Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box - C / C++ / MFC Discussion Boards

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50216-Feb-09 18:30

16-Feb-09 18:30

Hi Stuart,
I am using below code snippet in OnPaint method..
CRect rcLine1(baseSize_);
rcLine1.bottom /= 2;
rcLine1.SubtractRect(baseSize_, rcLine1);
rcLine1.OffsetRect(-offset_);
rcLine1.left += 15;
rcLine1.right = rcLine1.left;
rcLine1.top -= 700;
rcLine1.bottom -= 1300;

dc.MoveTo(rcLine1.left,rcLine1.right);
dc.LineTo(rcLine1.top,rcLine1.bottom);

this is how i am trying to draw the line..

still i am facing same problem...?

Thanks
Venkatesh

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson16-Feb-09 19:42

Stuart Dootson

16-Feb-09 19:42

Your co-ordinate use looks messed up.

You've got MoveTo(left, right); followed by LineTo(top, bottom);. That just doesn't seem right.

I added a horizontal line between two images with

dc.MoveTo(rcImage1.left+15, rcImage1.bottom);
dc.MoveTo(rcImage1.right-15, rcImage1.bottom);

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Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50216-Feb-09 21:48

John502

16-Feb-09 21:48

Hi Stuart,
Thanks for your help, I am able to draw veritcal line successfully across the images, we have given static pixels information for drawing a line right..? but now i want to move line across the images whenever i have clicked on button..

Can you please tell me how can i achive this..?

Thanks
Venkatesh.

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50217-Feb-09 3:50

John502

17-Feb-09 3:50

Hi Stuart,
I able to draw vertical line.. thanks for your help..
Thank you so much..

Thanks
Venki

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50218-Feb-09 22:42

John502

18-Feb-09 22:42

Hi Stuart,
Can you please help me regarding line drawing.. I want to draw line with the slider thumb positions.
I am using below code snippet for drawing line..
GetClientRect( &deflatedClientRect );
deflatedClientRect.DeflateRect( TB_WIDTH, TB_WIDTH );
slider_bar1.GetThumbRect( &thumbRect );
slider_bar1.ClientToScreen( &thumbRect );
ScreenToClient(&thumbRect);
ptStart.x = thumbRect.CenterPoint().x;
ptStart.y = TB_WIDTH;
ptEnd.x = ptStart.x;
ptEnd.y = deflatedClientRect.bottom;

using this code i will get the slider bar thumb position in terms of pixels, so using MoveTo and LineTo funtions i am drawing line..

but here i am not offsetting the pixels, so the line is getting erasing while moving scroll bar down..

Can you please help me regarding this.. please kindly give me reply as i have to deliver this app by tomorro... please

thanks in advance...

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson18-Feb-09 22:46

Stuart Dootson

18-Feb-09 22:46

venki502 wrote:
but here i am not offsetting the pixels, so the line is getting erasing while moving scroll bar down

Ummm - so what behaviour are you trying to achieve?

Offsetting ptSDtart and ptEnd is easy enough....

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50219-Feb-09 1:23

John502

19-Feb-09 1:23

Hi Stuart,
Thanks responding on this.. actually i have two horizontal sliders in between them i need to draw vertical line..

so using that code snippet i am able to get starting position of the top slider,
so i am using that..actually i also want to move that line along with slider positions... so that's the reason i am using that..

can you please tell me how can i do that..

thanks in advance..

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson19-Feb-09 2:07

Stuart Dootson

19-Feb-09 2:07

Seems pretty obvious to me that you need to get the thumb positions of the two sliders and draw between them:

slider_bar1.GetThumbRect( &thumbRect1 );
slider_bar1.ClientToScreen( &thumbRect1 );
ScreenToClient(&thumbRect1);
slider_bar2.GetThumbRect( &thumbRect2 );
slider_bar2.ClientToScreen( &thumbRect2 );
ScreenToClient(&thumbRect2);
ptStart.x = thumbRect1.CenterPoint().x;
ptStart.y = thumbRect1.bottom;
ptEnd.x = thumbRect2.CenterPoint().x;
ptEnd.y = thumbRect2.top;

?

[edit] changed slider_bar1 to slider_bar2 when manipulating thumbRect2 [/edit]

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50219-Feb-09 2:49

John502

19-Feb-09 2:49

Okay, we don't need to offset the pixels is it..? do we get the vertical scroll proble here..?
i will check and i will update you..

Thanks in advance

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson19-Feb-09 3:34

Stuart Dootson

19-Feb-09 3:34

venki502 wrote:
we don't need to offset the pixels is it..?

