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IDProjectCategoryView StatusLast Update
0003917JEDI VCL00 JVCL Componentspublic2007-06-19 03:54
ReporterZENsanAssigned Toobones 
Status resolvedResolutionfixed 
Product VersionDaily / GIT 
Target VersionFixed in Version3.34 
Summary0003917: State and AllowGreyed properties for TJvXPCheckbox...
DescriptionState and AllowGreyed properties for TJvXPCheckbox...
Is it possible?
TagsNo tags attached.



2006-09-22 10:28

reporter   ~0010154

I believe the AllowGreyed is only used when a checkbox component is DB aware,where the value is null, isn't it? So it wouldn't apply to this componente, that is either checked or not, right?
Or do you want to display it greyed if the component's property enable = false?
And the 'state' property you mention, what values would it have? Are you sure it's not the 'checked' property with a different name?
Take a look at line 395 of jvXpCheckCtrls.pas, see if you can't add something to that code yourself, it doesn't look too complicated. (I just don't have the time)
The JEDI appreciate any help/code from new users, you can contribute by trying some coding yourself and posting back here.
In case you do change this component's code, you will need to:
Open and recompile(build All) ($Jedi)\jvcl\packages\JvStdCtrlsD7R.dpk
and Open and recompile(build All) ($Jedi)\jvcl\packages\JvStdCtrlsD7D.dpk


2006-09-22 11:38

reporter   ~0010155

Ok, I will try to add it myself.
Checked - filter some values
Unchecked - filter other values
Greyed - do not filter anything

This is why I want State property.

2006-09-26 00:31 (15,977 bytes)


2006-09-26 00:33

reporter   ~0010174

Here is updated source file. Unit JvXPCheckCtrls.pas:
  property AllowGrayed: Boolean;
  property State: TJvXLCheckBoxState;

All this properties works interactively one with other. Demo program is included. Only problem - you may need to update bitmap in resources of package. I erases 4 dots in angles of square (fro cbGrayed state) beacase if I save all black square then nothing is drawed.


2006-09-26 00:37

reporter   ~0010175

And also I don't know how is better - save TCheckBoxState type or invent new TJVXpCheckBoxState..
I thnk may be better is to save old type for compatibility...


2006-09-26 00:40

reporter   ~0010176

Maybe something like that:
  TJVXPCheckBoxState = (jvcbUnchecked, jvcbChecked, jvcbGrayed);

2006-09-26 08:39 (5,174 bytes)


2006-09-26 08:40

reporter   ~0010187

Last edited: 2006-09-26 08:40

There is WinMerge patch file for unit. But Bitmap and reources I haven't touched.


2006-09-27 04:34

reporter   ~0010195

Well done!
I found 2 bugs in your SetState procedure.
The 1st is that you 1st set the new state (FState := Value), and then you check if FState <> Value to actually do some work, which means it never does anything, only sets the value,as that condition is always false.
The 2nd is that your fAllowGrayed wasn't being checked, so even if that was false, you would set FState = value, therefore it would be painted as grayed.
This is the fix to those:

procedure TJvXPCustomCheckControl.SetState(const Value: TJvXPCheckBoxState);
  if FState <> Value then
    if (not FAllowGrayed) and (Value=cbGrayed) then
      FState := cbUnchecked
      FState := Value;
    if FState = cbChecked then
      FChecked := True
      FChecked := False;

And another thing: I don't think you got the right bitmap to the grayed state.
I couldn't actually see any checkbox grayed by Windows itself, so I created one artificially, with a TMS component.
It seems to me that the grayed bitmap should be completely square, without the round corners that you used.
See my attached jpg. If you agree with me, can you update your JvXPCore.res file and attach it here?
Then we have the color problem. The only color available from jvXPCore.pas for the checkbox is the enabled one, does anyone know what is the constant for the disabled one, as it's brighter then the enabled, or where to lookup to find the right value?
If you see the next lines just after loading the bitmap from the resource, you see this:
        if Theme = WindowsXP then
          JvXPColorizeBitmap(Bitmap, dxColor_Chk_Enb_NmSymb_WXP)
where obviously we need to check now if FState = Grayed then (...) where we need to find out and create the disabled color constant.
BTW, I liked the idea of your TJvXPCheckBoxState being a replica of TCheckBoxState, as it keeps it easy to typecast and there is no need to include StdCtrls in the uses clauses.

