automatic button sizing

**willc0de4food** · 01-03-2006

hey... i was wondering if there was a way i could have my program size buttons automatically depending on the text contained within them. reason being i'd like to create a program that can allow the user to add custom buttons depending on if one they want isn't one i create by default. i was also considering having the user create all of the buttons they wanted / needed on their own so that i wouldn't have one there they're never going to use. but in any case - the length of the text contained on a button to me is unknown so it'd just be nice if i could take in the text the user wants displayed on the button, store it in the registry, and then create the button from there of the appropriate size.
any ideas?

**bithub** · 01-03-2006

Try something like this:

Code:

HWND hwndButton = the button;
HDC hdc = GetDC(hwndButton);
SIZE s;
TCHAR szButtonText[] = _T("The button text"); 
GetTextExtentPoint32(hdc,szButtonText, _tcslen(szButtonText),&s);

Then you resize the button so its width is greater than s.cx

**willc0de4food** · 01-03-2006

hMm...interesting. i'll give it a try once i get into coding it.
mm...its been a while. lol

::sigh::

**bithub** · 01-03-2006

Dont include the resource script. You should have a resource header which you include.

**willc0de4food** · 01-03-2006

what do you mean? i dont have an include for the resource script, but in my resource script i accidently had: #include res.h and yea. that was just a dumb mistake. lol so i dont have it included, i just have it added to my project.

**bithub** · 01-03-2006

That's strange... did you edit your post? I remember posting that last comment in regards to someone trying to #include a .rc file, but either I posted my comment in the wrong thread, or you edited your post =/

**willc0de4food** · 01-03-2006

lol i edited my post because i realized my stupidity :]

**willc0de4food** · 01-04-2006

kk, so uh...how do i resize the button? lol and did i do things correct?

Code:

case IDOK:
                {
                     int length = GetWindowTextLength(GetDlgItem(hwnd, IDC_TEXT));
                     TCHAR *title;
                     HWND hwndButton = CreateWindowEx(0, TEXT("BUTTON"), TEXT(""), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON | WS_TABSTOP,
                       ex, why, 80, 20, hwnd, (HMENU)btn, GetModuleHandle(NULL), 0);
                     HDC hdc = GetDC(hwndButton);
                     SIZE s;
                     
                     title = malloc(length + 1);
                     GetDlgItemText(hwnd, IDC_TEXT, title, length);
                     GetTextExtentPoint32(hdc,title, _tcslen(title),&s);
                }
                break;

thanks :]

**bithub** · 01-04-2006

also - which header is tcslen() declared in?

tchar.h
If you don't care about making your program unicode compliant, then you can skip that and just use strlen(). If you are sticking with unicode, then change your malloc call to:

Code:

title = malloc((length + 1) * sizeof(TCHAR));

how do i resize the button?

Use the MoveWindow() function.

**Tronic** · 01-04-2006

bithub..how do you know all of this stuff? x.x. Is there some vast archive of knowledge that I'm missing?

If said vast archive of knowledge is MSDN...well....I guess I just fail at navigating it or something x.x.

**willc0de4food** · 01-04-2006

my guess would be he knows it the same way you know how to make a hello world program.
seeing, reading, practicing :] lol

but thank you bithub - your help is greatly appreciated.
works like a champ.

now i just have to deal with the button positioning, lol

**bithub** · 01-04-2006

bithub..how do you know all of this stuff? x.x. Is there some vast archive of knowledge that I'm missing?

I've run into most of the problems posted in this forum at one time or another over the last decade or so. Over time I've gotten better at searching MSDN, and I've built up a code base of about 60 different Windows programs on my hard drive which I can search through when I need to remember how I tackled some problem.

but thank you bithub - your help is greatly appreciated.

**willc0de4food** · 01-04-2006

k so when the user wants to remove a button from the main window, i open a new dialog. in this new dialog is a select box with the title of each button. from here the user can choose to remove a single item or to clear the entire list. i've got down the removing items from / clearing the list, but how would i go about making it so that when the user removes an item from the list, it will also remove the corresponding button? here's my code for the remove and clear cases:

Code:

case IDC_REMOVE:
                {
                    // When the user clicks the Remove button, we first get the number
					// of selected items

					HWND hList = GetDlgItem(hwnd, IDC_LIST);
					int count = SendMessage(hList, LB_GETSELCOUNT, 0, 0);
					if(count != LB_ERR)
					{
						if(count != 0)
						{
							// And then allocate room to store the list of selected items.

							int i;
							int *buf = GlobalAlloc(GPTR, sizeof(int) * count);
							SendMessage(hList, LB_GETSELITEMS, (WPARAM)count, (LPARAM)buf);
							
							// Now we loop through the list and remove each item that was
							// selected.  

