QmlProject: Disable debug action if qmlobserver cannot be built

QmlObserver right now requires 4.7.1 minimum. There's no gain in
telling the user that he needs qmlobserver to debug, if it can't be
build with 4.7.0 anyway.

Reviewed-by: Christiaan Janssen

src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp

@@ -114,26 +114,22 @@ Internal::QmlProjectTarget *QmlProjectRunConfiguration::qmlTarget() const
 
 QString QmlProjectRunConfiguration::viewerPath() const
 {
-    if (m_qtVersionId == -1)
+    Qt4ProjectManager::QtVersion *version = qtVersion();
+    if (!version) {
         return QString();
-
-    Qt4ProjectManager::QtVersionManager *versionManager = Qt4ProjectManager::QtVersionManager::instance();
-    Qt4ProjectManager::QtVersion *version = versionManager->version(m_qtVersionId);
-    QTC_ASSERT(version, return QString());
-
+    } else {
         return version->qmlviewerCommand();
+    }
 }
 
 QString QmlProjectRunConfiguration::observerPath() const
 {
-    if (m_qtVersionId == -1)
+    Qt4ProjectManager::QtVersion *version = qtVersion();
+    if (!version) {
         return QString();
-
-    Qt4ProjectManager::QtVersionManager *versionManager = Qt4ProjectManager::QtVersionManager::instance();
-    Qt4ProjectManager::QtVersion *version = versionManager->version(m_qtVersionId);
-    QTC_ASSERT(version, return QString());
-
+    } else {
         return version->qmlObserverTool();
+    }
 }
 
 QStringList QmlProjectRunConfiguration::viewerArguments() const
@@ -162,6 +158,18 @@ QString QmlProjectRunConfiguration::workingDirectory() const
     return projectFile.absolutePath();
 }
 
+Qt4ProjectManager::QtVersion *QmlProjectRunConfiguration::qtVersion() const
+{
+    if (m_qtVersionId == -1)
+        return 0;
+
+    Qt4ProjectManager::QtVersionManager *versionManager = Qt4ProjectManager::QtVersionManager::instance();
+    Qt4ProjectManager::QtVersion *version = versionManager->version(m_qtVersionId);
+    QTC_ASSERT(version, return 0);
+
+    return version;
+}
+
 static bool caseInsensitiveLessThan(const QString &s1, const QString &s2)
 {
     return s1.toLower() < s2.toLower();
@@ -381,10 +389,10 @@ void QmlProjectRunConfiguration::updateEnabled()
     bool newValue = (QFileInfo(viewerPath()).exists()
                     || QFileInfo(observerPath()).exists()) && qmlFileFound;
 
-    if (m_isEnabled != newValue) {
+
+    // Always emit change signal to force reevaluation of run/debug buttons
     m_isEnabled = newValue;
     emit isEnabledChanged(m_isEnabled);
-    }
 }
 
 void QmlProjectRunConfiguration::updateQtVersions()

src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h

@@ -74,6 +74,7 @@ public:
     QString observerPath() const;
     QStringList viewerArguments() const;
     QString workingDirectory() const;
+    Qt4ProjectManager::QtVersion *qtVersion() const;
 
     // RunConfiguration
     virtual QWidget *createConfigurationWidget();

src/plugins/qmlprojectmanager/qmlprojectruncontrol.cpp

@@ -43,6 +43,8 @@
 #include <debugger/debuggeruiswitcher.h>
 #include <debugger/debuggerengine.h>
 #include <qmljsinspector/qmljsinspectorconstants.h>
+#include <qt4projectmanager/qtversionmanager.h>
+#include <qt4projectmanager/qmlobservertool.h>
 #include <qt4projectmanager/qt4projectmanagerconstants.h>
 
 #include <QApplication>
@@ -148,9 +150,18 @@ bool QmlRunControlFactory::canRun(RunConfiguration *runConfiguration,
     } else {
         bool qmlDebugSupportInstalled = Debugger::DebuggerUISwitcher::instance()->supportedLanguages()
                                         & Debugger::QmlLanguage;
-        // don't check for qmlobserver already here because we can't update the run buttons
-        // if it has been built in the meantime
-        return (config != 0) && qmlDebugSupportInstalled;
+
+        if (config && qmlDebugSupportInstalled) {
+            if (!config->observerPath().isEmpty()) {
+                return true;
+            }
+
+            if (config->qtVersion() && Qt4ProjectManager::QmlObserverTool::canBuild(config->qtVersion())) {
+                return true;
+            } else {
+                return false;
+            }
+        }
     }
 
     return false;