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42 #include "private/qdeclarativeborderimage_p.h"
43 #include "private/qdeclarativeborderimage_p_p.h"
45 #include <qdeclarativeinfo.h>
46 #include <private/qdeclarativeengine_p.h>
48 #include <QNetworkRequest>
49 #include <QNetworkReply>
55 \qmlclass BorderImage QDeclarativeBorderImage
56 \brief The BorderImage element provides an image that can be used as a border.
59 \ingroup qml-basic-visual-elements
61 The BorderImage element is used to create borders out of images by scaling or tiling
64 A BorderImage element breaks a source image, specified using the \l url property,
65 into 9 regions, as shown below:
67 \image declarative-scalegrid.png
69 When the image is scaled, regions of the source image are scaled or tiled to
70 create the displayed border image in the following way:
73 \i The corners (regions 1, 3, 7, and 9) are not scaled at all.
74 \i Regions 2 and 8 are scaled according to
75 \l{BorderImage::horizontalTileMode}{horizontalTileMode}.
76 \i Regions 4 and 6 are scaled according to
77 \l{BorderImage::verticalTileMode}{verticalTileMode}.
78 \i The middle (region 5) is scaled according to both
79 \l{BorderImage::horizontalTileMode}{horizontalTileMode} and
80 \l{BorderImage::verticalTileMode}{verticalTileMode}.
83 The regions of the image are defined using the \l border property group, which
84 describes the distance from each edge of the source image to use as a border.
86 \section1 Example Usage
88 The following examples show the effects of the different modes on an image.
89 Guide lines are overlaid onto the image to show the different regions of the
90 image as described above.
93 \image qml-borderimage-normal-image.png
96 An unscaled image is displayed using an Image element. The \l border property is
97 used to determine the parts of the image that will lie inside the unscaled corner
98 areas and the parts that will be stretched horizontally and vertically.
100 \snippet doc/src/snippets/declarative/borderimage/normal-image.qml normal image
104 \image qml-borderimage-scaled.png
107 A BorderImage element is used to display the image, and it is given a size that is
108 larger than the original image. Since the \l horizontalTileMode property is set to
109 \l{BorderImage::horizontalTileMode}{BorderImage.Stretch}, the parts of image in
110 regions 2 and 8 are stretched horizontally. Since the \l verticalTileMode property
111 is set to \l{BorderImage::verticalTileMode}{BorderImage.Stretch}, the parts of image
112 in regions 4 and 6 are stretched vertically.
114 \snippet doc/src/snippets/declarative/borderimage/borderimage-scaled.qml scaled border image
118 \image qml-borderimage-tiled.png
121 Again, a large BorderImage element is used to display the image. With the
122 \l horizontalTileMode property set to \l{BorderImage::horizontalTileMode}{BorderImage.Repeat},
123 the parts of image in regions 2 and 8 are tiled so that they fill the space at the
124 top and bottom of the element. Similarly, the \l verticalTileMode property is set to
125 \l{BorderImage::verticalTileMode}{BorderImage.Repeat}, the parts of image in regions
126 4 and 6 are tiled so that they fill the space at the left and right of the element.
128 \snippet doc/src/snippets/declarative/borderimage/borderimage-tiled.qml tiled border image
131 In some situations, the width of regions 2 and 8 may not be an exact multiple of the width
132 of the corresponding regions in the source image. Similarly, the height of regions 4 and 6
133 may not be an exact multiple of the height of the corresponding regions. It can be useful
134 to use \l{BorderImage::horizontalTileMode}{BorderImage.Round} instead of
135 \l{BorderImage::horizontalTileMode}{BorderImage.Repeat} in cases like these.
137 The \l{declarative/imageelements/borderimage}{BorderImage example} shows how a BorderImage
138 can be used to simulate a shadow effect on a rectangular item.
140 \section1 Quality and Performance
142 By default, any scaled regions of the image are rendered without smoothing to improve
143 rendering speed. Setting the \l smooth property improves rendering quality of scaled
144 regions, but may slow down rendering.
146 The source image may not be loaded instantaneously, depending on its original location.
147 Loading progress can be monitored with the \l progress property.
149 \sa Image, AnimatedImage
153 \qmlproperty bool BorderImage::asynchronous
155 Specifies that images on the local filesystem should be loaded
156 asynchronously in a separate thread. The default value is
157 false, causing the user interface thread to block while the
158 image is loaded. Setting \a asynchronous to true is useful where
159 maintaining a responsive user interface is more desirable
160 than having images immediately visible.