No, you don't need to offset, as the line position is calculated using rectangles derived from child controls, which are correctly adjusted for the scroll position.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box [modified]

John50219-Feb-09 7:02

John502

19-Feb-09 7:02

Hi stuart,
No the line is getting erasing.... i did the same thing whatever u have posted in the previous thread..
when i move vertical scroll bar down , the line is getting erasing..

For your information i have added that code in OnPaint function..
can you please tell me where i am doing wrong..?

thanks in advance..

modified on Thursday, February 19, 2009 1:23 PM

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson19-Feb-09 7:10

Stuart Dootson

19-Feb-09 7:10

No idea - I implemented a line drawing thing, it worked fine.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50219-Feb-09 8:28

John502

19-Feb-09 8:28

Hi Stuart,
I am using below code snippet :
GetClientRect( &deflatedClientRect );
deflatedClientRect.DeflateRect( TB_WIDTH, TB_WIDTH );
slider_bar1.GetThumbRect( &thumbRect1);
slider_bar1.ClientToScreen( &thumbRect1);
ScreenToClient(&thumbRect1);
m_bottom_slider_control.GetThumbRect(&thumbRect2);
m_bottom_slider_control.ClientToScreen(&thumbRect2);
ScreenToClient(&thumbRect2);
ptStart.x = thumbRect1.CenterPoint().x;
ptStart.y = thumbRect1.bottom;
ptEnd.x = thumbRect2.CenterPoint().x;
ptEnd.y = thumbRect2.bottom;
x1 = ptStart.x; y1 = ptStart.y; x2 = ptEnd.x; y2 = ptEnd.y;
int nOldmode=dc.SetROP2(R2_NOTXORPEN);
dc.MoveTo(old_x1,old_y1);
dc.LineTo(old_x2,old_y2);
dc.MoveTo(x1,y1);
dc.LineTo(x2,y2);
old_x1 = x1;
old_y1 = y1;
old_x2 = x2;
old_y2 = y2;

I am writing below code in OnPaint function, when i moved vertical scroll bar down it is getting erasing ..
please tell me where i am going wrong..?

thanks in advance...

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson19-Feb-09 9:03

Stuart Dootson

19-Feb-09 9:03

Don't know - can't see anything wrong with that.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50219-Feb-09 9:18

John502

19-Feb-09 9:18

r u able to keep the line while verical bar moving.. with your code...? if so can you please send me the code total code snippet, so that i can get some thing..

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson19-Feb-09 9:59

Stuart Dootson

19-Feb-09 9:59

Can't right now - the code's at work, I'm not, but I'll post it when I'm at work.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50219-Feb-09 10:10

John502

19-Feb-09 10:10

OK thanks stuart i will be waiting for your response.

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson20-Feb-09 2:17

Stuart Dootson

20-Feb-09 2:17

Here's the entirety of my OnPaint code. image1_ and image2_ are both member variables of type CImage. baseSize_ (also a member variable) is the initial size of the dialog. offset_ (also a member variable) is a CPoint holding the offset from the top-left point of the area on which I draw to the top-left of the visible area (i.e. the offset due to scrolling). slider_ is a member variable of type CSliderCtrl.

PAINTSTRUCT ps;
CDC* paintDC = BeginPaint(&ps);
CRect rcImage1(baseSize_);
rcImage1.bottom /= 2;
CRect rcImage2;
rcImage2.SubtractRect(baseSize_, rcImage1);
rcImage1.right -=100;
rcImage2.right -=100;
rcImage1.OffsetRect(-offset_);
rcImage2.OffsetRect(-offset_);
image1_.StretchBlt(*paintDC, rcImage1, SRCCOPY);
image2_.StretchBlt(*paintDC, rcImage2, SRCCOPY);


CPen redPen(PS_SOLID|PS_GEOMETRIC, 2, RGB(0xff, 0, 0));
CPen* oldPen = paintDC->SelectObject(&redPen);
CRect rcThumb;
slider_.GetThumbRect(&rcThumb);
slider_.MapWindowPoints(this, &rcThumb);
CPoint start(rcThumb.CenterPoint().x, rcThumb.bottom);
CPoint end(rcThumb.CenterPoint().x, rcImage2.bottom);
paintDC->MoveTo(start);
paintDC->LineTo(end);
paintDC->SelectObject(oldPen);
EndPaint(&ps);

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John50222-Feb-09 1:32

John502

22-Feb-09 1:32

Hi Start,
based on your code snippet i came to know that i did small mistake in my code..., now i am able to get that.. but when i move scroll down the previous line is not getting erasing.. the previous line is still appearing..,
and one more thing.. when i move vertical bar scroll very down, then the line is also getting drawing on entire window..

