gecko-dev/dom/html/HTMLLabelElement.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Implementation of HTML <label> elements.
*/
#include "HTMLLabelElement.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/dom/HTMLLabelElementBinding.h"
#include "nsFocusManager.h"
#include "nsIDOMMouseEvent.h"
// construction, destruction
NS_IMPL_NS_NEW_HTML_ELEMENT(Label)
namespace mozilla {
namespace dom {
HTMLLabelElement::~HTMLLabelElement()
{
}
JSObject*
HTMLLabelElement::WrapNode(JSContext *aCx)
{
return HTMLLabelElementBinding::Wrap(aCx, this);
}
// nsISupports
NS_IMPL_ISUPPORTS_INHERITED(HTMLLabelElement, nsGenericHTMLFormElement,
nsIDOMHTMLLabelElement)
// nsIDOMHTMLLabelElement
NS_IMPL_ELEMENT_CLONE(HTMLLabelElement)
NS_IMETHODIMP
HTMLLabelElement::GetForm(nsIDOMHTMLFormElement** aForm)
{
return nsGenericHTMLFormElement::GetForm(aForm);
}
NS_IMETHODIMP
HTMLLabelElement::GetControl(nsIDOMHTMLElement** aElement)
{
nsCOMPtr<nsIDOMHTMLElement> element = do_QueryObject(GetLabeledElement());
element.forget(aElement);
return NS_OK;
}
NS_IMETHODIMP
HTMLLabelElement::SetHtmlFor(const nsAString& aHtmlFor)
{
ErrorResult rv;
SetHtmlFor(aHtmlFor, rv);
return rv.ErrorCode();
}
NS_IMETHODIMP
HTMLLabelElement::GetHtmlFor(nsAString& aHtmlFor)
{
nsString htmlFor;
GetHtmlFor(htmlFor);
aHtmlFor = htmlFor;
return NS_OK;
}
void
HTMLLabelElement::Focus(ErrorResult& aError)
{
// retarget the focus method at the for content
nsIFocusManager* fm = nsFocusManager::GetFocusManager();
if (fm) {
nsCOMPtr<nsIDOMElement> elem = do_QueryObject(GetLabeledElement());
if (elem)
fm->SetFocus(elem, 0);
}
}
static bool
EventTargetIn(WidgetEvent* aEvent, nsIContent* aChild, nsIContent* aStop)
{
nsCOMPtr<nsIContent> c = do_QueryInterface(aEvent->target);
nsIContent *content = c;
while (content) {
if (content == aChild) {
return true;
}
if (content == aStop) {
break;
}
content = content->GetParent();
}
return false;
}
nsresult
HTMLLabelElement::PostHandleEvent(EventChainPostVisitor& aVisitor)
{
WidgetMouseEvent* mouseEvent = aVisitor.mEvent->AsMouseEvent();
if (mHandlingEvent ||
(!(mouseEvent && mouseEvent->IsLeftClickEvent()) &&
aVisitor.mEvent->message != NS_MOUSE_BUTTON_DOWN) ||
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;
}
// Strong ref because event dispatch is going to happen.
nsRefPtr<Element> content = GetLabeledElement();
if (content && !EventTargetIn(aVisitor.mEvent, content, this)) {
mHandlingEvent = true;
switch (aVisitor.mEvent->message) {
case NS_MOUSE_BUTTON_DOWN:
if (mouseEvent->button == WidgetMouseEvent::eLeftButton) {
// We reset the mouse-down point on every event because there is
// no guarantee we will reach the NS_MOUSE_CLICK code below.
LayoutDeviceIntPoint* curPoint =
new LayoutDeviceIntPoint(mouseEvent->refPoint);
SetProperty(nsGkAtoms::labelMouseDownPtProperty,
static_cast<void*>(curPoint),
nsINode::DeleteProperty<LayoutDeviceIntPoint>);
}
break;
case NS_MOUSE_CLICK:
if (mouseEvent->IsLeftClickEvent()) {
LayoutDeviceIntPoint* mouseDownPoint =
static_cast<LayoutDeviceIntPoint*>(
GetProperty(nsGkAtoms::labelMouseDownPtProperty));
bool dragSelect = false;
if (mouseDownPoint) {
LayoutDeviceIntPoint dragDistance = *mouseDownPoint;
DeleteProperty(nsGkAtoms::labelMouseDownPtProperty);
dragDistance -= mouseEvent->refPoint;
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->clickCount <= 1) {
nsIFocusManager* fm = nsFocusManager::GetFocusManager();
if (fm) {
// 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.
nsCOMPtr<nsIDOMElement> elem = do_QueryInterface(content);
fm->SetFocus(elem, nsIFocusManager::FLAG_BYMOVEFOCUS);
}
}
// 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
// this.) See bug 7554, bug 49897, and bug 96813.
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;
}
mHandlingEvent = false;
}
return NS_OK;
}
nsresult
HTMLLabelElement::Reset()
{
return NS_OK;
}
NS_IMETHODIMP
HTMLLabelElement::SubmitNamesValues(nsFormSubmission* aFormSubmission)
{
return NS_OK;
}
void
HTMLLabelElement::PerformAccesskey(bool aKeyCausesActivation,
bool aIsTrustedEvent)
{
if (!aKeyCausesActivation) {
nsRefPtr<Element> element = GetLabeledElement();
if (element)
element->PerformAccesskey(aKeyCausesActivation, aIsTrustedEvent);
} else {
nsPresContext *presContext = GetPresContext(eForUncomposedDoc);
if (!presContext)
return;
// Click on it if the users prefs indicate to do so.
WidgetMouseEvent event(aIsTrustedEvent, NS_MOUSE_CLICK,
nullptr, WidgetMouseEvent::eReal);
event.inputSource = nsIDOMMouseEvent::MOZ_SOURCE_KEYBOARD;
nsAutoPopupStatePusher popupStatePusher(aIsTrustedEvent ?
openAllowed : openAbused);
EventDispatcher::Dispatch(static_cast<nsIContent*>(this), presContext,
&event);
}
}
nsGenericHTMLElement*
HTMLLabelElement::GetLabeledElement() const
{
nsAutoString elementId;
if (!GetAttr(kNameSpaceID_None, 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 document
// and this element should be a labelable form control.
//XXXsmaug It is unclear how this should work in case the element is in
// Shadow DOM.
// See https://www.w3.org/Bugs/Public/show_bug.cgi?id=26365.
nsIDocument* doc = GetUncomposedDoc();
if (!doc) {
return nullptr;
}
Element* element = doc->GetElementById(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 = cur->IsElement() ? cur->AsElement() : nullptr;
if (element && element->IsLabelable()) {
return static_cast<nsGenericHTMLElement*>(element);
}
}
return nullptr;
}
} // namespace dom
} // namespace mozilla