QQmlInfo: Add qmlDebug & qmlWarning functions alongside qmlInfo

This way, we can correctly write to multiple levels of QDebug with QML context
information. A followup change will port all existing callers, and
subsequently change qmlInfo's message level to QtInfoMsg.

[ChangeLog][QtQml] Introduced qmlDebug & qmlWarning functions to qqmlinfo.h, in
addition to the pre-existing qmlInfo function. As a side effect, QQmlError has
also gained messageType() and setMessageType().

Change-Id: I04ced5952c5c3c58293a89a6767c7b545c03cc0a
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

5 files changed, 171 insertions, 28 deletions

diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index c2915c840b..3a95d353f5 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -1914,9 +1914,29 @@ void QQmlEnginePrivate::sendExit(int retCode)
 
 static void dumpwarning(const QQmlError &error)
 {
-    QMessageLogger(error.url().toString().toLatin1().constData(),
-                   error.line(), 0).warning().nospace()
-            << qPrintable(error.toString());
+    switch (error.messageType()) {
+    case QtDebugMsg:
+        QMessageLogger(error.url().toString().toLatin1().constData(),
+                       error.line(), 0).debug().nospace()
+                << qPrintable(error.toString());
+        break;
+    case QtInfoMsg:
+        QMessageLogger(error.url().toString().toLatin1().constData(),
+                       error.line(), 0).info().nospace()
+                << qPrintable(error.toString());
+        break;
+    case QtWarningMsg:
+    case QtFatalMsg: // fatal does not support streaming, and furthermore, is actually fatal. Probably not desirable for QML.
+        QMessageLogger(error.url().toString().toLatin1().constData(),
+                       error.line(), 0).warning().nospace()
+                << qPrintable(error.toString());
+        break;
+    case QtCriticalMsg:
+        QMessageLogger(error.url().toString().toLatin1().constData(),
+                       error.line(), 0).critical().nospace()
+                << qPrintable(error.toString());
+        break;
+    }
 }
 
 static void dumpwarning(const QList<QQmlError> &errors)
diff --git a/src/qml/qml/qqmlerror.cpp b/src/qml/qml/qqmlerror.cpp
index 0a6c7b4960..0cb82cdbd9 100644
--- a/src/qml/qml/qqmlerror.cpp
+++ b/src/qml/qml/qqmlerror.cpp
@@ -85,11 +85,12 @@ public:
     QString description;
     quint16 line;
     quint16 column;
+    QtMsgType messageType;
     QObject *object;
 };
 
 QQmlErrorPrivate::QQmlErrorPrivate()
-: line(0), column(0), object()
+: line(0), column(0), messageType(QtMsgType::QtWarningMsg), object()
 {
 }
 
@@ -125,6 +126,7 @@ QQmlError &QQmlError::operator=(const QQmlError &other)
         d->line = other.d->line;
         d->column = other.d->column;
         d->object = other.d->object;
+        d->messageType = other.d->messageType;
     }
     return *this;
 }
@@ -239,6 +241,29 @@ void QQmlError::setObject(QObject *object)
 }
 
 /*!
+    \since 5.9
+
+    Returns the message type.
+ */
+QtMsgType QQmlError::messageType() const
+{
+    if (d) return d->messageType;
+    else return QtMsgType::QtWarningMsg;
+}
+
+/*!
+    \since 5.9
+
+    Sets the \a messageType for this message. The message type determines which
+    QDebug handlers are responsible for recieving the message.
+ */
+void QQmlError::setMessageType(QtMsgType messageType)
+{
+    if (!d) d = new QQmlErrorPrivate;
+    d->messageType = messageType;
+}
+
+/*!
     Returns the error as a human readable string.
 */
 QString QQmlError::toString() const
diff --git a/src/qml/qml/qqmlerror.h b/src/qml/qml/qqmlerror.h
index e4c42223cf..ef529e3828 100644
--- a/src/qml/qml/qqmlerror.h
+++ b/src/qml/qml/qqmlerror.h
@@ -47,6 +47,7 @@
 
 QT_BEGIN_NAMESPACE
 
+// ### Qt 6: should this be called QQmlMessage, since it can have a message type?
 class QDebug;
 class QQmlErrorPrivate;
 class Q_QML_EXPORT QQmlError
@@ -69,6 +70,8 @@ public:
     void setColumn(int);
     QObject *object() const;
     void setObject(QObject *);
+    QtMsgType messageType() const;
+    void setMessageType(QtMsgType messageType);
 