Cheers, Alex

2006-09-27 04:37 (1,009 bytes)

2006-09-27 04:39


JediChkBox1.jpg (21,074 bytes)
JediChkBox1.jpg (21,074 bytes)


2006-09-27 04:42

reporter   ~0010196

I also edited the unit1.pas (.dfm) from your demo project, so it is easier to follow how the component is behaving. They are in


2006-09-28 09:02

reporter   ~0010201

About first bug - thanks, I forget to remove this line when copying part of code :)

I also changed SetState as follows - I think is better Value := FState but not to reset state to Unchecked:

procedure TJvXPCustomCheckControl.SetState(const Value: TJvXPCheckBoxState);
  if FState <> Value then
    if (not FAllowGrayed) and (Value=jvcbGrayed) then
      Value := FState;
    if FState = jvcbChecked then
      FChecked := True
      FChecked := False;

  TJvXPCheckBoxState = (jvcbUnchecked, jvcbChecked, jvcbGrayed);

2006-09-28 09:03



2006-09-28 09:04

reporter   ~0010202

And you have never seen that type of checkbox state in Windows :)?


2006-09-28 09:12

reporter   ~0010203

And what are you talking about Color? Why disabled? Simply another bitmap.. Or maybe I don't understand something.. Sorry if my answers are late - I am working and doing this in work time :)


2006-09-28 09:54

reporter   ~0010206

Sorry - I have some differences between that old and new version of my Units, so there is my little mistake:

    if (not FAllowGrayed) and (Value=jvcbGrayed) then
      Exit;//Value := FState;compilation error because const..


2006-09-28 11:45

reporter   ~0010209

Last edited: 2006-09-28 11:56

Well, the component objective is to mimic the visual aspects of Windows XP, right?
So it has to be as close to the ones drawn natively by Windows itself, not by my application or yours or anyone's, just like you showed in your .png.
Considering that a grayed checkbox got that name because originally in the other Windows versions it was gray, and not pure black (as in the checked state), we need to find out what is the correct color of a grayed checkbox in XP, as ironically, it's now green!
My whole point is: it's clearly a different color then the checked state, it's lighter, we need to know what RGB values that lighter green has.
I assume there has to be a table somewhere (MSDN?) specifying the color exact RGB values, but if we can't find it, we will have to use a capture screen tool to find out manually to include it in jvCore.pas.
Now, just to let you know why I'm insisting in fixing this component instead of using the TMS or any other 3rd party components that I already paid for: the Jedi ones are the only ones that work in Windows 2000 (and probably 9x, but I never tested) and in XP even if you disable the Themes service. So your applications (at least these components) are ALWAYS displayed identically across all plataforms, and make a notable difference when put side by side with any other app in W2K, for example.


2006-09-29 07:20

administrator   ~0010245

Just a side note: Please provide a patch file made with TortoiseSVN and only that one.
One question: Why create a new type for the state of the checkbox when one already exists for regular checkboxes? TCheckBoxState defined in StdCtrls.pas


2006-09-29 07:56

reporter   ~0010253

This is good because you do not need to include StdCtrls in this unit.


2006-09-29 08:07

administrator   ~0010256

To me it is not. And the XPCtrls package already requires the StdCtrls package anyway. So please do not duplicate this type.

2006-09-29 08:42 (3,779 bytes)


2006-09-29 08:44

reporter   ~0010258

I have to agree with Obones, because it's descendent of jvComponents, StdCtrls is already included, whether we want it or not.


2006-09-29 08:45

reporter   ~0010259

I removed new type from unit, included StdCtrls and made some omproveemnts.
I didn't find anything about how to determine color of check mark programmatically. I think better is to use as you said - screen capture method.


