Add backdrop change script map to Engine

Author: adazem009

include/scratchcpp/iengine.h

@@ -251,6 +251,9 @@ class LIBSCRATCHCPP_EXPORT IEngine
         /*! Registers the broadcast script. */
         virtual void addBroadcastScript(std::shared_ptr<Block> whenReceivedBlock, Broadcast *broadcast) = 0;
 
+        /*! Registers the backdrop change script. */
+        virtual void addBackdropChangeScript(std::shared_ptr<Block> hatBlock) = 0;
+
         /* Registers the given "when I start as clone" script. */
         virtual void addCloneInitScript(std::shared_ptr<Block> hatBlock) = 0;
 

src/blocks/eventblocks.cpp

@@ -82,7 +82,7 @@ void EventBlocks::compileWhenBroadcastReceived(Compiler *compiler)
 
 void EventBlocks::compileWhenBackdropSwitchesTo(Compiler *compiler)
 {
-    // TODO: Register this hat in engine
+    compiler->engine()->addBackdropChangeScript(compiler->block());
 }
 
 void EventBlocks::compileWhenKeyPressed(Compiler *compiler)

src/engine/internal/engine.cpp

@@ -588,8 +588,10 @@ bool Engine::broadcastByPtrRunning(Broadcast *broadcast, VirtualMachine *sourceS
                 assert(it != m_scripts.end());
                 auto topBlock = it->first;
 
-                // TODO: Add a map for "when backdrop switches to" hats
-                if ((topBlock->opcode() == "event_whenbackdropswitchesto") && (topBlock->findFieldById(EventBlocks::BACKDROP)->value().toString() == broadcast->name()))
+                const auto &scripts = m_backdropChangeHats[script->target()];
+                auto scriptIt = std::find(scripts.begin(), scripts.end(), script);
+
+                if ((scriptIt != scripts.end()) && (topBlock->findFieldById(EventBlocks::BACKDROP)->value().toString() == broadcast->name()))
                     return true;
             }
         }
@@ -760,6 +762,11 @@ void Engine::addBroadcastScript(std::shared_ptr<Block> whenReceivedBlock, Broadc
     addHatToMap(m_broadcastHats, script);
 }
 
+void Engine::addBackdropChangeScript(std::shared_ptr<Block> hatBlock)
+{
+    addHatToMap(m_backdropChangeHats, m_scripts[hatBlock].get());
+}
+
 void Engine::addCloneInitScript(std::shared_ptr<Block> hatBlock)
 {
     addHatToMap(m_cloneInitHats, m_scripts[hatBlock].get());
@@ -1078,7 +1085,7 @@ void Engine::addHatToMap(std::unordered_map<Target *, std::vector<Script *>> &ma
         map[target] = { script };
 }
 
-std::vector<Script *> Engine::getHats(Target *target, HatType type)
+const std::vector<Script *> &Engine::getHats(Target *target, HatType type)
 {
     assert(target);
 
@@ -1098,30 +1105,19 @@ std::vector<Script *> Engine::getHats(Target *target, HatType type)
         case HatType::BroadcastReceived:
             return m_broadcastHats[target];
 
-        case HatType::BackdropChanged: {
-            // TODO: Add a map for "when backdrop switches to" hats and return reference
-            std::vector<Script *> out;
-            const auto &blocks = target->blocks();
-
-            for (auto block : blocks) {
-                if (block->opcode() == "event_whenbackdropswitchesto") {
-                    assert(block->topLevel());
-                    assert(m_scripts.find(block) != m_scripts.cend());
-                    out.push_back(m_scripts[block].get());
-                }
-            }
-
-            return out;
-        }
+        case HatType::BackdropChanged:
+            return m_backdropChangeHats[target];
 
         case HatType::CloneInit:
             return m_cloneInitHats[target];
 
         case HatType::KeyPressed:
             return m_whenKeyPressedHats[target];
 
-        default:
-            return {};
+        default: {
+            static const std::vector<Script *> empty = {};
+            return empty;
+        }
     }
 }
 

src/engine/internal/engine.h

@@ -111,6 +111,7 @@ class Engine : public IEngine
 
         void addGreenFlagScript(std::shared_ptr<Block> hatBlock) override;
         void addBroadcastScript(std::shared_ptr<Block> whenReceivedBlock, Broadcast *broadcast) override;
+        void addBackdropChangeScript(std::shared_ptr<Block> hatBlock) override;
         void addCloneInitScript(std::shared_ptr<Block> hatBlock) override;
         void addKeyPressScript(std::shared_ptr<Block> hatBlock, std::string keyName) override;
 
@@ -163,7 +164,7 @@ class Engine : public IEngine
         std::shared_ptr<IBlockSection> blockSection(const std::string &opcode) const;
 
         void addHatToMap(std::unordered_map<Target *, std::vector<Script *>> &map, Script *script);
-        std::vector<Script *> getHats(Target *target, HatType type);
+        const std::vector<libscratchcpp::Script *> &getHats(Target *target, HatType type);
 
         void updateSpriteLayerOrder();
 
@@ -195,6 +196,7 @@ class Engine : public IEngine
         std::recursive_mutex m_eventLoopMutex;
 
         std::unordered_map<Target *, std::vector<Script *>> m_greenFlagHats;
+        std::unordered_map<Target *, std::vector<Script *>> m_backdropChangeHats;
         std::unordered_map<Target *, std::vector<Script *>> m_broadcastHats;
         std::unordered_map<Target *, std::vector<Script *>> m_cloneInitHats;
         std::unordered_map<Target *, std::vector<Script *>> m_whenKeyPressedHats;

test/blocks/event_blocks_test.cpp

@@ -310,6 +310,8 @@ TEST_F(EventBlocksTest, WhenBackdropSwitchesTo)
     auto backdrop = std::make_shared<Costume>("backdrop2", "a", "svg");
     stage.addCostume(backdrop);
 
+    EXPECT_CALL(m_engineMock, addBackdropChangeScript(block1));
+
     compiler.init();
     compiler.setBlock(block1);
     EventBlocks::compileWhenBackdropSwitchesTo(&compiler);

test/mocks/enginemock.h

@@ -93,6 +93,7 @@ class EngineMock : public IEngine
 
         MOCK_METHOD(void, addGreenFlagScript, (std::shared_ptr<Block>), (override));
         MOCK_METHOD(void, addBroadcastScript, (std::shared_ptr<Block>, Broadcast *), (override));
+        MOCK_METHOD(void, addBackdropChangeScript, (std::shared_ptr<Block>), (override));
         MOCK_METHOD(void, addCloneInitScript, (std::shared_ptr<Block>), (override));
         MOCK_METHOD(void, addKeyPressScript, (std::shared_ptr<Block>, std::string), (override));