From e6f2526afee594eb8d7319114f0c990afeab8d04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thorbj=C3=B8rn=20Lindeijer?= <bjorn@lindeijer.nl>
Date: Tue, 23 Jan 2024 18:07:17 +0100
Subject: [PATCH] Scripting: Added tiled.load to load assets without opening an
 editor

Still WIP, has known issues are likely also undiscovered ones.
---
 src/libtiled/object.h         |  2 ++
 src/tiled/document.cpp        | 13 --------
 src/tiled/document.h          |  8 +----
 src/tiled/editableasset.cpp   | 23 ++++++++++----
 src/tiled/editableasset.h     | 17 +++++-----
 src/tiled/editablemap.cpp     | 59 ++++++++++++++++++++++-------------
 src/tiled/editablemap.h       | 10 ++++++
 src/tiled/editableobject.h    |  2 +-
 src/tiled/editableproject.cpp | 15 ++++++++-
 src/tiled/editableproject.h   |  8 +++++
 src/tiled/editabletileset.cpp | 31 +++++++++++-------
 src/tiled/editabletileset.h   |  3 ++
 src/tiled/editableworld.cpp   | 15 ++++++++-
 src/tiled/editableworld.h     |  8 +++++
 src/tiled/mapdocument.cpp     |  9 ++----
 src/tiled/mapdocument.h       |  3 +-
 src/tiled/projectdocument.cpp |  4 +--
 src/tiled/projectdocument.h   |  2 +-
 src/tiled/scriptmodule.cpp    | 25 +++++++++++++--
 src/tiled/scriptmodule.h      |  1 +
 src/tiled/tilesetdocument.cpp | 27 +++++++---------
 src/tiled/tilesetdocument.h   | 10 +-----
 src/tiled/worlddocument.cpp   | 12 +++++--
 src/tiled/worlddocument.h     |  8 +++--
 24 files changed, 199 insertions(+), 116 deletions(-)

diff --git a/src/libtiled/object.h b/src/libtiled/object.h
index 2f9e8e9486..0e57c740f7 100644
--- a/src/libtiled/object.h
+++ b/src/libtiled/object.h
@@ -150,6 +150,8 @@ class TILEDSHARED_EXPORT Object
     static void setPropertyTypes(const SharedPropertyTypes &propertyTypes);
     static const PropertyTypes &propertyTypes();
 
+    QObject *editable() const { return mEditable; }
+
 private:
     const TypeId mTypeId;
     QString mClassName;
diff --git a/src/tiled/document.cpp b/src/tiled/document.cpp
index a014f02181..fdb68f43a2 100644
--- a/src/tiled/document.cpp
+++ b/src/tiled/document.cpp
@@ -64,19 +64,6 @@ Document::~Document()
     }
 }
 
-EditableAsset *Document::editable()
-{
-    if (!mEditable)
-        mEditable = createEditable();
-    return mEditable.get();
-}
-
-void Document::setEditable(std::unique_ptr<EditableAsset> editable)
-{
-    mEditable = std::move(editable);
-    mEditable->setDocument(this);
-}
-
 void Document::setFileName(const QString &fileName)
 {
     if (mFileName == fileName)
diff --git a/src/tiled/document.h b/src/tiled/document.h
index 5adfd9930c..c435a7f844 100644
--- a/src/tiled/document.h
+++ b/src/tiled/document.h
@@ -28,8 +28,6 @@
 #include <QString>
 #include <QVariant>
 
-#include <memory>
-
 class QUndoStack;
 
 namespace Tiled {
@@ -95,8 +93,7 @@ class Document : public QObject,
     QUndoStack *undoStack() const;
     bool isModified() const;
 
-    EditableAsset *editable();
-    void setEditable(std::unique_ptr<EditableAsset> editable);
+    virtual EditableAsset *editable() = 0;
 
     Object *currentObject() const { return mCurrentObject; }
     void setCurrentObject(Object *object);
@@ -149,7 +146,6 @@ class Document : public QObject,
     void ignoreBrokenLinksChanged(bool ignoreBrokenLinks);
 
 protected:
-    virtual std::unique_ptr<EditableAsset> createEditable() = 0;
     virtual bool isModifiedImpl() const;
 
     void updateIsModified();
@@ -163,8 +159,6 @@ class Document : public QObject,
     Object *mCurrentObject = nullptr;   /**< Current properties object. */
     Document *mCurrentObjectDocument = nullptr;
 