     QString toString() const;
 private:
diff --git a/src/qml/qml/qqmlinfo.cpp b/src/qml/qml/qqmlinfo.cpp
index 5b6e02d5b1..e87f29753a 100644
--- a/src/qml/qml/qqmlinfo.cpp
+++ b/src/qml/qml/qqmlinfo.cpp
@@ -50,13 +50,45 @@
 QT_BEGIN_NAMESPACE
 
 /*!
+    \fn QQmlInfo QtQml::qmlDebug(const QObject *object)
+    \relates QQmlEngine
+    \since 5.9
+
+    Prints debug messages that include the file and line number for the
+    specified QML \a object.
+
+    When QML types produce logging messages, it improves traceability
+    if they include the QML file and line number on which the
+    particular instance was instantiated.
+
+    To include the file and line number, an object must be passed.  If
+    the file and line number is not available for that instance
+    (either it was not instantiated by the QML engine or location
+    information is disabled), "unknown location" will be used instead.
+
+    For example,
+
+    \code
+    qmlDebug(object) << "Internal state: 42";
+    \endcode
+
+    prints
+
+    \code
+    QML MyCustomType (unknown location): Internal state: 42
+    \endcode
+
+    \sa QtQml::qmlInfo, QtQml::qmlWarning
+*/
+
+/*!
     \fn QQmlInfo QtQml::qmlInfo(const QObject *object)
     \relates QQmlEngine
 
-    Prints warning messages that include the file and line number for the
+    Prints informational messages that include the file and line number for the
     specified QML \a object.
 
-    When QML types display warning messages, it improves traceability
+    When QML types produce logging messages, it improves traceability
     if they include the QML file and line number on which the
     particular instance was instantiated.
 
@@ -76,14 +108,58 @@ QT_BEGIN_NAMESPACE
     \code
     QML MyCustomType (unknown location): component property is a write-once property
     \endcode
+
+    \note In versions prior to Qt 5.9, qmlInfo reported messages using a warning
+    QtMsgType. For Qt 5.9 and above, qmlInfo uses an info QtMsgType. To send
+    warnings, use qmlWarning.
+
+    \sa QtQml::qmlDebug, QtQml::qmlWarning
+*/
+
+
+/*!
+    \fn QQmlInfo QtQml::qmlWarning(const QObject *object)
+    \relates QQmlEngine
+    \since 5.9
+
+    Prints warning messages that include the file and line number for the
+    specified QML \a object.
+
+    When QML types produce logging messages, it improves traceability
+    if they include the QML file and line number on which the
+    particular instance was instantiated.
+
+    To include the file and line number, an object must be passed.  If
+    the file and line number is not available for that instance
+    (either it was not instantiated by the QML engine or location
+    information is disabled), "unknown location" will be used instead.
+
+    For example,
+
+    \code
+    qmlInfo(object) << tr("property cannot be set to 0");
+    \endcode
+
+    prints
+
+    \code
+    QML MyCustomType (unknown location): property cannot be set to 0
+    \endcode
+
+    \sa QtQml::qmlDebug, QtQml::qmlInfo
 */
 
 class QQmlInfoPrivate
 {
 public:
-    QQmlInfoPrivate() : ref (1), object(0) {}
+    QQmlInfoPrivate(QtMsgType type)
+        : ref (1)
+        , msgType(type)
+        , object(nullptr)
+    {}
 
     int ref;
+    QtMsgType msgType;
     const QObject *object;
     QString buffer;
     QList<QQmlError> errors;
@@ -110,6 +186,7 @@ QQmlInfo::~QQmlInfo()
 
         if (!d->buffer.isEmpty()) {
             QQmlError error;
+            error.setMessageType(d->msgType);
 
             QObject *object = const_cast<QObject *>(d->object);
 
