project: detect project version and show errors on incompatibility

app/core.cpp

@@ -68,6 +68,7 @@
 OLIVE_NAMESPACE_ENTER
 
 Core* Core::instance_ = nullptr;
+const uint Core::kProjectVersion = 201003;
 
 Core::Core(const CoreParams& params) :
   main_window_(nullptr),

app/core.h

@@ -268,6 +268,8 @@ public:
    */
   void CacheActiveSequence(bool in_out_only);
 
+  static const uint kProjectVersion;
+
 public slots:
   /**
    * @brief Starts an open file dialog to load a project from file

app/task/project/load/load.cpp

@@ -25,6 +25,7 @@
 #include <QXmlStreamReader>
 
 #include "common/xmlutils.h"
+#include "core.h"
 
 OLIVE_NAMESPACE_ENTER
 
@@ -45,7 +46,17 @@ bool ProjectLoadTask::Run()
       if (reader.name() == QStringLiteral("olive")) {
         while(XMLReadNextStartElement(&reader)) {
           if (reader.name() == QStringLiteral("version")) {
-            qDebug() << "Project version:" << reader.readElementText();
+            uint project_version = reader.readElementText().toUInt();
+
+            if (project_version > Core::kProjectVersion) {
+              // Project is newer than we support
+              SetError(tr("This project is newer than this version of Olive and cannot be opened."));
+              return false;
+            } else if (project_version < 201003) { // Change this if we drop support for a project version
+              // Project is older than we support
+              SetError(tr("This project is from a version of Olive that is no longer supported in this version."));
+              return false;
+            }
           } else if (reader.name() == QStringLiteral("project")) {
             ProjectPtr project = std::make_shared<Project>();
 
@@ -66,6 +77,11 @@ bool ProjectLoadTask::Run()
             reader.skipCurrentElement();
           }
         }
+      } else if (reader.name() == QStringLiteral("project")) {
+        // 0.1 projects use "project" as the root instead of Olive. We don't currently support
+        // these projects
+        SetError(tr("This project is from a version of Olive that is no longer supported in this version."));
+        return false;
       } else {
         reader.skipCurrentElement();
       }

app/task/project/save/save.cpp

@@ -25,6 +25,7 @@
 #include <QXmlStreamWriter>
 
 #include "common/filefunctions.h"
+#include "core.h"
 
 OLIVE_NAMESPACE_ENTER
 
@@ -49,7 +50,9 @@ bool ProjectSaveTask::Run()
 
     writer.writeStartElement("olive");
 
-    writer.writeTextElement("version", "0.2.0");
+    // Version is stored in YYMMDD from whenever the project format was last changed
+    // Allows easy integer math for checking project versions.
+    writer.writeTextElement("version", QString::number(Core::kProjectVersion));
 
     project_->Save(&writer);