-    std::unique_ptr<EditableAsset> mEditable;
-
 private:
     void currentObjectDocumentChanged(const ChangeEvent &change);
     void currentObjectDocumentDestroyed();
diff --git a/src/tiled/editableasset.cpp b/src/tiled/editableasset.cpp
index 757dec7d6a..b9323723a2 100644
--- a/src/tiled/editableasset.cpp
+++ b/src/tiled/editableasset.cpp
@@ -28,14 +28,16 @@
 
 namespace Tiled {
 
-EditableAsset::EditableAsset(Document *document, Object *object, QObject *parent)
+EditableAsset::EditableAsset(Object *object, QObject *parent)
     : EditableObject(this, object, parent)
-    , mDocument(document)
 {
-    if (document) {
-        connect(document, &Document::modifiedChanged,
-                this, &EditableAsset::modifiedChanged);
-    }
+}
+
+EditableAsset::~EditableAsset()
+{
+    // Prevent owned object from trying to delete us again
+    if (mDocument)
+        setObject(nullptr);
 }
 
 QString EditableAsset::fileName() const
@@ -126,6 +128,15 @@ void EditableAsset::redo()
         ScriptManager::instance().throwError(QCoreApplication::translate("Script Errors", "Undo system not available for this asset"));
 }
 
+void EditableAsset::setDocument(Document *document)
+{
+    Q_ASSERT(!mDocument && document);
+
+    mDocument = document->sharedFromThis();
+    connect(document, &Document::modifiedChanged,
+            this, &EditableAsset::modifiedChanged);
+}
+
 } // namespace Tiled
 
 #include "moc_editableasset.cpp"
diff --git a/src/tiled/editableasset.h b/src/tiled/editableasset.h
index a99c8727df..551b3ee6b8 100644
--- a/src/tiled/editableasset.h
+++ b/src/tiled/editableasset.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include "editableobject.h"
+#include "document.h"
 
 #include <QJSValue>
 #include <QSharedPointer>
@@ -57,7 +58,8 @@ class EditableAsset : public EditableObject
     Q_PROPERTY(AssetType::Value assetType READ assetType CONSTANT)
 
 public:
-    EditableAsset(Document *document, Object *object, QObject *parent = nullptr);
+    EditableAsset(Object *object, QObject *parent = nullptr);
+    ~EditableAsset() override;
 
     QString fileName() const;
     bool isReadOnly() const override = 0;
@@ -88,22 +90,17 @@ public slots:
     void modifiedChanged();
     void fileNameChanged(const QString &fileName, const QString &oldFileName);
 
-private:
-    friend class Document;
+protected:
     void setDocument(Document *document);
 
-    Document *mDocument;
+private:
+    DocumentPtr mDocument;
 };
 
 
 inline Document *EditableAsset::document() const
 {
-    return mDocument;
-}
-
-inline void EditableAsset::setDocument(Document *document)
-{
-    mDocument = document;
+    return mDocument.get();
 }
 
 } // namespace Tiled
diff --git a/src/tiled/editablemap.cpp b/src/tiled/editablemap.cpp
index c126681a2a..e4472d633f 100644
--- a/src/tiled/editablemap.cpp
+++ b/src/tiled/editablemap.cpp
@@ -49,25 +49,14 @@
 namespace Tiled {
 
 EditableMap::EditableMap(QObject *parent)
-    : EditableAsset(nullptr, new Map(), parent)
+    : EditableMap(std::make_unique<Map>(), parent)
 {
-    mDetachedMap.reset(map());
 }
 
 EditableMap::EditableMap(MapDocument *mapDocument, QObject *parent)
-    : EditableAsset(mapDocument, mapDocument->map(), parent)
-    , mSelectedArea(new EditableSelectedArea(mapDocument, this))
+    : EditableAsset(mapDocument->map(), parent)
 {
-    connect(mapDocument, &Document::fileNameChanged, this, &EditableAsset::fileNameChanged);
-    connect(mapDocument, &Document::changed, this, &EditableMap::documentChanged);
-    connect(mapDocument, &MapDocument::layerAdded, this, &EditableMap::attachLayer);
-    connect(mapDocument, &MapDocument::layerRemoved, this, &EditableMap::detachLayer);
-
-    connect(mapDocument, &MapDocument::currentLayerChanged, this, &EditableMap::currentLayerChanged);
-    connect(mapDocument, &MapDocument::selectedLayersChanged, this, &EditableMap::selectedLayersChanged);
-    connect(mapDocument, &MapDocument::selectedObjectsChanged, this, &EditableMap::selectedObjectsChanged);
-
-    connect(mapDocument, &MapDocument::regionEdited, this, &EditableMap::onRegionEdited);
+    setDocument(mapDocument);
 }
 
