Thread: Text Box

Hello everyone

To begin with, I have had some GUI programming experience with Python's Tkinter.
Manipulating the widgets is easy for prototyping. I am beginning to learn GUI programming with C++ now in order to get more control, as well as make individual .EXE executables that are otherwise interpreted in Python.

The compiler I am using right now is DevC++.

Here is my current code:

Code:

#include <windows.h>

const char ClassName[] = "WindowClass";

// Message Queue Commands
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg) // if&else commands to follow when interpreting the current message in queue
    {
        case WM_LBUTTONDOWN: //if message was a left button click
            MessageBox(hwnd, //if left button clicked inside current handle?
                       "Content", //Popup Window Content
                       "Current Directory", //Popup Window Title
                       MB_OK | MB_ICONINFORMATION); //Okay button
        break; //without break, program would close
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY: //if message was the cancel button [x]???
            PostQuitMessage(0);
        break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

//WinMain() instead of main()
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    //Window class
    WNDCLASSEX wc;
    //Window class parameters
    wc.cbSize        = sizeof(WNDCLASSEX); //???
    wc.style         = 0; //???
    wc.lpfnWndProc   = WndProc; //???
    wc.cbClsExtra    = 0; //???
    wc.cbWndExtra    = 0; //???
    wc.hInstance     = hInstance; //???
    wc.hIcon         = LoadIcon(NULL,IDI_APPLICATION); //Executable's desktop icon
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW); //Cursor
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); //Window color
    wc.lpszMenuName  = NULL; //No menu
    wc.lpszClassName = ClassName; //???
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION); //Window icon? , Sm = small?

    if(!RegisterClassEx(&wc)) //error handling
    {
        MessageBox(NULL, "Registration Failure", "Error", MB_OK); //Okay button
        return 0; //return fail
    }

    ////////////////////////////////////////////////////////////////////////////

    //The actual window
    HWND MyParentWindow;
    //The window's parameters
    MyParentWindow = CreateWindowEx(
        0, //Style
        ClassName, //Current class name , Does this mean MyParentWindow takes on wc's characteristics via the name ClassName?
        "Title", //Title
        WS_OVERLAPPEDWINDOW, //minimize, maximize, close
        0,//position x in pixels relative to screen
        0,//position y in pixels relative to screen
        500,//size x dimension in pixels
        500,//size y dimension in pixels
        NULL, //MyParentWindow is the parent window and it does not have a parent, thus NULL
        NULL, //no menu was defined
        hInstance, //???
        NULL); //???

    if(MyParentWindow == NULL) //error handling
    {
        MessageBox(NULL, "MyParentWindow Creation Failure", "Error", MB_OK); //okay button
        return 0;
    }

    ShowWindow(MyParentWindow, nCmdShow); //show the window called "MyParentWindow"
    UpdateWindow(MyParentWindow); //update the window called "MyParentWindow"

    ////////////////////////////////////////////////////////////////////////////

    // Message loop
    MSG Msg;
    //GetMessage() gets a message from message queue.
    while(GetMessage(&Msg, NULL, 0, 0) > 0) //while there are more than 0 messages?
    {
        TranslateMessage(&Msg); //current message interpreted???
        DispatchMessage(&Msg); //result of current message???
    }
    return Msg.wParam; //return result???
}

This summons a blank window whose internal region is 500x500 pixels squared.
When you click the region it opens up a message box.
Copy and pasting the code directly into an updated DevC++ compiler should work as is.


How do I put a text box in that region instead?
Do I have to define new content in an RC Resource file and use it in the CPP source file?

Thank you everyone for your time
I am new to C++ GUI programming, but I hope to learn.

