demos/qtdemo/imageitem.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/qtdemo/imageitem.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,114 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the demonstration applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "imageitem.h"
+#include "colors.h"
+
+ImageItem::ImageItem(const QImage &image, int maxWidth, int maxHeight, QGraphicsScene *scene,
+        QGraphicsItem *parent, bool adjustSize, float scale) : DemoItem(scene, parent)
+{
+    this->image = image;
+    this->maxWidth = maxWidth;
+    this->maxHeight = maxHeight;
+    this->adjustSize = adjustSize;
+    this->scale = scale;
+}
+
+QImage *ImageItem::createImage(const QMatrix &matrix) const
+{
+    QImage *original = new QImage(image);
+    if (original->isNull()){
+        return original; // nothing we can do about it...
+    }
+
+    QPoint size = matrix.map(QPoint(this->maxWidth, this->maxHeight));
+    float w = size.x(); // x, y is the used as width, height
+    float h = size.y();
+
+    // Optimization: if image is smaller than maximum allowed size, just return the loaded image
+    if (original->size().height() <= h && original->size().width() <= w && !this->adjustSize && this->scale == 1)
+        return original;
+
+    // Calculate what the size of the final image will be:
+    w = qMin(w, float(original->size().width()) * this->scale);
+    h = qMin(h, float(original->size().height()) * this->scale);
+
+    float adjustx = 1.0f;
+    float adjusty = 1.0f;
+    if (this->adjustSize){
+        adjustx = qMin(matrix.m11(), matrix.m22());
+        adjusty = matrix.m22() < adjustx ? adjustx : matrix.m22();
+        w *= adjustx;
+        h *= adjusty;
+    }
+
+    // Create a new image with correct size, and draw original on it
+    QImage *image = new QImage(int(w+2), int(h+2), QImage::Format_ARGB32_Premultiplied);
+    image->fill(QColor(0, 0, 0, 0).rgba());
+    QPainter painter(image);
+    painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
+    if (this->adjustSize)
+        painter.scale(adjustx, adjusty);
+    if (this->scale != 1)
+       painter.scale(this->scale, this->scale);
+    painter.drawImage(0, 0, *original);
+
+    if (!this->adjustSize){
+       // Blur out edges
+       int blur = 30;
+       if (h < original->height()){
+           QLinearGradient brush1(0, h - blur, 0, h);
+           brush1.setSpread(QGradient::PadSpread);
+           brush1.setColorAt(0.0, QColor(0, 0, 0, 0));
+           brush1.setColorAt(1.0, Colors::sceneBg1);
+           painter.fillRect(0, int(h) - blur, original->width(), int(h), brush1);
+       }
+       if (w < original->width()){
+           QLinearGradient brush2(w - blur, 0, w, 0);
+           brush2.setSpread(QGradient::PadSpread);
+           brush2.setColorAt(0.0, QColor(0, 0, 0, 0));
+           brush2.setColorAt(1.0, Colors::sceneBg1);
+           painter.fillRect(int(w) - blur, 0, int(w), original->height(), brush2);
+       }
+    }
+    delete original;
+    return image;
+}