QQuickPointerDeviceHandler: add acceptedModifiers

Sometimes you want to require holding down a key in order to enable
some interaction.  As with the other "accepted" flags, it's better to
do this with a property than with Javascript.

Change-Id: Ie29880f5f9f496ddca1bee462e2c0e6dd30fa9f5
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

2 files changed, 44 insertions, 1 deletions

diff --git a/src/quick/handlers/qquickpointerdevicehandler.cpp b/src/quick/handlers/qquickpointerdevicehandler.cpp
index 3a320fdb32..203f712179 100644
--- a/src/quick/handlers/qquickpointerdevicehandler.cpp
+++ b/src/quick/handlers/qquickpointerdevicehandler.cpp
@@ -53,6 +53,7 @@ QQuickPointerDeviceHandler::QQuickPointerDeviceHandler(QObject *parent)
     : QQuickPointerHandler(parent)
     , m_acceptedDevices(QQuickPointerDevice::AllDevices)
     , m_acceptedPointerTypes(QQuickPointerDevice::AllPointerTypes)
+    , m_acceptedModifiers(Qt::KeyboardModifierMask)
 {
 }
 
@@ -78,17 +79,54 @@ void QQuickPointerDeviceHandler::setAcceptedPointerTypes(QQuickPointerDevice::Po
     emit acceptedPointerTypesChanged();
 }
 
+/*!
+     \qmlproperty QQuickPointerDeviceHandler::acceptedModifiers
+
+     If this property is set, it will require the given keyboard modifiers to
+     be pressed in order to react to pointer events, and otherwise ignore them.
+
+     If this property is set to Qt.KeyboardModifierMask (the default value),
+     then the PointerHandler ignores the modifier keys.
+
+     For example an Item could have two handlers of the same type, one of which
+     is enabled only if the required keyboard modifiers are pressed:
+
+     \qml
+     Item {
+        TapHandler {
+            acceptedModifiers: Qt.ControlModifier
+            onTapped: console.log("control-tapped")
+        }
+        TapHandler {
+            acceptedModifiers: Qt.NoModifier
+            onTapped: console.log("tapped")
+        }
+     }
+     \endqml
+*/
+void QQuickPointerDeviceHandler::setAcceptedModifiers(Qt::KeyboardModifiers acceptedModifiers)
+{
+    if (m_acceptedModifiers == acceptedModifiers)
+        return;
+
+    m_acceptedModifiers = acceptedModifiers;
+    emit acceptedModifiersChanged();
+}
+
 bool QQuickPointerDeviceHandler::wantsPointerEvent(QQuickPointerEvent *event)
 {
     if (!QQuickPointerHandler::wantsPointerEvent(event))
         return false;
     qCDebug(lcPointerHandlerDispatch) << objectName()
         << "checking device type" << m_acceptedDevices
-        << "pointer type" << m_acceptedPointerTypes;
+        << "pointer type" << m_acceptedPointerTypes
+        << "modifiers" << m_acceptedModifiers;
     if ((event->device()->type() & m_acceptedDevices) == 0)
         return false;
     if ((event->device()->pointerType() & m_acceptedPointerTypes) == 0)
         return false;
+    if (m_acceptedModifiers != Qt::KeyboardModifierMask && event->modifiers() != m_acceptedModifiers)
+        return false;
     return true;
 }
 
diff --git a/src/quick/handlers/qquickpointerdevicehandler_p.h b/src/quick/handlers/qquickpointerdevicehandler_p.h
index 76c9cc44f0..9e30fa0be4 100644
--- a/src/quick/handlers/qquickpointerdevicehandler_p.h
+++ b/src/quick/handlers/qquickpointerdevicehandler_p.h
@@ -60,6 +60,7 @@ class Q_AUTOTEST_EXPORT QQuickPointerDeviceHandler : public QQuickPointerHandler
     Q_OBJECT
     Q_PROPERTY(QQuickPointerDevice::DeviceTypes acceptedDevices READ acceptedDevices WRITE setAcceptedDevices NOTIFY acceptedDevicesChanged)
     Q_PROPERTY(QQuickPointerDevice::PointerTypes acceptedPointerTypes READ acceptedPointerTypes WRITE setAcceptedPointerTypes NOTIFY acceptedPointerTypesChanged)
+    Q_PROPERTY(Qt::KeyboardModifiers acceptedModifiers READ acceptedModifiers WRITE setAcceptedModifiers NOTIFY acceptedModifiersChanged)
 
 public:
     explicit QQuickPointerDeviceHandler(QObject *parent = 0);
@@ -67,14 +68,17 @@ public:
 
     QQuickPointerDevice::DeviceTypes acceptedDevices() const { return m_acceptedDevices; }
     QQuickPointerDevice::PointerTypes acceptedPointerTypes() const { return m_acceptedPointerTypes; }
+    Qt::KeyboardModifiers acceptedModifiers() const { return m_acceptedModifiers; }
 
 public slots:
     void setAcceptedDevices(QQuickPointerDevice::DeviceTypes acceptedDevices);
     void setAcceptedPointerTypes(QQuickPointerDevice::PointerTypes acceptedPointerTypes);
+    void setAcceptedModifiers(Qt::KeyboardModifiers acceptedModifiers);
 
 Q_SIGNALS:
     void acceptedDevicesChanged();
     void acceptedPointerTypesChanged();
+    void acceptedModifiersChanged();
 
 protected:
     bool wantsPointerEvent(QQuickPointerEvent *event) override;
@@ -82,6 +86,7 @@ protected:
 protected:
     QQuickPointerDevice::DeviceTypes m_acceptedDevices;
     QQuickPointerDevice::PointerTypes m_acceptedPointerTypes;
+    Qt::KeyboardModifiers m_acceptedModifiers;
 };
 
 QT_END_NAMESPACE