Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/**
* Implementation of HTML <label> elements.
*/
#include "HTMLLabelElement.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/dom/HTMLLabelElementBinding.h"
#include "mozilla/dom/MouseEventBinding.h"
#include "nsFocusManager.h"
#include "nsIFrame.h"
#include "nsContentUtils.h"
#include "nsQueryObject.h"
#include "mozilla/dom/ShadowRoot.h"
// construction, destruction
NS_IMPL_NS_NEW_HTML_ELEMENT(Label)
namespace mozilla::dom {
HTMLLabelElement::~HTMLLabelElement() = default;
JSObject* HTMLLabelElement::WrapNode(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return HTMLLabelElement_Binding::Wrap(aCx, this, aGivenProto);
}
// nsIDOMHTMLLabelElement
NS_IMPL_ELEMENT_CLONE(HTMLLabelElement)
HTMLFormElement* HTMLLabelElement::GetForm() const {
// Not all labeled things have a form association. Stick to the ones that do.
const auto* formControl = nsIFormControl::FromNodeOrNull(GetControl());
if (!formControl) {
return nullptr;
}
return formControl->GetForm();
}
void HTMLLabelElement::Focus(const FocusOptions& aOptions,
const CallerType aCallerType,
ErrorResult& aError) {
{
nsIFrame* frame = GetPrimaryFrame(FlushType::Frames);
if (frame && frame->IsFocusable()) {
return nsGenericHTMLElement::Focus(aOptions, aCallerType, aError);
}
}
if (RefPtr<Element> elem = GetLabeledElement()) {
return elem->Focus(aOptions, aCallerType, aError);
}
}
nsresult HTMLLabelElement::PostHandleEvent(EventChainPostVisitor& aVisitor) {
WidgetMouseEvent* mouseEvent = aVisitor.mEvent->AsMouseEvent();
if (mHandlingEvent ||
(!(mouseEvent && mouseEvent->IsLeftClickEvent()) &&
aVisitor.mEvent->mMessage != eMouseDown) ||
aVisitor.mEventStatus == nsEventStatus_eConsumeNoDefault ||
!aVisitor.mPresContext ||
// Don't handle the event if it's already been handled by another label
aVisitor.mEvent->mFlags.mMultipleActionsPrevented) {
return NS_OK;
}
nsCOMPtr<Element> target =
do_QueryInterface(aVisitor.mEvent->GetOriginalDOMEventTarget());
if (nsContentUtils::IsInInteractiveHTMLContent(target, this)) {
return NS_OK;
}
// Strong ref because event dispatch is going to happen.
RefPtr<Element> content = GetLabeledElement();
if (!content || content->IsDisabled()) {
return NS_OK;
}
mHandlingEvent = true;
switch (aVisitor.mEvent->mMessage) {
case eMouseDown:
if (mouseEvent->mButton == MouseButton::ePrimary) {
// We reset the mouse-down point on every event because there is
// no guarantee we will reach the ePointerClick code below.
LayoutDeviceIntPoint* curPoint =
new LayoutDeviceIntPoint(mouseEvent->mRefPoint);
SetProperty(nsGkAtoms::labelMouseDownPtProperty,
static_cast<void*>(curPoint),
nsINode::DeleteProperty<LayoutDeviceIntPoint>);
}
break;
case ePointerClick:
if (mouseEvent->IsLeftClickEvent()) {
LayoutDeviceIntPoint* mouseDownPoint =
static_cast<LayoutDeviceIntPoint*>(
GetProperty(nsGkAtoms::labelMouseDownPtProperty));
bool dragSelect = false;
if (mouseDownPoint) {
LayoutDeviceIntPoint dragDistance = *mouseDownPoint;
RemoveProperty(nsGkAtoms::labelMouseDownPtProperty);
dragDistance -= mouseEvent->mRefPoint;
const int CLICK_DISTANCE = 2;
dragSelect = dragDistance.x > CLICK_DISTANCE ||
dragDistance.x < -CLICK_DISTANCE ||
dragDistance.y > CLICK_DISTANCE ||
dragDistance.y < -CLICK_DISTANCE;
}
// Don't click the for-content if we did drag-select text or if we
// have a kbd modifier (which adjusts a selection).
if (dragSelect || mouseEvent->IsShift() || mouseEvent->IsControl() ||
mouseEvent->IsAlt() || mouseEvent->IsMeta()) {
break;
}
// Only set focus on the first click of multiple clicks to prevent
// to prevent immediate de-focus.
if (mouseEvent->mClickCount <= 1) {
if (RefPtr<nsFocusManager> fm = nsFocusManager::GetFocusManager()) {
// Use FLAG_BYMOVEFOCUS here so that the label is scrolled to.
