feat: add shiftClick and hotbarSwap to SlotAction

core/src/SlotAction.cpp

@@ -151,3 +151,155 @@ SlotActionResult rightClick(ContainerMenu& menu, CursorStack& cursor, const Slot
     int index = action.slotIndex;
     if (!menu.validIndex(index)) return out;
 
+    if (cursor.empty()) {
+        if (menu.stackAt(index).empty()) return out;
+        int half = (menu.stackAt(index).count + 1) / 2;
+        MetaStack taken = takeFromSlot(menu, index, half, out);
+        if (taken.empty()) return out;
+        out.moved = taken.count;
+        cursor.held = taken;
+        out.cursorChanged = true;
+        out.applied = true;
+        return out;
+    }
+
+    if (isResultSlot(menu, index)) return out;
+
+    MetaStack single = splitOff(cursor.held, 1);
+    int moved = putIntoSlot(menu, index, single);
+    if (moved == 0) {
+        transferAll(single, cursor.held);
+        return out;
+    }
+    out.moved = moved;
+    out.cursorChanged = true;
+    out.applied = true;
+    return out;
+}
+
+SlotActionResult shiftClick(ContainerMenu& menu, const SlotAction& action) {
+    SlotActionResult out;
+    int index = action.slotIndex;
+    if (!menu.validIndex(index) || menu.stackAt(index).empty()) return out;
+
+    if (isResultSlot(menu, index)) {
+        CraftingView view = menu.crafting();
+        int rounds = view.craftAll(view.maxCrafts());
+        if (rounds <= 0) return out;
+        out.craftedResult = true;
+        out.craftedCount = rounds;
+        out.applied = true;
+        return out;
+    }
+
+    std::vector<int> targets = transferTargetsFor(menu, index);
+    MetaStack moving = menu.slot(index).cell.takeAll();
+    int moved = menu.distributeInto(targets, moving);
+    if (!moving.empty()) {
+        // Whatever did not fit goes straight back where it came from.
+        menu.slot(index).cell.insert(moving);
+    }
+    touchCraftInput(menu, index);
+    if (moved == 0) return out;
+    out.moved = moved;
+    out.applied = true;
+    return out;
+}
+
+SlotActionResult hotbarSwap(ContainerMenu& menu, const SlotAction& action) {
+    SlotActionResult out;
+    int index = action.slotIndex;
+    const MenuLayout& layout = menu.layout();
+    if (!menu.validIndex(index) || layout.hotbarFirst < 0) return out;
+    if (action.hotbarButton < 0 || action.hotbarButton >= layout.hotbarCount) return out;
+
+    int hotbarIndex = layout.hotbarFirst + action.hotbarButton;
+    if (hotbarIndex == index) return out;
+
+    if (isResultSlot(menu, index)) {
+        if (!menu.stackAt(hotbarIndex).empty()) return out;
+        MetaStack crafted = takeFromSlot(menu, index, menu.stackAt(index).count, out);
+        if (crafted.empty()) return out;
+        out.moved = crafted.count;
+        menu.slot(hotbarIndex).cell.stack = crafted;
+        out.applied = true;
+        return out;
+    }
+
+    MenuSlot& source = menu.slot(index);
+    MenuSlot& hotbar = menu.slot(hotbarIndex);
+    if (source.takeOnly) return out;
+    if (source.cell.stack.empty() && hotbar.cell.stack.empty()) return out;
+    if (!hotbar.cell.stack.empty()) {
+        if (!menu.canPlace(index, hotbar.cell.stack)) return out;
+        if (source.cell.limitFor(hotbar.cell.stack) < hotbar.cell.stack.count) return out;
+    }
+
+    out.moved = source.cell.stack.count + hotbar.cell.stack.count;
+    MetaStack carried = source.cell.stack;
+    source.cell.stack = hotbar.cell.stack;
+    hotbar.cell.stack = carried;
+    touchCraftInput(menu, index);
+    out.applied = true;
+    return out;
+}
+
+SlotActionResult middleClick(ContainerMenu& menu, CursorStack& cursor, const SlotAction& action) {
+    SlotActionResult out;
+    int index = action.slotIndex;
+    if (!menu.validIndex(index) || !menu.creativeMode()) return out;
+    if (!cursor.empty() || menu.stackAt(index).empty()) return out;
+
+    MetaStack clone = menu.stackAt(index);
+    clone.count = clone.maxCount();
+    out.created = clone.count;
+    cursor.held = clone;
+    out.cursorChanged = true;
+    out.applied = true;
+    return out;
+}
+
+SlotActionResult doubleClick(ContainerMenu& menu, CursorStack& cursor) {
+    SlotActionResult out;
+    if (cursor.empty() || cursor.held.room() == 0) return out;
+
+    // Partial stacks first: a double click is meant to tidy up leftovers before
+    // it starts breaking apart full stacks.
+    for (int pass = 0; pass < 2; ++pass) {
+        for (int i = 0; i < menu.slotCount(); ++i) {
+            if (cursor.held.room() == 0) break;
+            MenuSlot& source = menu.slot(i);
+            if (source.takeOnly || source.cell.stack.empty()) continue;
+            if (!stacksMergeable(source.cell.stack, cursor.held)) continue;
+            bool partial = source.cell.stack.count < source.cell.stack.maxCount();
+            if ((pass == 0) != partial) continue;
+            int before = cursor.held.count;
+            transferAll(source.cell.stack, cursor.held);
+            int gained = cursor.held.count - before;
+            if (gained > 0) {
+                out.moved += gained;
+                touchCraftInput(menu, i);
+            }
+        }
+    }
+    if (out.moved == 0) return out;
+    out.cursorChanged = true;
+    out.applied = true;
+    return out;
+}
+
+SlotActionResult dragStart(ContainerMenu& menu, CursorStack& cursor, DragState& drag,
+                           const SlotAction& action, bool rightButton) {
+    SlotActionResult out;
+    if (cursor.empty()) return out;
+    drag.reset();
+    drag.active = true;
+    drag.rightButton = rightButton;
+    drag.payload = cursor.held;
+    if (menu.validIndex(action.slotIndex) && menu.canPlace(action.slotIndex, cursor.held)) {
+        drag.paintedSlots.push_back(action.slotIndex);
+    }
+    out.applied = true;
+    return out;
+}
+