2 files changed, 33 insertions, 6 deletions

diff --git a/src/plugins/platforms/ios/qiosintegration.mm b/src/plugins/platforms/ios/qiosintegration.mm
index eaff0daf19..0e3da8dce8 100644
--- a/src/plugins/platforms/ios/qiosintegration.mm
+++ b/src/plugins/platforms/ios/qiosintegration.mm
@@ -89,10 +89,11 @@ QIOSIntegration::QIOSIntegration()
     // Set current directory to app bundle folder
     QDir::setCurrent(QString::fromUtf8([[[NSBundle mainBundle] bundlePath] UTF8String]));
 
+    UIScreen *mainScreen = [UIScreen mainScreen];
     NSMutableArray *screens = [[[UIScreen screens] mutableCopy] autorelease];
-    if (![screens containsObject:[UIScreen mainScreen]]) {
+    if (![screens containsObject:mainScreen]) {
         // Fallback for iOS 7.1 (QTBUG-42345)
-        [screens insertObject:[UIScreen mainScreen] atIndex:0];
+        [screens insertObject:mainScreen atIndex:0];
     }
 
     for (UIScreen *screen in screens)
@@ -103,7 +104,10 @@ QIOSIntegration::QIOSIntegration()
 
     m_touchDevice = new QTouchDevice;
     m_touchDevice->setType(QTouchDevice::TouchScreen);
-    m_touchDevice->setCapabilities(QTouchDevice::Position | QTouchDevice::NormalizedPosition);
+    QTouchDevice::Capabilities touchCapabilities = QTouchDevice::Position | QTouchDevice::NormalizedPosition;
+    if (mainScreen.traitCollection.forceTouchCapability == UIForceTouchCapabilityAvailable)
+        touchCapabilities |= QTouchDevice::Pressure;
+    m_touchDevice->setCapabilities(touchCapabilities);
     QWindowSystemInterface::registerTouchDevice(m_touchDevice);
     QMacInternalPasteboardMime::initializeMimeTypes();
 }
diff --git a/src/plugins/platforms/ios/quiview.mm b/src/plugins/platforms/ios/quiview.mm
index c6ef843b9f..53b3d30327 100644
--- a/src/plugins/platforms/ios/quiview.mm
+++ b/src/plugins/platforms/ios/quiview.mm
@@ -280,6 +280,19 @@
 
 // -------------------------------------------------------------------------
 
+- (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection
+{
+    [super traitCollectionDidChange: previousTraitCollection];
+
+    QTouchDevice *touchDevice = QIOSIntegration::instance()->touchDevice();
+    QTouchDevice::Capabilities touchCapabilities = touchDevice->capabilities();
+    if (self.traitCollection.forceTouchCapability == UIForceTouchCapabilityAvailable)
+        touchCapabilities |= QTouchDevice::Pressure;
+    else
+        touchCapabilities &= ~QTouchDevice::Pressure;
+    touchDevice->setCapabilities(touchCapabilities);
+}
+
 -(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
 {
     if (m_qioswindow->window()->flags() & Qt::WindowTransparentForInput)
@@ -289,6 +302,8 @@
 
 - (void)updateTouchList:(NSSet *)touches withState:(Qt::TouchPointState)state
 {
+    bool supportsPressure = QIOSIntegration::instance()->touchDevice()->capabilities() & QTouchDevice::Pressure;
+
     foreach (UITouch *uiTouch, m_activeTouches.keys()) {
         QWindowSystemInterface::TouchPoint &touchPoint = m_activeTouches[uiTouch];
         if (![touches containsObject:uiTouch]) {
@@ -309,9 +324,17 @@
             touchPoint.normalPosition = QPointF(globalScreenPosition.x() / screenSize.width(),
                                                 globalScreenPosition.y() / screenSize.height());
 
-            // We don't claim that our touch device supports QTouchDevice::Pressure,
-            // but fill in a meaningfull value in case clients use it anyways.
-            touchPoint.pressure = (state == Qt::TouchPointReleased) ? 0.0 : 1.0;
+            if (supportsPressure) {
+                // Note: iOS  will deliver touchesBegan with a touch force of 0, which
+                // we will reflect/propagate as a 0 pressure, but there is no clear
+                // alternative, as we don't want to wait for a touchedMoved before
+                // sending a touch press event to Qt, just to have a valid pressure.
+                touchPoint.pressure = uiTouch.force / uiTouch.maximumPossibleForce;
+            } else {
+                // We don't claim that our touch device supports QTouchDevice::Pressure,
+                // but fill in a meaningfull value in case clients use it anyways.
+                touchPoint.pressure = (state == Qt::TouchPointReleased) ? 0.0 : 1.0;
+            }
         }
     }
 }