1 files changed, 21 insertions, 1 deletions
diff --git a/src/session.h b/src/session.h
index 70bee42..01f8ad5 100644
--- a/src/session.h
+++ b/src/session.h
@@ -2,6 +2,7 @@
 #define VMCHOOSER_SESSION_H_
 
 #include <QVariant>
+#include <QMessageBox>
 
 class QString;
 class QIcon;
@@ -20,7 +21,20 @@ class Session {
 
     virtual bool isActive() const = 0;
     virtual bool isLocked() const = 0;
-    virtual bool isValid() const = 0;
+    virtual void checkCanRun() final {
+        error = checkCanRunInternal();
+    }
+    virtual bool canRun(bool showError = false) const final {
+        if (!error.isEmpty()) {
+            if (showError) {
+                QMessageBox::critical(
+                        nullptr, QObject::trUtf8("vmchooser"),
+                        QObject::trUtf8("Cannot start selected session:") + QStringLiteral("\n") + error);
+            }
+            return false;
+        }
+        return true;
+    }
     virtual int priority() const = 0;
     virtual QString shortDescription() const = 0;
     virtual QString description() const = 0;
@@ -40,5 +54,11 @@ class Session {
 
     virtual bool containsKeywords(const QList<QString>& keywords) const = 0;
 
+protected:
+    virtual QString checkCanRunInternal() const = 0;
+
+private:
+    QString error;
+
 };
 #endif /*VMCHOOSER_SESSION_H_*/