Doc: compile qimagewriter snippet

Done-with: Nico Vertriest <nico.vertriest@qt.io>
Task-number: QTBUG-81486
Change-Id: Ibb4087d7035c3061b2980b317ab4280fa38aab50
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

src/gui/doc/snippets/qimagewriter/main.cpp

@@ -47,25 +47,20 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-
 #include <QtGui>
 
-int main(int argc, char **argv)
-{
-    QApplication app(argc, argv);
-
+void wrapper() {
 //! [0]
-    QString imagePath(QStringLiteral("path/image.jpeg"));
-    QImage image(64, 64, QImage::Format_RGB32);
-    image.fill(Qt::red);
-    {
+QString imagePath(QStringLiteral("path/image.jpeg"));
+QImage image(64, 64, QImage::Format_RGB32);
+image.fill(Qt::red);
+{
     QImageWriter writer(imagePath);
     writer.write(image);
-    }
+}
 
-    QFile::rename(imagePath,
+QFile::rename(imagePath,
               QStringLiteral("path/other_image.jpeg"));
 //! [0]
 
-    return 0;
-}
+} // wrapper

src/gui/doc/snippets/qimagewriter/qimagewriter.pro

@@ -0,0 +1,7 @@
+TEMPLATE = lib
+TARGET = qimagewriter_snippets
+QT += core gui widgets
+
+SOURCES = \
+    main.cpp
+

src/gui/doc/snippets/snippets.pro

@@ -16,6 +16,7 @@ contains(QT_BUILD_PARTS, tests) {
         polygon \
         qfileopenevent \
         qfontdatabase \
+        qimagewriter \
         textblock-formats \
         textblock-fragments \
         textdocument-blocks \