[RESOLVED] how calculate nPos when we resize the window?

[Cambalinho]

the nPos is X. now i resize the window. the nPage and the nMax must be changed. until here it's fine. but how can i calculate, now, the new nPos depending on X?
(i don't know do these calculation)

[VictorN]

But who knows what nPos, X, nPage and the nMax are?

[Cambalinho]

But who knows what nPos, X, nPage and the nMax are?

nPos, nPage and the nMax are CROLLINFO structure members except the 'X', that was for a sample nothing more

[VictorN]

You do it the same way as you did it earlier. You usually recalculate it under the case WM_SIZE in the window procedure used by the widow you resize.

[Cambalinho]

You do it the same way as you did it earlier. You usually recalculate it under the case WM_SIZE in the window procedure used by the widow you resize.

but if i'm, for example, on half of the scrollbar, i lose the nMax

void setAutoScroll(bool autoscroll)
        {
            blnAutoScroll=autoscroll;
            if((GetWindowLong(hwnd,GWL_STYLE)& WS_VSCROLL))
            {
                SetWindowLong(hwnd,GWL_STYLE,GetWindowLong(hwnd,GWL_STYLE) &~WS_VSCROLL);
            }

            if((GetWindowLong(hwnd,GWL_STYLE)& WS_HSCROLL))
            {
                SetWindowLong(hwnd,GWL_STYLE,GetWindowLong(hwnd,GWL_STYLE) &~WS_HSCROLL);
            }

            if(blnAutoScroll==true)
            {
                POINT ws=GetClientWindowSize();//give me the last control position+width
                RECT rtcParent;
                GetClientRect(hwnd,&rtcParent);
                if(ws.y>rtcParent.bottom)
                {
                    SetWindowLong(hwnd, GWL_STYLE,GetWindowLong(hwnd, GWL_STYLE) | WS_VSCROLL);
                    SCROLLINFO SCinfo;
                    SCinfo.cbSize=sizeof(SCROLLINFO);
                    SCinfo.fMask=SIF_RANGE | SIF_PAGE;
                    SCinfo.nMin =0;
                    SCinfo.nMax =ws.y;
                    SCinfo.nPage=rtcParent.bottom;
                    SetScrollInfo(hwnd,SB_VERT,&SCinfo, TRUE);
                }
                if(ws.x>rtcParent.right)
                {
                    SetWindowLong(hwnd, GWL_STYLE,GetWindowLong(hwnd, GWL_STYLE) | WS_HSCROLL);
                    SCROLLINFO SCinfo;
                    SCinfo.cbSize=sizeof(SCROLLINFO);
                    SCinfo.fMask=SIF_RANGE | SIF_PAGE;
                    SCinfo.nMin =0;
                    SCinfo.nMax =ws.x;
                    SCinfo.nPage=rtcParent.right;
                    SetScrollInfo(hwnd,SB_HORZ,&SCinfo, TRUE);
                }
            }
            SetWindowPos(hwnd,NULL,0,0,0,0,SWP_NOSIZE | SWP_NOZORDER | SWP_NOMOVE | SWP_DRAWFRAME);
        }

SIF_RANGE is for nMax and nMin;
the SIF_PAGE is for nPage.
after resize the window(nPos!=0) and then scroll it to nMax, i can't see the left\top most child control

[VictorN]

Sorry, I have no idea what this function is for and where it is about to call from and when.

[Cambalinho]

Sorry, I have no idea what this function is for and where it is about to call from and when.

imagine that you have a child control with a position more big than window client size... for calculate that, i use the GetClientWindowSize() function. the rest is for show me scrollbars and give them a nMax( the child control with a position more big than window client size) and nPage.

[VictorN]

imagine that you have a child control with a position more big than window client size... for calculate that, i use the GetClientWindowSize() function. the rest is for show me scrollbars and give them a nMax( the child control with a position more big than window client size) and nPage.

