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42 #include "qquickborderimage_p.h"
43 #include "qquickborderimage_p_p.h"
44 #include "qquickninepatchnode_p.h"
46 #include <QtDeclarative/qdeclarativeinfo.h>
47 #include <QtCore/qfile.h>
49 #include <private/qdeclarativeengine_p.h>
55 \qmlclass BorderImage QQuickBorderImage
56 \inqmlmodule QtQuick 2
57 \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 QtQuick2::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 asynchronously.
166 QQuickBorderImage::QQuickBorderImage(QQuickItem *parent)
167 : QQuickImageBase(*(new QQuickBorderImagePrivate), parent)
171 QQuickBorderImage::~QQuickBorderImage()
173 Q_D(QQuickBorderImage);
175 d->sciReply->deleteLater();
179 \qmlproperty enumeration QtQuick2::BorderImage::status
181 This property describes the status of image loading. It can be one of:
184 \o BorderImage.Null - no image has been set
185 \o BorderImage.Ready - the image has been loaded
186 \o BorderImage.Loading - the image is currently being loaded
187 \o BorderImage.Error - an error occurred while loading the image
194 \qmlproperty real QtQuick2::BorderImage::progress
196 This property holds the progress of image loading, from 0.0 (nothing loaded)
203 \qmlproperty bool QtQuick2::BorderImage::smooth
205 Set this property if you want the image to be smoothly filtered when scaled or
206 transformed. Smooth filtering gives better visual quality, but is slower. If
207 the image is displayed at its natural size, this property has no visual or
210 By default, this property is set to false.
212 \note Generally scaling artifacts are only visible if the image is stationary on
213 the screen. A common pattern when animating an image is to disable smooth
214 filtering at the beginning of the animation and enable it at the conclusion.
218 \qmlproperty bool QtQuick2::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 QtQuick2::BorderImage::mirror
228 This property holds whether the image should be horizontally inverted
229 (effectively displaying a mirrored image).
231 The default value is false.
235 \qmlproperty url QtQuick2::BorderImage::source
237 This property holds the URL that refers to the source image.
239 BorderImage can handle any image format supported by Qt, loaded from any
240 URL scheme supported by Qt.
242 This property can also be used to refer to .sci files, which are
243 written in a QML-specific, text-based format that specifies the
244 borders, the image file and the tile rules for a given border image.
246 The following .sci file sets the borders to 10 on each side for the
247 image \c picture.png:
254 source: "picture.png"
257 The URL may be absolute, or relative to the URL of the component.
259 \sa QDeclarativeImageProvider
263 \qmlproperty QSize QtQuick2::BorderImage::sourceSize
265 This property holds the actual width and height of the loaded image.
267 In BorderImage, this property is read-only.
269 \sa Image::sourceSize
271 void QQuickBorderImage::setSource(const QUrl &url)
273 Q_D(QQuickBorderImage);
274 //equality is fairly expensive, so we bypass for simple, common case
275 if ((d->url.isEmpty() == url.isEmpty()) && url == d->url)
279 d->sciReply->deleteLater();
285 emit sourceChanged(d->url);
287 if (isComponentComplete())
291 void QQuickBorderImage::load()
293 Q_D(QQuickBorderImage);
294 if (d->progress != 0.0) {
296 emit progressChanged(d->progress);
299 if (d->url.isEmpty()) {
302 setImplicitSize(0, 0);
303 emit statusChanged(d->status);
307 if (d->url.path().endsWith(QLatin1String("sci"))) {
308 QString lf = QDeclarativeEnginePrivate::urlToLocalFileOrQrc(d->url);
311 file.open(QIODevice::ReadOnly);
312 setGridScaledImage(QQuickGridScaledImage(&file));
314 QNetworkRequest req(d->url);
315 d->sciReply = qmlEngine(this)->networkAccessManager()->get(req);
316 FAST_CONNECT(d->sciReply, SIGNAL(finished()), this, SLOT(sciRequestFinished()))
320 QDeclarativePixmap::Options options;
322 options |= QDeclarativePixmap::Asynchronous;
324 options |= QDeclarativePixmap::Cache;
326 d->pix.load(qmlEngine(this), d->url, options);
328 if (d->pix.isLoading()) {
329 d->pix.connectFinished(this, SLOT(requestFinished()));
330 d->pix.connectDownloadProgress(this, SLOT(requestProgress(qint64,qint64)));
332 QSize impsize = d->pix.implicitSize();
333 setImplicitSize(impsize.width(), impsize.height());
335 if (d->pix.isReady()) {
339 qmlInfo(this) << d->pix.error();
343 emit statusChanged(d->status);
344 emit progressChanged(d->progress);
350 emit statusChanged(d->status);
354 \qmlproperty int QtQuick2::BorderImage::border.left
355 \qmlproperty int QtQuick2::BorderImage::border.right
356 \qmlproperty int QtQuick2::BorderImage::border.top
357 \qmlproperty int QtQuick2::BorderImage::border.bottom
359 The 4 border lines (2 horizontal and 2 vertical) break the image into 9 sections,
362 \image declarative-scalegrid.png
364 Each border line (left, right, top, and bottom) specifies an offset in pixels
365 from the respective edge of the source image. By default, each border line has
368 For example, the following definition sets the bottom line 10 pixels up from
369 the bottom of the image:
378 The border lines can also be specified using a
379 \l {BorderImage::source}{.sci file}.
382 QQuickScaleGrid *QQuickBorderImage::border()
384 Q_D(QQuickBorderImage);
385 return d->getScaleGrid();
389 \qmlproperty enumeration QtQuick2::BorderImage::horizontalTileMode
390 \qmlproperty enumeration QtQuick2::BorderImage::verticalTileMode
392 This property describes how to repeat or stretch the middle parts of the border image.
395 \o BorderImage.Stretch - Scales the image to fit to the available area.