Can you please help me regarding this..?

Thanks in advance..

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John5021-Mar-09 19:07

John502

1-Mar-09 19:07

Hi Stuart,
I got strucked in one place, for further move i need your help.
I am able to draw line in between two sliders with the help of your code, that's fine it is working fine. But when i move vertical scroll bar down I am getting the values of thubmRect are negative values.
So i am getting start and end points are also negative values.
that's the reason it is not able to erase previous line when i move vertical scroll bar down.

Can you please help me regarding this..?

Thanks in advance..

Your help will be appriciated..........

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson1-Mar-09 20:56

Stuart Dootson

1-Mar-09 20:56

Well - negative co-ordinates say to me that the slider whose thumb you're retrieving the position of is outside the parent window's client area. That implies either that a) the line you're trying to erases is not in a visible area of the screen, or b) you're doing your calculations incorrectly.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John5021-Mar-09 21:58

John502

1-Mar-09 21:58

OnVScroll function i have written the following code snippet.
SCROLLINFO si = { sizeof(si), 0 };
GetScrollInfo(SB_VERT, &si, SIF_ALL);
CPoint newOffset(offset_);

switch (nSBCode)
{
case SB_LINEDOWN:
newOffset.y += si.nPage / 10;
break;
case SB_LINEUP:
newOffset.y -= si.nPage / 10;
break;
case SB_PAGEDOWN:
newOffset.y += si.nPage;
break;
case SB_THUMBTRACK:
case SB_THUMBPOSITION:
{
newOffset.y = nPos;
break;
}
case SB_PAGEUP:
{
newOffset.y -= si.nPage;
}
break;
default:
return;
}

LogMessage(__FILE__,__LINE__,TRACE_LOG_LEVEL,"VSroll bar clicked");
CRect currSize;
GetClientRect(&currSize);
const int maxOffset = baseSize_.Height() - currSize.Height();
newOffset.y = max(min(newOffset.y, maxOffset), 0);

SetScrollPos(SB_VERT,newOffset.y,TRUE);
ScrollWindow(0,offset_.y-newOffset.y);
offset_ = newOffset;

LogMessage(__FILE__,__LINE__,TRACE_LOG_LEVEL,"x = %d, y = %d",newOffset.x,newOffset.y);

CDialog::OnVScroll(nSBCode, nPos, pScrollBar);

And From OnTimer Function i am calling DrawLine function, that function contains the following code snippet:
CRect rect;
GetClientRect(&rect);
slider_bar1.GetThumbRect(&rcThumb1);
slider_bar1.MapWindowPoints(this, &rcThumb1);
m_bottom_slider_control.GetThumbRect(&rcThumb2);
m_bottom_slider_control.MapWindowPoints(this, &rcThumb2);
start.x = rcThumb1.CenterPoint().x;
start.y = rcThumb1.bottom;
if (start.y<0)
{
start.y = 0;
}
end.x = rcThumb1.CenterPoint().x;
end.y = rcThumb2.bottom;
if (end.y > rect.Height())
{
end.y = rect.Height();
}

CRect rc;
rc.left = start.x-10;
if (start.y >= 10)
rc.top = start.y-10;
else
rc.top = 0;
rc.right = end.x+10;
rc.bottom = end.y+10;

And OnPaint Contains the following code snippet:
int nOldmode=dc.SetROP2(R2_NOTXORPEN);
dc.MoveTo(old_x1,old_y1);
dc.LineTo(old_x2,old_y2);
dc.MoveTo(start);
dc.LineTo(end);
old_x1 = start.x;
old_y1 = start.y;
old_x2 = end.x;
old_y2 = end.y;

Still i am getting negative values,
Can you please see the code and let me know where i am going wrong..?

Thanks in advance..

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson1-Mar-09 22:06

Stuart Dootson

1-Mar-09 22:06

John502 wrote:
Can you please see the code and let me know where i am going wrong

I don't know where your problem is.

I would advise you to get familiar with the debugger and step through the code to see what values variables are taking, so you can see which ones aren't what you expect.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

John5021-Mar-09 22:28

John502

1-Mar-09 22:28

----------------------------------------------------------------------------------------------------

Hi Stuart, this is my debugging observation, even after seeing this info i am not getting any thing..
Can you please help me regarding this..?

