imgui: Refactor combo boxes. Fix #1895 #1868

src/slic3r/GUI/GLGizmo.cpp

@@ -2286,17 +2286,20 @@ RENDER_AGAIN:
         m_imgui->text(_(L("Shift + Left (+ drag) - select point(s)")));
         m_imgui->text(" ");  // vertical gap
 
-        std::vector<wxString> options = {"0.2", "0.4", "0.6", "0.8", "1.0"};
+        static const std::vector<float> options = {0.2f, 0.4f, 0.6f, 0.8f, 1.0f};
-        std::stringstream ss;
+        static const std::vector<std::string> options_str = {"0.2", "0.4", "0.6", "0.8", "1.0"};
-        ss << std::setprecision(1) << m_new_point_head_diameter;
+        int selection = -1;
-        wxString str = ss.str();
+        for (size_t i = 0; i < options.size(); i++) {
+            if (options[i] == m_new_point_head_diameter) { selection = (int)i; }
+        }
 
         bool old_combo_state = m_combo_box_open;
         // The combo is commented out for now, until the feature is supported by backend.
-        // m_combo_box_open = m_imgui->combo(_(L("Head diameter")), options, str);
+        // m_combo_box_open = m_imgui->combo(_(L("Head diameter")), options_str, selection);
         force_refresh |= (old_combo_state != m_combo_box_open);
 
-        float current_number = atof(str);
+        // float current_number = atof(str);
+        const float current_number = selection < options.size() ? options[selection] : m_new_point_head_diameter;
         if (old_combo_state && !m_combo_box_open) // closing the combo must always change the sizes (even if the selection did not change)
             for (auto& point_and_selection : m_editing_mode_cache)
                 if (point_and_selection.second) {

src/slic3r/GUI/ImGuiWrapper.cpp

@@ -254,44 +254,29 @@ void ImGuiWrapper::text(const wxString &label)
     this->text(into_u8(label).c_str());
 }
 
-
+bool ImGuiWrapper::combo(const wxString& label, const std::vector<std::string>& options, int& selection)
-bool ImGuiWrapper::combo(const wxString& label, const std::vector<wxString>& options, wxString& selection)
-{
-    std::string selection_u8 = into_u8(selection);
-
-    // this is to force the label to the left of the widget:
-    text(label);
-    ImGui::SameLine();
-    
-    if (ImGui::BeginCombo("", selection_u8.c_str())) {
-        for (const wxString& option : options) {
-            std::string option_u8 = into_u8(option);
-            bool is_selected = (selection_u8.empty()) ? false : (option_u8 == selection_u8);
-            if (ImGui::Selectable(option_u8.c_str(), is_selected))
-                selection = option_u8;
-        }
-        ImGui::EndCombo();
-        return true;
-    }
-    return false;
-}
-
-bool ImGuiWrapper::combo(const wxString& label, const std::vector<std::string>& options, std::string& selection)
 {
     // this is to force the label to the left of the widget:
     text(label);
     ImGui::SameLine();
 
-    if (ImGui::BeginCombo("", selection.c_str())) {
+    int selection_out = -1;
-        for (const std::string& option : options) {
+    bool res = false;
-            bool is_selected = (selection.empty()) ? false : (option == selection);
+
-            if (ImGui::Selectable(option.c_str(), is_selected))
+    const char *selection_str = selection < options.size() ? options[selection].c_str() : "";
-                selection = option;
+    if (ImGui::BeginCombo("", selection_str)) {
+        for (int i = 0; i < options.size(); i++) {
+            if (ImGui::Selectable(options[i].c_str(), i == selection)) {
+                selection_out = i;
             }
+        }
+
         ImGui::EndCombo();
-        return true;
+        res = true;
     }
-    return false;
+
+    selection = selection_out;
+    return res;
 }
 
 void ImGuiWrapper::disabled_begin(bool disabled)

src/slic3r/GUI/ImGuiWrapper.hpp

@@ -60,8 +60,7 @@ public:
     void text(const char *label);
     void text(const std::string &label);
     void text(const wxString &label);
-    bool combo(const wxString& label, const std::vector<std::string>& options, std::string& current_selection);
+    bool combo(const wxString& label, const std::vector<std::string>& options, int& selection);   // Use -1 to not mark any option as selected
-    bool combo(const wxString& label, const std::vector<wxString>& options, wxString& current_selection);
 
     void disabled_begin(bool disabled);
     void disabled_end();