HtmlEventProperties class

The dynamic event-payload bag passed to every HtmlElement.AddEventListener callback. Conceptually the IDE-side equivalent of the JavaScript Event object — fields like .key, .target.id, .target.value, .index are accessed dynamically through the bag’s [COMExtensible(True)] resolution.

Private Sub MyButtonClicked(ByVal eventInfo As HtmlEventProperties)
    Host.DebugConsole.PrintText "clicked: " & eventInfo.target.id
End Sub

Private Sub MyKeyUp(ByVal eventInfo As HtmlEventProperties)
    If eventInfo.key = "Enter" Then ProcessEntered(eventInfo.target.value)
End Sub

Important

This interface is [COMExtensible(True)]. Field names are resolved against the underlying event object at run time. The standard DOM event surface (.target → the element that fired the event; .key, .code, .altKey, .ctrlKey, .shiftKey for keyboard events; .clientX, .clientY for mouse events; .index for the IDE’s listview events; …) is forwarded as-is to the JavaScript-side event object. See MDN’s DOM Event documentation for the standard fields.

Custom-data fan-out from raiseEvent()
Asynchronous events (setAsyncResult)
Default member
Properties

Custom-data fan-out from `raiseEvent()`

When inline HTML inside a tool window calls the IDE-side raiseEvent(eventName, event, stopPropagation, ...customData) helper, the trailing customData values flow through to the addin’s listener as eventInfo.customData0, eventInfo.customData1, …, numerically indexed from zero. This is the mechanism the listview / virtual listview use to attach per-row context (file path, line number, …) to their item events.

' Inline HTML — sample 15:
'   <div class="match" onclick="raiseEvent('onClickMatch', event, true, 'C:/file.twin', 42, 8)">…</div>

Private Sub OnClickMatch(ByVal eventInfo As HtmlEventProperties)
    Dim filePath As String = eventInfo.customData0
    Dim lineNum  As Long   = eventInfo.customData1
    Dim colNum   As Long   = eventInfo.customData2
    Host.ActiveEditors.Open filePath, lineNum, colNum
End Sub

Asynchronous events (`setAsyncResult`)

Some events — notably the virtual listview’s onAsyncGetItemHTML — are asynchronous: the IDE asks the addin to produce content for a specific argument and expects the answer back through the event object itself. The argument arrives on the event as eventInfo.asyncArgument, and the listener responds by calling eventInfo.setAsyncResult(answer):

Private Sub OnAsyncGetItemHTML(ByVal eventInfo As HtmlEventProperties)
    Dim itemIndex As Long = eventInfo.asyncArgument
    eventInfo.setAsyncResult("<div>Row " & itemIndex & "</div>")
End Sub

This is the standard [COMExtensible(True)] resolution at work — setAsyncResult is not declared on the interface, it is dispatched through the dynamic mechanism just like .key or .target would be. See sample 14 (WaynesVirtualListViewAddIn) for the full pattern, including the cache-invalidation companion call listview.notifyChangedItem(idx).

Default member

The interface’s DefaultMember is Item — so eventInfo("target") is equivalent to eventInfo.Item("target"). The .target.id shorthand desugars accordingly.

Properties

Item

Looks up a field by name. Returns an HtmlEventProperty, which carries the field’s value plus a nested Properties for further drill-down.

Syntax: eventInfo( DomPropertyName ) As HtmlEventProperty

DomPropertyName: required The field name. String.