Introduced sessions

The session is currently implicit, being either the default session or a
project-based session saved alongside a project.

It stores the list of open files, the active file, recent files and the
last state for previously opened files. This makes it easier to switch
between different projects, which swaps all these things along with it.

Also improved the start location for the open file dialog, which now
starts at the active file, then the first recent file and finally the
user home directory (instead of starting at the current working
directory, usually at the binary).

Issue #1665

src/tiled/documentmanager.cpp

@@ -407,6 +407,16 @@ void DocumentManager::switchToDocument(int index)
     mTabBar->setCurrentIndex(index);
 }
 
+bool DocumentManager::switchToDocument(const QString &fileName)
+{
+    const int index = findDocument(fileName);
+    if (index != -1) {
+        switchToDocument(index);
+        return true;
+    }
+    return false;
+}
+
 /**
  * Switches to the given \a document, if there is already a tab open for it.
  * \return whether the switch was succesful
@@ -418,7 +428,6 @@ bool DocumentManager::switchToDocument(Document *document)
         switchToDocument(index);
         return true;
     }
-
     return false;
 }
 
@@ -532,6 +541,8 @@ void DocumentManager::insertDocument(int index, const DocumentPtr &document)
     if (mBrokenLinksModel->hasBrokenLinks())
         mBrokenLinksWidget->show();
 
+    updateSession();
+
     emit documentOpened(documentPtr);
 }
 
@@ -816,6 +827,8 @@ void DocumentManager::closeDocumentAt(int index)
             tilesetDocument->disconnect(this);
         }
     }
+
+    updateSession();
 }
 
 /**
@@ -913,6 +926,8 @@ void DocumentManager::currentIndexChanged()
 
     mBrokenLinksModel->setDocument(document);
 
+    updateSession();
+
     emit currentDocumentChanged(document);
 }
 
@@ -1134,6 +1149,20 @@ void DocumentManager::removeFromTilesetDocument(const SharedTileset &tileset, Ma
     }
 }
 
+void DocumentManager::updateSession() const
+{
+    QStringList fileList;
+    for (const auto &document : mDocuments)
+        fileList.append(document->fileName());
+
+    auto doc = currentDocument();
+    auto prefs = Preferences::instance();
+
+    prefs->session().setOpenFiles(fileList);
+    prefs->session().setActiveFile(doc ? doc->fileName() : QString());
+    prefs->saveSession();
+}
+
 MapDocument *DocumentManager::openMapFile(const QString &path)
 {
     openFile(path);

src/tiled/documentmanager.h

@@ -90,6 +90,7 @@ class DocumentManager : public QObject
     int findDocument(Document *document) const;
 
     void switchToDocument(int index);
+    bool switchToDocument(const QString &fileName);
     bool switchToDocument(Document *document);
     void switchToDocument(MapDocument *mapDocument, QPointF viewCenter, qreal scale);
 
@@ -201,6 +202,8 @@ public slots:
     void addToTilesetDocument(const SharedTileset &tileset, MapDocument *mapDocument);
     void removeFromTilesetDocument(const SharedTileset &tileset, MapDocument *mapDocument);
 
+    void updateSession() const;
+
     MapDocument *openMapFile(const QString &path);
     TilesetDocument *openTilesetFile(const QString &path);
 

src/tiled/main.cpp

@@ -504,12 +504,11 @@ int main(int argc, char *argv[])
     PluginManager::instance()->loadPlugins();
     ScriptManager::instance().initialize();
 
-    if (!commandLine.filesToOpen().isEmpty()) {
+    w.initializeSession();
+
+    if (!commandLine.filesToOpen().isEmpty())
         for (const QString &fileName : commandLine.filesToOpen())
             w.openFile(fileName);
-    } else if (Preferences::instance()->openLastFilesOnStartup()) {
-        w.openLastFiles();
-    }
 
     return a.exec();
 }