 /**
@@ -76,14 +65,13 @@ EditableMap::EditableMap(MapDocument *mapDocument, QObject *parent)
  * The map's lifetime must exceed that of the EditableMap instance.
  */
 EditableMap::EditableMap(const Map *map, QObject *parent)
-    : EditableAsset(nullptr, const_cast<Map*>(map), parent)
+    : EditableAsset(const_cast<Map*>(map), parent)
     , mReadOnly(true)
-    , mSelectedArea(nullptr)
 {
 }
 
 EditableMap::EditableMap(std::unique_ptr<Map> map, QObject *parent)
-    : EditableAsset(nullptr, map.get(), parent)
+    : EditableAsset(map.get(), parent)
     , mDetachedMap(std::move(map))
 {
 }
@@ -671,15 +659,26 @@ void EditableMap::setSelectedObjects(const QList<QObject *> &objects)
 QSharedPointer<Document> EditableMap::createDocument()
 {
     Q_ASSERT(mDetachedMap);
+    Q_ASSERT(!document());
 
     auto document = MapDocumentPtr::create(std::move(mDetachedMap));
-    document->setEditable(std::unique_ptr<EditableAsset>(this));
+    setDocument(document.data());
+
+    return document;
+}
 
-    mSelectedArea = new EditableSelectedArea(document.data(), this);
+EditableMap *EditableMap::get(MapDocument *mapDocument)
+{
+    if (!mapDocument)
+        return nullptr;
 
-    QQmlEngine::setObjectOwnership(this, QQmlEngine::CppOwnership);
+    auto editable = EditableMap::find(mapDocument->map());
+    if (editable)
+        return editable;
 
-    return document;
+    editable = new EditableMap(mapDocument);
+    // editable->moveOwnershipToCpp();
+    return editable;
 }
 
 void EditableMap::documentChanged(const ChangeEvent &change)
@@ -759,6 +758,24 @@ MapRenderer *EditableMap::renderer() const
     return mRenderer.get();
 }
 
+void EditableMap::setDocument(MapDocument *mapDocument)
+{
+    EditableAsset::setDocument(mapDocument);
+
+    mSelectedArea = new EditableSelectedArea(mapDocument, this);
+
+    connect(mapDocument, &Document::fileNameChanged, this, &EditableAsset::fileNameChanged);
+    connect(mapDocument, &Document::changed, this, &EditableMap::documentChanged);
+    connect(mapDocument, &MapDocument::layerAdded, this, &EditableMap::attachLayer);
+    connect(mapDocument, &MapDocument::layerRemoved, this, &EditableMap::detachLayer);
+
+    connect(mapDocument, &MapDocument::currentLayerChanged, this, &EditableMap::currentLayerChanged);
+    connect(mapDocument, &MapDocument::selectedLayersChanged, this, &EditableMap::selectedLayersChanged);
+    connect(mapDocument, &MapDocument::selectedObjectsChanged, this, &EditableMap::selectedObjectsChanged);
+
+    connect(mapDocument, &MapDocument::regionEdited, this, &EditableMap::onRegionEdited);
+}
+
 } // namespace Tiled
 
 #include "moc_editablemap.cpp"
diff --git a/src/tiled/editablemap.h b/src/tiled/editablemap.h
index e01e70890b..b96080887b 100644
--- a/src/tiled/editablemap.h
+++ b/src/tiled/editablemap.h
@@ -202,6 +202,9 @@ class EditableMap final : public EditableAsset
 
     QSharedPointer<Document> createDocument() override;
 
+    static EditableMap *find(Map *map);
+    static EditableMap *get(MapDocument *mapDocument);
+
 signals:
     void currentLayerChanged();
     void selectedLayersChanged();
@@ -221,6 +224,8 @@ class EditableMap final : public EditableAsset
 
