1 /****************************************************************************
3 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4 ** All rights reserved.
5 ** Contact: Nokia Corporation (qt-info@nokia.com)
7 ** This file is part of the QtDeclarative module of the Qt Toolkit.
9 ** $QT_BEGIN_LICENSE:LGPL$
10 ** GNU Lesser General Public License Usage
11 ** This file may be used under the terms of the GNU Lesser General Public
12 ** License version 2.1 as published by the Free Software Foundation and
13 ** appearing in the file LICENSE.LGPL included in the packaging of this
14 ** file. Please review the following information to ensure the GNU Lesser
15 ** General Public License version 2.1 requirements will be met:
16 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
18 ** In addition, as a special exception, Nokia gives you certain additional
19 ** rights. These rights are described in the Nokia Qt LGPL Exception
20 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
22 ** GNU General Public License Usage
23 ** Alternatively, this file may be used under the terms of the GNU General
24 ** Public License version 3.0 as published by the Free Software Foundation
25 ** and appearing in the file LICENSE.GPL included in the packaging of this
26 ** file. Please review the following information to ensure the GNU General
27 ** Public License version 3.0 requirements will be met:
28 ** http://www.gnu.org/copyleft/gpl.html.
31 ** Alternatively, this file may be used in accordance with the terms and
32 ** conditions contained in a signed written agreement between you and Nokia.
40 ****************************************************************************/
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 asynchonously.
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()) {
303 setImplicitHeight(0);
304 emit statusChanged(d->status);
308 if (d->url.path().endsWith(QLatin1String("sci"))) {
309 QString lf = QDeclarativeEnginePrivate::urlToLocalFileOrQrc(d->url);
312 file.open(QIODevice::ReadOnly);
313 setGridScaledImage(QQuickGridScaledImage(&file));
315 QNetworkRequest req(d->url);
316 d->sciReply = qmlEngine(this)->networkAccessManager()->get(req);
317 FAST_CONNECT(d->sciReply, SIGNAL(finished()), this, SLOT(sciRequestFinished()))
321 QDeclarativePixmap::Options options;
323 options |= QDeclarativePixmap::Asynchronous;
325 options |= QDeclarativePixmap::Cache;
327 d->pix.load(qmlEngine(this), d->url, options);
329 if (d->pix.isLoading()) {
330 d->pix.connectFinished(this, SLOT(requestFinished()));
331 d->pix.connectDownloadProgress(this, SLOT(requestProgress(qint64,qint64)));
333 QSize impsize = d->pix.implicitSize();
334 setImplicitWidth(impsize.width());
335 setImplicitHeight(impsize.height());
337 if (d->pix.isReady()) {
341 qmlInfo(this) << d->pix.error();
345 emit statusChanged(d->status);
346 emit progressChanged(d->progress);
352 emit statusChanged(d->status);
356 \qmlproperty int QtQuick2::BorderImage::border.left
357 \qmlproperty int QtQuick2::BorderImage::border.right
358 \qmlproperty int QtQuick2::BorderImage::border.top
359 \qmlproperty int QtQuick2::BorderImage::border.bottom
361 The 4 border lines (2 horizontal and 2 vertical) break the image into 9 sections,
364 \image declarative-scalegrid.png
366 Each border line (left, right, top, and bottom) specifies an offset in pixels
367 from the respective edge of the source image. By default, each border line has
370 For example, the following definition sets the bottom line 10 pixels up from
371 the bottom of the image:
380 The border lines can also be specified using a
381 \l {BorderImage::source}{.sci file}.
384 QQuickScaleGrid *QQuickBorderImage::border()
386 Q_D(QQuickBorderImage);
387 return d->getScaleGrid();
391 \qmlproperty enumeration QtQuick2::BorderImage::horizontalTileMode
392 \qmlproperty enumeration QtQuick2::BorderImage::verticalTileMode
394 This property describes how to repeat or stretch the middle parts of the border image.
397 \o BorderImage.Stretch - Scales the image to fit to the available area.
398 \o BorderImage.Repeat - Tile the image until there is no more space. May crop the last image.
399 \o BorderImage.Round - Like Repeat, but scales the images down to ensure that the last image is not cropped.
