1 files changed, 89 insertions, 0 deletions
diff --git a/src/states.cpp b/src/states.cpp
new file mode 100644
index 0000000..d7799b3
--- /dev/null
+++ b/src/states.cpp
@@ -0,0 +1,89 @@
+#include "states.h"
+
+// StateStack
+
+StateStack::StateStack(State::Context context)
+    : pendingOps_()
+    , context_(context)
+{
+}
+
+void StateStack::update(sf::Time dt){
+    for(State::Ptr &s: states_) {
+        s->update(dt);
+    }
+}
+
+void StateStack::render(){
+    for(State::Ptr &s: states_) {
+        s->render();
+    }
+}
+
+void StateStack::handleEvent(const sf::Event &event){
+    for(State::Ptr &s: states_) {
+        s->handleEvent(event);
+    }
+}
+
+void StateStack::requestOp(StateStack::Op op){
+    pendingOps_.push_back(op);
+}
+
+void StateStack::push(States::Id state){
+    states_.push_back(std::move(createState(state)));
+}
+
+void StateStack::pop(){
+    states_.pop_back();
+}
+
+void StateStack::clear(){
+    states_.clear();
+}
+
+void StateStack::applyPending(){
+    for(StateStack::Op &op: pendingOps_) {
+        switch(op.id){
+            case StateStack::OpId::Push:
+                push(op.state);
+                break;
+            case StateStack::OpId::Pop:
+                pop();
+                break;
+            case StateStack::OpId::Clear:
+                clear();
+                break;
+        }
+    }
+    pendingOps_.clear();
+}
+
+bool StateStack::isEmpty() const{
+    return states_.empty();
+}
+
+State::Ptr StateStack::createState(States::Id id){
+    return stateFactory_[id]();
+}
+
+
+// State
+
+State::State(StateStack &stack, State::Context context)
+    : context_(context)
+    , stack_(&stack)
+{}
+
+void State::requestPush(States::Id state_id){
+    StateStack::Op op {StateStack::OpId::Push, state_id};
+    stack_->requestOp(op);
+}
+void State::requestPop(){
+    StateStack::Op op {StateStack::OpId::Push};
+    stack_->requestOp(op);
+}
+void State::requestClear(){
+    StateStack::Op op {StateStack::OpId::Clear};
+    stack_->requestOp(op);
+}