     MapRenderer *renderer() const;
 
+    void setDocument(MapDocument *mapDocument);
+
     std::unique_ptr<Map> mDetachedMap;
     mutable std::unique_ptr<MapRenderer> mRenderer;
     bool mReadOnly = false;
@@ -380,6 +385,11 @@ inline MapDocument *EditableMap::mapDocument() const
     return static_cast<MapDocument*>(document());
 }
 
+inline EditableMap *EditableMap::find(Map *map)
+{
+    return static_cast<EditableMap*>(EditableObject::find(map));
+}
+
 } // namespace Tiled
 
 Q_DECLARE_METATYPE(Tiled::EditableMap*)
diff --git a/src/tiled/editableobject.h b/src/tiled/editableobject.h
index b8aedd215f..6a3986760e 100644
--- a/src/tiled/editableobject.h
+++ b/src/tiled/editableobject.h
@@ -154,7 +154,7 @@ inline void EditableObject::setAsset(EditableAsset *asset)
 
 inline EditableObject *EditableObject::find(Object *object)
 {
-    return object ? static_cast<EditableObject*>(object->mEditable.data())
+    return object ? static_cast<EditableObject*>(object->editable())
                   : nullptr;
 }
 
diff --git a/src/tiled/editableproject.cpp b/src/tiled/editableproject.cpp
index 77033d5d8a..1d8ef04527 100644
--- a/src/tiled/editableproject.cpp
+++ b/src/tiled/editableproject.cpp
@@ -26,8 +26,9 @@
 namespace Tiled {
 
 EditableProject::EditableProject(ProjectDocument *projectDocument, QObject *parent)
-    : EditableAsset(projectDocument, &projectDocument->project(), parent)
+    : EditableAsset(&projectDocument->project(), parent)
 {
+    setDocument(projectDocument);
 }
 
 QString EditableProject::extensionsPath() const
@@ -62,6 +63,18 @@ QSharedPointer<Document> EditableProject::createDocument()
     return nullptr;
 }
 
+EditableProject *EditableProject::get(ProjectDocument *projectDocument)
+{
+    if (!projectDocument)
+        return nullptr;
+
+    auto editable = find(&projectDocument->project());
+    if (editable)
+        return editable;
+
+    return new EditableProject(projectDocument);
+}
+
 } // namespace Tiled
 
 #include "moc_editableproject.cpp"
diff --git a/src/tiled/editableproject.h b/src/tiled/editableproject.h
index 6d309f4538..c52b0128ed 100644
--- a/src/tiled/editableproject.h
+++ b/src/tiled/editableproject.h
@@ -53,6 +53,9 @@ class EditableProject final : public EditableAsset
     Project *project() const;
 
     QSharedPointer<Document> createDocument() override;
+
+    static EditableProject *find(Project *project);
+    static EditableProject *get(ProjectDocument *projectDocument);
 };
 
 inline Project *EditableProject::project() const
@@ -60,6 +63,11 @@ inline Project *EditableProject::project() const
     return static_cast<Project*>(object());
 }
 
+inline EditableProject *EditableProject::find(Project *project)
+{
+    return static_cast<EditableProject*>(EditableObject::find(project));
+}
+
 } // namespace Tiled
 
 Q_DECLARE_METATYPE(Tiled::EditableProject*)
diff --git a/src/tiled/editabletileset.cpp b/src/tiled/editabletileset.cpp
index 7ea471b098..f8efe20176 100644
--- a/src/tiled/editabletileset.cpp
+++ b/src/tiled/editabletileset.cpp
@@ -35,14 +35,14 @@
 namespace Tiled {
 
 EditableTileset::EditableTileset(const QString &name, QObject *parent)
-    : EditableAsset(nullptr, nullptr, parent)
+    : EditableAsset(nullptr, parent)
     , mTileset(Tileset::create(name, 0, 0))
 {
     setObject(mTileset.data());
 }
 
 EditableTileset::EditableTileset(const Tileset *tileset, QObject *parent)
-    : EditableAsset(nullptr, const_cast<Tileset*>(tileset), parent)
+    : EditableAsset(const_cast<Tileset*>(tileset), parent)
     , mReadOnly(true)
     , mTileset(const_cast<Tileset*>(tileset)->sharedFromThis())    // keep alive
 {
@@ -50,14 +50,9 @@ EditableTileset::EditableTileset(const Tileset *tileset, QObject *parent)
 
