QtcProcess: Add starting() signal

Will be useful for VcsCommand controlling.

Change-Id: I6e0199c7a45948526cfd916907b098472b78219c
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/qtcprocess.cpp

@@ -704,6 +704,7 @@ public:
     void handleDone(const ProcessResultData &data);
     void clearForRun();
 
+    void emitStarting();
     void emitStarted();
     void emitDone();
     void emitReadyReadStandardOutput();
@@ -1149,6 +1150,7 @@ void QtcProcess::start()
         // Pass a dynamic property with info about blocking type
         d->m_process->setProperty(QTC_PROCESS_BLOCKING_TYPE, property(QTC_PROCESS_BLOCKING_TYPE));
     }
+    d->emitStarting();
     d->m_process->start();
 }
 
@@ -2031,6 +2033,12 @@ void QtcProcessPrivate::handleDone(const ProcessResultData &data)
     m_applicationMainThreadId = 0;
 }
 
+void QtcProcessPrivate::emitStarting()
+{
+    GuardLocker locker(m_guard);
+    emit q->starting();
+}
+
 void QtcProcessPrivate::emitStarted()
 {
     GuardLocker locker(m_guard);

src/libs/utils/qtcprocess.h

@@ -177,8 +177,9 @@ public:
     QString toStandaloneCommandLine() const;
 
 signals:
-    void started();
-    void done();
+    void starting(); // On NotRunning -> Starting state transition
+    void started();  // On Starting -> Running state transition
+    void done();     // On Starting | Running -> NotRunning state transition
     void readyReadStandardOutput();
     void readyReadStandardError();