Merge pull request #242 from scratchcpp/stage_getter

Add stage getter to Engine

Author: adazem009

include/scratchcpp/iengine.h

@@ -16,6 +16,7 @@ class Broadcast;
 class Block;
 class Target;
 class Sprite;
+class Stage;
 class Variable;
 class List;
 class Script;
@@ -215,6 +216,9 @@ class LIBSCRATCHCPP_EXPORT IEngine
         /*! Returns the index of the target with the given name. */
         virtual int findTarget(const std::string &targetName) const = 0;
 
+        /*! Returns the Stage. */
+        virtual Stage *stage() const = 0;
+
         /*! Returns the target which owns the given variable. If it is the stage, the variable is global. */
         virtual Target *variableOwner(Variable *variable) const = 0;
 

src/engine/internal/engine.cpp

@@ -4,6 +4,7 @@
 #include <scratchcpp/iblocksection.h>
 #include <scratchcpp/script.h>
 #include <scratchcpp/sprite.h>
+#include <scratchcpp/stage.h>
 #include <scratchcpp/broadcast.h>
 #include <scratchcpp/compiler.h>
 #include <scratchcpp/input.h>
@@ -653,6 +654,16 @@ int Engine::findTarget(const std::string &targetName) const
     return -1;
 }
 
+Stage *Engine::stage() const
+{
+    auto it = std::find_if(m_targets.begin(), m_targets.end(), [](std::shared_ptr<Target> target) { return target && target->isStage(); });
+
+    if (it == m_targets.end())
+        return nullptr;
+    else
+        return dynamic_cast<Stage *>((*it).get());
+}
+
 Target *Engine::variableOwner(Variable *variable) const
 {
     auto it = m_variableOwners.find(variable);

src/engine/internal/engine.h

@@ -89,6 +89,8 @@ class Engine : public IEngine
         Target *targetAt(int index) const override;
         int findTarget(const std::string &targetName) const override;
 
+        Stage *stage() const override;
+
         Target *variableOwner(Variable *variable) const override;
         Target *listOwner(List *list) const override;
 

test/engine/engine_test.cpp

@@ -1,6 +1,8 @@
 #include <scratchcpp/broadcast.h>
 #include <scratchcpp/block.h>
 #include <scratchcpp/project.h>
+#include <scratchcpp/sprite.h>
+#include <scratchcpp/stage.h>
 #include <scratchcpp/variable.h>
 #include <scratchcpp/list.h>
 #include <timermock.h>
@@ -369,6 +371,33 @@ TEST(EngineTest, Targets)
     ASSERT_EQ(block2->engine(), &engine);
 }
 
+TEST(EngineTest, Stage)
+{
+    Engine engine;
+    ASSERT_EQ(engine.stage(), nullptr);
+
+    auto t1 = std::make_shared<Sprite>();
+    t1->setName("Sprite1");
+    engine.setTargets({ t1 });
+    ASSERT_EQ(engine.stage(), nullptr);
+
+    auto t2 = std::make_shared<Stage>();
+    t2->setName("Stage");
+    engine.setTargets({ t1, t2 });
+    ASSERT_EQ(engine.stage(), t2.get());
+
+    auto t3 = std::make_shared<Sprite>();
+    t3->setName("Sprite2");
+    engine.setTargets({ t1, t2, t3 });
+    ASSERT_EQ(engine.stage(), t2.get());
+
+    engine.setTargets({ t2, t3 });
+    ASSERT_EQ(engine.stage(), t2.get());
+
+    engine.setTargets({ t1, t3 });
+    ASSERT_EQ(engine.stage(), nullptr);
+}
+
 TEST(EngineTest, VariableOwner)
 {
     Engine engine;

test/mocks/enginemock.h

@@ -75,6 +75,8 @@ class EngineMock : public IEngine
         MOCK_METHOD(Target *, targetAt, (int), (const, override));
         MOCK_METHOD(int, findTarget, (const std::string &), (const, override));
 
+        MOCK_METHOD(Stage *, stage, (), (const, override));
+
         MOCK_METHOD(Target *, variableOwner, (Variable *), (const, override));
         MOCK_METHOD(Target *, listOwner, (List *), (const, override));