I have a new question, but here is the updated source code with the text box whose size is equal to the maximum region's size:

Code:

#include <windows.h>
#define TextBoxDefined   101

const char ClassName[] = "WindowClass";

// Message Queue Commands
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg) // if&else commands to follow when interpreting the current message in queue
    {
        case WM_CREATE:
        {
            HWND TextBox;
            TextBox = CreateWindowEx(WS_EX_CLIENTEDGE,
                                   "EDIT",
                                   "Predefined Text",
                                   WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL | ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL,
                                   0,
                                   0,
                                   0,
                                   0,
                                   hwnd,
                                   (HMENU)TextBoxDefined,
                                   GetModuleHandle(NULL),
                                   NULL);
            if(TextBox == NULL)
                MessageBox(hwnd, "Text Box creation failed", "Error", MB_OK | MB_ICONERROR);

            HFONT hfDefault;
            hfDefault = (HFONT)GetStockObject(DEFAULT_GUI_FONT);

            SendMessage(TextBox, WM_SETFONT, (WPARAM)hfDefault, MAKELPARAM(FALSE,0));
        }
        break;
        
        case WM_SIZE:
        {
            HWND TextBox;
            TextBox = GetDlgItem(hwnd, TextBoxDefined);
            
            RECT FullWindow;
            GetClientRect(hwnd, &FullWindow);
            SetWindowPos(TextBox, //this object being our textbox
                         NULL, //???
                         0, //horizontal position from left
                         0, //vertical position from right
                         FullWindow.right, //full window horiztonal size
                         FullWindow.bottom, //full window vertical size
                         SWP_NOZORDER); //???
        }
        break;
        
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY: //if message was the cancel button [x]???
            PostQuitMessage(0);
        break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

//WinMain() instead of main()
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
 //Window class
    WNDCLASSEX wc;
    //Window class parameters
    wc.cbSize        = sizeof(WNDCLASSEX); //???
    wc.style         = 0; //???
    wc.lpfnWndProc   = WndProc; //???
    wc.cbClsExtra    = 0; //???
    wc.cbWndExtra    = 0; //???
    wc.hInstance     = hInstance; //???
    wc.hIcon         = LoadIcon(NULL,IDI_APPLICATION); //Executable's desktop icon
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW); //Cursor
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); //Window color
    wc.lpszMenuName  = NULL; //No menu
    wc.lpszClassName = ClassName; //???
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION); //Window icon? , Sm = small?

    if(!RegisterClassEx(&wc)) //error handling
    {
        MessageBox(NULL, "Registration Failure", "Error", MB_OK); //Okay button
        return 0; //return fail
    }

    ////////////////////////////////////////////////////////////////////////////

 //The actual window
    HWND MyParentWindow;
    //The window's parameters
    MyParentWindow = CreateWindowEx(
        0, //Style
        ClassName, //Current class name , Does this mean MyParentWindow takes on wc's characteristics via the name ClassName?
        "Title", //Title
        WS_OVERLAPPEDWINDOW, //minimize, maximize, close
        0,//position x in pixels relative to screen
        0,//position y in pixels relative to screen
        500,//size x dimension in pixels
        500,//size y dimension in pixels
        NULL, //MyParentWindow is the parent window and it does not have a parent, thus NULL
        NULL, //no menu was defined
        hInstance, //???
        NULL); //???

    if(MyParentWindow == NULL) //error handling
    {
        MessageBox(NULL, "MyParentWindow Creation Failure", "Error", MB_OK); //okay button
        return 0;
    }

    ShowWindow(MyParentWindow, nCmdShow); //show the window called "MyParentWindow"
    UpdateWindow(MyParentWindow); //update the window called "MyParentWindow"

    ////////////////////////////////////////////////////////////////////////////

 // Message loop
    MSG Msg;
    //GetMessage() gets a message from message queue.
    while(GetMessage(&Msg, NULL, 0, 0) > 0) //while there are more than 0 messages?
    {
        TranslateMessage(&Msg); //current message interpreted???
        DispatchMessage(&Msg); //result of current message???
    }
    return Msg.wParam; //return result???
}

My new question is this:
How do I edit the background color of this textbox?

If it is at all possible, I would greatly appreciate to see how to use the GetWindowText() function in an example, and how to use case WM_KEYDOWN to associate key strokes with certain actions (such as using CTRL+A to select all of the text).

These are the documentations I am looking at:
GetTextFunction()
and
WM_KEYDOWN

The information is there, I admit, but it's always nice to see concrete examples since I'm a little confused on the order of execution and the code placements.

My guess is that the case WM_KEYDOWN would be used first, with the specific keys associated (how would I use a key combination like CTRL+A, or even simple letters like 'A'?), and then the GetWindowText() would be applied. How would I store the content inside a character array?

Thank you everyone

For the color : WM_CTRLCOLOREDIT message.