C / C++ / MFC

27-Nov-07 21:55

They maybe are sometimes a bit rude, but usually the "nothing" answers have helpfull information too. Just need to re read and analize without "offended feeling" (at least that's what I try when I get a "rude" answer)

Greetings.

--------
M.D.V. Wink | ;)

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
“The First Rule of Program Optimization: Don't do it. The Second Rule of Program Optimization (for experts only!): Don't do it yet.” - Michael A. Jackson

Re: Offtopic

Vaclav_28-Nov-07 6:43

Vaclav_

28-Nov-07 6:43

Nelek, your comments are appreciated.
I am well aware that everybody is different.
I don't think Led Mike was rude. I am just not impressed by his "WTF" remark as his first reaction and than him restating the obvious that I did not know the subject well. His link was constructive suggestion and appreciated.
PS The “mystery” of utilizing RUNTIME_CLASS macro is almost solved thanks to everybody input.

Cheers
Vaclav

VScroll - speed up

josip cagalj27-Nov-07 3:54

josip cagalj

27-Nov-07 3:54

Hi,
I'm reposting my problem with vertical scroling since no one is replaying eany more on my first thread.
So what I want is wnen I use mouse wheel to get scrolling faster, so upon sugetion from Nelek I'm doing this:

<br />
BOOL CMyView::OnMouseWheel(UINT nFlags, short zDelta, CPoint pt)<br />
{<br />
int pos =GetScrollPos( SB_VERT );<br />
if (zDelta>0)<br />
OnVScroll(3*SB_LINEUP,pos,NULL);<br />
else if (zDelta<0)<br />
OnVScroll(3*SB_LINEDOWN,pos,NULL);<br />
return TRUE;<br />
}<br />

When I scroll by LINEDOWN it's OK, but when I do the oposite (SB_LINEUP) it has no effect, scrolling it slow again.
Why?
Thanks!

Nelek27-Nov-07 4:04

27-Nov-07 4:04

I don't know why, but have you tried with -3 * SB_LINEDOWN ??

Have you checked if SB_LINEDOWN == - SB_LINEUP ?

Mappng mode, one direction must be the different sign of the other

Greetings.

--------
M.D.V. Wink | ;)

What are you doing, man?

CPallini27-Nov-07 4:17

27-Nov-07 4:17

What are you doing, man?

josip cagalj wrote:
if (zDelta>0)
OnVScroll(3*SB_LINEUP,pos,NULL);
else if (zDelta<0)
OnVScroll(3*SB_LINEDOWN,pos,NULL);

Since (see winuser.h)

...
#define SB_LINEUP           0
#define SB_LINELEFT         0
#define SB_LINEDOWN         1
#define SB_LINERIGHT        1
#define SB_PAGEUP           2
#define SB_PAGELEFT         2
#define SB_PAGEDOWN         3
...

3*SB_LINEUP evaluates to SB_LINEUP itself.
while
SB_LINEDOWN evaluates to SB_PAGEDOWN.

Moving the wheel, you scroll a line up, a page down.

Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Nelek27-Nov-07 21:48

27-Nov-07 21:48

He wants to increase the speed on scrolling.

BTW, I thought the working area is 10 pages and 100 lines.

Quote from VC++ help:
You specify the amounts to scroll horizontally and vertically in logical units. By default, if the user clicks a scroll bar shaft outside of the scroll box, CScrollView scrolls a “page.” If the user clicks a scroll arrow at either end of a scroll bar, CScrollView scrolls a “line.” By default, a page is 1/10 of the total size of the view; a line is 1/10 of the page size. Override these default values by passing custom sizes in the SetScrollSizes member function. For example, you might set the horizontal size to some fraction of the width of the total size and the vertical size to the height of a line in the current font.

And winuser.h it says that page = 3*line...

Can you explain a bit more about? Because I am the one who told him to use the X*SB_PAGEUP/DOWN the other day. And now is a bit conusing for me too.

Greetings.

--------
M.D.V. Wink | ;)

CPallini27-Nov-07 22:09

27-Nov-07 22:09

Nelek wrote:
Override these default values by passing custom sizes in the SetScrollSizes member function

I think the above is the right approach.

On the other hand, the OP is hacking the nSBCode argument (of the method OnVScroll) that is just (MSDN):
a scroll-bar code that indicates the user's scrolling request.
i.e. a qualitative parameter rather than a quantitative one (like the amount of requested scroll).

Hope that helps
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Nelek27-Nov-07 22:27

27-Nov-07 22:27

CPallini wrote:
Nelek wrote:
Override these default values by passing custom sizes in the SetScrollSizes member function

I think the above is the right approach.

It depends on many things. I used this quantitative solution insteads of overriding the SetScrollSizes because my boss wanted UP/DOWN keys to scroll accuratelly and the wheel to do it faster but not changing a page that must stay as it was with PageUp/Down.