402 The default tile mode for each property is BorderImage.Stretch.
404 QQuickBorderImage::TileMode QQuickBorderImage::horizontalTileMode() const
406 Q_D(const QQuickBorderImage);
407 return d->horizontalTileMode;
410 void QQuickBorderImage::setHorizontalTileMode(TileMode t)
412 Q_D(QQuickBorderImage);
413 if (t != d->horizontalTileMode) {
414 d->horizontalTileMode = t;
415 emit horizontalTileModeChanged();
420 QQuickBorderImage::TileMode QQuickBorderImage::verticalTileMode() const
422 Q_D(const QQuickBorderImage);
423 return d->verticalTileMode;
426 void QQuickBorderImage::setVerticalTileMode(TileMode t)
428 Q_D(QQuickBorderImage);
429 if (t != d->verticalTileMode) {
430 d->verticalTileMode = t;
431 emit verticalTileModeChanged();
436 void QQuickBorderImage::setGridScaledImage(const QQuickGridScaledImage& sci)
438 Q_D(QQuickBorderImage);
439 if (!sci.isValid()) {
441 emit statusChanged(d->status);
443 QQuickScaleGrid *sg = border();
444 sg->setTop(sci.gridTop());
445 sg->setBottom(sci.gridBottom());
446 sg->setLeft(sci.gridLeft());
447 sg->setRight(sci.gridRight());
448 d->horizontalTileMode = sci.horizontalTileRule();
449 d->verticalTileMode = sci.verticalTileRule();
451 d->sciurl = d->url.resolved(QUrl(sci.pixmapUrl()));
453 QDeclarativePixmap::Options options;
455 options |= QDeclarativePixmap::Asynchronous;
457 options |= QDeclarativePixmap::Cache;
459 d->pix.load(qmlEngine(this), d->sciurl, options);
461 if (d->pix.isLoading()) {
462 static int thisRequestProgress = -1;
463 static int thisRequestFinished = -1;
464 if (thisRequestProgress == -1) {
465 thisRequestProgress =
466 QQuickBorderImage::staticMetaObject.indexOfSlot("requestProgress(qint64,qint64)");
467 thisRequestFinished =
468 QQuickBorderImage::staticMetaObject.indexOfSlot("requestFinished()");
471 d->pix.connectFinished(this, thisRequestFinished);
472 d->pix.connectDownloadProgress(this, thisRequestProgress);
476 QSize impsize = d->pix.implicitSize();
477 setImplicitWidth(impsize.width());
478 setImplicitHeight(impsize.height());
480 if (d->pix.isReady()) {
484 qmlInfo(this) << d->pix.error();
488 emit statusChanged(d->status);
489 emit progressChanged(1.0);
496 void QQuickBorderImage::requestFinished()
498 Q_D(QQuickBorderImage);
500 QSize impsize = d->pix.implicitSize();
501 if (d->pix.isError()) {
503 qmlInfo(this) << d->pix.error();
508 setImplicitWidth(impsize.width());
509 setImplicitHeight(impsize.height());
511 if (d->sourcesize.width() != d->pix.width() || d->sourcesize.height() != d->pix.height())
512 emit sourceSizeChanged();
515 emit statusChanged(d->status);
516 emit progressChanged(1.0);
520 #define BORDERIMAGE_MAX_REDIRECT 16
522 void QQuickBorderImage::sciRequestFinished()
524 Q_D(QQuickBorderImage);
527 if (d->redirectCount < BORDERIMAGE_MAX_REDIRECT) {
528 QVariant redirect = d->sciReply->attribute(QNetworkRequest::RedirectionTargetAttribute);
529 if (redirect.isValid()) {
530 QUrl url = d->sciReply->url().resolved(redirect.toUrl());
537 if (d->sciReply->error() != QNetworkReply::NoError) {
539 d->sciReply->deleteLater();
541 emit statusChanged(d->status);
543 QQuickGridScaledImage sci(d->sciReply);
544 d->sciReply->deleteLater();
546 setGridScaledImage(sci);
550 void QQuickBorderImage::doUpdate()
555 QSGNode *QQuickBorderImage::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
557 Q_D(QQuickBorderImage);
559 QSGTexture *texture = d->pix.texture(d->sceneGraphContext());
561 if (!texture || width() <= 0 || height() <= 0) {
566 QQuickNinePatchNode *node = static_cast<QQuickNinePatchNode *>(oldNode);
569 node = new QQuickNinePatchNode();
572 node->setTexture(texture);
574 // Don't implicitly create the scalegrid in the rendering thread...
576 const QQuickScaleGrid *border = d->getScaleGrid();
577 node->setInnerRect(QRectF(border->left(),
579 qMax(1, d->pix.width() - border->right() - border->left()),
580 qMax(1, d->pix.height() - border->bottom() - border->top())));
582 node->setInnerRect(QRectF(0, 0, width(), height()));
584 node->setRect(QRectF(0, 0, width(), height()));
585 node->setFiltering(d->smooth ? QSGTexture::Linear : QSGTexture::Nearest);
586 node->setHorzontalTileMode(d->horizontalTileMode);
587 node->setVerticalTileMode(d->verticalTileMode);
588 node->setMirror(d->mirror);
594 void QQuickBorderImage::pixmapChange()
596 Q_D(QQuickBorderImage);
598 d->pixmapChanged = true;