebKit/standards-positions/issues/598) (Will update
>>> the signal when the issue receives feedback)
>>>
>>> *Web developers*: Positive (
>>> https://github.com/w3c/pointerevents/issues/555) We have received
>>> developer feedback [1] regarding the browser's behavior with respect to the
>>> specification.
>>>
>>> *Other signals*:
>>>
>>> *WebView application risks*
>>>
>>> Does this intent deprecate or change behavior of existing APIs, such
>>> that it has potentially high risk for Android WebView-based applications?
>>> No, and if any issue is found, we have a feature flag acting as a kill
>>> switch (SuppressPointerStreamAfterDrag).
>>>
>>>
>>> *Debuggability*
>>> No additional functionality is needed to be added to debug this feature
>>>
>>> *Will this feature be supported on all six Blink platforms (Windows,
>>> Mac, Linux, ChromeOS, Android, and Android WebView)?*
>>> Yes
>>>
>>> *Is this feature fully tested by web-platform-tests
>>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?*
>>> Yes
>>> https://wpt.fyi/results/html/editing/dnd/events/pointer-suppression.html
>>> (currently failing because the change is behind a disabled feature flag)
>>>
>>
>> It seems to be passing right now, is that expected?
>>
>> Thanks!
>> Vlad
>>
>>
>>>
>>> *Flag name on about://flags*
>>> *No information provided*
>>>
>>> *Finch feature name*
>>> SuppressPointerStreamAfterDrag
>>>
>>> *Non-finch justification*
>>> The feature will be shipped enabled by default to be used as a
>>> kill-switch in case a severe issue is discovered.
>>>
>>> *Rollout plan*
>>> Will ship enabled for all users
>>>
>>> *Requires code in //chrome?*
>>> False
>>>
>>> *Tracking bug*
>>> https://issues.chromium.org/issues/452372355
>>>
>>> *Estimated milestones*
>>> Shipping on desktop 147
>>> Shipping on Android 147
>>>
>>> *Anticipated spec changes*
>>>
>>> Open questions about a feature may be a source of future web compat or
>>> interop issues. Please list open issues (e.g. links to known github issues
>>> in the project for the feature specification) whose resolution may
>>> introduce web compat/interop risk (e.g., changing to naming or structure of
>>> the API in a non-backward-compatible way).
>>> N/A
>>>
>>> *Link to entry on the Chrome Platform Status*
>>> https://chromestatus.com/feature/6732314958757888?gate=6606447989358592
>>>
>>> This intent message was generated by Chrome Platform Status
>>> <https://chromestatus.com>.
>>>
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>>> .
>>>
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