I ~~finally used that N*SB_LINEUP/DOWN~~ actually I used +-N*SB_LINEDOWN for the wheel to make it 3 times faster than keys or bar-arrow-clicks as he wanted.

And, as it worked fine for me (work right doesn't mean to be right, I know), I gave that option to him as well. Is there any way to do it just with "qualitative" parameter? Because I found no "fourth" messure to scroll a view. Just these 3: sizeTotal, sizePage, sizeLine...

VC++ 6.0

How can I solve that issue in a correct way?

Greetings.

--------
M.D.V. Wink | ;)

CPallini27-Nov-07 23:44

27-Nov-07 23:44

Nelek wrote:
+-N*SB_LINEDOWN

-N*SB_LINEDOWN (with N>0) should be meaningless to standard OnVScroll.

Even overriding OnVScroll to re-intepreter its first parameter doesn't seem to me a good design choice.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Nelek28-Nov-07 1:44

28-Nov-07 1:44

Aham,

then... how should I make to have a 3-speed scrolling as I explained but in a good structure? Line with arrow keys, middle with Wheel and Page with pageup/down keys or out the little bar at the scrollbar.

Greetings.

--------
M.D.V. Wink | ;)

CPallini28-Nov-07 2:24

Re: What are you doing, man? (secondary question solved)

28-Nov-07 2:24

Well a quite rude, but simple solution maybe issuing three times the call to OnVScroll (PostMessage ?) with either SB_LINEDOWN or SB_LINEUP.
Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Nelek28-Nov-07 3:05

Re: What are you doing, man? (secondary question solved)

28-Nov-07 3:05

I actually thought on that, but I figured that it would be worst than the other solution.

Many times, simplest ways are the best ones Wink | ;)

thanks I will change it Rose | [Rose]

Greetings.

--------
M.D.V. Wink | ;)

CPallini28-Nov-07 3:33

28-Nov-07 3:33

Nelek wrote:
I actually thought on that, but I figured that it would be worst than the other solution.

Don't change it just because I told about: before you have to find my points valid.

Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

josip cagalj27-Nov-07 22:37

josip cagalj

27-Nov-07 22:37

Once again thank you both for yours participation on this thread!
You helped me indeed.
If I realy did call pageup it suit's me. It's my fault for not checking this option before. I thought pageup/down would be big for my needs, but this is ok!
P.S.
For Nelek: pageup/down doesn't scroll a whole page (at least not in my case), I mesured when I do scroll(using mouse wheel) it takes 11 scroll lines (up/down keys)to go back at start position.

P.P.S.
my setscrollsize:
SetScrollSizes( MM_TEXT, CSize(m_nMaxX+30, m_nMaxY+90));
where m_nMaxX and m_nMaxY are from my Client rectangle!

Nelek27-Nov-07 23:13

27-Nov-07 23:13

With the term page I didn't mean a whole page. Read another time:

1 TotalSize = 10 Pages;
1 Page = 10 Lines;

NOTE: If you dont say anything else this is standard behaviour.

Just a question... why do u set Scroll size bigger than client area?

I.E. One DIN A-4 = 210 * 297 mm (Standard-printable-area 190 * 280 mm)
to have a ratio 5 Pixels : 1 mm in my app I used

CSize sizeTotal;
sizeTotal.cx = 950; sizeTotal.cy = 1400; //190*5 and 280*5
SetScrollSizes(MM_TEXT, sizeTotal);

Greetings.

--------
M.D.V. Wink | ;)

josip cagalj27-Nov-07 23:49

josip cagalj

27-Nov-07 23:49

Nelek wrote:
Just a question... why do u set Scroll size bigger than client area?

I use bigger scroll size because I'm placing some object's on backplane(MyView) and on my last placing I wont to enlarge my page so I can make place if user wont's to add more objects!
MyView(CFormView) is some kind of help for me because on the end I'm doing some coding (collect positions and relasionships betwen objects and then presenting it as something else....) my stuff, dont want to dother anyone with this...
Thanks everybody for their effort

basic type conversions

Joezer BH27-Nov-07 3:50

Joezer BH

27-Nov-07 3:50

Given a char c and an int i,
is there any difference between casting the int to the char: c = (char)i;
and just assigning it: c = i;
Confused | :confused:

many thanks

Tzumer

Maximilien27-Nov-07 3:55

Maximilien

27-Nov-07 3:55

Someone already answered that yesterday.

Maximilien Lincourt
Your Head A Splode - Strong Bad

CPallini27-Nov-07 4:04

27-Nov-07 4:04

The result is the same.
However, (depending on the warning level set), in the latter case, i.e.

e.tzumer wrote:
just assigning it: c = i;

the compiler may emit the following warning:

conversion from 'int' to 'char', possible loss of data

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

led mike27-Nov-07 4:35

led mike

27-Nov-07 4:35

What is wrong with you? Dead | X|