14:55:46:106- Scroll Dialog init dialog function called
14:55:46:472- old_x1 = -842150451,old_y1 = -842150451,old_x2 = -842150451,old_y2 = -842150451
14:55:46:486- SetRop2 is called with nOldmode and return value is : 13
14:55:46:487- x1 = 37,y1 = 68,x2 = 37,y2 = 827
14:55:49:472- old_x1 = 37,old_y1 = 68,old_x2 = 37,old_y2 = 827
14:55:49:486- SetRop2 is called with nOldmode and return value is : 13
14:55:49:487- x1 = 38,y1 = 68,x2 = 38,y2 = 577
14:55:49:472- old_x1 = 38,old_y1 = 68,old_x2 = 38,old_y2 = 577
14:55:49:486- SetRop2 is called with nOldmode and return value is : 13
14:55:49:487- x1 = 39,y1 = 68,x2 = 39,y2 = 577
14:55:50:472- old_x1 = 39,old_y1 = 68,old_x2 = 39,old_y2 = 577
14:55:50:486- SetRop2 is called with nOldmode and return value is : 13
14:55:50:487- x1 = 40,y1 = 68,x2 = 40,y2 = 577
14:55:50:472- old_x1 = 40,old_y1 = 68,old_x2 = 40,old_y2 = 577
14:55:50:486- SetRop2 is called with nOldmode and return value is : 13
14:55:50:487- x1 = 156,y1 = 68,x2 = 156,y2 = 577
14:55:50:472- old_x1 = 156,old_y1 = 68,old_x2 = 156,old_y2 = 577
14:55:50:486- SetRop2 is called with nOldmode and return value is : 13
14:55:50:487- x1 = 156,y1 = 68,x2 = 156,y2 = 577
14:55:51:472- old_x1 = 156,old_y1 = 68,old_x2 = 156,old_y2 = 577
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 68,x2 = 157,y2 = 577
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 0
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 2
14:55:51:472- old_x1 = 157,old_y1 = 68,old_x2 = 157,old_y2 = 577
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 66,x2 = 157,y2 = 825
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 5
14:55:51:472- old_x1 = 157,old_y1 = 66,old_x2 = 157,old_y2 = 825
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 63,x2 = 157,y2 = 822
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 17
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 23
14:55:51:472- old_x1 = 157,old_y1 = 63,old_x2 = 157,old_y2 = 822
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 45,x2 = 157,y2 = 804
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 48
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 64
14:55:51:472- old_x1 = 157,old_y1 = 45,old_x2 = 157,old_y2 = 804
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 4,x2 = 157,y2 = 763
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 103
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 123
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 137
14:55:51:472- old_x1 = 157,old_y1 = 4,old_x2 = 157,old_y2 = 763
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 0,x2 = 157,y2 = 690
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 190
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 209
14:55:51:472- old_x1 = 157,old_y1 = 0,old_x2 = 157,old_y2 = 690
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 0,x2 = 157,y2 = 618
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 229
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 237
14:55:51:472- old_x1 = 157,old_y1 = 0,old_x2 = 157,old_y2 = 618
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 0,x2 = 157,y2 = 590
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 254
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 259
14:55:51:472- old_x1 = 157,old_y1 = 0,old_x2 = 157,old_y2 = 590
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 0,x2 = 157,y2 = 568
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 266
14:55:51:472- old_x1 = 157,old_y1 = 0,old_x2 = 157,old_y2 = 568
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 0,x2 = 157,y2 = 561
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 268
14:55:51:472- old_x1 = 157,old_y1 = 0,old_x2 = 157,old_y2 = 561
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 157,y1 = 0,x2 = 157,y2 = 559
14:55:51:472- old_x1 = 157,old_y1 = 0,old_x2 = 157,old_y2 = 559
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 158,y1 = 0,x2 = 158,y2 = 559
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 263
14:55:51:210- VSroll bar clicked
14:55:51:220- x = 0, y = 263
14:55:51:472- old_x1 = 158,old_y1 = 0,old_x2 = 158,old_y2 = 559
14:55:51:486- SetRop2 is called with nOldmode and return value is : 13
14:55:51:487- x1 = 158,y1 = 0,x2 = 158,y2 = 564
14:55:52:472- old_x1 = 158,old_y1 = 0,old_x2 = 158,old_y2 = 564
14:55:52:486- SetRop2 is called with nOldmode and return value is : 13
14:55:52:487- x1 = 159,y1 = 0,x2 = 159,y2 = 564

Re: Need help on how to create image on child window and have to move along with vertical scroll bar to my dialog box

Stuart Dootson1-Mar-09 23:14

Stuart Dootson

1-Mar-09 23:14

The only negative numbers I see are at the start - that screams 'uninitialised data' to me.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

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