wasm: Handle stylus events by generating QTabletEvents

Pick-to: 6.6
Fixes: QTBUG-120327
Change-Id: I37a92b9850385712b638c30f9a43028d8134f416
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>
(cherry picked from commit bc578ec6efcf667e0be2ea5c3d68bd22135cadd0)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/plugins/platforms/wasm/qwasmevent.cpp

@@ -187,6 +187,10 @@ PointerEvent::PointerEvent(EventType type, emscripten::val event) : MouseEvent(t
     width = event["width"].as<qreal>();
     height = event["height"].as<qreal>();
     pressure = event["pressure"].as<qreal>();
+    tiltX = event["tiltX"].as<qreal>();
+    tiltY = event["tiltY"].as<qreal>();
+    tangentialPressure = event["tangentialPressure"].as<qreal>();
+    twist = event["twist"].as<qreal>();
     isPrimary = event["isPrimary"].as<bool>();
 }
 

src/plugins/platforms/wasm/qwasmevent.h

@@ -221,6 +221,10 @@ struct PointerEvent : public MouseEvent
     PointerType pointerType;
     int pointerId;
     qreal pressure;
+    qreal tiltX;
+    qreal tiltY;
+    qreal tangentialPressure;
+    qreal twist;
     qreal width;
     qreal height;
     bool isPrimary;

src/plugins/platforms/wasm/qwasmintegration.cpp

@@ -21,6 +21,7 @@
 #include <qpa/qwindowsysteminterface.h>
 #include <QtCore/qcoreapplication.h>
 #include <qpa/qplatforminputcontextfactory_p.h>
+#include <qpa/qwindowsysteminterface_p.h>
 
 #include <emscripten/bind.h>
 #include <emscripten/val.h>
@@ -94,6 +95,7 @@ QWasmIntegration::QWasmIntegration()
         qt_set_sequence_auto_mnemonic(false);
 
     touchPoints = emscripten::val::global("navigator")["maxTouchPoints"].as<int>();
+    QWindowSystemInterfacePrivate::TabletEvent::setPlatformSynthesizesMouse(false);
 
     // Create screens for container elements. Each container element will ultimately become a
     // div element. Qt historically supported supplying canvas for screen elements - these elements

src/plugins/platforms/wasm/qwasmscreen.cpp

@@ -92,6 +92,16 @@ QWasmScreen::QWasmScreen(const emscripten::val &containerOrCanvas)
             QPointingDevice::Capability::Position | QPointingDevice::Capability::Area
                     | QPointingDevice::Capability::NormalizedPosition,
             10, 0);
+    m_tabletDevice = std::make_unique<QPointingDevice>(
+            "stylus", 2, QInputDevice::DeviceType::Stylus,
+            QPointingDevice::PointerType::Pen,
+            QPointingDevice::Capability::Position | QPointingDevice::Capability::Pressure
+                | QPointingDevice::Capability::NormalizedPosition
+                | QInputDevice::Capability::MouseEmulation
+                | QInputDevice::Capability::Hover | QInputDevice::Capability::Rotation
+                | QInputDevice::Capability::XTilt | QInputDevice::Capability::YTilt
+                | QInputDevice::Capability::TangentialPressure,
+            0, 0);
 
     QWindowSystemInterface::registerInputDevice(m_touchDevice.get());
 }

src/plugins/platforms/wasm/qwasmscreen.h

@@ -39,6 +39,7 @@ public:
     QString eventTargetId() const;
     QString outerScreenId() const;
     QPointingDevice *touchDevice() { return m_touchDevice.get(); }
+    QPointingDevice *tabletDevice() { return m_tabletDevice.get(); }
 
     QWasmCompositor *compositor();
     QWasmDeadKeySupport *deadKeySupport() { return m_deadKeySupport.get(); }
@@ -82,6 +83,7 @@ private:
     emscripten::val m_shadowContainer;
     std::unique_ptr<QWasmCompositor> m_compositor;
     std::unique_ptr<QPointingDevice> m_touchDevice;
+    std::unique_ptr<QPointingDevice> m_tabletDevice;
     std::unique_ptr<QWasmDeadKeySupport> m_deadKeySupport;
     QRect m_geometry = QRect(0, 0, 100, 100);
     int m_depth = 32;

src/plugins/platforms/wasm/qwasmwindow.cpp

@@ -514,7 +514,7 @@ bool QWasmWindow::processKey(const KeyEvent &event)
 
 bool QWasmWindow::processPointer(const PointerEvent &event)
 {
-    if (event.pointerType != PointerType::Mouse)
+    if (event.pointerType != PointerType::Mouse && event.pointerType != PointerType::Pen)
         return false;
 
     switch (event.type) {

src/plugins/platforms/wasm/qwasmwindowclientarea.cpp

@@ -105,6 +105,31 @@ bool ClientArea::deliverEvent(const PointerEvent &event)
                         eventType, event.modifiers);
     }
 
+    if (event.pointerType == PointerType::Pen) {
+        qreal pressure;
+        switch (event.type) {
+            case EventType::PointerDown :
+            case EventType::PointerMove :
+                pressure = event.pressure;
+                break;
+            case EventType::PointerUp :
+                pressure = 0.0;
+                break;
+            default:
+                return false;
+        }
+        // Tilt in the browser is in the range +-90, but QTabletEvent only goes to +-60.
+        qreal xTilt = qBound(-60.0, event.tiltX, 60.0);
+        qreal yTilt = qBound(-60.0, event.tiltY, 60.0);
+        // Barrel rotation is reported as 0 to 359, but QTabletEvent wants a signed value.
+        qreal rotation = event.twist > 180.0 ? 360.0 - event.twist : event.twist;
+        return QWindowSystemInterface::handleTabletEvent(
+            m_window->window(), QWasmIntegration::getTimestamp(), m_screen->tabletDevice(),
+            m_window->window()->mapFromGlobal(targetPointClippedToScreen),
+            targetPointClippedToScreen, event.mouseButtons, pressure, xTilt, yTilt,
+            event.tangentialPressure, rotation, event.modifiers);
+    }
+
     QWindowSystemInterface::TouchPoint *touchPoint;
 
     QPointF pointInTargetWindowCoords =