Codejock Developer Community : Controls flicker in resizing dialog

Controls flicker in resizing dialog : Actually you can use CXTCheckListBox...

Mon, 19 Dec 2005 00:49:41 +0000

Author: Oleg
Subject: 3419
Posted: 19 December 2005 at 12:49am

Actually you can use CXTCheckListBox with OwnerDrawFixed and remove this assert

In the last version it looks like:

// Must be LBS_OWNERDRAWVARIABLE or LBS_OWNERDRAWFIXED and LBS_HASSTRINGS
ASSERT(GetStyle() & (LBS_OWNERDRAWFIXED | LBS_OWNERDRAWVARIABLE));
ASSERT(GetStyle() & (LBS_HASSTRINGS));

So it was bug in previous versions.

Controls flicker in resizing dialog : Oleg, 1) Thanks for the info...

Sun, 18 Dec 2005 12:02:06 +0000

Author: Warren
Subject: 3419
Posted: 18 December 2005 at 12:02pm

Oleg,

1) Thanks for the info about the CXTTreeCtrl. All my trees are derived from one class, so that was a one line fix for me. Sweet!

2) Based on your comment above ("Some classes can't useCXTNoFlickerWnd") I didn't go down that road any further, but I stillwanted to resolve my flickering issue. My requirements for thechecklistbox are the "simple" case (i.e. just a checkmark beside sometext - no fancy drawing or images) Here is what I found:

i) The image on the right is the standard MFC CCheckListBox control. The drawing is correct, but it flickers when resized.

ii) The image on the left is the CXTCheckListBox. I tried using this inplace of my CCheckListBox. It ASSERTed that it needed "variable" ownerdrawing, so I turned this on. Unfortunately the items are not beingdrawn correctly (the font is correct, the check boxes are the rightsize, but there is no space between the items).

iii) The image in the center, is from my derived class. All I did wastear out the ASSERT (on line 228 of xtchecklistbox.cpp
void CXTCheckListBox::DrawItem(LPDRAWITEMSTRUCT lpDIS)
{
// Must be LBS_OWNERDRAWVARIABLE | LBS_HASSTRINGS ASSERT((GetStyle() & (LBS_OWNERDRAWVARIABLE | LBS_HASSTRINGS)) ==
(LBS_OWNERDRAWVARIABLE | LBS_HASSTRINGS));

and set the control to "Fixed" Owner drawing. This mostly fixed theissue (i.e. there is no flickering), but the drawing is not quite thesame as the standard control drawing:

a) The text is slightly too high, compared to the checkbox
b) The focus is not drawn around the checkmark, like the standard control.

These drawing issues are not a BIG deal for me, but I thought you should know about them.

My primary question here is: "is thisthe right way/control to go about solving the flicker for myCCheckListBoxes ?", and if so, can you remove the ASSERT that it mustbe Owner-draw variable, as owner-draw fixed seems to otherwise work.

Thanks

Warren

Controls flicker in resizing dialog : Hi, Some classes can't use...

Sun, 18 Dec 2005 08:09:59 +0000

Author: Oleg
Subject: 3419
Posted: 18 December 2005 at 8:09am

Hi,

Some classes can't use CXTNoFlickerWnd (see its sources to understand how it works).

for tree cotnrols you can use CXTTreeCtrl classes.

Controls flicker in resizing dialog : I've got a resizing dialog...

Fri, 16 Dec 2005 11:43:20 +0000

Author: Warren
Subject: 3419
Posted: 16 December 2005 at 11:43am

I've got a resizing dialog (i.e. a dialog derived fromCXTResizeDialog), and a number of my controls flicker when I resizethem. I found CXTResizeGroupBox and that fixes the problem for groupboxes.

The flicker still occurs for Tree controls and Check-list-boxes (whichI use a LOT of in my application - so the flicker is quite noticable).

I tried using the CXTNoFlickerWnd, but when I tried it:

i.e.
writing this:
CXTNoFlickerWnd < CCheckListBox > m_list;
instead of:
CCheckListBox m_list;

The CCheckListBox did NOT drawproperly (the background of the area below where there were checkboxeswas grey, instead of white, and the area just a few pixels around thecheckboxes didn't draw properly)

Is CXTNoFlickerWnd the proper class, and I'm just doing something slightly wrong, or should I be using something else ????