QImageReader: Reduce code redundancy

Refactor methods to simplify the code and improve readability.
Replace calls to initHandler() and checks for handler support
with calls to the supportsOption() method directly.
Reduces code redundancy and improves the overall structure of the class.

Additionally, use supportScaledSize, supportClipRect, and supportScaledClipRect
to streamline the conditional logic and make it more understandable.

Change-Id: I77d5dab8bcdd0b0eb6d7e9edcf87751aa03b80c7
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 25 insertions, 40 deletions

diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index b2a95d70e4..c97fa63e5c 100644
--- a/src/gui/image/qimagereader.cpp
+++ b/src/gui/image/qimagereader.cpp
@@ -558,7 +558,7 @@ bool QImageReaderPrivate::initHandler()
 */
 void QImageReaderPrivate::getText()
 {
-    if (text.isEmpty() && initHandler() && handler->supportsOption(QImageIOHandler::Description))
+    if (text.isEmpty() && q->supportsOption(QImageIOHandler::Description))
         text = qt_getImageTextFromDescription(handler->option(QImageIOHandler::Description).toString());
 }
 
@@ -848,10 +848,7 @@ int QImageReader::quality() const
 */
 QSize QImageReader::size() const
 {
-    if (!d->initHandler())
-        return QSize();
-
-    if (d->handler->supportsOption(QImageIOHandler::Size))
+    if (supportsOption(QImageIOHandler::Size))
         return d->handler->option(QImageIOHandler::Size).toSize();
 
     return QSize();
@@ -871,10 +868,7 @@ QSize QImageReader::size() const
 */
 QImage::Format QImageReader::imageFormat() const
 {
-    if (!d->initHandler())
-        return QImage::Format_Invalid;
-
-    if (d->handler->supportsOption(QImageIOHandler::ImageFormat))
+    if (supportsOption(QImageIOHandler::ImageFormat))
         return (QImage::Format)d->handler->option(QImageIOHandler::ImageFormat).toInt();
 
     return QImage::Format_Invalid;
@@ -996,9 +990,7 @@ QRect QImageReader::scaledClipRect() const
 */
 void QImageReader::setBackgroundColor(const QColor &color)
 {
-    if (!d->initHandler())
-        return;
-    if (d->handler->supportsOption(QImageIOHandler::BackgroundColor))
+    if (supportsOption(QImageIOHandler::BackgroundColor))
         d->handler->setOption(QImageIOHandler::BackgroundColor, color);
 }
 
@@ -1013,9 +1005,7 @@ void QImageReader::setBackgroundColor(const QColor &color)
 */
 QColor QImageReader::backgroundColor() const
 {
-    if (!d->initHandler())
-        return QColor();
-    if (d->handler->supportsOption(QImageIOHandler::BackgroundColor))
+    if (supportsOption(QImageIOHandler::BackgroundColor))
         return qvariant_cast<QColor>(d->handler->option(QImageIOHandler::BackgroundColor));
     return QColor();
 }
@@ -1030,9 +1020,7 @@ QColor QImageReader::backgroundColor() const
 */
 bool QImageReader::supportsAnimation() const
 {
-    if (!d->initHandler())
-        return false;
-    if (d->handler->supportsOption(QImageIOHandler::Animation))
+    if (supportsOption(QImageIOHandler::Animation))
         return d->handler->option(QImageIOHandler::Animation).toBool();
     return false;
 }
@@ -1044,10 +1032,7 @@ bool QImageReader::supportsAnimation() const
 */
 QByteArray QImageReader::subType() const
 {
-    if (!d->initHandler())
-        return QByteArray();
-
-    if (d->handler->supportsOption(QImageIOHandler::SubType))
+    if (supportsOption(QImageIOHandler::SubType))
         return d->handler->option(QImageIOHandler::SubType).toByteArray();
     return QByteArray();
 }
@@ -1059,10 +1044,7 @@ QByteArray QImageReader::subType() const
 */
 QList<QByteArray> QImageReader::supportedSubTypes() const
 {
-    if (!d->initHandler())
-        return QList<QByteArray>();
-
-    if (d->handler->supportsOption(QImageIOHandler::SupportedSubTypes))
+    if (supportsOption(QImageIOHandler::SupportedSubTypes))
         return qvariant_cast<QList<QByteArray> >(d->handler->option(QImageIOHandler::SupportedSubTypes));
     return QList<QByteArray>();
 }
@@ -1078,7 +1060,7 @@ QList<QByteArray> QImageReader::supportedSubTypes() const
 QImageIOHandler::Transformations QImageReader::transformation() const
 {
     int option = QImageIOHandler::TransformationNone;
-    if (d->initHandler() && d->handler->supportsOption(QImageIOHandler::ImageTransformation))
+    if (supportsOption(QImageIOHandler::ImageTransformation))
         option = d->handler->option(QImageIOHandler::ImageTransformation).toInt();
     return QImageIOHandler::Transformations(option);
 }
@@ -1196,20 +1178,23 @@ bool QImageReader::read(QImage *image)
     if (!d->initHandler())
         return false;
 
