Allow the platform to specify a press and hold delay.

Press and hold is an interaction available on many platforms,
particularly when touch is involved. In Qt Quick this is exposed to the
user via MouseArea::onPressAndHold. This value should not be hard-coded,
but rather use a platform-specified default. This commit adds the
low-level hooks necessary for that to happen.

Task-number: QTBUG-24793
Change-Id: I621a8ac9de66b881e34336228056bffbb6306a70
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/gui/kernel/qplatformtheme.cpp b/src/gui/kernel/qplatformtheme.cpp
index 1844232efe..8b4b5c1812 100644
--- a/src/gui/kernel/qplatformtheme.cpp
+++ b/src/gui/kernel/qplatformtheme.cpp
@@ -79,6 +79,9 @@ QT_BEGIN_NAMESPACE
     \value MouseDoubleClickInterval (int) Mouse double click interval in ms,
                                     overriding QPlatformIntegration::styleHint.
 
+    \value MousePressAndHoldInterval (int) Mouse press and hold interval in ms,
+                                    overriding QPlatformIntegration::styleHint.
+
     \value StartDragDistance (int) Start drag distance,
                              overriding QPlatformIntegration::styleHint.
 
@@ -423,6 +426,8 @@ QVariant QPlatformTheme::themeHint(ThemeHint hint) const
         return QGuiApplicationPrivate::platformIntegration()->styleHint(QPlatformIntegration::PasswordMaskDelay);
     case QPlatformTheme::PasswordMaskCharacter:
         return QGuiApplicationPrivate::platformIntegration()->styleHint(QPlatformIntegration::PasswordMaskCharacter);
+    case QPlatformTheme::MousePressAndHoldInterval:
+        return QGuiApplicationPrivate::platformIntegration()->styleHint(QPlatformIntegration::MousePressAndHoldInterval);
     default:
         return QPlatformTheme::defaultThemeHint(hint);
     }
@@ -488,6 +493,8 @@ QVariant QPlatformTheme::defaultThemeHint(ThemeHint hint)
         return QVariant::fromValue(QList<int>());
     case DialogSnapToDefaultButton:
         return QVariant(false);
+    case MousePressAndHoldInterval:
+        return QVariant(800);
     }
     return QVariant();
 }