@@ -139,28 +216,32 @@ QQmlInfo::~QQmlInfo()
 
 namespace QtQml {
 
-QQmlInfo qmlInfo(const QObject *me)
-{
-    QQmlInfoPrivate *d = new QQmlInfoPrivate;
-    d->object = me;
-    return QQmlInfo(d);
-}
+#define MESSAGE_FUNCS(FuncName, MessageLevel) \
+    QQmlInfo FuncName(const QObject *me) \
+    { \
+        QQmlInfoPrivate *d = new QQmlInfoPrivate(MessageLevel); \
+        d->object = me; \
+        return QQmlInfo(d); \
+    } \
+    QQmlInfo FuncName(const QObject *me, const QQmlError &error) \
+    { \
+        QQmlInfoPrivate *d = new QQmlInfoPrivate(MessageLevel); \
+        d->object = me; \
+        d->errors << error; \
+        return QQmlInfo(d); \
+    } \
+    QQmlInfo FuncName(const QObject *me, const QList<QQmlError> &errors) \
+    { \
+        QQmlInfoPrivate *d = new QQmlInfoPrivate(MessageLevel); \
+        d->object = me; \
+        d->errors = errors; \
+        return QQmlInfo(d); \
+    }
 
-QQmlInfo qmlInfo(const QObject *me, const QQmlError &error)
-{
-    QQmlInfoPrivate *d = new QQmlInfoPrivate;
-    d->object = me;
-    d->errors << error;
-    return QQmlInfo(d);
-}
+MESSAGE_FUNCS(qmlDebug, QtMsgType::QtDebugMsg)
+MESSAGE_FUNCS(qmlInfo, QtMsgType::QtWarningMsg) // XXX: temporary, switch to QtInfoMsg when callers are ported
+MESSAGE_FUNCS(qmlWarning, QtMsgType::QtWarningMsg)
 
-QQmlInfo qmlInfo(const QObject *me, const QList<QQmlError> &errors)
-{
-    QQmlInfoPrivate *d = new QQmlInfoPrivate;
-    d->object = me;
-    d->errors = errors;
-    return QQmlInfo(d);
-}
 
 } // namespace QtQml
 
diff --git a/src/qml/qml/qqmlinfo.h b/src/qml/qml/qqmlinfo.h
index ab0281a688..673125632e 100644
--- a/src/qml/qml/qqmlinfo.h
+++ b/src/qml/qml/qqmlinfo.h
@@ -48,11 +48,19 @@ QT_BEGIN_NAMESPACE
 
 class QQmlInfo;
 
+// declared in namespace to avoid symbol conflicts with QtDeclarative
 namespace QtQml {
-    // declared in namespace to avoid symbol conflicts with QtDeclarative
+    Q_QML_EXPORT QQmlInfo qmlDebug(const QObject *me);
+    Q_QML_EXPORT QQmlInfo qmlDebug(const QObject *me, const QQmlError &error);
+    Q_QML_EXPORT QQmlInfo qmlDebug(const QObject *me, const QList<QQmlError> &errors);
+
     Q_QML_EXPORT QQmlInfo qmlInfo(const QObject *me);
     Q_QML_EXPORT QQmlInfo qmlInfo(const QObject *me, const QQmlError &error);
     Q_QML_EXPORT QQmlInfo qmlInfo(const QObject *me, const QList<QQmlError> &errors);
+
+    Q_QML_EXPORT QQmlInfo qmlWarning(const QObject *me);
+    Q_QML_EXPORT QQmlInfo qmlWarning(const QObject *me, const QQmlError &error);
+    Q_QML_EXPORT QQmlInfo qmlWarning(const QObject *me, const QList<QQmlError> &errors);
 }
 QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wheader-hygiene")
@@ -93,9 +101,15 @@ public:
 #endif
 
 private:
+    friend Q_QML_EXPORT QQmlInfo QtQml::qmlDebug(const QObject *me);
+    friend Q_QML_EXPORT QQmlInfo QtQml::qmlDebug(const QObject *me, const QQmlError &error);
+    friend Q_QML_EXPORT QQmlInfo QtQml::qmlDebug(const QObject *me, const QList<QQmlError> &errors);
     friend Q_QML_EXPORT QQmlInfo QtQml::qmlInfo(const QObject *me);
     friend Q_QML_EXPORT QQmlInfo QtQml::qmlInfo(const QObject *me, const QQmlError &error);
     friend Q_QML_EXPORT QQmlInfo QtQml::qmlInfo(const QObject *me, const QList<QQmlError> &errors);
+    friend Q_QML_EXPORT QQmlInfo QtQml::qmlWarning(const QObject *me);
+    friend Q_QML_EXPORT QQmlInfo QtQml::qmlWarning(const QObject *me, const QQmlError &error);
+    friend Q_QML_EXPORT QQmlInfo QtQml::qmlWarning(const QObject *me, const QList<QQmlError> &errors);
 
     QQmlInfo(QQmlInfoPrivate *);
     QQmlInfoPrivate *d;