// File: gui-basic1.cpp

// Brief: Minimal Windows GUI Program with Win32 API.

// Author: Caio Rodrigues

//

// Build with:

// $ cl.exe gui-basic1.cpp /EHsc /Zi /nologo /Fe:GuiApp.exe user32.lib gdi32.lib

//--------------------------------------------------------------------------------------

#include <iostream>

#include <string>

#include <map>

#include <set>

#include <sstream>

#include <windows.h>

LRESULT CALLBACK windowProcedure( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

auto WinMessageToString(UINT msg) -> std::string;

int WINAPI WinMain(

// Handle to current application isntance

HINSTANCE hInstance,

HINSTANCE hPrevInstance,

// Command line

LPSTR lpCmdLine,

int nCmdShow

){

OutputDebugString("Starting WinMain Application");

std::puts("It will not print to Console - Starting WinMain Application");

//Window class name must be unique

const char wincClassName [] = "NameOfWindow";

// Win32 Window class structure

WNDCLASSEX wc;

// Win32 message structure

MSG Msg;

// Name to identify the class with.

wc.lpszClassName = wincClassName;

//Pointer to the window procedure for this window class.

wc.lpfnWndProc = windowProcedure;

// 1 - Register Windows Size

wc.cbSize = sizeof(WNDCLASSEX);

wc.style = 0;

//Amount of extra data allocated for this class in memory. Usually 0

wc.cbClsExtra = 0;

//Amount of extra data allocated in memory per window of this type. Usually 0.

wc.cbWndExtra = 0;

//Handle to application instance (that we got in the first parameter of WinMain()).

wc.hInstance = hInstance;

// Large (usually 32x32) icon shown when the user presses Alt+Tab.

wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);

// Cursor that will be displayed over our window.

wc.hCursor = LoadCursor(NULL, IDC_ARROW);

// Background Brush to set the color of our window.

wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); // (HBRUSH) CreateSolidBrush(RGB(10, 20, 30)); //

// Background Brush to set the color of our window.

wc.lpszMenuName = NULL;

// Small (usually 16x16) icon to show in the taskbar and in the top left corner of the window.

wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

OutputDebugString("Registered Window Class OK.");

if(!RegisterClassEx(&wc)) {

MessageBox(NULL,

"Window Registration Failed!",

"Error!",

MB_ICONEXCLAMATION | MB_OK);

//Error status code

return -1;

}

std::cout << "Class Registered" << std::endl;

int width = 500, height = 400;

int pos_left = 400, pos_top = 100;

HWND hwnd = CreateWindowA(

wc.lpszClassName,

"Title of Window",

WS_OVERLAPPEDWINDOW,

pos_left,

pos_top,

width,

height,

nullptr,

nullptr,

hInstance,

nullptr

);

OutputDebugString(" [INFO] Window created OK");

if(hwnd == NULL){

MessageBox(NULL,

"Error: Failure to create Window",

"Error Report",

MB_ICONEXCLAMATION | MB_OK);

return -1;

}

ShowWindow(hwnd, nCmdShow);

std::cout << "nCmdShow = " << nCmdShow << std::endl;

UpdateWindow(hwnd);

//---- Message Loop ----------//

while(GetMessage(&Msg, NULL, 0, 0) > 0 ){

TranslateMessage(&Msg);

DispatchMessage(&Msg);

}

OutputDebugString(" [INFO] Exiting application. OK.");

// Success status code

return 0;

}

// ------------ End of Main ------------------------- //

// Window Procedure - Process window messages or events

LRESULT CALLBACK windowProcedure (

HWND hwnd // Window Handle (Window object)

,UINT msg // Window Message

,WPARAM wParam // Additional message information

,LPARAM lParam // Additional message information

){

// Variable initialized one.

static auto ignored_messages = std::set<UINT>{

WM_MOUSEMOVE, WM_NCHITTEST, WM_SETCURSOR, WM_IME_NOTIFY

};

