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42 #include "qsgrectangle_p.h"
43 #include "qsgrectangle_p_p.h"
45 #include <private/qsgcontext_p.h>
46 #include <private/qsgadaptationlayer_p.h>
48 #include <QtGui/qpixmapcache.h>
49 #include <QtCore/qstringbuilder.h>
50 #include <QtCore/qmath.h>
54 // XXX todo - should we change rectangle to draw entirely within its width/height?
58 \brief The QSGPen class provides a pen used for drawing rectangle borders on a QSGView.
60 By default, the pen is invalid and nothing is drawn. You must either set a color (then the default
61 width is 1) or a width (then the default color is black).
63 A width of 1 indicates is a single-pixel line on the border of the item being painted.
74 QSGPen::QSGPen(QObject *parent)
83 qreal QSGPen::width() const
88 void QSGPen::setWidth(qreal w)
90 if (m_width == w && m_valid)
94 m_valid = m_color.alpha() && (qRound(m_width) >= 1 || (!m_aligned && m_width > 0));
98 QColor QSGPen::color() const
103 void QSGPen::setColor(const QColor &c)
106 m_valid = m_color.alpha() && (qRound(m_width) >= 1 || (!m_aligned && m_width > 0));
110 bool QSGPen::aligned() const
115 void QSGPen::setAligned(bool aligned)
117 if (aligned == m_aligned)
120 m_valid = m_color.alpha() && (qRound(m_width) >= 1 || (!m_aligned && m_width > 0));
124 bool QSGPen::isValid() const
130 \qmlclass GradientStop QSGGradientStop
131 \inqmlmodule QtQuick 2
132 \ingroup qml-basic-visual-elements
133 \brief The GradientStop item defines the color at a position in a Gradient.
139 \qmlproperty real QtQuick2::GradientStop::position
140 \qmlproperty color QtQuick2::GradientStop::color
142 The position and color properties describe the color used at a given
143 position in a gradient, as represented by a gradient stop.
145 The default position is 0.0; the default color is black.
149 QSGGradientStop::QSGGradientStop(QObject *parent)
154 qreal QSGGradientStop::position() const
159 void QSGGradientStop::setPosition(qreal position)
161 m_position = position; updateGradient();
164 QColor QSGGradientStop::color() const
169 void QSGGradientStop::setColor(const QColor &color)
171 m_color = color; updateGradient();
174 void QSGGradientStop::updateGradient()
176 if (QSGGradient *grad = qobject_cast<QSGGradient*>(parent()))
181 \qmlclass Gradient QSGGradient
182 \inqmlmodule QtQuick 2
183 \ingroup qml-basic-visual-elements
184 \brief The Gradient item defines a gradient fill.
186 A gradient is defined by two or more colors, which will be blended seamlessly.
188 The colors are specified as a set of GradientStop child items, each of
189 which defines a position on the gradient from 0.0 to 1.0 and a color.
190 The position of each GradientStop is defined by setting its
191 \l{GradientStop::}{position} property; its color is defined using its
192 \l{GradientStop::}{color} property.
194 A gradient without any gradient stops is rendered as a solid white fill.
196 Note that this item is not a visual representation of a gradient. To display a
197 gradient, use a visual element (like \l Rectangle) which supports the use
200 \section1 Example Usage
202 \div {class="float-right"}
203 \inlineimage qml-gradient.png
206 The following example declares a \l Rectangle item with a gradient starting
207 with red, blending to yellow at one third of the height of the rectangle,
208 and ending with green:
210 \snippet doc/src/snippets/declarative/gradient.qml code
213 \section1 Performance and Limitations
215 Calculating gradients can be computationally expensive compared to the use
216 of solid color fills or images. Consider using gradients for static items
219 In Qt 4.7, only vertical, linear gradients can be applied to items. If you
220 need to apply different orientations of gradients, a combination of rotation
221 and clipping will need to be applied to the relevant items. This can
222 introduce additional performance requirements for your application.
224 The use of animations involving gradient stops may not give the desired
225 result. An alternative way to animate gradients is to use pre-generated
226 images or SVG drawings containing gradients.