396 \o BorderImage.Repeat - Tile the image until there is no more space. May crop the last image.
397 \o BorderImage.Round - Like Repeat, but scales the images down to ensure that the last image is not cropped.
400 The default tile mode for each property is BorderImage.Stretch.
402 QQuickBorderImage::TileMode QQuickBorderImage::horizontalTileMode() const
404 Q_D(const QQuickBorderImage);
405 return d->horizontalTileMode;
408 void QQuickBorderImage::setHorizontalTileMode(TileMode t)
410 Q_D(QQuickBorderImage);
411 if (t != d->horizontalTileMode) {
412 d->horizontalTileMode = t;
413 emit horizontalTileModeChanged();
418 QQuickBorderImage::TileMode QQuickBorderImage::verticalTileMode() const
420 Q_D(const QQuickBorderImage);
421 return d->verticalTileMode;
424 void QQuickBorderImage::setVerticalTileMode(TileMode t)
426 Q_D(QQuickBorderImage);
427 if (t != d->verticalTileMode) {
428 d->verticalTileMode = t;
429 emit verticalTileModeChanged();
434 void QQuickBorderImage::setGridScaledImage(const QQuickGridScaledImage& sci)
436 Q_D(QQuickBorderImage);
437 if (!sci.isValid()) {
439 emit statusChanged(d->status);
441 QQuickScaleGrid *sg = border();
442 sg->setTop(sci.gridTop());
443 sg->setBottom(sci.gridBottom());
444 sg->setLeft(sci.gridLeft());
445 sg->setRight(sci.gridRight());
446 d->horizontalTileMode = sci.horizontalTileRule();
447 d->verticalTileMode = sci.verticalTileRule();
449 d->sciurl = d->url.resolved(QUrl(sci.pixmapUrl()));
451 QDeclarativePixmap::Options options;
453 options |= QDeclarativePixmap::Asynchronous;
455 options |= QDeclarativePixmap::Cache;
457 d->pix.load(qmlEngine(this), d->sciurl, options);
459 if (d->pix.isLoading()) {
460 static int thisRequestProgress = -1;
461 static int thisRequestFinished = -1;
462 if (thisRequestProgress == -1) {
463 thisRequestProgress =
464 QQuickBorderImage::staticMetaObject.indexOfSlot("requestProgress(qint64,qint64)");
465 thisRequestFinished =
466 QQuickBorderImage::staticMetaObject.indexOfSlot("requestFinished()");
469 d->pix.connectFinished(this, thisRequestFinished);
470 d->pix.connectDownloadProgress(this, thisRequestProgress);
474 QSize impsize = d->pix.implicitSize();
475 setImplicitSize(impsize.width(), impsize.height());
477 if (d->pix.isReady()) {
481 qmlInfo(this) << d->pix.error();
485 emit statusChanged(d->status);
486 emit progressChanged(1.0);
493 void QQuickBorderImage::requestFinished()
495 Q_D(QQuickBorderImage);
497 QSize impsize = d->pix.implicitSize();
498 if (d->pix.isError()) {
500 qmlInfo(this) << d->pix.error();
505 setImplicitSize(impsize.width(), impsize.height());
507 if (d->sourcesize.width() != d->pix.width() || d->sourcesize.height() != d->pix.height())
508 emit sourceSizeChanged();
511 emit statusChanged(d->status);
512 emit progressChanged(1.0);
516 #define BORDERIMAGE_MAX_REDIRECT 16
518 void QQuickBorderImage::sciRequestFinished()
520 Q_D(QQuickBorderImage);
523 if (d->redirectCount < BORDERIMAGE_MAX_REDIRECT) {
524 QVariant redirect = d->sciReply->attribute(QNetworkRequest::RedirectionTargetAttribute);
525 if (redirect.isValid()) {
526 QUrl url = d->sciReply->url().resolved(redirect.toUrl());
533 if (d->sciReply->error() != QNetworkReply::NoError) {
535 d->sciReply->deleteLater();
537 emit statusChanged(d->status);
539 QQuickGridScaledImage sci(d->sciReply);
540 d->sciReply->deleteLater();
542 setGridScaledImage(sci);
546 void QQuickBorderImage::doUpdate()
551 QSGNode *QQuickBorderImage::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
553 Q_D(QQuickBorderImage);
555 QSGTexture *texture = d->sceneGraphContext()->textureForFactory(d->pix.textureFactory());
557 if (!texture || width() <= 0 || height() <= 0) {
562 QQuickNinePatchNode *node = static_cast<QQuickNinePatchNode *>(oldNode);
565 node = new QQuickNinePatchNode();
568 node->setTexture(texture);
570 // Don't implicitly create the scalegrid in the rendering thread...
572 const QQuickScaleGrid *border = d->getScaleGrid();
573 node->setInnerRect(QRectF(border->left(),
575 qMax(1, d->pix.width() - border->right() - border->left()),
576 qMax(1, d->pix.height() - border->bottom() - border->top())));
578 node->setInnerRect(QRectF(0, 0, d->pix.width(), d->pix.height()));
580 node->setRect(QRectF(0, 0, width(), height()));
581 node->setFiltering(d->smooth ? QSGTexture::Linear : QSGTexture::Nearest);
582 node->setHorzontalTileMode(d->horizontalTileMode);
583 node->setVerticalTileMode(d->verticalTileMode);
584 node->setMirror(d->mirror);
590 void QQuickBorderImage::pixmapChange()
592 Q_D(QQuickBorderImage);
594 d->pixmapChanged = true;
596 // When the pixmap changes, such as being deleted, we need to update the textures