 EditableTileset::EditableTileset(TilesetDocument *tilesetDocument,
                                  QObject *parent)
-    : EditableAsset(tilesetDocument, tilesetDocument->tileset().data(), parent)
+    : EditableAsset(tilesetDocument->tileset().data(), parent)
 {
-    connect(tilesetDocument, &Document::fileNameChanged, this, &EditableAsset::fileNameChanged);
-    connect(tilesetDocument, &TilesetDocument::tilesAdded, this, &EditableTileset::attachTiles);
-    connect(tilesetDocument, &TilesetDocument::tilesRemoved, this, &EditableTileset::detachTiles);
-    connect(tilesetDocument, &TilesetDocument::tileObjectGroupChanged, this, &EditableTileset::tileObjectGroupChanged);
-    connect(tilesetDocument->wangSetModel(), &TilesetWangSetModel::wangSetAdded, this, &EditableTileset::wangSetAdded);
-    connect(tilesetDocument->wangSetModel(), &TilesetWangSetModel::wangSetRemoved, this, &EditableTileset::wangSetRemoved);
+    setDocument(tilesetDocument);
 }
 
 EditableTileset::~EditableTileset()
@@ -225,13 +220,13 @@ EditableTileset *EditableTileset::get(Tileset *tileset)
     if (!tileset)
         return nullptr;
 
-    if (auto document = TilesetDocument::findDocumentForTileset(tileset->sharedFromThis()))
-        return document->editable();
-
     auto editable = EditableTileset::find(tileset);
     if (editable)
         return editable;
 
+    if (auto document = TilesetDocument::findDocumentForTileset(tileset->sharedFromThis()))
+        return new EditableTileset(document);
+
     editable = new EditableTileset(tileset);
     editable->moveOwnershipToCpp();
     return editable;
@@ -432,6 +427,18 @@ void EditableTileset::wangSetRemoved(WangSet *wangSet)
     detachWangSets({ wangSet });
 }
 
+void EditableTileset::setDocument(TilesetDocument *tilesetDocument)
+{
+    EditableAsset::setDocument(tilesetDocument);
+
+    connect(tilesetDocument, &Document::fileNameChanged, this, &EditableAsset::fileNameChanged);
+    connect(tilesetDocument, &TilesetDocument::tilesAdded, this, &EditableTileset::attachTiles);
+    connect(tilesetDocument, &TilesetDocument::tilesRemoved, this, &EditableTileset::detachTiles);
+    connect(tilesetDocument, &TilesetDocument::tileObjectGroupChanged, this, &EditableTileset::tileObjectGroupChanged);
+    connect(tilesetDocument->wangSetModel(), &TilesetWangSetModel::wangSetAdded, this, &EditableTileset::wangSetAdded);
+    connect(tilesetDocument->wangSetModel(), &TilesetWangSetModel::wangSetRemoved, this, &EditableTileset::wangSetRemoved);
+}
+
 } // namespace Tiled
 
 #include "moc_editabletileset.cpp"
diff --git a/src/tiled/editabletileset.h b/src/tiled/editabletileset.h
index ce9e01579c..59295499aa 100644
--- a/src/tiled/editabletileset.h
+++ b/src/tiled/editabletileset.h
@@ -182,6 +182,9 @@ public slots:
     void wangSetAdded(Tileset *tileset, int index);
     void wangSetRemoved(WangSet *wangSet);
 
+    friend class TilesetDocument;
+    void setDocument(TilesetDocument *tilesetDocument);
+
     bool mReadOnly = false;
     SharedTileset mTileset;
 };
diff --git a/src/tiled/editableworld.cpp b/src/tiled/editableworld.cpp
index 92426c563a..32e9df05d8 100644
--- a/src/tiled/editableworld.cpp
+++ b/src/tiled/editableworld.cpp
@@ -31,8 +31,9 @@
 namespace Tiled {
 
 EditableWorld::EditableWorld(WorldDocument *worldDocument, QObject *parent)
-    : EditableAsset(worldDocument, nullptr, parent)
+    : EditableAsset(nullptr, parent)
 {
+    setDocument(worldDocument);
     setObject(WorldManager::instance().worlds().value(worldDocument->fileName()));
 }
 
