GUI: add backdrop if system file picker is open

TODO.md

@@ -13,7 +13,6 @@
 - maybe YMU759 ADPCM channel
 - ADPCM chips
 - more effects for FM param control
-- store system presets in new file
 - Game Boy envelope macro/sequence
 - option to display chip names instead of "multi-system" on title bar
 - rewrite the system name detection function anyway

src/gui/fileDialog.cpp

@@ -95,6 +95,10 @@ bool FurnaceGUIFileDialog::render(const ImVec2& min, const ImVec2& max) {
   }
 }
 
+bool FurnaceGUIFileDialog::isOpen() {
+  return opened;
+}
+
 String FurnaceGUIFileDialog::getPath() {
   if (sysDialog) {
     if (curPath.size()>1) {

src/gui/fileDialog.h

@@ -24,6 +24,7 @@ class FurnaceGUIFileDialog {
     bool accepted();
     void close();
     bool render(const ImVec2& min, const ImVec2& max);
+    bool isOpen();
     String getPath();
     String getFileName();
     explicit FurnaceGUIFileDialog(bool system):

src/gui/gui.cpp

@@ -2882,6 +2882,19 @@ bool FurnaceGUI::loop() {
 #endif
     }
 
+    if (fileDialog->isOpen() && settings.sysFileDialog) {
+      ImGui::OpenPopup("System File Dialog Pending");
+    }
+
+    if (ImGui::BeginPopupModal("System File Dialog Pending",NULL,ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoBackground|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoMove)) {
+      if (!fileDialog->isOpen()) {
+        ImGui::CloseCurrentPopup();
+      }
+      ImDrawList* dl=ImGui::GetForegroundDrawList();
+      dl->AddRectFilled(ImVec2(0.0f,0.0f),ImVec2(scrW*dpiScale,scrH*dpiScale),ImGui::ColorConvertFloat4ToU32(uiColors[GUI_COLOR_MODAL_BACKDROP]));
+      ImGui::EndPopup();
+    }
+
     if (fileDialog->render(ImVec2(600.0f*dpiScale,400.0f*dpiScale),ImVec2(scrW*dpiScale,scrH*dpiScale))) {
       bool openOpen=false;
       //ImGui::GetIO().ConfigFlags&=~ImGuiConfigFlags_NavEnableKeyboard;