diff options
author | Bea Lam <bea.lam@nokia.com> | 2010-05-04 01:13:24 (GMT) |
---|---|---|
committer | Bea Lam <bea.lam@nokia.com> | 2010-05-04 01:14:11 (GMT) |
commit | 56dcdada14f1a499da5a458bdada2127e73dc630 (patch) | |
tree | 8abc1ebc66ee494461ec3eda7fd29b468340ac04 /doc/src/declarative/dynamicobjects.qdoc | |
parent | 536d0f141a13474122f99daf98bf6b54e635b474 (diff) | |
download | Qt-56dcdada14f1a499da5a458bdada2127e73dc630.zip Qt-56dcdada14f1a499da5a458bdada2127e73dc630.tar.gz Qt-56dcdada14f1a499da5a458bdada2127e73dc630.tar.bz2 |
Doc improvements
Diffstat (limited to 'doc/src/declarative/dynamicobjects.qdoc')
-rw-r--r-- | doc/src/declarative/dynamicobjects.qdoc | 48 |
1 files changed, 18 insertions, 30 deletions
diff --git a/doc/src/declarative/dynamicobjects.qdoc b/doc/src/declarative/dynamicobjects.qdoc index 5cdd768..dc0277d 100644 --- a/doc/src/declarative/dynamicobjects.qdoc +++ b/doc/src/declarative/dynamicobjects.qdoc @@ -132,36 +132,24 @@ do not have an id in QML. \section1 Deleting Objects Dynamically -You should generally avoid dynamically deleting objects that you did not -dynamically create. In many UIs, it is sufficient to set the opacity to 0 or -to move the item off of the edge of the screen. If you have lots of dynamically -created items however, deleting them when they are no longer used will provide -a worthwhile performance benefit. Note that you should never manually delete -items which were dynamically created by QML Elements such as \l{Loader}. - -To manually delete a QML item, call its destroy method. This method has one -argument, which is an approximate delay in milliseconds and which defaults to zero. This -allows you to wait until the completion of an animation or transition. An example: - -\code - Component { - id: fadesOut - Rectangle{ - id: rect - width: 40; height: 40; - NumberAnimation on opacity { from:1; to:0; duration: 1000 } - Component.onCompleted: rect.destroy(1000); - } - } - function createFadesOut(parentItem) - { - var object = fadesOut.createObject(); - object.parent = parentItem; - } -\endcode - -In the above example, the dynamically created rectangle calls destroy as soon as it is created, - but delays long enough for its fade out animation to be played. +In many user interfaces, it is sufficient to set an item's opacity to 0 or +to move the item off the screen instead of deleting the item. If you have +lots of dynamically created items, however, you may receive a worthwhile +performance benefit if unused items are deleted. + +Note that you should never manually delete items that were dynamically created +by QML elements (such as \l Loader). Also, you should generally avoid deleting +items that you did not dynamically create yourself. + +Items can be deleted using the \c destroy() method. This method has an optional +argument (which defaults to 0) that specifies the approximate delay in milliseconds +before the object is to be destroyed. This allows you to wait until the completion of +an animation or transition. An example: + +\snippet doc/src/snippets/declarative/dynamicObjects.qml 0 + +Here, \c Rectangle objects are destroyed one second after they are created, which is long +enough for the \c NumberAnimation to be played before the object is destroyed. */ |