@@ -154,6 +155,18 @@ QSharedPointer<Document> EditableWorld::createDocument()
     return nullptr;
 }
 
+EditableWorld *EditableWorld::get(WorldDocument *worldDocument)
+{
+    if (!worldDocument)
+        return nullptr;
+
+    auto editable = find(worldDocument->world());
+    if (editable)
+        return editable;
+
+    return new EditableWorld(worldDocument);
+}
+
 } // namespace Tiled
 
 #include "moc_editableworld.cpp"
diff --git a/src/tiled/editableworld.h b/src/tiled/editableworld.h
index e7f9a6d681..952b78507b 100644
--- a/src/tiled/editableworld.h
+++ b/src/tiled/editableworld.h
@@ -59,6 +59,9 @@ class EditableWorld final : public EditableAsset
     Q_INVOKABLE void removeMap(EditableMap *map);
 
     QSharedPointer<Document> createDocument() override;
+
+    static EditableWorld *find(World *world);
+    static EditableWorld *get(WorldDocument *worldDocument);
 };
 
 inline World *EditableWorld::world() const
@@ -66,6 +69,11 @@ inline World *EditableWorld::world() const
     return static_cast<World*>(object());
 }
 
+inline EditableWorld *EditableWorld::find(World *world)
+{
+    return static_cast<EditableWorld*>(EditableObject::find(world));
+}
+
 } // namespace Tiled
 
 Q_DECLARE_METATYPE(Tiled::EditableWorld*)
diff --git a/src/tiled/mapdocument.cpp b/src/tiled/mapdocument.cpp
index d8bb893f7a..a1c448807e 100644
--- a/src/tiled/mapdocument.cpp
+++ b/src/tiled/mapdocument.cpp
@@ -114,11 +114,6 @@ MapDocument::~MapDocument()
 {
     // Clear any previously found issues in this document
     IssuesModel::instance().removeIssuesWithContext(this);
-
-    // Needs to be deleted before the Map instance is deleted, because it may
-    // cause script values to detach from the map, in which case they'll need
-    // to be able to copy the data.
-    mEditable.reset();
 }
 
 bool MapDocument::save(const QString &fileName, QString *error)
@@ -235,9 +230,9 @@ QString MapDocument::displayName() const
     return displayName;
 }
 
-std::unique_ptr<EditableAsset> MapDocument::createEditable()
+EditableAsset *MapDocument::editable()
 {
-    return std::make_unique<EditableMap>(this, this);
+    return EditableMap::get(this);
 }
 
 /**
diff --git a/src/tiled/mapdocument.h b/src/tiled/mapdocument.h
index 2589e298f4..6663686f43 100644
--- a/src/tiled/mapdocument.h
+++ b/src/tiled/mapdocument.h
@@ -92,6 +92,8 @@ class TILED_EDITOR_EXPORT MapDocument : public Document
 
     bool save(const QString &fileName, QString *error = nullptr) override;
 
+    EditableAsset *editable() override;
+
     /**
      * Loads a map and returns a MapDocument instance on success. Returns null
      * on error and sets the \a error message.
@@ -373,7 +375,6 @@ public slots:
     void deselectObjects(const QList<MapObject*> &objects);
 
 protected:
-    std::unique_ptr<EditableAsset> createEditable() override;
 
 private:
     void onChanged(const ChangeEvent &change);
diff --git a/src/tiled/projectdocument.cpp b/src/tiled/projectdocument.cpp
index 26849d85f4..7fbdeba208 100644
--- a/src/tiled/projectdocument.cpp
+++ b/src/tiled/projectdocument.cpp
@@ -72,9 +72,9 @@ void ProjectDocument::setLastExportFileName(const QString &/* fileName */)
     // do nothing
 }
 
-std::unique_ptr<EditableAsset> ProjectDocument::createEditable()
+EditableAsset *ProjectDocument::editable()
 {
-    return std::make_unique<EditableProject>(this, this);
+    return EditableProject::get(this);
 }
 
 } // namespace Tiled
diff --git a/src/tiled/projectdocument.h b/src/tiled/projectdocument.h
index 310bd83c22..476e3478d5 100644
--- a/src/tiled/projectdocument.h
+++ b/src/tiled/projectdocument.h
@@ -40,7 +40,7 @@ class ProjectDocument : public Document
     FileFormat *exportFormat() const override;
     QString lastExportFileName() const override;
     void setLastExportFileName(const QString &fileName) override;
-    std::unique_ptr<EditableAsset> createEditable() override;
+    EditableAsset *editable() override;
 
