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  1. Qt
  2. QTBUG-22625

Behavior on value types doesn't work for all combinations

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    • f18b66ac6cfc734d217ec9d44876774f25e5d900

      Issue 1: In the following example, the Behavior is never created (CREATE_SIMPLE and STORE_VALUE_INTERCEPTOR instructions are not generated for the Behavior)

      import QtQuick 2.0

Rectangle {
    width: 400
    height: 400
    color.r: 0
    color.g: 1
    color.b: 0

    Behavior on color { ColorAnimation { duration: 500; } }
}

      Issue 2: In the following example, the error "Property has already been assigned a value" is produced:

      import QtQuick 2.0

Rectangle {
    width: 400
    height: 400
    color: "green"

    Behavior on color.r { ColorAnimation { duration: 500; } }
}

      The following patch gets rid of the error for issue 2, but still doesn't not allow the two color-related assignments to play well with each other:

      diff --git a/src/declarative/qml/qdeclarativecompiler.cpp b/src/declarative/qml/qdeclarativecompiler.cpp
index fb98a8c..900ffd3 100644
--- a/src/declarative/qml/qdeclarativecompiler.cpp
+++ b/src/declarative/qml/qdeclarativecompiler.cpp
@@ -1997,10 +1997,15 @@ bool QDeclarativeCompiler::buildGroupedProperty(QDeclarativeScript::Property *pr
         if (prop->type >= 0 && enginePrivate->valueTypes[prop->type]) {
 
             if (!prop->values.isEmpty()) {
-                if (prop->values.first()->location < prop->value->location) {
-                    COMPILE_EXCEPTION(prop->value, tr( "Property has already been assigned a value"));
-                } else {
-                    COMPILE_EXCEPTION(prop->values.first(), tr( "Property has already been assigned a value"));
+                //only error if we are assigning values, and not e.g. a property interceptor
+                for (Property *dotProp = prop->value->properties.first(); dotProp; dotProp = prop->value->properties.next(dotProp)) {
+                    if (!dotProp->values.isEmpty()) {
+                        if (prop->values.first()->location < prop->value->location) {
+                            COMPILE_EXCEPTION(prop->value, tr( "Property has already been assigned a value"));
+                        } else {
+                            COMPILE_EXCEPTION(prop->values.first(), tr( "Property has already been assigned a value"));
+                        }
+                    }
                 }
             }

      The issue is caused at the compiler level where the two assignments appear to be mutually exclusive, e.g. either buildGroupedProperty or buildPropertyAssignment will be called, but not both.

        For Gerrit Dashboard: QTBUG-22625
        # Subject Branch Project Status CR V
        29856,4 Make Behaviors work correctly with value types. master qt/qtdeclarative Status: MERGED +2 0

            glwatson Glenn Watson
            brasser Michael Brasser (closed Nokia identity) (Inactive)
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              Created:
              Updated:
              Resolved:

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