162 Note that this property is only valid for images read from the
163 local filesystem. Images loaded via a network resource (e.g. HTTP)
164 are always loaded asynchonously.
166 QDeclarativeBorderImage::QDeclarativeBorderImage(QDeclarativeItem *parent)
167 : QDeclarativeImageBase(*(new QDeclarativeBorderImagePrivate), parent)
171 QDeclarativeBorderImage::~QDeclarativeBorderImage()
173 Q_D(QDeclarativeBorderImage);
175 d->sciReply->deleteLater();
178 \qmlproperty enumeration BorderImage::status
180 This property describes the status of image loading. It can be one of:
183 \o BorderImage.Null - no image has been set
184 \o BorderImage.Ready - the image has been loaded
185 \o BorderImage.Loading - the image is currently being loaded
186 \o BorderImage.Error - an error occurred while loading the image
193 \qmlproperty real BorderImage::progress
195 This property holds the progress of image loading, from 0.0 (nothing loaded)
202 \qmlproperty bool BorderImage::smooth
204 Set this property if you want the image to be smoothly filtered when scaled or
205 transformed. Smooth filtering gives better visual quality, but is slower. If
206 the image is displayed at its natural size, this property has no visual or
209 By default, this property is set to false.
211 \note Generally scaling artifacts are only visible if the image is stationary on
212 the screen. A common pattern when animating an image is to disable smooth
213 filtering at the beginning of the animation and enable it at the conclusion.
217 \qmlproperty bool BorderImage::cache
220 Specifies whether the image should be cached. The default value is
221 true. Setting \a cache to false is useful when dealing with large images,
222 to make sure that they aren't cached at the expense of small 'ui element' images.
226 \qmlproperty bool BorderImage::mirror
229 This property holds whether the image should be horizontally inverted
230 (effectively displaying a mirrored image).
232 The default value is false.
236 \qmlproperty url BorderImage::source
238 This property holds the URL that refers to the source image.
240 BorderImage can handle any image format supported by Qt, loaded from any
241 URL scheme supported by Qt.
243 This property can also be used to refer to .sci files, which are
244 written in a QML-specific, text-based format that specifies the
245 borders, the image file and the tile rules for a given border image.
247 The following .sci file sets the borders to 10 on each side for the
248 image \c picture.png:
255 source: "picture.png"
258 The URL may be absolute, or relative to the URL of the component.
260 \sa QDeclarativeImageProvider
264 \qmlproperty QSize BorderImage::sourceSize
266 This property holds the actual width and height of the loaded image.
268 In BorderImage, this property is read-only.
270 \sa Image::sourceSize
272 void QDeclarativeBorderImage::setSource(const QUrl &url)
274 Q_D(QDeclarativeBorderImage);
275 //equality is fairly expensive, so we bypass for simple, common case
276 if ((d->url.isEmpty() == url.isEmpty()) && url == d->url)
280 d->sciReply->deleteLater();
286 emit sourceChanged(d->url);
288 if (isComponentComplete())
292 void QDeclarativeBorderImage::load()
294 Q_D(QDeclarativeBorderImage);
295 if (d->progress != 0.0) {
297 emit progressChanged(d->progress);
300 if (d->url.isEmpty()) {
304 setImplicitHeight(0);
305 emit statusChanged(d->status);
309 if (d->url.path().endsWith(QLatin1String("sci"))) {
310 #ifndef QT_NO_LOCALFILE_OPTIMIZED_QML
311 QString lf = QDeclarativeEnginePrivate::urlToLocalFileOrQrc(d->url);
314 file.open(QIODevice::ReadOnly);
315 setGridScaledImage(QDeclarativeGridScaledImage(&file));
319 QNetworkRequest req(d->url);
320 d->sciReply = qmlEngine(this)->networkAccessManager()->get(req);
