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authorBea Lam <bea.lam@nokia.com>2011-01-31 06:56:38 (GMT)
committerBea Lam <bea.lam@nokia.com>2011-02-02 02:59:47 (GMT)
commit634589cdcdeb608352e17007360c5fb7d916a527 (patch)
treeff44ab20bfa1bdad50165f763d1825dce9c9be3c /src/declarative/graphicsitems
parent501180c6fbed0857126da2bb0ff1f17ee35472c6 (diff)
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Improve docs on Item::visible and Item::opacity
Task-number: QTBUG-16973
Diffstat (limited to 'src/declarative/graphicsitems')
-rw-r--r--src/declarative/graphicsitems/qdeclarativeitem.cpp43
1 files changed, 33 insertions, 10 deletions
diff --git a/src/declarative/graphicsitems/qdeclarativeitem.cpp b/src/declarative/graphicsitems/qdeclarativeitem.cpp
index e1c138f..ac5d55c 100644
--- a/src/declarative/graphicsitems/qdeclarativeitem.cpp
+++ b/src/declarative/graphicsitems/qdeclarativeitem.cpp
@@ -1911,11 +1911,26 @@ void QDeclarativeItem::setClip(bool c)
/*!
\qmlproperty bool Item::visible
- Whether the item is visible. By default this is true.
+ This property holds whether the item is visible. By default this is true.
- \note visible is not linked to actual visibility; if an item
- moves off screen, or the opacity changes to 0, this will
- not affect the visible property.
+ Setting this property directly affects the \c visible value of child
+ items. When set to \c false, the \c visible values of all child items also
+ become \c false. When set to \c true, the \c visible values of child items
+ are returned to \c true, unless they have explicitly been set to \c false.
+
+ (Because of this flow-on behavior, using the \c visible property may not
+ have the intended effect if a property binding should only respond to
+ explicit property changes. In such cases it may be better to use the
+ \l opacity property instead.)
+
+ Setting this property to \c false automatically causes \l focus to be set
+ to \c false, and this item will longer receive mouse and keyboard events.
+ (In contrast, setting the \l opacity to 0 does not affect the \l focus
+ property and the receiving of key events.)
+
+ \note This property's value is only affected by changes to this property or
+ the parent's \c visible property. It does not change, for example, if this
+ item moves off-screen, or if the \l opacity changes to 0.
*/
@@ -2289,13 +2304,15 @@ void QDeclarativeItem::setBaselineOffset(qreal offset)
/*!
\qmlproperty real Item::opacity
- The opacity of the item. Opacity is specified as a number between 0
- (fully transparent) and 1 (fully opaque). The default is 1.
+ This property holds the opacity of the item. Opacity is specified as a
+ number between 0 (fully transparent) and 1 (fully opaque). The default is 1.
- Opacity is an \e inherited attribute. That is, the opacity is
- also applied individually to child items. In almost all cases this
- is what you want, but in some cases (like the following example)
- it may produce undesired results.
+ When this property is set, the specified opacity is also applied
+ individually to child items. In almost all cases this is what you want,
+ but in some cases it may produce undesired results. For example in the
+ second set of rectangles below, the red rectangle has specified an opacity
+ of 0.5, which affects the opacity of its blue child rectangle even though
+ the child has not specified an opacity.
\table
\row
@@ -2330,6 +2347,12 @@ void QDeclarativeItem::setBaselineOffset(qreal offset)
}
\endqml
\endtable
+
+ If an item's opacity is set to 0, the item will no longer receive mouse
+ events, but will continue to receive key events and will retain the keyboard
+ \l focus if it has been set. (In contrast, setting the \l visible property
+ to \c false stops both mouse and keyboard events, and also removes focus
+ from the item.)
*/
/*!