Thread: Custom Tab Control

Hi!

Well I don't seem to get a custom Tab control to work. I read several Tut's and looked at several Code examples, but I don't get it. I'm trying to do these smaller tabs that are aligned under a parent element, not above. (You know, like the worksheet-tabs in MS Excel)

I'm using the API, not MFC.

Thanks for any help.


PrivatePanic

well, my problem is I completely don't understand these custom tabs and I'd appreciate some push in the right direction to figure it out by myself. That's why I can't give you any code.... I read the tuts and the chapter about custom tab controls in the MSDN but that didn't help me much... so I thought someone here may explain to me roughly the general usage of the custom tab controls.

If your answer is "RTFM again until you get it" it's okay too, I willl do that then, ....but maybe here is actually someone who can explain this topic to me in a more understandable way

It is always difficult to answer a question like this because one simply doesn't know where to begin, i.e. what it is you don't understand!

A tab control is created with CreateWindow() using the WC_TABCONTROL class. Initially it has no tabs, you insert them, you can either use SendMessage() with the TCM_INSERTITEM message, or use the TabCtrl_InsertItem() macro. Once you've done this, the tab control sends you WM_NOTIFY messages when the user does anything. WM_NOTIFY returns a pointer to a NMHDR structure which contains the action code, (there are more than one), and the tab which sent it.

Here is a self contained program which creates a very simple tab control sized to fit the screen, with four tabs. All the tabs do is put a message up saying which has been pressed. Have a look at it and see where you go.

Incidently, the position of the tabs is simply a style issue, if you want to move them around, look at the TCS_x styles.

Thanks for that example, but you're right, I'm sorry I didn't give more informations what exactly I'm not able to do. I am able to do the Tab Controls, as you described me, that's not the problem. My problem is to create a Custom Tab Control. What I mean is a Tab Control that has not the standard "Tab graphics" but customized ones. I want to have the smaller, white, trapezoid-shaped Tabs like the Tabs u choose the worksheets in MS Excel with.

I'll attach a small Screenshot to show these Tabs to u.

I know I can't use the normal TabCtrl for these Tabs, it has to be a customized one; but I have no Idea how to do that.

Sorry again for the inconvenience and thanks for any helpful hints

Pry

Okay I figured out that I have to use the TCS_OWNERDRAWFIXED style on my TabControl and that I then have to process the WM_DRAWITEM message.

MSDN says:

The tab control sends this message whenever a tab needs to be painted. The lParam parameter specifies the address of a DRAWITEMSTRUCT structure, which contains the index of the tab, its bounding rectangle, and the device context (DC) in which to draw.

But I still don't know how to implement this. *sigh*

OK, briefly this is what you have to do. Not compleate as I am pressed for time (Friday afternoon and all that)
the msg you will have to deal with to repaint the TAB ctrl is

Code:

case WM_DRAWITEM:
pDrawItem = (DRAWITEMSTRUCT *)lParam;
if(pDrawItem->hwndItem==hWndTAB_Ctrl)
{
//process the paint msg
}

//To paint the tabs white with black border
HBRUSH   hWhite=NULL,hBlack=NULL;

hWhite=GetStockObject(WHITE_BRUSH);//get a white brush to draw with
hBlack=GetStockObject(BLACK_BRUSH);
FillRect(pDrawItem->hDC,&(pDrawItem->rcItem),hWhite);//paint the area white
FrameRect(pDrawItem->hDC,&(pDrawItem->rcItem), hBlack);//draw a black frame around tab
//don't have to delete stock objects but it does not harm and GDI resources must be released
DeleteObject(hWhite);
DeleteObject(hBlack);

//text
//get the text on the tab
//this will be a macro, you can find this and store the string in sBuffer

//then use this to determine its actual length so you can see if it fits, center it ect.
GetTextExtentPoint32(pDrawItem->hDC, sBuffer, lstrlen(sBuffer), &Size);
//Size.cx and Size.cy now contain the 'size' of the string
//find the center start= (total_width-string_width)/2
xStart=(int)((pDrawItem->rcItem.right-pDrawItem->rcItem.left)-Size.cx)/2;

TextOut(pDrawItem->hDC, xStart,  pDrawItem->rcItem.top, sBuffer, lstrlen(sBuffer));

Yeah, Friday and all that... I started fiddling with this as well and had modified the test program to deal with the WM_DRAWITEM message in much the same way, however, the controls don't look quite right so far. Next week maybe...