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Diffstat (limited to 'src/quick/doc/src/appdevguide/performance.qdoc')
| -rw-r--r-- | src/quick/doc/src/appdevguide/performance.qdoc | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/quick/doc/src/appdevguide/performance.qdoc b/src/quick/doc/src/appdevguide/performance.qdoc index 4f0590d554..28217e06d6 100644 --- a/src/quick/doc/src/appdevguide/performance.qdoc +++ b/src/quick/doc/src/appdevguide/performance.qdoc @@ -128,14 +128,14 @@ sorts of optimizations. \section2 Type-Conversion One major cost of using JavaScript is that in most cases when a property from a QML -element is accessed, a JavaScript object with an external resource containing the +type is accessed, a JavaScript object with an external resource containing the underlying C++ data (or a reference to it) is created. In most cases, this is fairly inexpensive, but in others it can be quite expensive. One example of where it is expensive is assigning a C++ QVariantMap Q_PROPERTY to a QML "variant" property. Lists can also be expensive, although sequences of specific types (QList of int, qreal, bool, QString, and QUrl) should be inexpensive; other list types involve an -expensive conversion cost (creating a new JavaScript Array, and adding new elements -one by one, with per-element conversion from C++ type instance to JavaScript value). +expensive conversion cost (creating a new JavaScript Array, and adding new types +one by one, with per-type conversion from C++ type instance to JavaScript value). Converting between some basic property types (such as "string" and "url" properties) can also be expensive. Using the closest matching property type will avoid unnecessary @@ -156,7 +156,7 @@ possible. In the following example, we have a block of code which is run often (in this case, it is the contents of an explicit loop; but it could be a commonly-evaluated binding expression, -for example) and in it, we resolve the element with the "rect" id and its "color" property +for example) and in it, we resolve the object with the "rect" id and its "color" property multiple times: \qml |