diff options
author | David Boddie <david.boddie@nokia.com> | 2010-09-14 18:35:48 (GMT) |
---|---|---|
committer | David Boddie <david.boddie@nokia.com> | 2010-09-14 18:35:48 (GMT) |
commit | a4b6572b8fb8eb247a7bd952dca7e99e5d4e5707 (patch) | |
tree | f0832cacbc891f40c811dc16917ced81706b6155 /src/declarative/graphicsitems/qdeclarativerectangle.cpp | |
parent | b82889e235b0ad7fc85a0d4c7bada4e82b930c02 (diff) | |
download | Qt-a4b6572b8fb8eb247a7bd952dca7e99e5d4e5707.zip Qt-a4b6572b8fb8eb247a7bd952dca7e99e5d4e5707.tar.gz Qt-a4b6572b8fb8eb247a7bd952dca7e99e5d4e5707.tar.bz2 |
Doc: Continued work on the QML documentation.
Diffstat (limited to 'src/declarative/graphicsitems/qdeclarativerectangle.cpp')
-rw-r--r-- | src/declarative/graphicsitems/qdeclarativerectangle.cpp | 59 |
1 files changed, 49 insertions, 10 deletions
diff --git a/src/declarative/graphicsitems/qdeclarativerectangle.cpp b/src/declarative/graphicsitems/qdeclarativerectangle.cpp index 9238004..e33969d 100644 --- a/src/declarative/graphicsitems/qdeclarativerectangle.cpp +++ b/src/declarative/graphicsitems/qdeclarativerectangle.cpp @@ -95,7 +95,12 @@ void QDeclarativePen::setWidth(int w) \qmlproperty real GradientStop::position \qmlproperty color GradientStop::color - Sets a \e color at a \e position in a gradient. + The position and color properties describe the color used at a given + position in a gradient, as represented by a gradient stop. + + The default position is 0.0; the default color is black. + + \sa Gradient */ void QDeclarativeGradientStop::updateGradient() @@ -107,20 +112,50 @@ void QDeclarativeGradientStop::updateGradient() /*! \qmlclass Gradient QDeclarativeGradient \ingroup qml-basic-visual-elements - \since 4.7 + \since 4.7 \brief The Gradient item defines a gradient fill. - A gradient is defined by two or more colors, which will be blended seemlessly. The - colors are specified at their position in the range 0.0 - 1.0 via - the GradientStop item. For example, the following code paints a - rectangle with a gradient starting with red, blending to yellow at 1/3 of the - size of the rectangle, and ending with Green: + A gradient is defined by two or more colors, which will be blended seamlessly. - \snippet doc/src/snippets/declarative/gradient.qml code + The colors are specified as a set of GradientStop child items, each of + which defines a position on the gradient from 0.0 to 1.0 and a color. + The position of each GradientStop is defined by setting its + \l{GradientStop::}{position} property; its color is defined using its + \l{GradientStop::}{color} property. + + A gradient without any gradient stops is rendered as a solid white fill. Note that this item is not a visual representation of a gradient. To display a - gradient use a visual item (like rectangle) which supports having a gradient set - on it for display. + gradient, use a visual element (like \l Rectangle) which supports the use + of gradients. + + \section1 Example Usage + + \beginfloatright + \inlineimage qml-gradient.png + \endfloat + + The following example declares a \l Rectangle item with a gradient starting + with red, blending to yellow at one third of the height of the rectangle, + and ending with green: + + \snippet doc/src/snippets/declarative/gradient.qml code + + \clearfloat + \section1 Performance and Limitations + + Calculating gradients can be computationally expensive compared to the use + of solid color fills or images. Consider using gradients for static items + in a user interface. + + In Qt 4.7, only vertical, linear gradients can be applied to items. If you + need to apply different orientations of gradients, a combination of rotation + and clipping will need to be applied to the relevant items. This can + introduce additional performance requirements for your application. + + The use of animations involving gradient stops may not give the desired + result. An alternative way to animate gradients is to use pre-generated + images or SVG drawings containing gradients. \sa GradientStop */ @@ -128,6 +163,10 @@ void QDeclarativeGradientStop::updateGradient() /*! \qmlproperty list<GradientStop> Gradient::stops This property holds the gradient stops describing the gradient. + + By default, this property contains an empty list. + + To set the gradient stops, define them as children of the Gradient element. */ const QGradient *QDeclarativeGradient::gradient() const |