Auto-resizing a text box object with the main window

[RankoKurotsuki]

I am currently working on writing a Notepad clone from scratch. I have a good base set up, but I am having trouble figuring out how to get the text box object to resize itself with the main window. Here is the code for the text box:

	RECT rect;
	GetWindowRect(hWnd, &rect);
	HWND hEdit = CreateWindowEx(WS_EX_CLIENTEDGE,
				"EDIT",
				"",	
                                WS_CHILD|WS_VISIBLE|ES_MULTILINE|ES_AUTOVSCROLL,
				0,
				0,
				((rect.right - rect.left) - 15),
                                ((rect.bottom - rect.top) - 55),
				hWnd,
				(HMENU)IDC_MAIN_EDIT,
				GetModuleHandle(NULL),
				NULL);

Can anyone help me out with this?

[freddie1]

Use GetClientRect instead of GetWindowRect, and for cx and cy just use rect.right and rect.bottom.

[RankoKurotsuki]

It didn't work. Here is the rest of the code:

// N0T3p4DCl0N3.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "N0T3p4DCl0N3.h"

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;								// current instance
TCHAR szTitle[MAX_LOADSTRING];					// The title bar text
TCHAR szWindowClass[MAX_LOADSTRING];			// the main window class name

// Forward declarations of functions included in this code module:
ATOM				MyRegisterClass(HINSTANCE hInstance);
BOOL				InitInstance(HINSTANCE, int);
LRESULT CALLBACK	WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK	About(HWND, UINT, WPARAM, LPARAM);
bool				NewFile();
bool				SaveFile();
bool				SaveFileAs(HWND hWnd);

int APIENTRY _tWinMain(HINSTANCE hInstance,
						HINSTANCE hPrevInstance,
						LPTSTR    lpCmdLine,
						int       nCmdShow)
{
	UNREFERENCED_PARAMETER(hPrevInstance);
	UNREFERENCED_PARAMETER(lpCmdLine);

	// TODO: Place code here.
	MSG msg;
	HACCEL hAccelTable;

	// Initialize global strings
	LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
	LoadString(hInstance, IDC_N0T3P4DCL0N3, szWindowClass, MAX_LOADSTRING);
	MyRegisterClass(hInstance);

	// Perform application initialization:
	if (!InitInstance (hInstance, nCmdShow))
	{
		return FALSE;
	}

	hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_N0T3P4DCL0N3));

	// Main message loop:
	while (GetMessage(&msg, NULL, 0, 0))
	{
		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}

	return (int) msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage are only necessary if you want this code
//    to be compatible with Win32 systems prior to the 'RegisterClassEx'
//    function that was added to Windows 95. It is important to call this function
//    so that the application will get 'well formed' small icons associated
//    with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
	WNDCLASSEX wcex;

	wcex.cbSize = sizeof(WNDCLASSEX);

	wcex.style			= CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc	= WndProc;
	wcex.cbClsExtra		= 0;
	wcex.cbWndExtra		= 0;
	wcex.hInstance		= hInstance;
	wcex.hIcon			= LoadIcon(hInstance, MAKEINTRESOURCE(IDI_N0T3P4DCL0N3));
	wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1);
	wcex.lpszMenuName	= MAKEINTRESOURCE(IDC_N0T3P4DCL0N3);
	wcex.lpszClassName	= szWindowClass;
	wcex.hIconSm		= LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

	return RegisterClassEx(&wcex);
}

//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
	HWND hWnd;

	hInst = hInstance; // Store instance handle in our global variable

	hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
	  CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

	if (!hWnd)
	{
	  return FALSE;
	}

	ShowWindow(hWnd, nCmdShow);
	UpdateWindow(hWnd);
	RECT rect;
	GetClientRect(hWnd, &rect);
	HWND hEdit = CreateWindowEx(WS_EX_CLIENTEDGE,
								"EDIT",
								"",
								WS_CHILD|WS_VISIBLE|ES_MULTILINE|ES_AUTOVSCROLL,
								0,
								0,
								rect.right,
								rect.bottom,
								hWnd,
								(HMENU)IDC_MAIN_EDIT,
								GetModuleHandle(NULL),
								NULL);
	return TRUE;
}

