Dynamic GUI

[compman9902]

People, first of all thank you for reading my post.
I would like to start off by saying that I have read Prorgramming Windows and I have found no information that contributes to what I need to do.
Here is what I need help with. I need to make a windown with text in the middle of it that displays "Percent: %X" X being a intiger that I submit to the function that makes thew window.
Basicaly, a funtion that when I send a intiger to it, it opens up and then displays what is above. Then, it just dosn't close after it initially opens.
I really need help on this.
Thank you.

[weaknessforcats]

And you can't build a string containing your display and just use TextOut() ??

[Studlyami]

I'm not quite sure i fully understand the question. You need help closing the winodw? or creating the window? or centering the text?

[compman9902]

I'm not quite sure i fully understand the question. You need help closing the winodw? or creating the window? or centering the text?

All of the above
And then some

[kreagan]

All of the above
And then some

Would message pop up work for you?
MessageBox

[Studlyami]

Message box is nice and it provides and OK which will close it when clicked.

As for centering text here are the basic steps needed.


Get total window width and height (windowrect.right - windowrect.left; windowrect.bottom - windowrect.top)

divided total height and width by 2 (you want the center of the window).

Now we have the center of the window we need to subtract half the size of the string width and half of the string height.

Use GetTextExtentPoint32 and divide that number by 2 that will be your x,y value for drawing the font. You'll need to look up the parameters for GetTextExtentPoint32 i can never remember exactly how it works

[compman9902]

Message box is nice and it provides and OK which will close it when clicked.

As for centering text here are the basic steps needed.


Get total window width and height (windowrect.right - windowrect.left; windowrect.bottom - windowrect.top)

divided total height and width by 2 (you want the center of the window).

Now we have the center of the window we need to subtract half the size of the string width and half of the string height.

Use GetTextExtentPoint32 and divide that number by 2 that will be your x,y value for drawing the font. You'll need to look up the parameters for GetTextExtentPoint32 i can never remember exactly how it works

It would only work if the window would close automatically when a new number was submitted to the function and then opened up another with the submitted number.
Actually.
The above sounds perfect.
If you can, please post code.

[Studlyami]

Here is the basic way of centering the text on a given window. I was unable to get the dynamic window to work, but im sure a couple of the other people can help you out with that.

RECT TempRect;
GetWindowRect(hWnd, &TempRect);
LPCSTR myString = "This is the string to output";
SIZE StringSize;
GetTextExtentPoint32(GetDC(hWnd), (LPCTSTR) myString, 28, &StringSize);
int Textx = (TempRect.right - TempRect.left)/2 - (StringSize.cx/2);
int Texty =    (TempRect.bottom - TempRect.top)/2 - (StringSize.cy/2);
TextOut(GetDC(hWnd),Textx,Texty,myString,28);
 

That 28 is the number of chars in the string. I'm sure there is a way to get that dynamically, but im tired.

[compman9902]

Here is the basic way of centering the text on a given window. I was unable to get the dynamic window to work, but im sure a couple of the other people can help you out with that.

RECT TempRect;
GetWindowRect(hWnd, &TempRect);
LPCSTR myString = "This is the string to output";
SIZE StringSize;
GetTextExtentPoint32(GetDC(hWnd), (LPCTSTR) myString, 28, &StringSize);
int Textx = (TempRect.right - TempRect.left)/2 - (StringSize.cx/2);
int Texty =    (TempRect.bottom - TempRect.top)/2 - (StringSize.cy/2);
TextOut(GetDC(hWnd),Textx,Texty,myString,28);
 

That 28 is the number of chars in the string. I'm sure there is a way to get that dynamically, but im tired.

Thank yoyu very much..But, where do I put this to make the code work?

[Studlyami]

That would go after the new window is created. Instead of grabbing the rect for hWnd you would use the new window handle. If someone could help out with the dynamic window creation applying that code would make a lot more sense.

[compman9902]

That would go after the new window is created. Instead of grabbing the rect for hWnd you would use the new window handle. If someone could help out with the dynamic window creation applying that code would make a lot more sense.

Then it is agreed, I need help.
Anyone?

[compman9902]

And you can't build a string containing your display and just use TextOut() ??

Could you maybe write an example of how to use it? Becasue I have next to no experience with GUI in C++, so that would be great.

[compman9902]

Actually, I just thought of something. All I need is what goes under the "WM_PAINT" case and then I'll be golden.

[Studlyami]

So, you don't want a new window to be created then? If so, you don't want that code under the WM_PAINT.

[compman9902]

So, you don't want a new window to be created then? If so, you don't want that code under the WM_PAINT.

Oh, then I'm stuck. Any Tips? Anybody?
Also, just for future refrence, I was wondering what include to put in to the textout() function works. I'm using Dev-C++. Thanks.