// Also, within HTMLInputElement::PostHandleEvent, inputs will
// be selected only when focused via a key or when the navigation
// flag is used and we want to select the text on label clicks as
// well.
// If the label has been clicked by the user, we also want to
// pass FLAG_BYMOUSE so that we get correct focus ring behavior,
// but we don't want to pass FLAG_BYMOUSE if this click event was
// caused by the user pressing an accesskey.
bool byMouse = (mouseEvent->mInputSource !=
MouseEvent_Binding::MOZ_SOURCE_KEYBOARD);
bool byTouch = (mouseEvent->mInputSource ==
MouseEvent_Binding::MOZ_SOURCE_TOUCH);
fm->SetFocus(content,
nsIFocusManager::FLAG_BYMOVEFOCUS |
(byMouse ? nsIFocusManager::FLAG_BYMOUSE : 0) |
(byTouch ? nsIFocusManager::FLAG_BYTOUCH : 0));
}
}
// Dispatch a new click event to |content|
// (For compatibility with IE, we do only left click. If
// we wanted to interpret the HTML spec very narrowly, we
// would do nothing. If we wanted to do something
// sensible, we might send more events through like
nsEventStatus status = aVisitor.mEventStatus;
// Ok to use aVisitor.mEvent as parameter because DispatchClickEvent
// will actually create a new event.
EventFlags eventFlags;
eventFlags.mMultipleActionsPrevented = true;
DispatchClickEvent(aVisitor.mPresContext, mouseEvent, content, false,
&eventFlags, &status);
// Do we care about the status this returned? I don't think we do...
// Don't run another <label> off of this click
mouseEvent->mFlags.mMultipleActionsPrevented = true;
}
break;
default:
break;
}
mHandlingEvent = false;
return NS_OK;
}
Result<bool, nsresult> HTMLLabelElement::PerformAccesskey(
bool aKeyCausesActivation, bool aIsTrustedEvent) {
if (!aKeyCausesActivation) {
RefPtr<Element> element = GetLabeledElement();
if (element) {
return element->PerformAccesskey(aKeyCausesActivation, aIsTrustedEvent);
}
return Err(NS_ERROR_ABORT);
}
RefPtr<nsPresContext> presContext = GetPresContext(eForUncomposedDoc);
if (!presContext) {
return Err(NS_ERROR_UNEXPECTED);
}
// Click on it if the users prefs indicate to do so.
AutoHandlingUserInputStatePusher userInputStatePusher(aIsTrustedEvent);
AutoPopupStatePusher popupStatePusher(
aIsTrustedEvent ? PopupBlocker::openAllowed : PopupBlocker::openAbused);
DispatchSimulatedClick(this, aIsTrustedEvent, presContext);
// XXXedgar, do we need to check whether the focus is really changed?
return true;
}
nsGenericHTMLElement* HTMLLabelElement::GetLabeledElement() const {
nsAutoString elementId;
if (!GetAttr(nsGkAtoms::_for, elementId)) {
// No @for, so we are a label for our first form control element.
// Do a depth-first traversal to look for the first form control element.
return GetFirstLabelableDescendant();
}
// We have a @for. The id has to be linked to an element in the same tree
// and this element should be a labelable form control.
Element* element = nullptr;
if (ShadowRoot* shadowRoot = GetContainingShadow()) {
element = shadowRoot->GetElementById(elementId);
} else if (Document* doc = GetUncomposedDoc()) {
element = doc->GetElementById(elementId);
} else {
element =
nsContentUtils::MatchElementId(SubtreeRoot()->AsContent(), elementId);
}
if (element && element->IsLabelable()) {
return static_cast<nsGenericHTMLElement*>(element);
}
return nullptr;
}
nsGenericHTMLElement* HTMLLabelElement::GetFirstLabelableDescendant() const {
for (nsIContent* cur = nsINode::GetFirstChild(); cur;
cur = cur->GetNextNode(this)) {
Element* element = Element::FromNode(cur);
if (element && element->IsLabelable()) {
return static_cast<nsGenericHTMLElement*>(element);
}
}
return nullptr;
}
} // namespace mozilla::dom