Factor out qt_getImageText() and qt_getImageTextFromDescription()

... and re-use them in QImageReader, QJpegHandler, QPngHandler.

Change-Id: Iec89e47205f3c420e1e7eb4a2d3c1fbfe887fd8c
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

src/gui/image/qimage.cpp

@@ -5216,4 +5216,33 @@ Q_GUI_EXPORT void qt_imageTransform(QImage &src, QImageIOHandler::Transformation
     }
 }
 
+QMap<QString, QString> qt_getImageText(const QImage &image, const QString &description)
+{
+    QMap<QString, QString> text = qt_getImageTextFromDescription(description);
+    const auto textKeys = image.textKeys();
+    for (const QString &key : textKeys) {
+        if (!key.isEmpty() && !text.contains(key))
+            text.insert(key, image.text(key));
+    }
+    return text;
+}
+
+QMap<QString, QString> qt_getImageTextFromDescription(const QString &description)
+{
+    QMap<QString, QString> text;
+    const auto pairs = description.splitRef(QLatin1String("\n\n"));
+    for (const QStringRef &pair : pairs) {
+        int index = pair.indexOf(QLatin1Char(':'));
+        if (index >= 0 && pair.indexOf(QLatin1Char(' ')) < index) {
+            if (!pair.trimmed().isEmpty())
+                text.insert(QLatin1String("Description"), pair.toString().simplified());
+        } else {
+            const QStringRef key = pair.left(index);
+            if (!key.trimmed().isEmpty())
+                text.insert(key.toString(), pair.mid(index + 2).toString().simplified());
+        }
+    }
+    return text;
+}
+
 QT_END_NAMESPACE

src/gui/image/qimage_p.h

@@ -212,6 +212,9 @@ inline QImage::Format qt_alphaVersionForPainting(QImage::Format format)
     return toFormat;
 }
 
+Q_GUI_EXPORT QMap<QString, QString> qt_getImageText(const QImage &image, const QString &description);
+Q_GUI_EXPORT QMap<QString, QString> qt_getImageTextFromDescription(const QString &description);
+
 QT_END_NAMESPACE
 
 #endif // QIMAGE_P_H

src/gui/image/qimagereader.cpp

@@ -147,6 +147,9 @@
 #include <private/qfactoryloader_p.h>
 #include <QMutexLocker>
 
+// for qt_getImageText
+#include <private/qimage_p.h>
+
 // image handlers
 #include <private/qbmphandler_p.h>
 #include <private/qppmhandler_p.h>
@@ -592,18 +595,8 @@ bool QImageReaderPrivate::initHandler()
 */
 void QImageReaderPrivate::getText()
 {
-    if (!text.isEmpty() || (!handler && !initHandler()) || !handler->supportsOption(QImageIOHandler::Description))
-        return;
-    foreach (const QString &pair, handler->option(QImageIOHandler::Description).toString().split(
-                QLatin1String("\n\n"))) {
-        int index = pair.indexOf(QLatin1Char(':'));
-        if (index >= 0 && pair.indexOf(QLatin1Char(' ')) < index) {
-            text.insert(QLatin1String("Description"), pair.simplified());
-        } else {
-            QString key = pair.left(index);
-            text.insert(key, pair.mid(index + 2).simplified());
-        }
-    }
+    if (text.isEmpty() && (handler || initHandler()) && handler->supportsOption(QImageIOHandler::Description))
+        text = qt_getImageTextFromDescription(handler->option(QImageIOHandler::Description).toString());
 }
 
 /*!

src/gui/image/qpnghandler.cpp

@@ -49,6 +49,8 @@
 #include <qvariant.h>
 #include <qvector.h>
 
+#include <private/qimage_p.h> // for qt_getImageText
+
 #include <png.h>
 #include <pngconf.h>
 
@@ -718,27 +720,10 @@ void QPNGImageWriter::setGamma(float g)
     gamma = g;
 }
 
-
 static void set_text(const QImage &image, png_structp png_ptr, png_infop info_ptr,
                      const QString &description)
 {
-    QMap<QString, QString> text;
-    foreach (const QString &key, image.textKeys()) {
-        if (!key.isEmpty())
-            text.insert(key, image.text(key));
-    }
-    foreach (const QString &pair, description.split(QLatin1String("\n\n"))) {
-        int index = pair.indexOf(QLatin1Char(':'));
-        if (index >= 0 && pair.indexOf(QLatin1Char(' ')) < index) {
-            QString s = pair.simplified();
-            if (!s.isEmpty())
-                text.insert(QLatin1String("Description"), s);
-        } else {
-            QString key = pair.left(index);
-            if (!key.simplified().isEmpty())
-                text.insert(key, pair.mid(index + 2).simplified());
-        }
-    }
+    const QMap<QString, QString> text = qt_getImageText(image, description);
 
     if (text.isEmpty())
         return;

src/plugins/imageformats/jpeg/jpeg.pro

@@ -1,6 +1,6 @@
 TARGET  = qjpeg
 
-QT += core-private
+QT += core-private gui-private
 
 SOURCES += main.cpp qjpeghandler.cpp
 HEADERS += main.h qjpeghandler_p.h

src/plugins/imageformats/jpeg/qjpeghandler.cpp

@@ -45,6 +45,7 @@
 #include <qbuffer.h>
 #include <qmath.h>
 #include <private/qsimd_p.h>
+#include <private/qimage_p.h>   // for qt_getImageText
 
 #include <stdio.h>      // jpeglib needs this to be pre-included
 #include <setjmp.h>
@@ -491,30 +492,10 @@ inline my_jpeg_destination_mgr::my_jpeg_destination_mgr(QIODevice *device)
     free_in_buffer = max_buf;
 }
 
-
 static inline void set_text(const QImage &image, j_compress_ptr cinfo, const QString &description)
 {
-    QMap<QString, QString> text;
-    foreach (const QString &key, image.textKeys()) {
-        if (!key.isEmpty())
-            text.insert(key, image.text(key));
-    }
-    foreach (const QString &pair, description.split(QLatin1String("\n\n"))) {
-        int index = pair.indexOf(QLatin1Char(':'));
-        if (index >= 0 && pair.indexOf(QLatin1Char(' ')) < index) {
-            QString s = pair.simplified();
-            if (!s.isEmpty())
-                text.insert(QLatin1String("Description"), s);
-        } else {
-            QString key = pair.left(index);
-            if (!key.simplified().isEmpty())
-                text.insert(key, pair.mid(index + 2).simplified());
-        }
-    }
-    if (text.isEmpty())
-        return;
-
-    for (QMap<QString, QString>::ConstIterator it = text.constBegin(); it != text.constEnd(); ++it) {
+    const QMap<QString, QString> text = qt_getImageText(image, description);
+    for (auto it = text.begin(), end = text.end(); it != end; ++it) {
         QByteArray comment = it.key().toLatin1();
         if (!comment.isEmpty())
             comment += ": ";