Handle non-qmake projects without kits

Make it possible to add kits again after all kits were removed
from a non qmake project.

Task-number: QTCREATORBUG-7814
Change-Id: I38967cd4c106b95288b7020fe325d8cfe2688a7c
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/projectexplorer/project.cpp

@@ -439,6 +439,11 @@ void Project::configureAsExampleProject(const QStringList &platforms)
     Q_UNUSED(platforms);
 }
 
+bool Project::supportsNoTargetPanel() const
+{
+    return false;
+}
+
 void Project::onBuildDirectoryChanged()
 {
     Target *target = qobject_cast<Target *>(sender());

src/plugins/projectexplorer/project.h

@@ -124,6 +124,8 @@ public:
     virtual bool needsConfiguration() const;
     virtual void configureAsExampleProject(const QStringList &platforms);
 
+    virtual bool supportsNoTargetPanel() const;
+
 signals:
     void displayNameChanged();
     void fileListChanged();

src/plugins/projectexplorer/projectwindow.cpp

@@ -384,7 +384,7 @@ void ProjectWindow::showProperties(int index, int subIndex)
         m_previousTargetSubIndex = previousPanelWidget->currentSubIndex();
     }
 
-    if (m_hasTarget.value(project)) {
+    if (m_hasTarget.value(project) || !project->supportsNoTargetPanel()) {
         if (subIndex == 0) {
             // Targets page
             removeCurrentWidget();

src/plugins/projectexplorer/targetsettingspanel.cpp

@@ -115,7 +115,7 @@ void TargetSettingsPanelWidget::setupUi()
     QVBoxLayout *noTargetLayout = new QVBoxLayout(m_noTargetLabel);
     noTargetLayout->setMargin(0);
     QLabel *label = new QLabel(m_noTargetLabel);
-    label->setText(tr("No kit defined."));
+    label->setText(tr("No kit defined in this project."));
     {
         QFont f = label->font();
         f.setPointSizeF(f.pointSizeF() * 1.4);

src/plugins/qt4projectmanager/qt4project.cpp

@@ -1367,6 +1367,11 @@ void Qt4Project::configureAsExampleProject(const QStringList &platforms)
     ProjectExplorer::ProjectExplorerPlugin::instance()->requestProjectModeUpdate(this);
 }
 
+bool Qt4Project::supportsNoTargetPanel() const
+{
+    return true;
+}
+
 // All the Qt4 run configurations should share code.
 // This is a rather suboptimal way to do that for disabledReason()
 // but more pratical then duplicated the code everywhere

src/plugins/qt4projectmanager/qt4project.h

@@ -129,6 +129,8 @@ public:
 
     void configureAsExampleProject(const QStringList &platforms);
 
+    bool supportsNoTargetPanel() const;
+
     /// \internal
     QString disabledReasonForRunConfiguration(const QString &proFilePath);