Implemented UI_Choice (a combobox) with tests.

src/CMakeLists.txt

@@ -179,6 +179,7 @@ set(UI_TEST_SOURCES
     ${GUI_TESTDIR}/test_field_checkbox.cpp
     ${GUI_TESTDIR}/test_field_spinctrl.cpp
     ${GUI_TESTDIR}/test_field_textbox.cpp
+    ${GUI_TESTDIR}/test_field_choice.cpp
 )
 set(SLIC3R_TEST_SOURCES
     ${TESTDIR}/test_harness.cpp

src/GUI/OptionsGroup/Field.hpp

@@ -11,6 +11,8 @@
 #include "wx/spinctrl.h"
 #include "wx/checkbox.h"
 #include "wx/textctrl.h"
+#include "wx/combobox.h"
+#include "wx/arrstr.h"
 
 namespace Slic3r { namespace GUI {
 
@@ -90,8 +92,6 @@ public:
     std::function<void (const std::string&, bool value)> on_change {nullptr};
 
 protected:
-    wxCheckBox* _check {nullptr};
-
     virtual std::string LogChannel() override { return "UI_Checkbox"s; }
 
     void _on_change(std::string opt_id) {
@@ -99,6 +99,8 @@ protected:
             this->on_change(opt_id, this->get_bool());
         }
     }
+private:
+    wxCheckBox* _check {nullptr};
 
 };
 
@@ -139,7 +141,6 @@ protected:
 
 private:
     wxSpinCtrl* _spin {nullptr};
-    int _tmp {0};
 };
 
 class UI_TextCtrl : public UI_Window {
@@ -188,7 +189,62 @@ protected:
 
 private:
     wxTextCtrl* _text {nullptr};
-    int _tmp {0};
+};
+
+class UI_Choice : public UI_Window {
+public:
+    UI_Choice(wxWindow* parent, Slic3r::ConfigOptionDef _opt, wxWindowID id = wxID_ANY) : UI_Window(parent, _opt) {
+        int style {0};
+        style |= wxTE_PROCESS_ENTER;
+        if (opt.gui_type.size() > 0 && opt.gui_type.compare("select_open"s)) style |= wxCB_READONLY;
+
+        /// Load the values
+        auto values {wxArrayString()};
+        for (auto v : opt.enum_values) values.Add(wxString(v));
+
+        _choice = new wxComboBox(parent, id, 
+        (opt.default_value != nullptr ? opt.default_value->getString() : ""),
+        wxDefaultPosition, _default_size(), values, style);
+        window = _choice;
+
+        _choice->Bind(wxEVT_COMBOBOX, [this](wxCommandEvent& e) { this->_on_change(""); e.Skip(); });
+        _choice->Bind(wxEVT_TEXT_ENTER, [this](wxCommandEvent& e) { this->_on_change(""); e.Skip(); });
+        _choice->Bind(wxEVT_KILL_FOCUS, [this](wxFocusEvent& e) { if (this->on_kill_focus != nullptr) {this->on_kill_focus(""); this->_on_change("");} e.Skip(); });
+    }
+    std::string get_string() override { 
+        if (opt.enum_values.size() > 0) {
+            auto idx = this->_choice->GetSelection();
+            if (idx != wxNOT_FOUND) return this->opt.enum_values.at(idx);
+        }
+        return this->_choice->GetValue().ToStdString();
+    }
+
+
+    /// Returns a bare pointer to the underlying combobox, usually for test interface
+    wxComboBox* choice() { return this->_choice; }
+
+    void set_value(boost::any value) override {
+        auto result {std::find(opt.enum_values.cbegin(), opt.enum_values.cend(), boost::any_cast<std::string>(value))};
+        if (result == opt.enum_values.cend()) {
+            this->_choice->SetValue(wxString(boost::any_cast<std::string>(value)));
+        } else {
+            auto idx = std::distance(opt.enum_values.cbegin(), result);
+            this->_choice->SetSelection(idx);
+        }
+    }
+
+    /// Function to call when the contents of this change.
+    std::function<void (const std::string&, std::string value)> on_change {nullptr};
+protected:
+    virtual std::string LogChannel() override { return "UI_Choice"s; }
+
+    void _on_change(std::string opt_id) {
+        if (!this->disable_change_event && this->window->IsEnabled() && this->on_change != nullptr) {
+            this->on_change(opt_id, this->get_string());
+        }
+    }
+private:
+    wxComboBox* _choice {nullptr};
 };
 
