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#include "common.h"
namespace window
{
class base
{
private:
protected:
HWND handle;
public:
static LRESULT CALLBACK message_forwarder(HWND, UINT, WPARAM, LPARAM);
virtual LRESULT CALLBACK message_handler(HWND, UINT, WPARAM, LPARAM) = 0;
virtual bool create(HINSTANCE,
LPCTSTR,
LPCTSTR,
HWND,
DWORD,
HMENU,
int,
int,
int,
int,
DWORD);
base(){}
};
bool base::create(HINSTANCE instance,
LPCTSTR window_name,
LPCTSTR class_name,
HWND parent = 0,
DWORD style = WS_OVERLAPPEDWINDOW,
HMENU menu = 0,
int x = CW_USEDEFAULT,
int y = CW_USEDEFAULT,
int w = CW_USEDEFAULT,
int h = CW_USEDEFAULT,
DWORD exstyle = WS_EX_CLIENTEDGE)
{
handle = CreateWindowEx(exstyle,
class_name,
window_name,
style,
x,
y,
w,
h,
parent,
menu,
instance,
this);
handle_error();
if(handle)
{
return true;
}
else
{
return false;
}
}
LRESULT CALLBACK base::message_forwarder(HWND handle, UINT message, WPARAM wparam, LPARAM lparam)
{
base* base_ptr = 0;
if(message == WM_NCCREATE)
{
SetWindowLong(handle, GWL_USERDATA, (long)LPCREATESTRUCT(lparam)->lpCreateParams);
handle_error();
return 0;
}
base_ptr = (base*)GetWindowLong(handle, GWL_USERDATA);
handle_error();
if(base_ptr)
{
base_ptr->message_handler(handle, message, wparam, lparam);
return 0;
}
else
{
return DefWindowProc(handle, message, wparam, lparam);
}
}
//--------------------------------------------------------
class main : public base
{
private:
protected:
public:
virtual LRESULT CALLBACK message_handler(HWND, UINT, WPARAM, LPARAM);
void show();
main(){}
};
LRESULT CALLBACK main::message_handler(HWND handle, UINT message, WPARAM wparam, LPARAM lparam)
{
switch(message)
{
case WM_CREATE:
MessageBox(handle, L"Window created.", L"", MB_OK);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
case WM_LBUTTONDOWN:
MessageBox(handle, L"Left button pressed", L"", MB_OK);
return 0;
default:
return DefWindowProc(handle, message, wparam, lparam);
}
}
void main::show()
{
ShowWindow(handle, SW_SHOW);
UpdateWindow(handle);
handle_error();
}
//--------------------------------------------------------
class classex : protected WNDCLASSEX
{
private:
protected:
public:
virtual bool register_ex();
virtual void create(HINSTANCE, LPCTSTR);
classex(){}
};
void classex::create(HINSTANCE instance, LPCTSTR class_name)
{
hInstance = instance;
lpfnWndProc = base::message_forwarder;
lpszClassName = class_name;
lpszMenuName = 0;
cbSize = sizeof(WNDCLASSEX);
cbClsExtra = 0;
cbWndExtra = 0;
style = 0;
hIcon = LoadIcon(0, IDI_APPLICATION);
hIconSm = LoadIcon(0, IDI_APPLICATION);
hCursor = LoadCursor(0, IDC_ARROW);
hbrBackground = (HBRUSH)GetStockObject(COLOR_BTNFACE);
}
bool classex::register_ex()
{
if(RegisterClassEx(this))
{
return true;
}
else
{
handle_error();
return false;
}
}
}
INT WINAPI WinMain(HINSTANCE instance,
HINSTANCE previous_instance,
LPSTR command_line_options,
int show_style)
{
window::classex the_classex;
the_classex.create(instance, L"main");
if(!the_classex.register_ex())
{
MessageBox(0, L"Failed to register window class.", L"Error", MB_OK);
return -1;
}
window::main the_window;
//this triggers the error
if(!the_window.create(instance, L"Main window.", L"main"))
{
MessageBox(0, L"Failed to create window.", L"Error", MB_OK);
return -1;
}
the_window.show();
MSG message;
int result = 0;
while((result = GetMessage(&message, 0, 0, 0)) != 0)
{
if(result == -1)
{
handle_error();
break;
}
TranslateMessage(&message);
DispatchMessage(&message);
}
return message.wParam;
}
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