232 \qmlproperty list<GradientStop> QtQuick2::Gradient::stops
235 This property holds the gradient stops describing the gradient.
237 By default, this property contains an empty list.
239 To set the gradient stops, define them as children of the Gradient element.
241 QSGGradient::QSGGradient(QObject *parent)
242 : QObject(parent), m_gradient(0)
246 QSGGradient::~QSGGradient()
251 QDeclarativeListProperty<QSGGradientStop> QSGGradient::stops()
253 return QDeclarativeListProperty<QSGGradientStop>(this, m_stops);
256 const QGradient *QSGGradient::gradient() const
258 if (!m_gradient && !m_stops.isEmpty()) {
259 m_gradient = new QLinearGradient(0,0,0,1.0);
260 for (int i = 0; i < m_stops.count(); ++i) {
261 const QSGGradientStop *stop = m_stops.at(i);
262 m_gradient->setCoordinateMode(QGradient::ObjectBoundingMode);
263 m_gradient->setColorAt(stop->position(), stop->color());
270 void QSGGradient::doUpdate()
277 int QSGRectanglePrivate::doUpdateSlotIdx = -1;
280 \qmlclass Rectangle QSGRectangle
281 \inqmlmodule QtQuick 2
282 \ingroup qml-basic-visual-elements
283 \brief The Rectangle item provides a filled rectangle with an optional border.
286 Rectangle items are used to fill areas with solid color or gradients, and are
287 often used to hold other items.
291 Each Rectangle item is painted using either a solid fill color, specified using
292 the \l color property, or a gradient, defined using a Gradient element and set
293 using the \l gradient property. If both a color and a gradient are specified,
294 the gradient is used.
296 You can add an optional border to a rectangle with its own color and thickness
297 by settting the \l border.color and \l border.width properties.
299 You can also create rounded rectangles using the \l radius property. Since this
300 introduces curved edges to the corners of a rectangle, it may be appropriate to
301 set the \l smooth property to improve its appearance.
303 \section1 Example Usage
305 \div {class="float-right"}
306 \inlineimage declarative-rect.png
309 The following example shows the effects of some of the common properties on a
310 Rectangle item, which in this case is used to create a square:
312 \snippet doc/src/snippets/declarative/rectangle/rectangle.qml document
315 \section1 Performance
317 Using the \l smooth property improves the appearance of a rounded rectangle at
318 the cost of rendering performance. You should consider unsetting this property
319 for rectangles in motion, and only set it when they are stationary.
324 QSGRectangle::QSGRectangle(QSGItem *parent)
325 : QSGItem(*(new QSGRectanglePrivate), parent)
327 setFlag(ItemHasContents);
330 void QSGRectangle::doUpdate()
335 if (d->pen && d->pen->isValid()) {
336 if (d->pen->aligned()) {
337 const int pw = qRound(d->pen->width());
338 penMargin = qreal(0.5) * pw;
339 penOffset = (pw & 1) * qreal(0.5);
341 penMargin = qreal(0.5) * d->pen->width();
344 if (penMargin != d->penMargin || penOffset != d->penOffset) {
345 d->penMargin = penMargin;
346 d->penOffset = penOffset;
347 d->dirty(QSGItemPrivate::Size); // update clip
353 \qmlproperty int QtQuick2::Rectangle::border.width
354 \qmlproperty color QtQuick2::Rectangle::border.color
356 The width and color used to draw the border of the rectangle.
358 A width of 1 creates a thin line. For no line, use a width of 0 or a transparent color.
360 \note The width of the rectangle's border does not affect the geometry of the
361 rectangle itself or its position relative to other items if anchors are used.
363 If \c border.width is an odd number, the rectangle is painted at a half-pixel offset to retain
364 border smoothness. Also, the border is rendered evenly on either side of the
365 rectangle's boundaries, and the spare pixel is rendered to the right and below the
366 rectangle (as documented for QRect rendering). This can cause unintended effects if
367 \c border.width is 1 and the rectangle is \l{Item::clip}{clipped} by a parent item:
369 \div {class="float-right"}
370 \inlineimage rect-border-width.png
373 \snippet doc/src/snippets/declarative/rectangle/rect-border-width.qml 0
376 Here, the innermost rectangle's border is clipped on the bottom and right edges by its
377 parent. To avoid this, the border width can be set to two instead of one.