     Project &project() { return *mProject; }
 
diff --git a/src/tiled/scriptmodule.cpp b/src/tiled/scriptmodule.cpp
index 148bcf1f8a..24834081ea 100644
--- a/src/tiled/scriptmodule.cpp
+++ b/src/tiled/scriptmodule.cpp
@@ -198,8 +198,11 @@ bool ScriptModule::setActiveAsset(EditableAsset *asset) const
     if (asset->checkReadOnly())
         return false;
 
-    if (auto document = asset->document())
-        return documentManager->switchToDocument(document);
+    if (auto document = asset->document()) {
+        if (!documentManager->switchToDocument(document))
+            documentManager->addDocument(document->sharedFromThis());
+        return true;
+    }
 
     if (auto document = asset->createDocument()) {
         documentManager->addDocument(document);
@@ -274,6 +277,24 @@ bool ScriptModule::versionLessThan(const QString &a, const QString &b)
     return QVersionNumber::fromString(a) < QVersionNumber::fromString(b);
 }
 
+EditableAsset *ScriptModule::load(const QString &fileName) const
+{
+    auto documentManager = DocumentManager::maybeInstance();
+    if (!documentManager) {
+        ScriptManager::instance().throwError(QCoreApplication::translate("Script Errors", "Editor not available"));
+        return nullptr;
+    }
+
+    QString error;
+    if (auto document = documentManager->loadDocument(fileName, nullptr, &error)) {
+        return document->editable();
+    } else {
+        ScriptManager::instance().throwError(error);
+    }
+
+    return nullptr;
+}
+
 EditableAsset *ScriptModule::open(const QString &fileName) const
 {
     auto documentManager = DocumentManager::maybeInstance();
diff --git a/src/tiled/scriptmodule.h b/src/tiled/scriptmodule.h
index 5b56296165..759ef66abf 100644
--- a/src/tiled/scriptmodule.h
+++ b/src/tiled/scriptmodule.h
@@ -111,6 +111,7 @@ class ScriptModule : public QObject
     Q_INVOKABLE bool versionLessThan(const QString &a);
     Q_INVOKABLE bool versionLessThan(const QString &a, const QString &b);
 
+    Q_INVOKABLE Tiled::EditableAsset *load(const QString &fileName) const;
     Q_INVOKABLE Tiled::EditableAsset *open(const QString &fileName) const;
     Q_INVOKABLE bool close(Tiled::EditableAsset *asset) const;
     Q_INVOKABLE Tiled::EditableAsset *reload(Tiled::EditableAsset *asset) const;
diff --git a/src/tiled/tilesetdocument.cpp b/src/tiled/tilesetdocument.cpp
index 3f5123576b..e097fce915 100644
--- a/src/tiled/tilesetdocument.cpp
+++ b/src/tiled/tilesetdocument.cpp
@@ -67,12 +67,10 @@ TilesetDocument::TilesetDocument(const SharedTileset &tileset)
     Q_ASSERT(!sTilesetToDocument.contains(tileset));
     sTilesetToDocument.insert(tileset, this);
 
-    // If there already happens to be an editable for this tileset, take
-    // ownership of it.
-    if (auto editable = EditableTileset::find(tileset.data())) {
-        setEditable(std::unique_ptr<EditableAsset>(editable));
-        QQmlEngine::setObjectOwnership(editable, QQmlEngine::CppOwnership);
-    }
+    // If there already happens to be an editable for this tileset, make sure
+    // it knows about us.
+    if (auto editable = EditableTileset::find(tileset.data()))
+        editable->setDocument(this);
 
     mCurrentObject = tileset.data();
 
@@ -95,11 +93,6 @@ TilesetDocument::~TilesetDocument()
     IssuesModel::instance().removeIssuesWithContext(this);
 
     sTilesetToDocument.remove(mTileset);
-
-    // Needs to be deleted before the Tileset instance is deleted, because it
-    // may cause script values to detach from the map, in which case they'll
-    // need to be able to copy the data.
-    mEditable.reset();
 }
 
 bool TilesetDocument::save(const QString &fileName, QString *error)
@@ -258,18 +251,20 @@ void TilesetDocument::swapTileset(SharedTileset &tileset)
     // Bring pointers to safety
     setSelectedTiles(QList<Tile*>());
     setCurrentObject(mTileset.data());
-    mEditable.reset();
 
