Add delayed property to Binding.

Provide a way to avoid potentially expensive or unexpected intermediate
values.

[ChangeLog][Binding] Add delayed property to Binding as a way to avoid potentially expensive or unexpected intermediate values.

Change-Id: I6aaca570859cc1344eeb9c9f19f32660e8c0b4e0
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlbinding/data/delayed.qml b/tests/auto/qml/qqmlbinding/data/delayed.qml
new file mode 100644
index 0000000000..6f8281cc33
--- /dev/null
+++ b/tests/auto/qml/qqmlbinding/data/delayed.qml
@@ -0,0 +1,26 @@
+import QtQuick 2.8
+
+Item {
+    width: 400
+    height: 400
+
+    property int changeCount: 0
+
+    property string text1
+    property string text2
+
+    function updateText() {
+        text1 = "Hello"
+        text2 = "World"
+    }
+
+    Text {
+        anchors.centerIn: parent
+        Binding on text {
+            value: text1 + " " + text2
+            delayed: true
+        }
+        onTextChanged: ++changeCount
+    }
+}
+