							// WARNING!!!  
							// We loop backwards, because if we removed items
							// from top to bottom, it would change the indexes of the other
							// items!!!
							if (count == 1)
							    SetDlgItemText(hwnd, IDC_STATIC, msg1);
			                else if (count > 1)
			                    SetDlgItemText(hwnd, IDC_STATIC, msg2);
                            else
                                MessageBox(NULL, "Error 1000101;\n\nPlease report this error.",
                                  "Error!", MB_OK | MB_ICONEXCLAMATION);

							for(i = count - 1; i >= 0; i--)
							{
								SendMessage(hList, LB_DELETESTRING, (WPARAM)buf[i], 0);
							}

							GlobalFree(buf);
						}
						else 
						{
							MessageBox(hwnd, "No items selected.", "Warning", MB_OK);
						}
					}
					else
					{
						MessageBox(hwnd, "Error counting items :(", "Warning", MB_OK);
					}
                 }
                break;
                case IDC_CLEAR:
                {
                    // When the user clicks the Clear button, we first select all of the
					// items and then go ahead just as we did previously with the Remove
                    // button to delete all of the items in the select box. 
                    
					HWND hList = GetDlgItem(hwnd, IDC_LIST);
					int count = 0;
					
					SendMessage(hList, LB_SETSEL, (WPARAM)TRUE, (LPARAM)-1);
					count = SendMessage(hList, LB_GETSELCOUNT, 0, 0);
					
					if(count != LB_ERR)
					{
						if(count != 0)
						{
							// And then allocate room to store the list of selected items.

							int i;
							int *buf = GlobalAlloc(GPTR, sizeof(int) * count);
							SendMessage(hList, LB_GETSELITEMS, (WPARAM)count, (LPARAM)buf);
							
							// Now we loop through the list and remove each item that was
							// selected.  

							// WARNING!!!  
							// We loop backwards, because if we removed items
							// from top to bottom, it would change the indexes of the other
							// items!!!
							
							if (count == 1)
							    SetDlgItemText(hwnd, IDC_STATIC, msg1);
			                else if (count > 1)
			                    SetDlgItemText(hwnd, IDC_STATIC, msg2);
                            else
                                MessageBox(NULL, "Error 1000101;\n\nPlease report this error.",
                                  "Error!", MB_OK | MB_ICONEXCLAMATION);

							for(i = count - 1; i >= 0; i--)
							{
								SendMessage(hList, LB_DELETESTRING, (WPARAM)buf[i], 0);
							}

							GlobalFree(buf);
						}
						else 
						{
							MessageBox(hwnd, "There are no items to be removed.", "Warning", MB_OK);
						}
					}
					else
					{
						MessageBox(hwnd, "Error counting items :(", "Warning", MB_OK);
					}
                 }
                break;

thanks

**bithub** · 01-04-2006

You are making this way harder than it needs to be

To clear all items from a list:

Code:

SendMessage(hwndList,LB_RESETCONTENT,0,0);

Also, don't use GlobalAlloc() unless you are sure you need to. Just use malloc(). malloc() is faster, and easier to use.

Here is how I would handle button removal. Each button should have a separate ID. This is the value that gets passed as the HMENU parameter of CreateWindow(). You use this ID to get a handle to the button's HWND, and then you can delete it. The trick is how to get the button ID from a listbox selection.

When you load the listbox with the button strings, you can also save the button ID. Like this:

Code:

int nListboxIndex;
nListboxIndex = SendMessage(hwndList, LB_ADDSTRING,0,(LPARAM)szButtonString);
SendMessage(hwndList,LB_SETITEMDATA, nListboxIndex,buttonID);

Then when a user selects an item from the listbox...

Code:

int nSel = the listbox selection;
int buttonID = SendMessage(hwndList, LB_GETITEMDATA, nSel,0);
HWND hwndButton = GetDlgItem(hwndDlg,buttonID);

**willc0de4food** · 01-04-2006

kk. i have a variable that starts where the initially created buttons end. when a button is created, its created with the variable and then after creation the variable has 1 added to it that way they all have an id :] i was thinking ahead.
thanks for the help. i'll incorporate the thoughts and code you've given me and we can see what happens..

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