Gadget flickering

NoahPhense · Post by **NoahPhense** » Tue Jun 29, 2004 12:59 am

I have the solution. It just need to be converted from another language.

- np

PB · Post by PB » Tue Jun 29, 2004 1:32 am

> I just tried the exact same code again, and now I get the same nasty
> flickering like my home PC.

Confirmed: Your original post is now flickering for me too! 8O
It's probably related to how intensive the CPU is working, because
I haven't done anything different to before, yet before it didn't
flicker for me either. Weird. To me, the "flickering" looks a bit
like "mouse pointer trails", if you've ever seen those, but done
to the window instead of the mouse. I haven't changed my screen
resolution, refresh rate, or any other display settings. Strange!

Sparkie · Post by **Sparkie** » Tue Jun 29, 2004 2:03 am

@PB - Thanks for the confirmation. The odds that my age is affecting my mind/eyes/sanity has just dropped a few percentage points.

PolyVector · Post by **PolyVector** » Tue Jun 29, 2004 2:06 am

I was tinkering with my 'solution' trying to get it to work for my SkinBuilder app I'm designing... this thing is far more complicated (and flickers far more) than the example apps here...

Best solution to date (for me):
When processing the #PB_Event_SizeWindow event, resize all your gadgets as you normally would.
Then, insert this line at the very end of your size routine:

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RedrawWindow_(WindowID(#Window_Main),0,0,#RDW_INTERNALPAINT|#RDW_UPDATENOW)

This is a bit inefficient since some of the window/gadgets have already been drawn, but maybe someone can optimize it?

Edit:
This works just as well (and it's easier on the keyboard) :

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UpdateWindow_(WindowID())

NoahPhense · Post by **NoahPhense** » Tue Jun 29, 2004 3:03 am

Try this..

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SetWindowLong_(WindowID(#Window_0), #GWL_EXSTYLE, GetWindowLong_(WindowID(#Window_0), #GWL_EXSTYLE) | $02000000) ; #WS_EX_COMPOSITED)

...
full listing

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Declare Resize()

Enumeration
  #Window_0
EndEnumeration

Enumeration
  #Listview_0
  #String_0
  #Button_0
  #Text_0
EndEnumeration

; don't really need to be global.. 
Global cx.l, cy.l, wpi.l, f.l

Procedure Open_Window_0()
  If OpenWindow(#Window_0, 311, 255, 596, 292,  #PB_Window_SystemMenu | #PB_Window_SizeGadget | #PB_Window_TitleBar | #PB_Window_ScreenCentered , "blah..")
    ; **
    SetWindowLong_(WindowID(#Window_0), #GWL_EXSTYLE, GetWindowLong_(WindowID(#Window_0), #GWL_EXSTYLE) | $02000000) ; #WS_EX_COMPOSITED)

    If CreateGadgetList(WindowID())
      ListViewGadget(#Listview_0, 0, 5, 290, 175)
      StringGadget(#String_0, 300, 5, 295, 175, "")
      ButtonGadget(#Button_0, 5, 185, 285, 105, "")
      TextGadget(#Text_0, 325, 205, 155, 30, "This is a test...")
      ReSize()
    EndIf
  EndIf
EndProcedure

Open_Window_0()

Repeat
  
  Event = WaitWindowEvent()
  
  If Event = #PB_EventGadget
      ; Debug "WindowID: " + Str(EventWindowID())
    GadgetID = EventGadgetID()
    
    If GadgetID = #Listview_0
      ;
    ElseIf GadgetID = #String_0
      ;
    ElseIf GadgetID = #Button_0
      ;
    EndIf
  
  ElseIf Event = #PB_Event_SizeWindow 
    ReSize()  
  EndIf
  
Until Event = #PB_EventCloseWindow

End
;

Procedure ReSize() 

  f = #SWP_NOACTIVATE|#SWP_NOZORDER 
  cy = WindowHeight()
  cx = WindowWidth()
  hw = cx/2 
  hh = cy/2 

  wpi = BeginDeferWindowPos_(4) ; Pass the number of windows To be re-sized
;          Params For DeferWindowPos 
;          1) The value passed from BeginDeferWindowPos 
;          2) The Window handle (retrieved from GetDlgItem) 
;          3) A value specifing 'Z-order' (ignored here) 
;          4) x,y,w,h of window 
;          5) Flags (the values in 'f' seem To work best 
      DeferWindowPos_(wpi,GetDlgItem_(WindowID(#Window_0),0),0,0,0,hw,hh,f) 
      DeferWindowPos_(wpi,GetDlgItem_(WindowID(#Window_0),1),0,hw+1,0,(cx-(hw+1)),hh,f) 
      DeferWindowPos_(wpi,GetDlgItem_(WindowID(#Window_0),2),0,0,hh+1,hw,cy-(hh+1),f) 
      DeferWindowPos_(wpi,GetDlgItem_(WindowID(#Window_0),3),0,hw+1,hh+1,(cx-(hw+1)),cy-(hh+1),f) 
   EndDeferWindowPos_(wpi)
   wpi = 0 ; clearit
EndProcedure

Question, has anyone tried what Fred has suggested on page 1?

