Allow more fine grained control over QFlags debug output

Useful in contexts such as other QDebug operators, where the class
is already known, and the full scope of the flags is not needed.

Change-Id: I546381b1722c9c846e2412e56763563b8f625212
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 54 insertions, 4 deletions

diff --git a/src/corelib/io/qdebug.cpp b/src/corelib/io/qdebug.cpp
index cc77db28de..15c5e0ce96 100644
--- a/src/corelib/io/qdebug.cpp
+++ b/src/corelib/io/qdebug.cpp
@@ -976,17 +976,67 @@ QDebug qt_QMetaEnum_debugOperator(QDebug &dbg, int value, const QMetaObject *met
     return dbg;
 }
 
+/*!
+    \fn QDebug qt_QMetaEnum_flagDebugOperator(QDebug &, quint64 value, const QMetaObject *, const char *name)
+    \internal
+
+    Formats the given flag \a value for debug output.
+
+    The supported verbosity are:
+
+      0: Just the key(s):
+
+         MyFlag1
+         MyFlag2|MyFlag3
+         MyScopedFlag(MyFlag2)
+         MyScopedFlag(MyFlag2|MyFlag3)
+
+      1: Same as 0, but treating all flags as scoped:
+
+         MyFlag(MyFlag1)
+         MyFlag(MyFlag2|MyFlag3)
+         MyScopedFlag(MyFlag2)
+         MyScopedFlag(MyFlag2|MyFlag3)
+
+      2: The QDebug default. Same as 1, and includes class/namespace scope:
+
+         QFlags<MyNamespace::MyClass::MyFlag>(MyFlag1)
+         QFlags<MyNamespace::MyClass::MyFlag>(MyFlag2|MyFlag3)
+         QFlags<MyNamespace::MyClass::MyScopedFlag>(MyFlag2)
+         QFlags<MyNamespace::MyClass::MyScopedFlag>(MyFlag2|MyFlag3)
+ */
 QDebug qt_QMetaEnum_flagDebugOperator(QDebug &debug, quint64 value, const QMetaObject *meta, const char *name)
 {
+    const int verbosity = debug.verbosity();
+
     QDebugStateSaver saver(debug);
     debug.resetFormat();
     debug.noquote();
     debug.nospace();
-    debug << "QFlags<";
+
     const QMetaEnum me = meta->enumerator(meta->indexOfEnumerator(name));
-    if (const char *scope = me.scope())
-        debug << scope << "::";
-    debug << me.enumName() << ">(" << me.valueToKeys(value) << ')';
+
+    const bool classScope = verbosity >= QDebug::DefaultVerbosity;
+    if (classScope) {
+        debug << "QFlags<";
+
+        if (const char *scope = me.scope())
+            debug << scope << "::";
+    }
+
+    const bool enumScope = me.isScoped() || verbosity > QDebug::MinimumVerbosity;
+    if (enumScope) {
+        debug << me.enumName();
+        if (classScope)
+            debug << ">";
+        debug << "(";
+    }
+
+    debug << me.valueToKeys(value);
+
+    if (enumScope)
+        debug << ')';
+
     return debug;
 }
 #endif // !QT_NO_QOBJECT