322 static int sciReplyFinished = -1;
323 static int thisSciRequestFinished = -1;
324 if (sciReplyFinished == -1) {
326 QNetworkReply::staticMetaObject.indexOfSignal("finished()");
327 thisSciRequestFinished =
328 QDeclarativeBorderImage::staticMetaObject.indexOfSlot("sciRequestFinished()");
331 QMetaObject::connect(d->sciReply, sciReplyFinished, this,
332 thisSciRequestFinished, Qt::DirectConnection);
336 QDeclarativePixmap::Options options;
338 options |= QDeclarativePixmap::Asynchronous;
340 options |= QDeclarativePixmap::Cache;
342 d->pix.load(qmlEngine(this), d->url, options);
344 if (d->pix.isLoading()) {
345 d->pix.connectFinished(this, SLOT(requestFinished()));
346 d->pix.connectDownloadProgress(this, SLOT(requestProgress(qint64,qint64)));
348 QSize impsize = d->pix.implicitSize();
349 setImplicitWidth(impsize.width());
350 setImplicitHeight(impsize.height());
352 if (d->pix.isReady()) {
356 qmlInfo(this) << d->pix.error();
360 emit statusChanged(d->status);
361 emit progressChanged(d->progress);
368 emit statusChanged(d->status);
372 \qmlproperty int BorderImage::border.left
373 \qmlproperty int BorderImage::border.right
374 \qmlproperty int BorderImage::border.top
375 \qmlproperty int BorderImage::border.bottom
377 The 4 border lines (2 horizontal and 2 vertical) break the image into 9 sections,
380 \image declarative-scalegrid.png
382 Each border line (left, right, top, and bottom) specifies an offset in pixels
383 from the respective edge of the source image. By default, each border line has
386 For example, the following definition sets the bottom line 10 pixels up from
387 the bottom of the image:
396 The border lines can also be specified using a
397 \l {BorderImage::source}{.sci file}.
400 QDeclarativeScaleGrid *QDeclarativeBorderImage::border()
402 Q_D(QDeclarativeBorderImage);
403 return d->getScaleGrid();
407 \qmlproperty enumeration BorderImage::horizontalTileMode
408 \qmlproperty enumeration BorderImage::verticalTileMode
410 This property describes how to repeat or stretch the middle parts of the border image.
413 \o BorderImage.Stretch - Scales the image to fit to the available area.
414 \o BorderImage.Repeat - Tile the image until there is no more space. May crop the last image.
415 \o BorderImage.Round - Like Repeat, but scales the images down to ensure that the last image is not cropped.
418 The default tile mode for each property is BorderImage.Stretch.
420 QDeclarativeBorderImage::TileMode QDeclarativeBorderImage::horizontalTileMode() const
422 Q_D(const QDeclarativeBorderImage);
423 return d->horizontalTileMode;
426 void QDeclarativeBorderImage::setHorizontalTileMode(TileMode t)
428 Q_D(QDeclarativeBorderImage);
429 if (t != d->horizontalTileMode) {
430 d->horizontalTileMode = t;
431 emit horizontalTileModeChanged();
436 QDeclarativeBorderImage::TileMode QDeclarativeBorderImage::verticalTileMode() const
438 Q_D(const QDeclarativeBorderImage);
439 return d->verticalTileMode;
442 void QDeclarativeBorderImage::setVerticalTileMode(TileMode t)
444 Q_D(QDeclarativeBorderImage);
445 if (t != d->verticalTileMode) {
446 d->verticalTileMode = t;
447 emit verticalTileModeChanged();
452 void QDeclarativeBorderImage::setGridScaledImage(const QDeclarativeGridScaledImage& sci)
454 Q_D(QDeclarativeBorderImage);
455 if (!sci.isValid()) {
457 emit statusChanged(d->status);
459 QDeclarativeScaleGrid *sg = border();
460 sg->setTop(sci.gridTop());
461 sg->setBottom(sci.gridBottom());
462 sg->setLeft(sci.gridLeft());
463 sg->setRight(sci.gridRight());
464 d->horizontalTileMode = sci.horizontalTileRule();
465 d->verticalTileMode = sci.verticalTileRule();
467 d->sciurl = d->url.resolved(QUrl(sci.pixmapUrl()));
