Move tga support from Qt3d to QtImageFormats.

Rev-By: Samuel Rodal
Fix-for: QTBUG-21955

Part of fix for https://bugreports.qt.nokia.com/browse/QTBUG-21955

Having tga plugin inside a Qt add-on causes packaging problems.

There have been many queries over the years for tga support even tho it
is a niche image format. It is particularly useful for OpenGL work as a
texture format since it is a blittable bitmap, but it is very
innefficient compared to png or jpg.

For this reason only read support is added, and this is documented.
Also add one unit test.

(based on cherry picked from Qt 4.8 commit 951a997893407b0a26f21fe0acec4701fa3d4279)

Adds code removed from Qt3D.
http://codereview.qt-project.org/#change,13898

Conflicts:

tests/auto/qimagereader/qimagereader.pro
tests/auto/qimagereader/tst_qimagereader.cpp

Change-Id: Ia1b7420dd3461cb1d2f1d857d11444a0a533de43
Reviewed-by: Sarah Jane Smith <sarah.j.smith@nokia.com>
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>

1 files changed, 131 insertions, 0 deletions

diff --git a/src/plugins/imageformats/tga/qtgahandler.cpp b/src/plugins/imageformats/tga/qtgahandler.cpp
new file mode 100644
index 0000000..2fa0530
--- /dev/null
+++ b/src/plugins/imageformats/tga/qtgahandler.cpp
@@ -0,0 +1,131 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the TGA plugin in the Qt ImageFormats module.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qtgahandler.h"
+#include "qtgafile.h"
+
+#include <QtCore/QVariant>
+#include <QtCore/QDebug>
+#include <QtGui/QImage>
+
+QT_BEGIN_NAMESPACE
+
+QTgaHandler::QTgaHandler()
+    : QImageIOHandler()
+    , tga(0)
+{
+}
+
+QTgaHandler::~QTgaHandler()
+{
+    delete tga;
+}
+
+bool QTgaHandler::canRead() const
+{
+    if (!tga)
+        tga = new QTgaFile(device());
+    if (tga->isValid())
+    {
+        setFormat("tga");
+        return true;
+    }
+    return false;
+}
+
+bool QTgaHandler::canRead(QIODevice *device)
+{
+    if (!device) {
+        qWarning("QTgaHandler::canRead() called with no device");
+        return false;
+    }
+
+    // TGA reader implementation needs a seekable QIODevice, so
+    // sequential devices are not supported
+    qint64 pos = device->pos();
+    bool isValid;
+    {
+        QTgaFile tga(device);
+        isValid = tga.isValid();
+    }
+    device->seek(pos);
+    return isValid;
+}
+
+bool QTgaHandler::read(QImage *image)
+{
+    if (!canRead())
+        return false;
+    *image = tga->readImage();
+    return !image->isNull();
+}
+
+QByteArray QTgaHandler::name() const
+{
+    return "tga";
+}
+
+QVariant QTgaHandler::option(ImageOption option) const
+{
+    if (option == Size && canRead()) {
+        return tga->size();
+    } else if (option == CompressionRatio) {
+        return tga->compression();
+    } else if (option == ImageFormat) {
+        return QImage::Format_ARGB32;
+    }
+    return QVariant();
+}
+
+void QTgaHandler::setOption(ImageOption option, const QVariant &value)
+{
+    Q_UNUSED(option);
+    Q_UNUSED(value);
+}
+
+bool QTgaHandler::supportsOption(ImageOption option) const
+{
+    return option == CompressionRatio
+            || option == Size
+            || option == ImageFormat;
+}
+
+QT_END_NAMESPACE