Persist window size via .ini file

CMakeLists.txt

@@ -40,7 +40,7 @@ add_executable(${PROJECT_NAME} src/rig_reconfigure.cpp src/service_wrapper.cpp s
 #target_compile_options(${PROJECT_NAME} PRIVATE -g -fsanitize=thread)
 #target_link_options(${PROJECT_NAME} PRIVATE -fsanitize=thread)
 
-target_include_directories(${PROJECT_NAME} PRIVATE include external/imspinner external/lodepng)
+target_include_directories(${PROJECT_NAME} PRIVATE include external/lodepng)
 target_link_libraries(${PROJECT_NAME} imgui rclcpp::rclcpp ament_index_cpp::ament_index_cpp)
 
 install(TARGETS ${PROJECT_NAME}

src/node_window.cpp

@@ -19,7 +19,7 @@ struct TreeNode {
     std::string name; // node name (leaf node) / namespace (other)
     std::string fullName; // full node name for easier usage
 
-    std::vector<std::shared_ptr<TreeNode>> children;
+    std::vector<std::shared_ptr<TreeNode>> children = {};
 };
 
 class NodeTree {

src/rig_reconfigure.cpp

@@ -15,9 +15,10 @@
 #include <imgui_internal.h>
 #include <vector>
 
+#include <lodepng.h>
+
 #include "service_wrapper.hpp"
 #include "utils.hpp"
-#include "lodepng.h"
 #include "node_window.hpp"
 #include "parameter_window.hpp"
 
@@ -27,6 +28,8 @@ constexpr auto STATUS_WARNING_COLOR = ImVec4(1, 0, 0, 1);
 constexpr auto NODES_AUTO_REFRESH_INTERVAL = 1s; // unit: seconds
 constexpr auto DESIRED_FRAME_RATE = 30;
 constexpr std::chrono::duration<float> DESIRED_FRAME_DURATION_MS = 1000ms / DESIRED_FRAME_RATE;
+constexpr auto DEFAULT_WINDOW_WIDTH = 600;
+constexpr auto DEFAULT_WINDOW_HEIGHT = 800;
 
 // window names
 constexpr auto NODE_WINDOW_NAME = "Nodes";
@@ -59,36 +62,50 @@ int main(int argc, char *argv[]) {
     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
 
-    // Create window with graphics context
-    GLFWwindow *window = glfwCreateWindow(600, 800, "Parameter modification editor",
-                                          nullptr, nullptr);
-    if (window == nullptr) {
-        return 1;
-    }
-    glfwMakeContextCurrent(window);
-    glfwSwapInterval(1); // Enable vsync
-
-    const auto resourcePath = findResourcePath(argv[0]);
-
-    loadWindowIcon(window, resourcePath);
-
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
 
     // place the imgui.ini config file within the users home directory (instead of current working directory)
     const std::filesystem::path config_file_dir(std::string(std::getenv("HOME")) + "/.config/rig_reconfigure");
+    const std::string config_file_path = config_file_dir.string() + "/imgui.ini";
 
     if (!std::filesystem::exists(config_file_dir)) {
         std::filesystem::create_directory(config_file_dir);
     }
 
-    const std::string config_file_path = config_file_dir.string() + "/imgui.ini";
-    ImGui::GetIO().IniFilename = config_file_path.c_str();
+    ImGui::GetIO().IniFilename = config_file_path.c_str(); // important for automatic saving of .ini file
+    ImGui::GetIO().ConfigFlags |= ImGuiConfigFlags_DockingEnable;
 
+    // load window size if already stored from last iteration
     bool configFileExisting = std::filesystem::exists(config_file_path);
+    auto window_width = DEFAULT_WINDOW_WIDTH;
+    auto window_height = DEFAULT_WINDOW_HEIGHT;
+
+    if (configFileExisting) {
+        // manual loading of the .ini file since we require the window size before creating the glfw window
+        ImGui::LoadIniSettingsFromDisk(config_file_path.c_str());
+        ImGuiID id = ImHashStr("Root window");
+        ImGuiWindowSettings* root_window_settings = ImGui::FindWindowSettingsByID(id);
+
+        if (root_window_settings != nullptr) {
+            window_width = root_window_settings->Size.x;
+            window_height = root_window_settings->Size.y;
+        }
+    }
 
-    ImGui::GetIO().ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+    // Create window with graphics context
+    GLFWwindow *window = glfwCreateWindow(window_width, window_height, "Parameter modification editor",
+                                          nullptr, nullptr);
+    if (window == nullptr) {
+        return 1;
+    }
+    glfwMakeContextCurrent(window);
+    glfwSwapInterval(1); // Enable vsync
+
+    const auto resourcePath = findResourcePath(argv[0]);
+
+    loadWindowIcon(window, resourcePath);
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();