[Studlyami]

WM_PAINT message gets sent on a lot of different occasions so having a create within that message would be bad. the textout function takes textout(<window handle>, <X location to draw>, <Y location to draw>, <String to be drawn>, <number of characters in string>). That code up above is all you need to center text on a given window. The only thing that needs to change is the handle to the window. The problem you are running into is the dynamic window creation in win32. After you create the dynamic window you will have a handle to that window.

[compman9902]

WM_PAINT message gets sent on a lot of different occasions so having a create within that message would be bad. the textout function takes textout(<window handle>, <X location to draw>, <Y location to draw>, <String to be drawn>, <number of characters in string>). That code up above is all you need to center text on a given window. The only thing that needs to change is the handle to the window. The problem you are running into is the dynamic window creation in win32. After you create the dynamic window you will have a handle to that window.

I wanted to try out the textout() function, so I created the following program:

#include <windows.h>
#include <string>
#include <vector>
using namespace std;
 
/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
 
/*  Make the class name into a global variable  */
char szClassName[ ] = "WindowsApp";
 
int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)
 
{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */
 
    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);
 
    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
 
    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;
 
    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Windows App",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           544,                 /* The programs width */
           375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );
 
    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);
 
    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }
 
    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}
 
 
/*  This function is called by the Windows function DispatchMessage()  */
 
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_PAINT:
            PAINTSTRUCT paintStruct;
            HDC hdc;
            hdc = GetDC (hwnd);
            BeginPaint (hwnd, &paintStruct);
            textout(hdc, 500, 500, "yo", 2);
            EndPaint(hwnd, &paintStruct);
            ReleaseDC (hwnd, hdc);
            return 0;
        break;
        case WM_DESTROY:
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }
 
    return 0;
}

When I try to compile it, I get the following error:
87 C:\Documents and Settings\DBE\Desktop\main.cpp `textout' undeclared (first use this function)
That is what I was asking about in my last post. The dynamic text thing is a different matter, but still needs attending to.

[Studlyami]

You textout needs to be TextOut(...)
capital T capital O

[compman9902]

You textout needs to be TextOut(...)
capital T capital O

That fixes that error.
Now I get tge error message:
[Linker error] undefined reference to `TextOutA@20'
ld returned 1 exit status

[Studlyami]

Did you try creating a new project and pasting the code in or was this a code file downloaded from somewhere? If it was a code file downloaded from somewhere try creating a new win32 project and copy that code and paste it in the new project. I copied your code made the change and it works fine. I'm using Visual studios 2003 to build it.

[compman9902]

Did you try creating a new project and pasting the code in or was this a code file downloaded from somewhere? If it was a code file downloaded from somewhere try creating a new win32 project and copy that code and paste it in the new project. I copied your code made the change and it works fine. I'm using Visual studios 2003 to build it.

Neat, it works.
Well, now all I need is how to get it to be dynamic whenever I pass an intiger into the function that creates the window, and then it displays that.

[compman9902]

I would just like to remind everyone involved with this post that the issue has not been resolved.
It seems like everyone has forgotten since the last post was 29 days ago

[weaknessforcats]

I would just like to remind everyone involved with this post that the issue has not been resolved.
It seems like everyone has forgotten since the last post was 29 days ago

The code sample doesn't compile.

There are various errors. Mainly attempting to use a char array as an LPWSTR. For that I added the include of tchar.h and used the standard TCHAR mappings you are supposed to use in Windows code.

All I did was take you code, create a Win32 Project in Visual Studio.NET 2005 and fix errors. I did rework the WM_PAINT message handling.

The code below works and displays the yo in the center of the window. Have a look and you will see where my changes are.

I had no idea that the code was never compilng.

#include <windows.h>
#include <string>
#include <vector>
using namespace std;
#include <tchar.h>
 
/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
 
/*  Make the class name into a global variable  */
TCHAR szClassName[ ] = TEXT("WindowsApp");
 
int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)
 
{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */
 
    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);
 
    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
 
    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;
 
    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           TEXT("Windows App"),       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           CW_USEDEFAULT,        /* The programs width */
           CW_USEDEFAULT,        /* and height in pixels */
           //544,                 /* The programs width */
           //375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );
 
    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);
 
    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }
 
    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}
 
 
/*  This function is called by the Windows function DispatchMessage()  */
 
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;
    switch (message)                  /* handle the messages */
    {
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            GetClientRect(hwnd, &rect);
            DrawText(hdc, TEXT("yo"), -1, &rect,
                  DT_SINGLELINE | DT_CENTER | DT_VCENTER);
            EndPaint(hwnd, &ps);
            return 0;
        break;
        case WM_DESTROY:
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }
 
    return 0;
}