wxWidgets Panel not Receiving Mouse Events - c++

Question

I am having trouble capturing and handling mouse events within a panel.
Binding mouse events to my main window frame works as expected. However, when I bind events to a child panel, they successfully don't go my frame, but are not correctly handled by my panel. Any help would be appreciated.
I am using wxWidgets v3.1.5
Below is my simplest example: a single panel inside a parent frame.
Clicking the panel should turn itself yellow. Clicking the surrounding frame area should turn the panel green.
// wxWidgets in full of strcpy
#pragma warning(disable : 4996)
#include <wx/wx.h>
class cPanel : public wxPanel {
public:
cPanel(wxWindow* parent, wxSize size)
: wxPanel(parent, wxID_ANY, wxDefaultPosition, size) {
this->Bind(wxEVT_LEFT_DOWN, &cPanel::OnLeftClick, this);
}
void OnLeftClick(wxMouseEvent& event) {
SetBackgroundColour(wxColour("yellow"));
Refresh();
};
};
class cFrame : public wxFrame {
public:
wxPanel* child;
cFrame()
: wxFrame(nullptr, wxID_ANY, "Example Title", wxPoint(200, 200),
wxSize(800, 500)) {
child = new wxPanel(this, wxID_ANY, wxDefaultPosition, wxSize(300, 300));
auto top = new wxBoxSizer(wxHORIZONTAL);
top->Add(child, 0, wxALL, 20);
SetSizer(top);
this->Bind(wxEVT_LEFT_DOWN, &cFrame::OnLeftClick, this);
};
void OnLeftClick(wxMouseEvent& event) {
child->SetBackgroundColour(wxColour("green"));
child->Refresh();
}
};
class cApp : public wxApp {
public:
cFrame* frame = nullptr;
cApp(){};
~cApp(){};
virtual bool OnInit() {
frame = new cFrame();
frame->Show();
return true;
}
};
wxIMPLEMENT_APP(cApp);

Answer 1

Only wxCommandEvents (and classes derived from it) will filter up to parent windows. wxMouseEvent does not derive from wxCommandEvent, so a mouse event on the panel that is not handled by the panel will not filter up to the frame.
Consequently, you'll need to Bind the mouse event handler to the panel instead of the frame. Here's an example of how to change the last few lines of your cFrame class to do that.
this->Bind(wxEVT_LEFT_DOWN, &cFrame::OnLeftClick, this);
child->Bind(wxEVT_LEFT_DOWN, &cFrame::OnChildLeftClick, this);
};
void OnLeftClick(wxMouseEvent& event) {
child->SetBackgroundColour(wxColour("green"));
child->Refresh();
}
void OnChildLeftClick(wxMouseEvent& event) {
child->SetBackgroundColour(wxColour("yellow"));
child->Refresh();
}
};
There are many ways of accomplishing the same thing, but I think something like this is probably the simplest.