469 QDeclarativePixmap::Options options;
471 options |= QDeclarativePixmap::Asynchronous;
473 options |= QDeclarativePixmap::Cache;
475 d->pix.load(qmlEngine(this), d->sciurl, options);
477 if (d->pix.isLoading()) {
478 static int thisRequestProgress = -1;
479 static int thisRequestFinished = -1;
480 if (thisRequestProgress == -1) {
481 thisRequestProgress =
482 QDeclarativeBorderImage::staticMetaObject.indexOfSlot("requestProgress(qint64,qint64)");
483 thisRequestFinished =
484 QDeclarativeBorderImage::staticMetaObject.indexOfSlot("requestFinished()");
487 d->pix.connectFinished(this, thisRequestFinished);
488 d->pix.connectDownloadProgress(this, thisRequestProgress);
492 QSize impsize = d->pix.implicitSize();
493 setImplicitWidth(impsize.width());
494 setImplicitHeight(impsize.height());
496 if (d->pix.isReady()) {
500 qmlInfo(this) << d->pix.error();
504 emit statusChanged(d->status);
505 emit progressChanged(1.0);
512 void QDeclarativeBorderImage::requestFinished()
514 Q_D(QDeclarativeBorderImage);
516 QSize impsize = d->pix.implicitSize();
517 if (d->pix.isError()) {
519 qmlInfo(this) << d->pix.error();
524 setImplicitWidth(impsize.width());
525 setImplicitHeight(impsize.height());
527 if (d->sourcesize.width() != d->pix.width() || d->sourcesize.height() != d->pix.height())
528 emit sourceSizeChanged();
531 emit statusChanged(d->status);
532 emit progressChanged(1.0);
536 #define BORDERIMAGE_MAX_REDIRECT 16
538 void QDeclarativeBorderImage::sciRequestFinished()
540 Q_D(QDeclarativeBorderImage);
543 if (d->redirectCount < BORDERIMAGE_MAX_REDIRECT) {
544 QVariant redirect = d->sciReply->attribute(QNetworkRequest::RedirectionTargetAttribute);
545 if (redirect.isValid()) {
546 QUrl url = d->sciReply->url().resolved(redirect.toUrl());
553 if (d->sciReply->error() != QNetworkReply::NoError) {
555 d->sciReply->deleteLater();
557 emit statusChanged(d->status);
559 QDeclarativeGridScaledImage sci(d->sciReply);
560 d->sciReply->deleteLater();
562 setGridScaledImage(sci);
566 void QDeclarativeBorderImage::doUpdate()
571 void QDeclarativeBorderImage::paint(QPainter *p, const QStyleOptionGraphicsItem *, QWidget *)
573 Q_D(QDeclarativeBorderImage);
574 if (d->pix.isNull() || d->width() <= 0.0 || d->height() <= 0.0)
577 bool oldAA = p->testRenderHint(QPainter::Antialiasing);
578 bool oldSmooth = p->testRenderHint(QPainter::SmoothPixmapTransform);
579 QTransform oldTransform;
581 p->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform, d->smooth);
583 oldTransform = p->transform();
585 mirror.translate(d->width(), 0).scale(-1, 1.0);
586 p->setWorldTransform(mirror * oldTransform);
589 const QDeclarativeScaleGrid *border = d->getScaleGrid();
590 int left = border->left();
591 int right = border->right();
592 qreal borderWidth = left + right;
593 if (borderWidth > 0.0 && d->width() < borderWidth) {
594 qreal diff = borderWidth - d->width() - 1;
595 left -= qRound(diff * qreal(left) / borderWidth);
596 right -= qRound(diff * qreal(right) / borderWidth);
598 int top = border->top();
599 int bottom = border->bottom();
600 qreal borderHeight = top + bottom;
601 if (borderHeight > 0.0 && d->height() < borderHeight) {
602 qreal diff = borderHeight - d->height() - 1;
603 top -= qRound(diff * qreal(top) / borderHeight);
604 bottom -= qRound(diff * qreal(bottom) / borderHeight);
606 QMargins margins(left, top, right, bottom);
607 QTileRules rules((Qt::TileRule)d->horizontalTileMode, (Qt::TileRule)d->verticalTileMode);
608 qDrawBorderPixmap(p, QRect(0, 0, (int)d->width(), (int)d->height()), margins, d->pix, d->pix.rect(), margins, rules);
610 p->setRenderHint(QPainter::Antialiasing, oldAA);
611 p->setRenderHint(QPainter::SmoothPixmapTransform, oldSmooth);
614 p->setWorldTransform(oldTransform);