Added Swap Tiles action

This swaps the usage of the two selected tiles on the current tile
layer. It is only enabled when exactly two tiles are selected.

Change rebased and amended by @bjorn.

src/tiled/swaptiles.cpp

@@ -0,0 +1,95 @@
+/*
+ * swaptiles.cpp
+ * Copyright 2015, Alexander "theHacker" Münch <git@thehacker.biz>
+ *
+ * This file is part of Tiled.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "swaptiles.h"
+
+#include "mapdocument.h"
+#include "tilelayer.h"
+#include "tileset.h"
+
+#include <QCoreApplication>
+
+#include <limits.h>
+
+namespace Tiled {
+namespace Internal {
+
+SwapTiles::SwapTiles(MapDocument *mapDocument,
+                     TileLayer *tileLayer,
+                     Tile *tile1,
+                     Tile *tile2)
+    : QUndoCommand(QCoreApplication::translate("Undo Commands",
+                                               "Swap Tiles"))
+    , mMapDocument(mapDocument)
+    , mTileLayer(tileLayer)
+    , mTile1(tile1)
+    , mTile2(tile2)
+{}
+
+void SwapTiles::swap()
+{
+    // Remember smallest and largest x/y to give emitRegionChanged() the smallest possible rectangle
+    int minXChanged = INT_MAX;
+    int minYChanged = INT_MAX;
+    int maxXChanged = INT_MIN;
+    int maxYChanged = INT_MIN;
+
+    for (int y = 0; y < mTileLayer->height(); y++) {
+        for (int x = 0; x < mTileLayer->width(); x++) {
+            bool tileSwapped = false;
+
+            const Cell &cell = mTileLayer->cellAt(x, y);
+            if (cell.tile() == mTile1) {
+                Cell swapCell = cell;
+                swapCell.setTile(mTile2);
+                mTileLayer->setCell(x, y, swapCell);
+
+                tileSwapped = true;
+            } else if (cell.tile() == mTile2) {
+                Cell swapCell = cell;
+                swapCell.setTile(mTile1);
+                mTileLayer->setCell(x, y, swapCell);
+
+                tileSwapped = true;
+            }
+
+            if (tileSwapped) {
+                if (x < minXChanged) minXChanged = x;
+                if (y < minYChanged) minYChanged = y;
+                if (x > maxXChanged) maxXChanged = x;
+                if (y > maxYChanged) maxYChanged = y;
+            }
+        }
+    }
+
+    // We changed at least one tile? Call emitRegionChanged() to redraw
+    if (minXChanged != INT_MAX) {
+        QRegion regionChanged(
+            minXChanged,
+            minYChanged,
+            maxXChanged - minXChanged + 1,
+            maxYChanged - minYChanged + 1
+        );
+        emit mMapDocument->regionChanged(regionChanged, mTileLayer);
+    }
+}
+
+} // namespace Internal
+} // namespace Tiled

src/tiled/swaptiles.h

@@ -0,0 +1,73 @@
+/*
+ * swaptiles.h
+ * Copyright 2015, Alexander "theHacker" Münch <git@thehacker.biz>
+ *
+ * This file is part of Tiled.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef SWAPTILES_H
+#define SWAPTILES_H
+
+#include "undocommands.h"
+
+#include <QUndoCommand>
+
+namespace Tiled {
+
+class Tile;
+class TileLayer;
+
+namespace Internal {
+
+class MapDocument;
+
+/**
+ * A command that swaps two tiles on a TileLayer
+ */
+class SwapTiles : public QUndoCommand
+{
+public:
+    /**
+     * Constructor.
+     *
+     * @param mapDocument the map document that's being edited
+     * @param tileLayer   the TileLayer to swap the tiles
+     * @param tile1       the first tile
+     * @param tile2       the second tile
+     */
+    SwapTiles(MapDocument *mapDocument,
+              TileLayer *tileLayer,
+              Tile *tile1,
+              Tile *tile2);
+
+    ~SwapTiles() {}
+
+    void undo() { swap(); }
+    void redo() { swap(); }
+
+private:
+    void swap();
+
+    MapDocument *mMapDocument;
+    TileLayer *mTileLayer;
+    Tile *mTile1;
+    Tile *mTile2;
+};
+
+} // namespace Internal
+} // namespace Tiled
+
+#endif // SWAPTILES_H

src/tiled/tiled.pro

@@ -202,6 +202,7 @@ SOURCES += aboutdialog.cpp \
     stampbrush.cpp \
     standardautoupdater.cpp \
     stylehelper.cpp \
+    swaptiles.cpp \
     terrainbrush.cpp \
     terraindock.cpp \
     terrainmodel.cpp \
@@ -371,6 +372,7 @@ HEADERS += aboutdialog.h \
     stampbrush.h \
     standardautoupdater.h \
     stylehelper.h \
+    swaptiles.h \
     terrainbrush.h \
     terraindock.h \
     terrainmodel.h \

src/tiled/tiled.qbs

@@ -330,6 +330,8 @@ QtGuiApplication {
         "standardautoupdater.h",
         "stylehelper.cpp",
         "stylehelper.h",
+        "swaptiles.cpp",
+        "swaptiles.h",
         "terrainbrush.cpp",
         "terrainbrush.h",
         "terraindock.cpp",

