Doc: Make Qt Gui snippets compilable - textdocument-listitems

Task-number: QTBUG-81486
Change-Id: I7bbecd3cbf086243ea3a03fb7822064bde85201c
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

src/gui/doc/snippets/snippets.pro

@@ -17,5 +17,6 @@ contains(QT_BUILD_PARTS, tests) {
         textdocument-frames \
         textdocument-imagedrop \
         textdocument-imageformat \
-        textdocument-images
+        textdocument-images \
+        textdocument-listitems
 }

src/gui/doc/snippets/textdocument-listitems/main.cpp

@@ -49,6 +49,8 @@
 ****************************************************************************/
 
 #include <QtGui>
+#include <QApplication>
+#include <QTextEdit>
 
 #include "mainwindow.h"
 

src/gui/doc/snippets/textdocument-listitems/mainwindow.cpp

@@ -47,11 +47,14 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-
-#include <QtGui>
-
 #include "mainwindow.h"
 
+#include <QMenu>
+#include <QMenuBar>
+#include <QTextEdit>
+#include <QTextList>
+#include <QTreeWidget>
+
 MainWindow::MainWindow()
 {
     QMenu *fileMenu = new QMenu(tr("&File"));

src/gui/doc/snippets/textdocument-listitems/mainwindow.h

@@ -75,8 +75,8 @@ public slots:
 
 private:
     QString currentFile;
-    QTextEdit *editor;
-    QTextDocument *document;
+    QTextEdit *editor = nullptr;
+    QTextDocument *document = nullptr;
     QList<QTextList*> listStructures;
     QList<QTreeWidgetItem*> previousItems;
     QList<QTreeWidgetItem*> parentItems;

src/gui/doc/snippets/textdocument-listitems/textdocument-listitems.pro

@@ -1,3 +1,10 @@
-HEADERS     = mainwindow.h
-SOURCES     = main.cpp \
-              mainwindow.cpp
+TEMPLATE = lib
+TARGET = textdocument-listitems
+QT += widgets core gui
+
+HEADERS = \
+    mainwindow.h
+SOURCES = \
+    main.cpp \
+    mainwindow.cpp
+