379 QSGPen *QSGRectangle::border()
386 \qmlproperty Gradient QtQuick2::Rectangle::gradient
388 The gradient to use to fill the rectangle.
390 This property allows for the construction of simple vertical gradients.
391 Other gradients may by formed by adding rotation to the rectangle.
393 \div {class="float-left"}
394 \inlineimage declarative-rect_gradient.png
397 \snippet doc/src/snippets/declarative/rectangle/rectangle-gradient.qml rectangles
400 If both a gradient and a color are specified, the gradient will be used.
404 QSGGradient *QSGRectangle::gradient() const
406 Q_D(const QSGRectangle);
410 void QSGRectangle::setGradient(QSGGradient *gradient)
413 if (d->gradient == gradient)
415 static int updatedSignalIdx = -1;
416 if (updatedSignalIdx < 0)
417 updatedSignalIdx = QSGGradient::staticMetaObject.indexOfSignal("updated()");
418 if (d->doUpdateSlotIdx < 0)
419 d->doUpdateSlotIdx = QSGRectangle::staticMetaObject.indexOfSlot("doUpdate()");
421 QMetaObject::disconnect(d->gradient, updatedSignalIdx, this, d->doUpdateSlotIdx);
422 d->gradient = gradient;
424 QMetaObject::connect(d->gradient, updatedSignalIdx, this, d->doUpdateSlotIdx);
429 \qmlproperty real QtQuick2::Rectangle::radius
430 This property holds the corner radius used to draw a rounded rectangle.
432 If radius is non-zero, the rectangle will be painted as a rounded rectangle, otherwise it will be
433 painted as a normal rectangle. The same radius is used by all 4 corners; there is currently
434 no way to specify different radii for different corners.
436 qreal QSGRectangle::radius() const
438 Q_D(const QSGRectangle);
442 void QSGRectangle::setRadius(qreal radius)
445 if (d->radius == radius)
450 emit radiusChanged();
454 \qmlproperty color QtQuick2::Rectangle::color
455 This property holds the color used to fill the rectangle.
457 The default color is white.
459 \div {class="float-right"}
460 \inlineimage rect-color.png
463 The following example shows rectangles with colors specified
464 using hexadecimal and named color notation:
466 \snippet doc/src/snippets/declarative/rectangle/rectangle-colors.qml rectangles
469 If both a gradient and a color are specified, the gradient will be used.
473 QColor QSGRectangle::color() const
475 Q_D(const QSGRectangle);
479 void QSGRectangle::setColor(const QColor &c)
490 QSGNode *QSGRectangle::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *data)
495 if (width() <= 0 || height() <= 0) {
500 QSGRectangleNode *rectangle = static_cast<QSGRectangleNode *>(oldNode);
501 if (!rectangle) rectangle = d->sceneGraphContext()->createRectangleNode();
503 rectangle->setRect(QRectF(0, 0, width(), height()));
504 rectangle->setColor(d->color);
506 if (d->pen && d->pen->isValid()) {
507 rectangle->setPenColor(d->pen->color());
508 rectangle->setPenWidth(d->pen->width());
509 rectangle->setAligned(d->pen->aligned());
511 rectangle->setPenWidth(0);
514 rectangle->setRadius(d->radius);
516 QGradientStops stops;
518 QList<QSGGradientStop *> qxstops = d->gradient->m_stops;
519 for (int i = 0; i < qxstops.size(); ++i){
521 while (j < stops.size() && stops.at(j).first < qxstops[i]->position())
523 stops.insert(j, QGradientStop(qxstops.at(i)->position(), qxstops.at(i)->color()));
526 rectangle->setGradientStops(stops);
533 \qmlproperty bool QtQuick2::Rectangle::smooth
535 Set this property if you want the item to be smoothly scaled or
536 transformed. Smooth filtering gives better visual quality, but is slower. If
537 the item is displayed at its natural size, this property has no visual or
540 \note Generally scaling artifacts are only visible if the item is stationary on
541 the screen. A common pattern when animating an item is to disable smooth
542 filtering at the beginning of the animation and reenable it at the conclusion.
544 \image rect-smooth.png
545 On this image, smooth is turned off on the top half and on on the bottom half.
548 QRectF QSGRectangle::boundingRect() const
550 Q_D(const QSGRectangle);
551 return QRectF(d->penOffset - d->penMargin, d->penOffset - d->penMargin,
552 d->width + 2 * d->penMargin, d->height + 2 * d->penMargin);