Track metatile in MetatileLayersItem using ID instead of pointer

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project somewhat adheres to [Semantic Versioning](https://semver.org/sp
 ### Fixed
 - Fix crash on older versions of Qt when reopening a project with certain windows open.
 - Fix potential crash when painting and the cursor leaves the map area.
+- Fix potential crash when changing maps with the Tileset Editor open.
 - Fix rare crash while quitting Porymap.
 - Fix `Edit > Clear Map Entries` in the Region Map Editor not saving the applied changes.
 - Fix `Edit > Undo/Redo` appearing enabled even when they don't do anything.

include/ui/metatilelayersitem.h

@@ -9,14 +9,14 @@
 class MetatileLayersItem: public SelectablePixmapItem {
     Q_OBJECT
 public:
-    MetatileLayersItem(Metatile *metatile,
+    MetatileLayersItem(uint16_t metatileId,
                        Tileset *primaryTileset,
                        Tileset *secondaryTileset,
                        Qt::Orientation orientation = Qt::Vertical);
 
     void draw() override;
     void setTilesets(Tileset*, Tileset*);
-    void setMetatile(Metatile*);
+    void setMetatileId(uint16_t);
 
     bool hasCursor() const { return this->cursorCellPos != QPoint(-1,-1); }
     Tile tileUnderCursor() const;
@@ -29,7 +29,7 @@ public:
 
     bool showGrid;
 private:
-    Metatile* metatile;
+    uint16_t metatileId = 0;
     Tileset *primaryTileset;
     Tileset *secondaryTileset;
     Qt::Orientation orientation;
@@ -41,6 +41,7 @@ private:
     QPoint getBoundedPos(const QPointF &);
     void updateSelection();
     bool setCursorCellPos(const QPoint &pos);
+    Metatile* getMetatile() const { return Tileset::getMetatile(this->metatileId, this->primaryTileset, this->secondaryTileset); }
 signals:
     void tileChanged(const QPoint &pos);
     void paletteChanged(const QPoint &pos);

src/ui/metatilelayersitem.cpp

@@ -3,9 +3,9 @@
 #include "imageproviders.h"
 #include <QPainter>
 
-MetatileLayersItem::MetatileLayersItem(Metatile *metatile, Tileset *primaryTileset, Tileset *secondaryTileset, Qt::Orientation orientation)
+MetatileLayersItem::MetatileLayersItem(uint16_t metatileId, Tileset *primaryTileset, Tileset *secondaryTileset, Qt::Orientation orientation)
     : SelectablePixmapItem(16, 16, Metatile::tileWidth(),  Metatile::tileHeight()),
-     metatile(metatile),
+     metatileId(metatileId),
      primaryTileset(primaryTileset),
      secondaryTileset(secondaryTileset)
 {
@@ -60,9 +60,10 @@ void MetatileLayersItem::draw() {
     QPainter painter(&pixmap);
 
     // Draw tile images
-    int numTiles = qMin(projectConfig.getNumTilesInMetatile(), this->metatile ? this->metatile->tiles.length() : 0);
+    const Metatile* metatile = getMetatile();
+    int numTiles = qMin(projectConfig.getNumTilesInMetatile(), metatile ? metatile->tiles.length() : 0);
     for (int i = 0; i < numTiles; i++) {
-        Tile tile = this->metatile->tiles.at(i);
+        Tile tile = metatile->tiles.at(i);
         QImage tileImage = getPalettedTileImage(tile.tileId,
                                                 this->primaryTileset,
                                                 this->secondaryTileset,
@@ -92,8 +93,8 @@ void MetatileLayersItem::draw() {
     this->setPixmap(pixmap);
 }
 
-void MetatileLayersItem::setMetatile(Metatile *metatile) {
-    this->metatile = metatile;
+void MetatileLayersItem::setMetatileId(uint16_t metatileId) {
+    this->metatileId = metatileId;
     draw();
 }
 
@@ -167,10 +168,8 @@ void MetatileLayersItem::hoverLeaveEvent(QGraphicsSceneHoverEvent *) {
 
 Tile MetatileLayersItem::tileUnderCursor() const {
     int tileIndex = posToTileIndex(this->cursorCellPos);
-    if (tileIndex < 0 || !this->metatile || tileIndex >= this->metatile->tiles.length()) {
-        return Tile();
-    }
-    return this->metatile->tiles.at(tileIndex);
+    const Metatile* metatile = getMetatile();
+    return metatile ? metatile->tiles.value(tileIndex) : Tile();
 }
 
 QPoint MetatileLayersItem::getBoundedPos(const QPointF &pos) {

src/ui/tileseteditor.cpp

@@ -309,8 +309,7 @@ void TilesetEditor::addWidgetToMetatileProperties(QWidget *w, int *row, int rowS
 }
 
 void TilesetEditor::initMetatileLayersItem() {
-    Metatile *metatile = Tileset::getMetatile(this->getSelectedMetatileId(), this->primaryTileset, this->secondaryTileset);
-    this->metatileLayersItem = new MetatileLayersItem(metatile, this->primaryTileset, this->secondaryTileset);
+    this->metatileLayersItem = new MetatileLayersItem(getSelectedMetatileId(), this->primaryTileset, this->secondaryTileset);
     connect(this->metatileLayersItem, &MetatileLayersItem::tileChanged, [this](const QPoint &pos) { paintSelectedLayerTiles(pos); });
     connect(this->metatileLayersItem, &MetatileLayersItem::paletteChanged, [this](const QPoint &pos) { paintSelectedLayerTiles(pos, true); });
     connect(this->metatileLayersItem, &MetatileLayersItem::selectedTilesChanged, this, &TilesetEditor::onMetatileLayerSelectionChanged);
@@ -504,7 +503,7 @@ void TilesetEditor::onSelectedMetatileChanged(uint16_t metatileId) {
         if (updatedMetatile) *this->metatile = *updatedMetatile;
     }
 
-    this->metatileLayersItem->setMetatile(metatile);
+    this->metatileLayersItem->setMetatileId(metatileId);
 
     MetatileLabelPair labels = Tileset::getMetatileLabelPair(metatileId, this->primaryTileset, this->secondaryTileset);
     this->ui->lineEdit_MetatileLabel->setText(labels.owned);