FilePickerCtrl.cpp

#include <wx/app.h>
#include <wx/filepicker.h>
#include <wx/frame.h>
#include <wx/panel.h>
#include <wx/stattext.h>
#include <wx/sysopt.h>

// Workaround : with wxWidgets version <= 3.2 wxFilePickerCtrl::SetFilterIndex doesn't work on macOS
#if !defined(__APPLE__)
using FilePickerCtrl = wxFilePickerCtrl;
#else
class FilePickerCtrl : public wxFilePickerCtrl {
public:
  FilePickerCtrl(wxWindow* parent, wxWindowID id, const wxString& path = wxEmptyString, const wxString& message = wxFileSelectorPromptStr, const wxString& wildcard = wxFileSelectorDefaultWildcardStr, const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxDefaultSize, long style = wxFLP_DEFAULT_STYLE, const wxValidator& validator = wxDefaultValidator, const wxString& name = wxFilePickerCtrlNameStr) : wxFilePickerCtrl {parent, id, path, message, wildcard, pos, size, style, validator, name} {
    auto pickerCtrl = GetPickerCtrl();
    if (size == wxDefaultSize) SetSize(150, GetSize().GetHeight());
    auto wx_dialog_style = 0;
    if ((style & wxFLP_OPEN) == wxFLP_OPEN) wx_dialog_style |= wxFD_OPEN;
    if ((style & wxFLP_SAVE) == wxFLP_SAVE) wx_dialog_style |= wxFD_SAVE;
    if ((style & wxFLP_OVERWRITE_PROMPT) == wxFLP_OVERWRITE_PROMPT) wx_dialog_style |= wxFD_OVERWRITE_PROMPT;
    if ((style & wxFLP_FILE_MUST_EXIST) == wxFLP_FILE_MUST_EXIST) wx_dialog_style |= wxFD_FILE_MUST_EXIST;
    if ((style & wxFLP_CHANGE_DIR) == wxFLP_CHANGE_DIR) wx_dialog_style |= wxFD_CHANGE_DIR;
    pickerCtrl->Bind(wxEVT_BUTTON, [=](wxCommandEvent& event) {
      auto openFileDialog = wxFileDialog {parent, message, path, wxEmptyString, wildcard, wx_dialog_style};
      openFileDialog.SetFilterIndex(0);
      if (openFileDialog.ShowModal() == wxID_OK) {
        SetPath(openFileDialog.GetPath());
        wxPostEvent(this, wxFileDirPickerEvent(wxEVT_FILEPICKER_CHANGED, this, id, GetPath()));
      }
    });
  }
};
#endif

namespace FilePickerCtrlExample {
  class Frame : public wxFrame {
  public:
    Frame() : wxFrame {nullptr, wxID_ANY, "FilePickerCtrl example"} {
      picker->Bind(wxEVT_FILEPICKER_CHANGED, [&](wxFileDirPickerEvent& event) {
        label->SetLabel(wxString::Format("File = %s", picker->GetPath()));
      });
    }
    
  private:
    wxPanel* panel = new wxPanel {this};
    wxStaticText* label = new wxStaticText {panel, wxID_ANY, "File = ", wxPoint(10, 50)};
    FilePickerCtrl* picker = new FilePickerCtrl {panel, wxID_ANY, wxEmptyString, wxEmptyString, "Text Files (*.txt)|*.txt|All Files (*.*)|*.*", {10, 10}, wxDefaultSize, wxFLP_DEFAULT_STYLE|wxFLP_SMALL};
  };

  class Application : public wxApp {
    bool OnInit() override {
      wxSystemOptions::SetOption("osx.openfiledialog.always-show-types", 1);
      return (new Frame)->Show();
    }
  };
}

wxIMPLEMENT_APP(FilePickerCtrlExample::Application);