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-rw-r--r--dom/html/HTMLLabelElement.cpp246
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diff --git a/dom/html/HTMLLabelElement.cpp b/dom/html/HTMLLabelElement.cpp
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+/* -*- 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
+ * 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 "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 {
+ nsGenericHTMLElement* control = GetControl();
+ if (!control) {
+ return nullptr;
+ }
+
+ // Not all labeled things have a form association. Stick to the ones that do.
+ nsCOMPtr<nsIFormControl> formControl = do_QueryObject(control);
+ 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 eMouseClick code below.
+ LayoutDeviceIntPoint* curPoint =
+ new LayoutDeviceIntPoint(mouseEvent->mRefPoint);
+ SetProperty(nsGkAtoms::labelMouseDownPtProperty,
+ static_cast<void*>(curPoint),
+ nsINode::DeleteProperty<LayoutDeviceIntPoint>);
+ }
+ break;
+
+ case eMouseClick:
+ 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
+ // 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;
+
+ 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(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 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