// Ignore messages which can flood the logging

// if(msg != WM_MOUSEMOVE && msg != WM_NCMOUSEMOVE

// && msg != WM_QUIT && msg != WM_NCHITTEST )

if(ignored_messages.find(msg) == ignored_messages.end())

OutputDebugString(WinMessageToString(msg).c_str());

// Process messages

switch(msg)

{

case WM_CREATE:

SetWindowTextA(hwnd, "Change Window Title");

OutputDebugString(" [INFO] Window created. OK.");

break;

case WM_CLOSE:

OutputDebugString(" [INFO] Window closed. OK.");

DestroyWindow(hwnd);

break;

case WM_DESTROY:

OutputDebugString(" [INFO] Exiting application. OK.");

PostQuitMessage(0);

break;

case WM_MOVE:

std::cerr << " [INFO] Move window." << std::endl;

break;

case WM_PAINT:

{

// GDI - Graphics Devices Interface Here

//--------------------------------------------

PAINTSTRUCT ps;

HDC hdc;

// std::cerr << " [INFO] Windown painting" << std::endl;

hdc = BeginPaint(hwnd, &ps);

std::string text = "Hello world Window!";

TextOutA(hdc, 125, 200, text.c_str(), text.size());

Ellipse(hdc, 100, 100, 160, 160);

Rectangle(hdc, 100, 100, 160, 160);

EndPaint(hwnd, &ps);

}

break;

default:

return DefWindowProc(hwnd, msg, wParam, lParam);

}

return 0;

}

/** Get a human-readable description of a Windows message as a string */

auto WinMessageToString(UINT msg) -> std::string {

/** Database of Windows messages - full list of messages here:

* https://wiki.winehq.org/List_Of_Windows_Messages

*/

static auto WindowMessages = std::map<UINT, std::string>{

{1, "WM_CREATE"}, {2, "WM_DESTROY"}, {5, "WM_SIZE"},

{6, "WM_ACTIVATE"}, {13, "WM_SIZE"}, {22, "WM_SETVISIBLE"},

{23, "WM_ENABLE"}, {29, "WM_PAINT"}, {3, "WM_MOVE"}, {30, "WM_CLOSE"},

{32, "WM_SETCURSOR"}, {72, "WM_FULLSCREEN"}, {85, "WM_COPYDATA"},

{512, "WM_MOUSEMOVE"},{132, "WM_NCHITTEST"}, {641, "WM_IME_SETCONTEXT"},

{8, "WM_KILLFOCUS"}, {134, "WM_NCACTIVATE"}, {28, "WM_ACTIVATEAPP"},

{160, "WM_NCMOUSEMOVE"}, {161, "WM_NCLBUTTONDOWN"},

{36, "WM_GETMINMAXINFO"}, {642, "WM_IME_NOTIFY"}, {433, "WM_CAPTURECHANGED"},

{534, "WM_MOVING"}, {674, "WM_NCMOUSELEAVE"}, {675, "WM_MOUSELEAVE"},

{532, "WM_SIZING"}, {533, "WM_CAPTURECHANGED"}, {127, "WM_GETICON"},

{20, "WM_ERASEBKGND"}, {70, "WM_WINDOWPOSCHANGING"}, {71, "WM_WINDOWPOSCHANGED"},

{273, "WM_COMMAND"}, {274, "WM_SYSCOMMAND"}, {275, "WM_TIMER"}, {513, "WM_LBUTTONDOWN"},

{514, "WM_LBUTTONUP"}

};

// Code for debugging messages sent to Window

static std::stringstream ss;

ss.str("");

ss << " [TRACE] WNPROC Message => "

<< " Code = " << msg;

if(WindowMessages.find(msg) != WindowMessages.end())

ss << " ; Message = " << WindowMessages[msg];

else

ss << " ; Message = Unknown ";

return ss.str();

}