+    const bool supportScaledSize = supportsOption(QImageIOHandler::ScaledSize) && d->scaledSize.isValid();
+    const bool supportClipRect = supportsOption(QImageIOHandler::ClipRect) && !d->clipRect.isNull();
+    const bool supportScaledClipRect = supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull();
+
     // set the handler specific options.
-    if (d->handler->supportsOption(QImageIOHandler::ScaledSize) && d->scaledSize.isValid()) {
-        if ((d->handler->supportsOption(QImageIOHandler::ClipRect) && !d->clipRect.isNull())
-            || d->clipRect.isNull()) {
+    if (supportScaledSize) {
+        if (supportClipRect || d->clipRect.isNull()) {
             // Only enable the ScaledSize option if there is no clip rect, or
             // if the handler also supports ClipRect.
             d->handler->setOption(QImageIOHandler::ScaledSize, d->scaledSize);
         }
     }
-    if (d->handler->supportsOption(QImageIOHandler::ClipRect) && !d->clipRect.isNull())
+    if (supportClipRect)
         d->handler->setOption(QImageIOHandler::ClipRect, d->clipRect);
-    if (d->handler->supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull())
+    if (supportScaledClipRect)
         d->handler->setOption(QImageIOHandler::ScaledClipRect, d->scaledClipRect);
-    if (d->handler->supportsOption(QImageIOHandler::Quality))
+    if (supportsOption(QImageIOHandler::Quality))
         d->handler->setOption(QImageIOHandler::Quality, d->quality);
 
     // read the image
@@ -1230,9 +1215,9 @@ bool QImageReader::read(QImage *image)
 
     // provide default implementations for any unsupported image
     // options
-    if (d->handler->supportsOption(QImageIOHandler::ClipRect) && !d->clipRect.isNull()) {
-        if (d->handler->supportsOption(QImageIOHandler::ScaledSize) && d->scaledSize.isValid()) {
-            if (d->handler->supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull()) {
+    if (supportClipRect) {
+        if (supportScaledSize) {
+            if (supportScaledClipRect) {
                 // all features are supported by the handler; nothing to do.
             } else {
                 // the image is already scaled, so apply scaled clipping.
@@ -1240,7 +1225,7 @@ bool QImageReader::read(QImage *image)
                     *image = image->copy(d->scaledClipRect);
             }
         } else {
-            if (d->handler->supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull()) {
+            if (supportScaledClipRect) {
                 // supports scaled clipping but not scaling, most
                 // likely a broken handler.
             } else {
@@ -1253,8 +1238,8 @@ bool QImageReader::read(QImage *image)
             }
         }
     } else {
-        if (d->handler->supportsOption(QImageIOHandler::ScaledSize) && d->scaledSize.isValid() && d->clipRect.isNull()) {
-            if (d->handler->supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull()) {
+        if (supportScaledSize && d->clipRect.isNull()) {
+            if (supportScaledClipRect) {
                 // nothing to do (ClipRect is ignored!)
             } else {
                 // provide all workarounds.
@@ -1263,7 +1248,7 @@ bool QImageReader::read(QImage *image)
                 }
             }
         } else {
-            if (d->handler->supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull()) {
+            if (supportScaledClipRect) {
                 // this makes no sense; a handler that supports
                 // ScaledClipRect but not ScaledSize is broken, and we
                 // can't work around it.