SVGZoomEvent::SVGZoomEvent(EventTarget* aOwner,
nsPresContext* aPresContext,
WidgetGUIEvent* aEvent)
: UIEvent(aOwner, aPresContext,
aEvent ? aEvent : new WidgetGUIEvent(false, NS_SVG_ZOOM, 0))
, mPreviousScale(0)
, mNewScale(0)
{
if (aEvent) {
mEventIsInternal = false;
}
else {
mEventIsInternal = true;
mEvent->eventStructType = NS_SVGZOOM_EVENT;
mEvent->time = PR_Now();
}
mEvent->mFlags.mCancelable = false;
// We must store the "Previous" and "New" values before this event is
// dispatched. Reading the values from the root 'svg' element after we've
// been dispatched is not an option since event handler code may change
// currentScale and currentTranslate in response to this event.
nsIPresShell *presShell;
if (mPresContext && (presShell = mPresContext->GetPresShell())) {
nsIDocument *doc = presShell->GetDocument();
if (doc) {
Element *rootElement = doc->GetRootElement();
if (rootElement) {
// If the root element isn't an SVG 'svg' element
// (e.g. if this event was created by calling createEvent on a
// non-SVGDocument), then the "New" and "Previous"
// properties will be left null which is probably what we want.
if (rootElement->IsSVG(nsGkAtoms::svg)) {
SVGSVGElement *SVGSVGElem =
static_cast<SVGSVGElement*>(rootElement);
mNewScale = SVGSVGElem->GetCurrentScale();
mPreviousScale = SVGSVGElem->GetPreviousScale();
const SVGPoint& translate = SVGSVGElem->GetCurrentTranslate();
mNewTranslate =
new DOMSVGPoint(translate.GetX(), translate.GetY());
mNewTranslate->SetReadonly(true);
const SVGPoint& prevTranslate = SVGSVGElem->GetPreviousTranslate();
mPreviousTranslate =
new DOMSVGPoint(prevTranslate.GetX(), prevTranslate.GetY());
mPreviousTranslate->SetReadonly(true);
}
}
}
}
}