- np

PolyVector · Post by **PolyVector** » Tue Jun 29, 2004 6:17 am

@NoahPhense
Your code updates HORRIBLY slow when the window is large on my computer... If I take out this line, it solves the major slowdown, but flickering still occurs...

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SetWindowLong_(WindowID(#Window_0), #GWL_EXSTYLE, GetWindowLong_(WindowID(#Window_0), #GWL_EXSTYLE) | $02000000) ; #WS_EX_COMPOSITED)

I do, however, like the DeferWindowPos_() part... I'll be using it

I did try Fred's method when he posted it, but couldn't get it to work correctly...

DoubleDutch · Post by **DoubleDutch** » Tue Jun 29, 2004 9:54 am

I treid freds method on my ConsoleX library - it flickered on resize on my machine.

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If Message=#WM_ERASEBKGND
    Result=-1 ; or #NULL the result is the same...
EndIf

It stopped the flicker completely. This was a resizing window screen.

But if you try it with gadgets it seem to still flicker.

El_Choni · Post by **El_Choni** » Tue Jun 29, 2004 10:48 am

Has anybody tried adding #WS_CLIPCHILDREN to the window #GWL_STYLE, as I suggested? (I think OpenWindow should use it by default)

Excludes the area occupied by child windows [gadgets] when drawing occurs within the parent window. This style is used when creating the parent window.

Has always worked for me.

NoahPhense · Post by **NoahPhense** » Tue Jun 29, 2004 2:49 pm

El_Choni wrote:Has anybody tried adding #WS_CLIPCHILDREN to the window #GWL_STYLE, as I suggested? (I think OpenWindow should use it by default)

Excludes the area occupied by child windows [gadgets] when drawing occurs within the parent window. This style is used when creating the parent window.
Has always worked for me.

I tried it. Can't say if it worked or not. Because I've yet to encounter
any flicker on any window, yet..

- np

halo · Post by **halo** » Tue Jun 29, 2004 4:54 pm

There shouldn't be anything wrong with the code. I did not write this. I just copied it out of the "samples" directory because I knew it would flicker, just like every other PureBasic program I run.

NoahPhense · Post by **NoahPhense** » Tue Jun 29, 2004 5:27 pm

halo wrote:There shouldn't be anything wrong with the code. I did not write this. I just copied it out of the "samples" directory because I knew it would flicker, just like every other PureBasic program I run.

No I just meant that I don't have flickering, so it's hard for me to code
for something I cannot see. But I'm still trying..

- np

Try this out.. lemme know what happens:

no_flicker.rar

PolyVector · Post by **PolyVector** » Wed Jun 30, 2004 2:52 am

Has anybody tried adding #WS_CLIPCHILDREN to the window #GWL_STYLE, as I suggested? (I think OpenWindow should use it by default)

I Know what the problem was with using WS_CLIPCHILDREN... you can't simply use it on the main window... you must use it on all gadgets that are parents of anything that gets resized... When you do this, there is absolutly no flickering!

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Procedure ReduceFlicker_Enum(handle.l,Param.l)
  SetWindowLong_(handle,#GWL_STYLE,GetWindowLong_(handle,#GWL_STYLE)|#WS_CLIPCHILDREN)
  ProcedureReturn #True
EndProcedure

Procedure ReduceFlicker(WindowNumber.l)
  ReduceFlicker_Enum(WindowID(WindowNumber),0)
  EnumChildWindows_(WindowID(WindowNumber),@ReduceFlicker_Enum(),0)
EndProcedure

All you have to do now is call ReduceFlicker(WindowNumber) after all gadgets are created...
Then call UpdateWindow_(WindowID(WindowNum)) after you resize all your gadgets on the #PB_Event_SizeWindow event...

It has near-perfect results for me... Although there is some garbling on some things...hrmmmmm

tinman · Post by **tinman** » Wed Jun 30, 2004 8:54 am

Putting

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LockWindowUpdate_(WindowID())
...
LockWindowUpdate_(0)
UpdateWindow_(WindowID())

around your resize code seems to help here although there is still some slight flickering on my system.

@PolyVector: are there any problems making all gadgets have the clipchildren style? Is it safe to use on gadgets which have no children?

DoubleDutch · Post by **DoubleDutch** » Wed Jun 30, 2004 9:11 am

This method works great...

UNLESS

your using "PanelGadget":(

With PanelGadget the backgound of the PanelGadget is not erased on resize when you use your modification.

Is panelgadget created by PureBasic or Windows itself?

If its by PureBasic, FRED can u look into this? FRED, if you want to see what I mean I can send you an exe.

-Anthony

DoubleDutch · Post by **DoubleDutch** » Wed Jun 30, 2004 10:15 am

if you create another gadget AFTER your "ReduceFlicker(window#)" code, what is the process of making this new gadget "flickerfree"?

Do I just call ReduceFlicker(Window#) again?