Now, along with the mouse events we also dispatch pointerup, pointerdown
and pointermove.
With this change shape painting works on https://excalidraw.com/
For example, in the following HTML:
```html
<label>
<input type="radio" name="fruit" value="apple" id="radio1">
<span class="box"></span>
</label>
```
When any descendant of a <label> element is clicked, a "click" event
must be dispatched on the <input> element nested within the <label>, in
addition to the "click" event dispatched on the clicked descendant.
Previously, this behavior was implemented only for text node descendants
by "overriding" the mouse event target using `mouse_event_target()` in
the TextPaintable. This approach was incorrect because it was limited to
text nodes, whereas the behavior should apply to any box. Moreover, the
"click" event for the input control must be dispatched *in addition* to
the event on the clicked element, rather than redirecting it.
We have support for using (shift+)tab to move focus to the next/previous
element on the page. However, there were several ways for this to crash
as written. This updates our implementation to check if we did not find
a node to move focus to, and to reset focus to the first/last node in
the document.
This doesn't seem to work when wrapping around from the first to the
last node. A FIXME has been added for that, as this would already not
work before this patch (the main focus here is not crashing).
Our handling of left vs. right modifiers keys (shift, ctrl, etc.) was
largely not to spec. This patch adds explicit UIEvents::KeyCode values
for these keys, and updates the UI to match native key events to these
keys (as best as we are able).
We were generating click events always using the primary mouse button
instead of the provided button, and with the buttons field set to that
provided button.
We should only block the escape key from being sent to the web page if
the CloseWatcherManager actually closed something.
We use the escape key in the Inspector to cancel editing a DOM field.
This unconditional early return broke this feature.
This returns the secondary target of a mouse event. For `onmouseenter`
and `onmouseover` events, this is the EventTarget the mouse exited
from. For `onmouseleave` and `onmouseout` events, this is the
EventTarget the mouse entered to.