src/tiled/tilesetdock.cpp

@@ -34,6 +34,7 @@
 #include "objectgroup.h"
 #include "preferences.h"
 #include "replacetileset.h"
+#include "swaptiles.h"
 #include "terrain.h"
 #include "tile.h"
 #include "tilelayer.h"
@@ -508,6 +509,9 @@ void TilesetDock::createTilesetView(int index, TilesetDocument *tilesetDocument)
             this, &TilesetDock::tileImageSourceChanged);
     connect(tilesetDocument, &TilesetDocument::tileAnimationChanged,
             this, &TilesetDock::tileAnimationChanged);
+
+    connect(view, &TilesetView::swapTilesRequested,
+            this, &TilesetDock::swapTiles);
 }
 
 void TilesetDock::deleteTilesetView(int index)
@@ -923,3 +927,16 @@ void TilesetDock::refreshTilesetMenu()
         mTilesetMenuMapper->setMapping(action, i);
     }
 }
+
+void TilesetDock::swapTiles(Tile *tileA, Tile *tileB)
+{
+    if (!mMapDocument)
+        return;
+
+    TileLayer *tileLayer = dynamic_cast<TileLayer*>(mMapDocument->currentLayer());
+    if (!tileLayer)
+        return;
+
+    QUndoStack *undoStack = mMapDocument->undoStack();
+    undoStack->push(new SwapTiles(mMapDocument, tileLayer, tileA, tileB));
+}

src/tiled/tilesetdock.h

@@ -129,6 +129,8 @@ private slots:
 
     void refreshTilesetMenu();
 
+    void swapTiles(Tile *tileA, Tile *tileB);
+
 private:
     void setCurrentTile(Tile *tile);
     void setCurrentTiles(TileLayer *tiles);

src/tiled/tilesetview.cpp

@@ -698,6 +698,17 @@ void TilesetView::contextMenuEvent(QContextMenuEvent *event)
             Utils::setThemeIcon(tileProperties, "document-properties");
             connect(tileProperties, SIGNAL(triggered()),
                     SLOT(editTileProperties()));
+        } else {
+            // Assuming we're used in the MapEditor
+
+            // Enable "swap" if there are exactly 2 tiles selected
+            bool exactlyTwoTilesSelected =
+                    (selectionModel()->selectedIndexes().size() == 2);
+
+            QAction *swapTilesAction = menu.addAction(tr("&Swap Tiles"));
+            swapTilesAction->setEnabled(exactlyTwoTilesSelected);
+            connect(swapTilesAction, SIGNAL(triggered()),
+                    SLOT(swapTiles()));
         }
 
         menu.addSeparator();
@@ -738,6 +749,22 @@ void TilesetView::editTileProperties()
     emit mTilesetDocument->editCurrentObject();
 }
 
+void TilesetView::swapTiles()
+{
+    const QModelIndexList selectedIndexes = selectionModel()->selectedIndexes();
+    if (selectedIndexes.size() != 2)
+        return;
+
+    const TilesetModel *model = tilesetModel();
+    Tile *tile1 = model->tileAt(selectedIndexes[0]);
+    Tile *tile2 = model->tileAt(selectedIndexes[1]);
+
+    if (!tile1 || !tile2)
+        return;
+
+    emit swapTilesRequested(tile1, tile2);
+}
+
 void TilesetView::setDrawGrid(bool drawGrid)
 {
     mDrawGrid = drawGrid;

src/tiled/tilesetview.h

@@ -116,6 +116,7 @@ class TilesetView : public QTableView
 signals:
     void createNewTerrain(Tile *tile);
     void terrainImageSelected(Tile *tile);
+    void swapTilesRequested(Tile *tileA, Tile *tileB);
 
 protected:
     bool event(QEvent *event) override;
@@ -130,6 +131,7 @@ private slots:
     void addTerrainType();
     void selectTerrainImage();
     void editTileProperties();
+    void swapTiles();
     void setDrawGrid(bool drawGrid);
 
     void adjustScale();

translations/tiled_de.ts

@@ -4391,6 +4391,11 @@ Bitte Format angeben.</translation>
     </message>
     <message>
         <location line="+16"/>
+        <source>&amp;Swap Tiles</source>
+        <translation>Kacheln ver&amp;tauschen</translation>
+    </message>
+    <message>
+        <location line="+9"/>
         <source>Show &amp;Grid</source>
         <translation>&amp;Raster anzeigen</translation>
     </message>
@@ -4789,6 +4794,11 @@ Bitte Format angeben.</translation>
         <source>Change Layer Data Format</source>
         <translation>Ebenen-Datenformat ändern</translation>
     </message>
+    <message>
+        <location filename="../src/tiled/swaptiles.cpp" line="+35"/>
+        <source>Swap Tiles</source>
+        <translation>Kacheln vertauschen</translation>
+    </message>
     <message>
         <location filename="../src/tiled/changetileprobability.cpp" line="+41"/>
         <location line="+14"/>