-    sTilesetToDocument.remove(mTileset);
+    // Delete the editable and have it deal with any child editables that were
+    // created, because their document and object references would no longer be
+    // valid after the swap.
+    delete mTileset->editable();
+
     mTileset->swap(*tileset);
-    sTilesetToDocument.insert(mTileset, this);
 
     emit tilesetChanged(mTileset.data());
 }
 
-std::unique_ptr<EditableAsset> TilesetDocument::createEditable()
+EditableTileset *TilesetDocument::editable()
 {
-    return std::make_unique<EditableTileset>(this, this);
+    return EditableTileset::get(mTileset.data());
 }
 
 /**
diff --git a/src/tiled/tilesetdocument.h b/src/tiled/tilesetdocument.h
index 05f54db726..b9740f8567 100644
--- a/src/tiled/tilesetdocument.h
+++ b/src/tiled/tilesetdocument.h
@@ -84,7 +84,7 @@ class TilesetDocument : public Document
     void swapTileset(SharedTileset &tileset);
     const SharedTileset &tileset() const;
 
-    EditableTileset *editable();
+    EditableTileset *editable() override;
 
     bool isEmbedded() const;
     void setClean();
@@ -164,9 +164,6 @@ class TilesetDocument : public Document
      */
     void selectedTilesChanged();
 
-protected:
-    std::unique_ptr<EditableAsset> createEditable() override;
-
 private:
     void onPropertyAdded(Object *object, const QString &name);
     void onPropertyRemoved(Object *object, const QString &name);
@@ -192,11 +189,6 @@ inline const SharedTileset &TilesetDocument::tileset() const
     return mTileset;
 }
 
-inline EditableTileset *TilesetDocument::editable()
-{
-    return static_cast<EditableTileset*>(Document::editable());
-}
-
 inline bool TilesetDocument::isEmbedded() const
 {
     return fileName().isEmpty() && mMapDocuments.count() == 1;
diff --git a/src/tiled/worlddocument.cpp b/src/tiled/worlddocument.cpp
index d61c232dd0..5222e2deb0 100644
--- a/src/tiled/worlddocument.cpp
+++ b/src/tiled/worlddocument.cpp
@@ -80,14 +80,20 @@ void WorldDocument::onWorldSaved(const QString &fileName)
 
 bool WorldDocument::isModifiedImpl() const
 {
-    const World *world = WorldManager::instance().worlds().value(fileName());
+    const World *world = this->world();
     return Document::isModifiedImpl() || (world && world->hasUnsavedChanges);
 }
 
-std::unique_ptr<EditableAsset> WorldDocument::createEditable()
+EditableAsset *WorldDocument::editable()
 {
-    return std::make_unique<EditableWorld>(this, this);
+    return EditableWorld::get(this);
 }
+
+World *WorldDocument::world() const
+{
+    return WorldManager::instance().worlds().value(fileName());
+}
+
 } // namespace Tiled
 
 #include "moc_worlddocument.cpp"
diff --git a/src/tiled/worlddocument.h b/src/tiled/worlddocument.h
index 01fd491816..72a2ac4eb0 100644
--- a/src/tiled/worlddocument.h
+++ b/src/tiled/worlddocument.h
@@ -24,10 +24,10 @@
 #include "document.h"
 #include "editableasset.h"
 
-class WorldManager;
-
 namespace Tiled {
 
+class World;
+
 /**
  * Represents an editable world document.
  */
@@ -44,7 +44,7 @@ class WorldDocument : public Document
 
     FileFormat *writerFormat() const override { return nullptr; }
 
-    std::unique_ptr<EditableAsset> createEditable() override;
+    EditableAsset *editable() override;
 
     // Exporting not supported for worlds
     QString lastExportFileName() const override { return QString(); }
@@ -52,6 +52,8 @@ class WorldDocument : public Document
     FileFormat *exportFormat() const override { return nullptr; }
     void setExportFormat(FileFormat *) override {}
 
+    World *world() const;
+
 private:
     void onWorldsChanged();
     void onWorldReloaded(const QString &filename);