//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND	- process the application menu
//  WM_PAINT	- Paint the main window
//  WM_DESTROY	- post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	int wmId, wmEvent;
	PAINTSTRUCT ps;
	HDC hdc;

	switch (message)
	{
	case WM_COMMAND:
		wmId    = LOWORD(wParam);
		wmEvent = HIWORD(wParam);
		// Parse the menu selections:
		switch (wmId)
		{
		case IDM_NFILE:
			NewFile();
			break;				// TODO: Add code for New/Open file, and save functions.
		case IDM_OFILE:
			break;
		case IDM_SAVE:
			SaveFile();
			break;
		case IDM_SAVEAS:
			SaveFileAs(hWnd);
			break;
		case IDM_COPY:
			break;				// No code is needed
		case IDM_CUT:
			break;				// No code is needed
		case IDM_PASTE:
			break;				// No code is needed
		case IDM_ABOUT:
			DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
			break;
		case IDM_EXIT:
			DestroyWindow(hWnd);
			break;
		default:
			return DefWindowProc(hWnd, message, wParam, lParam);
		}
		break;
	case WM_PAINT:
		hdc = BeginPaint(hWnd, &ps);
		// TODO: Add any drawing code here...
		EndPaint(hWnd, &ps);
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hWnd, message, wParam, lParam);
	}
	return 0;
}

// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	UNREFERENCED_PARAMETER(lParam);
	switch (message)
	{
	case WM_INITDIALOG:
		return (INT_PTR)TRUE;

	case WM_COMMAND:
		if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
		{
			EndDialog(hDlg, LOWORD(wParam));
			return (INT_PTR)TRUE;
		}
		break;
	}
	return (INT_PTR)FALSE;
}

bool NewFile()
{
	return TRUE;
}

bool SaveFile()
{
	return TRUE;
}

bool SaveFileAs(HWND hWnd)
{
	return TRUE;
}

What's wrong with it?

[andywestken]

1. I should really create your child windows in WM_CREATE and destroy them in WM_DESTROY

2. You also need to implement WM_SIZE to resize the child windows as the main window is resized

[andywestken]

Are you using VC++ Express 2010?

[RankoKurotsuki]

no. I'm using VC++ Express 2008. and I'm using the standard startup code for a Win32 program. any ideas?

[webJose]

Yes, do as andy said.

Plus: On IDM_EXIT, you should SendMessage() a WM_CLOSE message; your window procedure should catch WM_CLOSE and determine if the document is dirty, and if it is, offer the user to save it before exiting. The standard options for the end user would be Yes, No, and Cancel. Cancel should avoid DestroyWindow() at all costs, while the other two would call for DestroyWindow(), maybe after saving the document, if the user chose to.

Oh, and on WM_DESTROY, you should PostQuitMessage(<return value here>); .

[RankoKurotsuki]

the WM_CREATE message won't work because that message won't occur in my program. can you come up with something that will work?

[freddie1]

Oh! Sorry I posted bum advice! I didn't catch the part about having it resize. Andy told you what to do in anycase. You need to put a WM_CREATE handler in your main program WndProc. Of course a WM_CREATE msg will come through!

And like Andy said, you need a WM_SIZE handler for your main window because the parameters of that msg will tell you the present size of the window, and you'll need that info to do a MoveWindow() call on your edit control to size it.

[RankoKurotsuki]

I tried that and the compiler said that the code for the WM_CREATE handler is skipped by the rest of the messages. any ideas?

[andywestken]

Sounds like you need to close the case statement in braces (a variables initialization is being skipped?).

I do this for all non-trival cases in a switch statement, so I can declare variables in as tight a scope as possible.

For example, I would code WM_PAINT as

	case WM_PAINT:
	{
		PAINTSTRUCT ps = {0};
		HDC hdc = BeginPaint(hWnd, &ps);
		// TODO: Add any drawing code here...
		EndPaint(hWnd, &ps);
	}
	break;