1 files changed, 108 insertions, 0 deletions
diff --git a/src/tangara/ui/screen_lua.cpp b/src/tangara/ui/screen_lua.cpp
new file mode 100644
index 00000000..685e43cb
--- /dev/null
+++ b/src/tangara/ui/screen_lua.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "screen_lua.hpp"
+
+#include "core/lv_obj_tree.h"
+#include "lua.h"
+#include "lua.hpp"
+#include "property.hpp"
+#include "themes.hpp"
+
+#include "lua_thread.hpp"
+#include "luavgl.h"
+
+namespace ui {
+namespace screens {
+
+Lua::Lua() : s_(nullptr), obj_ref_() {
+  themes::Theme::instance()->ApplyStyle(root_, "root");
+}
+
+Lua::~Lua() {
+  if (s_ && obj_ref_) {
+    luaL_unref(s_, LUA_REGISTRYINDEX, *obj_ref_);
+  }
+}
+
+auto Lua::onShown() -> void {
+  callMethod("onShown");
+  forEachBinding([&](lua::Binding* b) { b->active = true; });
+}
+
+auto Lua::onHidden() -> void {
+  callMethod("onHidden");
+  forEachBinding([&](lua::Binding* b) { b->active = false; });
+}
+
+auto Lua::canPop() -> bool {
+  if (!s_ || !obj_ref_) {
+    return true;
+  }
+  lua_rawgeti(s_, LUA_REGISTRYINDEX, *obj_ref_);
+  lua_pushliteral(s_, "canPop");
+
+  if (lua_gettable(s_, -2) == LUA_TFUNCTION) {
+    // If we got a callback instead of a value, then invoke it to turn it into
+    // value.
+    lua_pushvalue(s_, -2);
+    lua::CallProtected(s_, 1, 1);
+  }
+  bool ret = lua_toboolean(s_, -1);
+
+  lua_pop(s_, 2);
+  return ret;
+}
+
+auto Lua::SetObjRef(lua_State* s) -> void {
+  assert(s_ == nullptr);
+  s_ = s;
+  obj_ref_ = luaL_ref(s, LUA_REGISTRYINDEX);
+}
+
+auto Lua::callMethod(std::string name) -> void {
+  if (!s_ || !obj_ref_) {
+    return;
+  }
+  lua_rawgeti(s_, LUA_REGISTRYINDEX, *obj_ref_);
+  lua_pushlstring(s_, name.data(), name.size());
+
+  if (lua_gettable(s_, -2) == LUA_TFUNCTION) {
+    lua_pushvalue(s_, -2);
+    lua::CallProtected(s_, 1, 0);
+  } else {
+    lua_pop(s_, 1);
+  }
+
+  lua_pop(s_, 1);
+}
+
+auto Lua::forEachBinding(std::function<void(lua::Binding*)> fn) -> void {
+  if (!s_ || !obj_ref_) {
+    return;
+  }
+  lua_rawgeti(s_, LUA_REGISTRYINDEX, *obj_ref_);
+  lua_pushliteral(s_, "bindings");
+
+  if (lua_gettable(s_, -2) != LUA_TTABLE) {
+    lua_pop(s_, 2);
+    return;
+  }
+
+  lua_pushnil(s_);
+  while (lua_next(s_, -2) != 0) {
+    lua::Binding* b = lua::Binding::get(s_, -1);
+    if (b) {
+      std::invoke(fn, b);
+    }
+    lua_pop(s_, 1);
+  }
+
+  lua_pop(s_, 2);
+}
+
+}  // namespace screens
+}  // namespace ui