Implement actual overload resolution

This implements host-side overload resolution. If a client invokes a method
by its name instead of its id, the overload resolution tries to find the best
match for the given arguments.
The JavaScript client implementation now defaults to invocation-by-name, except
when a method is invoked by its full signature. In that case, the invocation
is still performed by method id.

Change-Id: I09f12bdbfee2e84ff66a1454608468113f96e3ed
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/webchannel/qmetaobjectpublisher_p.h b/src/webchannel/qmetaobjectpublisher_p.h
index 23a9b96..6030de2 100644
--- a/src/webchannel/qmetaobjectpublisher_p.h
+++ b/src/webchannel/qmetaobjectpublisher_p.h
@@ -148,6 +148,14 @@ public:
     void sendPendingPropertyUpdates();
 
     /**
+     * Invoke the @p method on @p object with the arguments @p args.
+     *
+     * The return value of the method invocation is then serialized and a response message
+     * is returned.
+     */
+    QVariant invokeMethod(QObject *const object, const QMetaMethod &method, const QJsonArray &args);
+
+    /**
      * Invoke the method of index @p methodIndex on @p object with the arguments @p args.
      *
      * The return value of the method invocation is then serialized and a response message
@@ -156,6 +164,16 @@ public:
     QVariant invokeMethod(QObject *const object, const int methodIndex, const QJsonArray &args);
 
     /**
+     * Invoke the method of name @p methodName on @p object with the arguments @p args.
+     *
+     * This method performs overload resolution on @p methodName.
+     *
+     * The return value of the method invocation is then serialized and a response message
+     * is returned.
+     */
+    QVariant invokeMethod(QObject *const object, const QByteArray &methodName, const QJsonArray &args);
+
+    /**
      * Set the value of property @p propertyIndex on @p object to @p value.
      */
     void setProperty(QObject *object, const int propertyIndex, const QJsonValue &value);
@@ -177,6 +195,26 @@ public:
     QVariant toVariant(const QJsonValue &value, int targetType) const;
 
     /**
+     * Assigns a score for the conversion from @p value to @p targetType.
+     *
+     * Scores can be compared to find the best match. The lower the score, the
+     * more preferable is the conversion.
+     *
+     * @sa invokeMethod, methodOverloadBadness
+     */
+    int conversionScore(const QJsonValue &value, int targetType) const;
+
+    /**
+     * Scores @p method against @p args.
+     *
+     * Scores can be compared to find the best match from a set of overloads.
+     * The lower the score, the more preferable is the method.
+     *
+     * @sa invokeMethod, conversionScore
+     */
+    int methodOverloadBadness(const QMetaMethod &method, const QJsonArray &args) const;
+
+    /**
      * Remove wrapped objects which last transport relation is with the passed transport object.
      */
     void transportRemoved(QWebChannelAbstractTransport *transport);