path: root/src/plugins/platforms/wasm/qwasmaccessibility.cpp

// Copyright (C) 2022 The Qt Company Ltd.// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only#include"qwasmaccessibility.h"#include"qwasmscreen.h"#include"qwasmwindow.h"#include"qwasmintegration.h"#include <QtCore/private/qwasmsuspendresumecontrol_p.h>#include <QtGui/qwindow.h>#include <sstream>#if QT_CONFIG(accessibility)#include <QtGui/private/qaccessiblebridgeutils_p.h>Q_LOGGING_CATEGORY(lcQpaAccessibility,"qt.qpa.accessibility")// Qt WebAssembly a11y backend//// This backend implements accessibility support by creating "shadowing" html// elements for each Qt UI element. We access the DOM by using Emscripten's// val.h API.//// Currently, html elements are created in response to notifyAccessibilityUpdate// events. In addition or alternatively, we could also walk the accessibility tree// from setRootObject().QWasmAccessibility::QWasmAccessibility(){ s_instance =this;if(qEnvironmentVariableIntValue("QT_WASM_ENABLE_ACCESSIBILITY") ==1)enableAccessibility();// Register accessibility element event handler QWasmSuspendResumeControl *suspendResume =QWasmSuspendResumeControl::get();Q_ASSERT(suspendResume); m_eventHandlerIndex = suspendResume->registerEventHandler([this](constemscripten::val event){this->handleEventFromHtmlElement(event);});}QWasmAccessibility::~QWasmAccessibility(){// Remove accessibility element event handler QWasmSuspendResumeControl *suspendResume =QWasmSuspendResumeControl::get();Q_ASSERT(suspendResume); suspendResume->removeEventHandler(m_eventHandlerIndex); s_instance =nullptr;} QWasmAccessibility *QWasmAccessibility::s_instance =nullptr; QWasmAccessibility*QWasmAccessibility::get(){return s_instance;}voidQWasmAccessibility::addAccessibilityEnableButton(QWindow *window){get()->addAccessibilityEnableButtonImpl(window);}voidQWasmAccessibility::removeAccessibilityEnableButton(QWindow *window){get()->removeAccessibilityEnableButtonImpl(window);}voidQWasmAccessibility::onShowWindow(QWindow *window){get()->onShowWindowImpl(window);}voidQWasmAccessibility::addAccessibilityEnableButtonImpl(QWindow *window){if(m_accessibilityEnabled)return;emscripten::val container =getContainer(window);emscripten::val document =getDocument(container);emscripten::val button = document.call<emscripten::val>("createElement",std::string("button")); button.set("innerText",std::string("Enable Screen Reader")); button["classList"].call<void>("add",emscripten::val("hidden-visually-read-by-screen-reader")); container.call<void>("appendChild", button);auto enableContext =std::make_tuple(button,std::make_unique<qstdweb::EventCallback>(button,std::string("click"), [this](emscripten::val) {enableAccessibility(); })); m_enableButtons.insert(std::make_pair(window,std::move(enableContext)));}voidQWasmAccessibility::onShowWindowImpl(QWindow *window){if(!m_accessibilityEnabled)return;populateAccessibilityTree(QAccessible::queryAccessibleInterface(window));}voidQWasmAccessibility::removeAccessibilityEnableButtonImpl(QWindow *window){auto it = m_enableButtons.find(window);if(it == m_enableButtons.end())return;// Remove buttonauto[element, callback] = it->second;Q_UNUSED(callback); element["parentElement"].call<void>("removeChild", element); m_enableButtons.erase(it);}voidQWasmAccessibility::enableAccessibility(){// Enable accessibility. Remove all "enable" buttons and populate the// accessibility tree for each window.Q_ASSERT(!m_accessibilityEnabled); m_accessibilityEnabled =true;setActive(true);for(constauto& [key, value] : m_enableButtons) {constauto&[element, callback] = value;Q_UNUSED(key);Q_UNUSED(callback);onShowWindowImpl(key); element["parentElement"].call<void>("removeChild", element);} m_enableButtons.clear();}emscripten::val QWasmAccessibility::getContainer(QWindow *window){constauto wasmWindow =QWasmWindow::fromWindow(window);return(wasmWindow) ? wasmWindow->a11yContainer() :emscripten::val::undefined();}emscripten::val QWasmAccessibility::getContainer(QAccessibleInterface *iface){if(!iface)returnemscripten::val::undefined();returngetContainer(getWindow(iface));} QWindow *QWasmAccessibility::getWindow(QAccessibleInterface *iface){ QWindow *window = iface->window();// this is needed to add tabs as the window is not availableif(!window && iface->parent()) window = iface->parent()->window();return window;}emscripten::val QWasmAccessibility::getDocument(constemscripten::val &container){if(container.isUndefined())returnemscripten::val::global("document");return container["ownerDocument"];}emscripten::val QWasmAccessibility::getDocument(QAccessibleInterface *iface){returngetDocument(getContainer(iface));}emscripten::val QWasmAccessibility::createHtmlElement(QAccessibleInterface *iface){// Get the html container element for the interface; this depends on which// QScreen it is on. If the interface is not on a screen yet we get an undefined// container, and the code below handles that case as well.emscripten::val container =getContainer(iface);// Get the correct html document for the container, or fall back// to the global document. TODO: Does using the correct document actually matter?emscripten::val document =getDocument(container);// Translate the Qt a11y elemen role into html element type + ARIA role.// Here we can either create <div> elements with a spesific ARIA role,// or create e.g. <button> elements which should have built-in accessibility.emscripten::val element = [this, iface, document] {emscripten::val element =emscripten::val::undefined();switch(iface->role()) {caseQAccessible::Button: { element = document.call<emscripten::val>("createElement",std::string("button")); element.call<void>("addEventListener",emscripten::val("click"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::CheckBox: { element = document.call<emscripten::val>("createElement",std::string("input")); element.call<void>("setAttribute",std::string("type"),std::string("checkbox"));if(iface->state().checked) { element.call<void>("setAttribute",std::string("checked"),std::string("true"));} element.call<void>("addEventListener",emscripten::val("change"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::RadioButton: { element = document.call<emscripten::val>("createElement",std::string("input")); element.call<void>("setAttribute",std::string("type"),std::string("radio"));if(iface->state().checked) { element.call<void>("setAttribute",std::string("checked"),std::string("true"));} element.set(std::string("name"),std::string("buttonGroup")); element.call<void>("addEventListener",emscripten::val("change"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::SpinBox: { element = document.call<emscripten::val>("createElement",std::string("input")); element.call<void>("setAttribute",std::string("type"),std::string("number"));std::string valueString = iface->valueInterface()->currentValue().toString().toStdString(); element.call<void>("setAttribute",std::string("value"), valueString); element.call<void>("addEventListener",emscripten::val("change"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::Slider: { element = document.call<emscripten::val>("createElement",std::string("input")); element.call<void>("setAttribute",std::string("type"),std::string("range"));std::string valueString = iface->valueInterface()->currentValue().toString().toStdString(); element.call<void>("setAttribute",std::string("value"), valueString); element.call<void>("addEventListener",emscripten::val("change"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::PageTabList:{ element = document.call<emscripten::val>("createElement",std::string("div")); element.call<void>("setAttribute",std::string("role"),std::string("tablist"));for(int i =0; i < iface->childCount(); ++i) {if(iface->child(i)->role() ==QAccessible::PageTab){emscripten::val elementTab =emscripten::val::undefined(); elementTab =ensureHtmlElement(iface->child(i));setHtmlElementGeometry(iface->child(i));}}}break;caseQAccessible::PageTab:{ element = document.call<emscripten::val>("createElement",std::string("button")); element.call<void>("setAttribute",std::string("role"),std::string("tab")); QString text = iface->text(QAccessible::Name); element.call<void>("setAttribute",std::string("title"), text.toStdString()); element.call<void>("addEventListener",emscripten::val("click"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::ScrollBar: { element = document.call<emscripten::val>("createElement",std::string("div")); element.call<void>("setAttribute",std::string("role"),std::string("scrollbar"));std::string valueString = iface->valueInterface()->currentValue().toString().toStdString(); element.call<void>("setAttribute",std::string("aria-valuenow"), valueString); element.call<void>("addEventListener",emscripten::val("change"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::StaticText: { element = document.call<emscripten::val>("createElement",std::string("textarea")); element.call<void>("setAttribute",std::string("readonly"),std::string("true"));}break;caseQAccessible::Dialog: { element = document.call<emscripten::val>("createElement",std::string("dialog"));}break;caseQAccessible::ToolBar:{ element = document.call<emscripten::val>("createElement",std::string("div")); QString text = iface->text(QAccessible::Name); element.call<void>("setAttribute",std::string("role"),std::string("toolbar")); element.call<void>("setAttribute",std::string("title"), text.toStdString()); element.call<void>("addEventListener",emscripten::val("click"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::MenuItem:caseQAccessible::ButtonMenu: { element = document.call<emscripten::val>("createElement",std::string("button")); QString text = iface->text(QAccessible::Name); element.call<void>("setAttribute",std::string("role"),std::string("menuitem")); element.call<void>("setAttribute",std::string("title"), text.toStdString()); element.call<void>("addEventListener",emscripten::val("click"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;caseQAccessible::MenuBar:caseQAccessible::PopupMenu: { element = document.call<emscripten::val>("createElement",std::string("div")); QString text = iface->text(QAccessible::Name); element.call<void>("setAttribute",std::string("role"),std::string("menubar")); element.call<void>("setAttribute",std::string("title"), text.toStdString());for(int i =0; i < iface->childCount(); ++i) {emscripten::val childElement =emscripten::val::undefined(); childElement=ensureHtmlElement(iface->child(i)); childElement.call<void>("setAttribute",std::string("aria-owns"), text.toStdString());setHtmlElementTextName(iface->child(i));setHtmlElementGeometry(iface->child(i));}}break;caseQAccessible::EditableText: { element = document.call<emscripten::val>("createElement",std::string("input")); element.call<void>("setAttribute",std::string("type"),std::string("text")); element.call<void>("addEventListener",emscripten::val("input"),QWasmSuspendResumeControl::get()->jsEventHandlerAt(m_eventHandlerIndex),true);}break;default:qCDebug(lcQpaAccessibility) <<"TODO: createHtmlElement() handle"<< iface->role(); element = document.call<emscripten::val>("createElement",std::string("div"));}return element;}();// Add the html element to the container if we have one. If not there// is a second chance when handling the ObjectShow event.if(!container.isUndefined()) container.call<void>("appendChild", element);return element;}voidQWasmAccessibility::destroyHtmlElement(QAccessibleInterface *iface){Q_UNUSED(iface);qCDebug(lcQpaAccessibility) <<"TODO destroyHtmlElement";}emscripten::val QWasmAccessibility::ensureHtmlElement(QAccessibleInterface *iface){auto it = m_elements.find(iface);if(it != m_elements.end())return it.value();emscripten::val element =createHtmlElement(iface); m_elements.insert(iface, element);return element;}voidQWasmAccessibility::setHtmlElementVisibility(QAccessibleInterface *iface,bool visible){emscripten::val element =ensureHtmlElement(iface);emscripten::val container =getContainer(iface);if(container.isUndefined()) {qCDebug(lcQpaAccessibility) <<"TODO: setHtmlElementVisibility: unable to find html container for element"<< iface;return;} container.call<void>("appendChild", element); visible = visible && !iface->state().invisible && !iface->state().disabled; element.set("ariaHidden", !visible);// ariaHidden mean completely hidden; maybe some sort of soft-hidden should be used.