[Cambalinho]

see these image:

the GetClientWindowSize() function see where is the button for give me it's bottom value(scroll dimentions).
then from return values, i show the scrollbars and give them the nMax and nPos values.
these code works fine. but when the parent window is resized, i call the setAutoScroll() for change it's values. but i'm getting problems on continues with nPos value, when the form is resized

[VictorN]

... but when the parent window is resized, i call the setAutoScroll() for change it's values. but i'm getting problems on continues with nPos value, when the form is resized

See my posts##4 and 6.

[Cambalinho]

someone, before, told me that, when the parent is resized, that only the nPage is changed. so thinking on that, more, i change more the code and now works fine:

void setAutoScroll(bool autoscroll)
        {
            blnAutoScroll=autoscroll;
            if((GetWindowLong(hwnd,GWL_STYLE)& WS_VSCROLL))
            {
                SetWindowLong(hwnd,GWL_STYLE,GetWindowLong(hwnd,GWL_STYLE) &~WS_VSCROLL);
            }

            if((GetWindowLong(hwnd,GWL_STYLE)& WS_HSCROLL))
            {
                SetWindowLong(hwnd,GWL_STYLE,GetWindowLong(hwnd,GWL_STYLE) &~WS_HSCROLL);
            }

            if(blnAutoScroll==true)
            {
                POINT ws=GetClientWindowSize();
                RECT rtcParent;
                GetClientRect(hwnd,&rtcParent);
                if(ws.y>rtcParent.bottom)
                {
                    SetWindowLong(hwnd, GWL_STYLE,GetWindowLong(hwnd, GWL_STYLE) | WS_VSCROLL);
                    SCROLLINFO SCinfo;
                    SCinfo.cbSize=sizeof(SCROLLINFO);
                    SCinfo.fMask=SIF_RANGE | SIF_PAGE;
                    SCinfo.nMin =0;
                    SCinfo.nMax =ws.y;
                    SCinfo.nPage=rtcParent.bottom;
                    SetScrollInfo(hwnd,SB_VERT,&SCinfo, TRUE);
                }
                if(ws.x>rtcParent.right)
                {
                    SetWindowLong(hwnd, GWL_STYLE,GetWindowLong(hwnd, GWL_STYLE) | WS_HSCROLL);
                    SCROLLINFO SCinfo;
                    SCinfo.cbSize=sizeof(SCROLLINFO);
                    SCinfo.fMask=SIF_RANGE | SIF_PAGE;
                    SCinfo.nMin =0;
                    SCinfo.nMax =ws.x;
                    SCinfo.nPage=rtcParent.right;
                    SetScrollInfo(hwnd,SB_HORZ,&SCinfo, TRUE);
                }
            }
            SetWindowPos(hwnd,NULL,0,0,0,0,SWP_NOSIZE | SWP_NOZORDER | SWP_NOMOVE | SWP_DRAWFRAME);
        }

and when the parent is resized:

case WM_SIZING:
                case WM_SIZE:
                {
                    if(inst->getAutoScroll()==true)
                    {
                        RECT a;
                        GetClientRect(inst->hwnd,&a);
                        SCROLLINFO SCinfo;
                        SCinfo.cbSize=sizeof(SCROLLINFO);
                        SCinfo.fMask=SIF_PAGE;
                        GetScrollInfo(inst->hwnd,SB_VERT,&SCinfo);
                        SCinfo.nPage=a.bottom;
                        SetScrollInfo(inst->hwnd,SB_VERT,&SCinfo, TRUE);
                        GetScrollInfo(inst->hwnd,SB_HORZ,&SCinfo);
                        SCinfo.nPage=a.right;
                        SetScrollInfo(inst->hwnd,SB_HORZ,&SCinfo, TRUE);
                    }
                    RECT a;
                    GetWindowRect(inst->hwnd,&a);
                    ScreenToClient(GetParent(inst->hwnd),&a);
                    InvalidateRect(inst->hwnd, &a,true);
                    inst->Resize();
                    return 0;
                }
                break;

these simple code give me 1 idea :P
- when i add\resize a child control i send a message(SendMessage()) to parent(include the control handle) and just test it's client rectangle for change the vertical or horizontal nMax on scrollbar, instead see the client rectangle of all controls.