QDBusAbstractInterface/Doc: fix example to match the description

The docs say "This example illustrates function calling with 0, 1 and 2
parameters" because it was copied from the synchronous call()
documentation. But the snippet didn't do that, because back in Qt 4 when
this was created, it was too difficult to exemplify that for
asynchronous use. It now no longer is, with lambdas.

Drive-by update the docs for both functions to refer to each other.

Fixes: QTBUG-121873
Pick-to: 6.6 6.7
Change-Id: I664b9f014ffc48cbb49bfffd17b089b7f77c1cde
Reviewed-by: Ievgenii Meshcheriakov <ievgenii.meshcheriakov@qt.io>

1 files changed, 15 insertions, 5 deletions

diff --git a/src/dbus/doc/snippets/code/src_qdbus_qdbusabstractinterface.cpp b/src/dbus/doc/snippets/code/src_qdbus_qdbusabstractinterface.cpp
index 85945ac2c7..92b9dea909 100644
--- a/src/dbus/doc/snippets/code/src_qdbus_qdbusabstractinterface.cpp
+++ b/src/dbus/doc/snippets/code/src_qdbus_qdbusabstractinterface.cpp
@@ -47,12 +47,22 @@ else
 void Abstract_DBus_Interface::asyncCall()
 {
 //! [1]
-QString value = retrieveValue();
-QDBusPendingCall pcall = interface->asyncCall("Process"_L1, value);
-
-QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(pcall);
+QDBusPendingCall pcall = interface->asyncCall("GetAPIVersion"_L1);
+auto watcher = new QDBusPendingCallWatcher(pcall, this);
 
 QObject::connect(watcher, &QDBusPendingCallWatcher::finished, this,
-                 &Abstract_DBus_Interface::callFinishedSlot);
+                 [&](QDBusPendingCallWatcher *w) {
+    QString value = retrieveValue();
+    QDBusPendingReply<int> reply(*w);
+    QDBusPendingCall pcall;
+    if (reply.argumentAt<0>() >= 14)
+        pcall = interface->asyncCall("ProcessWorkUnicode"_L1, value);
+    else
+        pcall = interface->asyncCall("ProcessWork"_L1, "UTF-8"_L1, value.toUtf8());
+
+    w = new QDBusPendingCallWatcher(pcall);
+    QObject::connect(w,  &QDBusPendingCallWatcher::finished, this,
+                     &Abstract_DBus_Interface::callFinishedSlot);
+});
 //! [1]
 }