 } } // Namespace Slic3r::GUI

src/test/GUI/test_field_choice.cpp

@@ -0,0 +1,143 @@
+#include <catch.hpp>
+
+#ifndef WX_PRECOMP
+#include "wx/app.h"
+#include "wx/uiaction.h"
+#endif // WX_PRECOMP
+
+#include <iostream>
+#include "testableframe.h"
+#include "OptionsGroup/Field.hpp"
+#include "ConfigBase.hpp"
+
+using namespace std::string_literals;
+
+SCENARIO( "UI_Choice: default values from options") {
+    wxTestableFrame* old = dynamic_cast<wxTestableFrame*>(wxTheApp->GetTopWindow()); 
+    old->Destroy();
+    wxTheApp->SetTopWindow(new wxTestableFrame());
+    wxUIActionSimulator sim;
+    wxMilliSleep(500);
+
+    GIVEN( "I have a UI Choice with 3 options from ConfigOptionDef and a default_value that is not in the enumeration.") {
+        auto  simple_option {ConfigOptionDef()};
+        auto* default_string {new ConfigOptionString("A")};
+
+        simple_option.default_value = default_string; // owned by ConfigOptionDef
+        simple_option.enum_values.push_back("B");
+        simple_option.enum_values.push_back("C");
+        simple_option.enum_values.push_back("D");
+
+        auto test_field {Slic3r::GUI::UI_Choice(wxTheApp->GetTopWindow(), simple_option)};
+        WHEN( "I don't explicitly select any option in the drop-down") {
+            THEN( "get_value() returns the the value associuted with the listed default option in the related ConfigOptionDef") {
+                REQUIRE(simple_option.default_value->getString() == test_field.get_string());
+            }
+        }
+        WHEN( "I select the first option in the drop-down") {
+            test_field.choice()->SetSelection(0);
+            THEN( "get_value() returns the the value associuted with the first option in the related ConfigOptionDef") {
+                REQUIRE(simple_option.enum_values[0] == test_field.get_string());
+            }
+        }
+        WHEN( "I select the second option in the drop-down") {
+            test_field.choice()->SetSelection(1);
+            THEN( "get_value() returns the the value associuted with the second option in the related ConfigOptionDef") {
+                REQUIRE(simple_option.enum_values[1] == test_field.get_string());
+            }
+        }
+        WHEN( "I select the third option in the drop-down") {
+            test_field.choice()->SetSelection(2);
+            THEN( "get_value() returns the the value associuted with the third option in the related ConfigOptionDef") {
+                REQUIRE(simple_option.enum_values[2] == test_field.get_string());
+            }
+        }
+    }
+    GIVEN( "I have a UI Choice with 3 options from ConfigOptionDef and a default_value that is in the enumeration.") {
+        auto  simple_option {ConfigOptionDef()};
+        auto* default_string {new ConfigOptionString("B"s)};
+
+        simple_option.default_value = default_string; // owned by ConfigOptionDef
+        simple_option.enum_values.push_back("B"s);
+        simple_option.enum_values.push_back("C"s);
+        simple_option.enum_values.push_back("D"s);
+
+        auto test_field {Slic3r::GUI::UI_Choice(wxTheApp->GetTopWindow(), simple_option)};
+        WHEN( "I don't explicitly select any option in the drop-down") {
+            THEN( "get_value() returns the first value in the related ConfigOptionDef") {
+                REQUIRE(simple_option.enum_values[0] == test_field.get_string());
+                REQUIRE(test_field.choice()->FindString(simple_option.enum_values[0]) == 0);
+            }
+        }
+        WHEN( "I set the string value to another item in the enumeration") {
+            test_field.choice()->SetValue("C"s);
+            THEN( "get_string() returns the matching item in ConfigOptionDef") {
+                REQUIRE(test_field.get_string() == "C"s);
+                REQUIRE(test_field.choice()->FindString(simple_option.enum_values[1]) == 1);
+            }
+        }
+        WHEN( "I set the string value to another item that is not in the enumeration") {
+            test_field.choice()->SetValue("F"s);
+            THEN( "get_string() returns the matching item in ConfigOptionDef") {
+                REQUIRE(test_field.get_string() == "F"s);
+                REQUIRE(test_field.choice()->GetSelection() == wxNOT_FOUND);
+            }
+        }
+    }
+}
+
+
+SCENARIO( "UI_Choice: event handling for on_change and on_kill_focus") {
+    auto event_count {0};
+    auto killfunc {[&event_count](const std::string& opt_id) { event_count += 1; }};
+    auto changefunc {[&event_count](const std::string& opt_id, std::string value) { event_count += 1; }};
+    GIVEN( "I have a UI Choice with 2 options from ConfigOptionDef, no default value, and an on_change handler and on_kill_focus handler.") {
+        auto  simple_option {ConfigOptionDef()};
+        auto* default_string {new ConfigOptionString("B")};
+
+        simple_option.default_value = default_string; // owned by ConfigOptionDef
+        simple_option.enum_values.push_back("B");
+        simple_option.enum_values.push_back("C");
+
+        auto test_field {Slic3r::GUI::UI_Choice(wxTheApp->GetTopWindow(), simple_option)};
+
+        test_field.on_kill_focus = killfunc;
+        test_field.on_change = changefunc;
+
+        WHEN( "I receive a wxEVT_COMBOBOX event") {
+            event_count = 0;
+            wxMilliSleep(250);
+
+            auto ev {wxCommandEvent(wxEVT_COMBOBOX, test_field.choice()->GetId())};
+            ev.SetEventObject(test_field.choice());
+            test_field.choice()->ProcessWindowEvent(ev);
+            THEN( "on_change handler is executed.") {
+                REQUIRE(event_count == 1);
+            }
+        }
+        WHEN( "I receive a wxEVT_TEXT_ENTER event") {
+            event_count = 0;
+            wxMilliSleep(250);
+
+            auto ev {wxCommandEvent(wxEVT_TEXT_ENTER, test_field.choice()->GetId())};
+            ev.SetEventObject(test_field.choice());
+            test_field.choice()->ProcessWindowEvent(ev);
+            THEN( "on_change handler is executed.") {
+                REQUIRE(event_count == 1);
+            }
+        }
+        WHEN( "My control loses focus.") {
+            event_count = 0;
+            test_field.choice()->SetFocus();
+            wxMilliSleep(250);
+
+            auto ev {wxFocusEvent(wxEVT_KILL_FOCUS, test_field.choice()->GetId())};
+            ev.SetEventObject(test_field.choice());
+            test_field.choice()->ProcessWindowEvent(ev);
+
+            THEN( "on_change handler is executed and on_kill_focus handler is executed.") {
+                REQUIRE(event_count == 2);
+            }
+        }
+    }
+}