}voidQWasmAccessibility::setHtmlElementGeometry(QAccessibleInterface *iface){emscripten::val element =ensureHtmlElement(iface);// QAccessibleInterface gives us the geometry in global (screen) coordinates. Translate that// to window geometry in order to position elements relative to window origin. QWindow *window =getWindow(iface);if(!window)qCWarning(lcQpaAccessibility) <<"Unable to find window for"<< iface <<"setting null geometry"; QRect screenGeometry = iface->rect(); QPoint windowPos = window ? window->mapFromGlobal(screenGeometry.topLeft()) :QPoint(); QRect windowGeometry(windowPos, screenGeometry.size());setHtmlElementGeometry(element, windowGeometry);}voidQWasmAccessibility::setHtmlElementGeometry(emscripten::val element, QRect geometry){// Position the element using "position: absolute" in order to place// it under the corresponding Qt element in the screen.emscripten::val style = element["style"]; style.set("position",std::string("absolute")); style.set("z-index",std::string("-1"));// FIXME: "0" should be sufficient to order beheind the// screen element, but isn't style.set("left",std::to_string(geometry.x()) +"px"); style.set("top",std::to_string(geometry.y()) +"px"); style.set("width",std::to_string(geometry.width()) +"px"); style.set("height",std::to_string(geometry.height()) +"px");}voidQWasmAccessibility::setHtmlElementTextName(QAccessibleInterface *iface){emscripten::val element =ensureHtmlElement(iface);const QString name = iface->text(QAccessible::Name);if(name.isEmpty()) element.call<void>("removeAttribute",std::string("aria-label"));else element.call<void>("setAttribute",std::string("aria-label"), name.toStdString());}voidQWasmAccessibility::setHtmlElementTextNameLE(QAccessibleInterface *iface) {emscripten::val element =ensureHtmlElement(iface); QString text = iface->text(QAccessible::Name); element.call<void>("setAttribute",std::string("name"), text.toStdString()); QString value = iface->text(QAccessible::Value); element.set("innerHTML", value.toStdString());}voidQWasmAccessibility::setHtmlElementDescription(QAccessibleInterface *iface) {emscripten::val element =ensureHtmlElement(iface); QString desc = iface->text(QAccessible::Description); element.call<void>("setAttribute",std::string("aria-description"), desc.toStdString());}voidQWasmAccessibility::setHtmlElementFocus(QAccessibleInterface *iface){auto element =ensureHtmlElement(iface); element.call<void>("focus");}voidQWasmAccessibility::handleStaticTextUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement handleStaticTextUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleLineEditUpdate(QAccessibleEvent *event) {switch(event->type()) {caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::Focus:caseQAccessible::TextRemoved:caseQAccessible::TextInserted:caseQAccessible::TextCaretMoved: {setHtmlElementTextNameLE(event->accessibleInterface());}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement handleLineEditUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleEventFromHtmlElement(constemscripten::val event){ QAccessibleInterface *iface = m_elements.key(event["target"]);if(iface ==nullptr) {return;}else{ QString eventType =QString::fromStdString(event["type"].as<std::string>());constauto& actionNames =QAccessibleBridgeUtils::effectiveActionNames(iface);if(eventType =="focus") {if(actionNames.contains(QAccessibleActionInterface::setFocusAction())) iface->actionInterface()->doAction(QAccessibleActionInterface::setFocusAction());}else if(actionNames.contains(QAccessibleActionInterface::pressAction())) { iface->actionInterface()->doAction(QAccessibleActionInterface::pressAction());}else if(actionNames.contains(QAccessibleActionInterface::toggleAction())) { iface->actionInterface()->doAction(QAccessibleActionInterface::toggleAction());}else if(actionNames.contains(QAccessibleActionInterface::increaseAction()) || actionNames.contains(QAccessibleActionInterface::decreaseAction())) { QString val =QString::fromStdString(event["target"]["value"].as<std::string>()); iface->valueInterface()->setCurrentValue(val.toInt());}else if(eventType =="input") {// as EditableTextInterface is not implemented in qml accessibility// so we need to check the role for text to update in the textbox during accessibilityif(iface->editableTextInterface() || iface->role() ==QAccessible::EditableText) {std::string insertText = event["target"]["value"].as<std::string>(); iface->setText(QAccessible::Value,QString::fromStdString(insertText));}}}}voidQWasmAccessibility::handleButtonUpdate(QAccessibleEvent *event){qCDebug(lcQpaAccessibility) <<"TODO: implement handleButtonUpdate for event"<< event->type();}voidQWasmAccessibility::handleCheckBoxUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::Focus:caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::StateChanged: { QAccessibleInterface *accessible = event->accessibleInterface();emscripten::val element =ensureHtmlElement(accessible);bool checkedString = accessible->state().checked ?true:false; element.call<void>("setAttribute",std::string("checked"), checkedString);}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement handleCheckBoxUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleToolUpdate(QAccessibleEvent *event){ QAccessibleInterface *iface = event->accessibleInterface(); QString text = iface->text(QAccessible::Name); QString desc = iface->text(QAccessible::Description);switch(event->type()) {caseQAccessible::NameChanged:caseQAccessible::StateChanged:{emscripten::val element =ensureHtmlElement(iface); element.call<void>("setAttribute",std::string("title"), text.toStdString());}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement handleToolUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleMenuUpdate(QAccessibleEvent *event){ QAccessibleInterface *iface = event->accessibleInterface(); QString text = iface->text(QAccessible::Name); QString desc = iface->text(QAccessible::Description);switch(event->type()) {caseQAccessible::Focus:caseQAccessible::NameChanged:caseQAccessible::MenuStart ://"TODO: To implement latercaseQAccessible::StateChanged:{emscripten::val element =ensureHtmlElement(iface); element.call<void>("setAttribute",std::string("title"), text.toStdString());}break;caseQAccessible::PopupMenuStart: {ensureHtmlElement(iface);if(iface->childCount() >0) m_elements[iface->child(0)].call<void>("focus");}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement handleMenuUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleDialogUpdate(QAccessibleEvent *event) {switch(event->type()) {caseQAccessible::NameChanged:caseQAccessible::Focus:caseQAccessible::DialogStart:caseQAccessible::StateChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement handleLineEditUpdate for event"<< event->type();break;}}voidQWasmAccessibility::populateAccessibilityTree(QAccessibleInterface *iface){if(!iface)return;// We ignore toplevel windows which is categorized// by getWindow(iface->parent()) != getWindow(iface) QWindow *window1 =getWindow(iface); QWindow *window0 = (iface->parent()) ?getWindow(iface->parent()) :nullptr;if(window1 && window0 == window1) {// Create html element for the interface, sync up properties.ensureHtmlElement(iface);setHtmlElementVisibility(iface,true);setHtmlElementGeometry(iface);setHtmlElementTextName(iface);setHtmlElementDescription(iface);handleIdentifierUpdate(iface);}for(int i =0; i < iface->childCount(); ++i)populateAccessibilityTree(iface->child(i));}voidQWasmAccessibility::handleRadioButtonUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::Focus:caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::StateChanged: { QAccessibleInterface *accessible = event->accessibleInterface();emscripten::val element =ensureHtmlElement(accessible);std::string checkedString = accessible->state().checked ?"true":"false"; element.call<void>("setAttribute",std::string("checked"), checkedString);}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qDebug() <<"TODO: implement handleRadioButtonUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleSpinBoxUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::Focus:caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::ValueChanged: { QAccessibleInterface *accessible = event->accessibleInterface();emscripten::val element =ensureHtmlElement(accessible);std::string valueString = accessible->valueInterface()->currentValue().toString().toStdString(); element.call<void>("setAttribute",std::string("value"), valueString);}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qDebug() <<"TODO: implement handleSpinBoxUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleSliderUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::Focus:caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::ValueChanged: { QAccessibleInterface *accessible = event->accessibleInterface();emscripten::val element =ensureHtmlElement(accessible);std::string valueString = accessible->valueInterface()->currentValue().toString().toStdString(); element.call<void>("setAttribute",std::string("value"), valueString);}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qDebug() <<"TODO: implement handleSliderUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleScrollBarUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::Focus:caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::ValueChanged: { QAccessibleInterface *accessible = event->accessibleInterface();emscripten::val element =ensureHtmlElement(accessible);std::string valueString = accessible->valueInterface()->currentValue().toString().toStdString(); element.call<void>("setAttribute",std::string("aria-valuenow"), valueString);}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qDebug() <<"TODO: implement handleSliderUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handlePageTabUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::Focus: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qDebug() <<"TODO: implement handlePageTabUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handlePageTabListUpdate(QAccessibleEvent *event){switch(event->type()) {caseQAccessible::NameChanged: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::Focus: {setHtmlElementTextName(event->accessibleInterface());}break;caseQAccessible::DescriptionChanged: {setHtmlElementDescription(event->accessibleInterface());}break;default:qDebug() <<"TODO: implement handlePageTabUpdate for event"<< event->type();break;}}voidQWasmAccessibility::handleIdentifierUpdate(QAccessibleInterface *iface){emscripten::val element =ensureHtmlElement(iface); QString id = iface->text(QAccessible::Identifier).replace(" ","_");if(id.isEmpty() && iface->role() ==QAccessible::PageTabList) {std::ostringstream oss; oss <<"tabList_0x"<< (void*)iface; id =QString::fromUtf8(oss.str());}if(!id.isEmpty()) { element.call<void>("setAttribute",std::string("id"), id.toStdString());if(iface->role() ==QAccessible::PageTabList) {for(int i =0; i < iface->childCount(); ++i) {auto child =ensureHtmlElement(iface->child(i)); child.call<void>("setAttribute",std::string("aria-owns"), id.toStdString());}}}else{ element.call<void>("removeAttribute",std::string("id"));}}voidQWasmAccessibility::notifyAccessibilityUpdate(QAccessibleEvent *event){if(!m_accessibilityEnabled)return; QAccessibleInterface *iface = event->accessibleInterface();if(!iface) {qWarning() <<"notifyAccessibilityUpdate with null a11y interface";return;}// Handle some common event types. See// https://doc.qt.io/qt-5/qaccessible.html#Event-enumswitch(event->type()) {caseQAccessible::Focus:setHtmlElementFocus(iface);break;caseQAccessible::IdentifierChanged:handleIdentifierUpdate(iface);return;caseQAccessible::ObjectShow:setHtmlElementVisibility(iface,true);// Sync up properties on show;setHtmlElementGeometry(iface);setHtmlElementTextName(iface);setHtmlElementDescription(iface);return;caseQAccessible::ObjectHide:setHtmlElementVisibility(iface,false);return;caseQAccessible::LocationChanged:setHtmlElementGeometry(iface);return;// TODO: maybe handle more types heredefault:break;};// Switch on interface role, see// https://doc.qt.io/qt-5/qaccessibleinterface.html#roleswitch(iface->role()) {caseQAccessible::StaticText:handleStaticTextUpdate(event);break;caseQAccessible::Button:handleStaticTextUpdate(event);break;caseQAccessible::CheckBox:handleCheckBoxUpdate(event);break;caseQAccessible::EditableText:handleLineEditUpdate(event);break;caseQAccessible::Dialog:handleDialogUpdate(event);break;caseQAccessible::MenuItem:caseQAccessible::MenuBar:caseQAccessible::PopupMenu:handleMenuUpdate(event);break;caseQAccessible::ToolBar:caseQAccessible::ButtonMenu:handleToolUpdate(event);caseQAccessible::RadioButton:handleRadioButtonUpdate(event);break;caseQAccessible::SpinBox:handleSpinBoxUpdate(event);break;caseQAccessible::Slider:handleSliderUpdate(event);break;caseQAccessible::PageTab:handlePageTabUpdate(event);break;caseQAccessible::PageTabList:handlePageTabListUpdate(event);break;caseQAccessible::ScrollBar:handleScrollBarUpdate(event);break;default:qCDebug(lcQpaAccessibility) <<"TODO: implement notifyAccessibilityUpdate for role"<< iface->role();};}voidQWasmAccessibility::setRootObject(QObject *root){ m_rootObject = root;}voidQWasmAccessibility::initialize(){}voidQWasmAccessibility::cleanup(){}#endif// QT_CONFIG(accessibility)