2006-09-29 10:00

reporter   ~0010260

I created the color I believe is the right one,
 dxColor_Chk_Enb_GraSymb_WXP = TColor($0071C671);

Then added the code to use it: ~line 460

        IF FState = cbChecked THEN
          Bitmap.LoadFromResourceName(HInstance, 'JvXPCheckboxCHECKBOX')
          Bitmap.LoadFromResourceName(HInstance, 'JvXPCheckboxCHECKBOXGRAY');
        IF Theme = WindowsXP THEN
-> IF FState = cbChecked THEN
            JvXPColorizeBitmap(Bitmap, dxColor_Chk_Enb_NmSymb_WXP)
-> JvXPColorizeBitmap(Bitmap, dxColor_Chk_Enb_GraSymb_WXP)
          IF (dsClicked IN DrawState) AND (dsHighlight IN DrawState) THEN
            JvXPColorizeBitmap(Bitmap, clWhite);
But for some reason, JvXPColorizeBitmap() always paints it in a dark gray, as like it's failing to apply the new color, any ideas?
Interesting enough, if you just change the color to a lower level of R and B, like $0041C641, it works.
Try yourself, just replace even the current Checked enabled color to the one I mentioned and you will see.


2006-10-06 03:01

administrator   ~0010304

anudedeus, can you provide the files you modified ?

2006-10-10 05:40 (2,339 bytes)


2006-10-10 05:44

reporter   ~0010339

Ok, changes are uploaded.
2 patch files and 1 .res file.
The bitmap for the grayed state has to be 256 colors to work fine, and cannot be transparent. Because of that, I decided to increase the original JvXPCheckboxCHECKBOX resource from jvXpCore.res to 256 colors as well, so they have both same format/number of colors.
The final result is really good.


2006-10-23 10:41

reporter   ~0010383

So, is everything alright with my latest files (


2006-11-01 06:52

administrator   ~0010402

Well, thanks for the res file, but what I need are the BMP files because the res file is generated from the BMP and .RC files present in the images folder.

2006-11-01 07:49 (1,236 bytes)


2006-11-01 07:51

reporter   ~0010405

Ok, bmps are now uploaded.
Note that it includes the new JVXPCHECKBOXCHECKBOXGRAY.bmp and the modified
(superVga) version of the previous JVXPCHECKBOXCHECKBOX.bmp.


2006-11-16 07:46

reporter   ~0010438

So when it will be in release?


2007-06-19 03:53

administrator   ~0013400

This is now in SVN.
Next time please respect the coding style and use TortoiseSVN to create the patch files. Thanks.

Issue History

Date Modified Username Field Change
2006-09-20 09:27 ZENsan New Issue
2006-09-22 10:28 anudedeus Note Added: 0010154
2006-09-22 11:38 ZENsan Note Added: 0010155
2006-09-26 00:31 ZENsan File Added:
2006-09-26 00:33 ZENsan Note Added: 0010174
2006-09-26 00:37 ZENsan Note Added: 0010175
2006-09-26 00:40 ZENsan Note Added: 0010176
2006-09-26 08:39 ZENsan File Added:
2006-09-26 08:40 ZENsan Note Added: 0010187
2006-09-26 08:40 ZENsan Note Edited: 0010187
2006-09-27 04:34 anudedeus Note Added: 0010195
2006-09-27 04:37 anudedeus File Added:
2006-09-27 04:39 anudedeus File Added: JediChkBox1.jpg
2006-09-27 04:42 anudedeus Note Added: 0010196
2006-09-28 09:02 ZENsan Note Added: 0010201
2006-09-28 09:03 ZENsan File Added: Windows Grayed checkbox!.png
2006-09-28 09:04 ZENsan Note Added: 0010202
2006-09-28 09:12 ZENsan Note Added: 0010203
2006-09-28 09:54 ZENsan Note Added: 0010206
2006-09-28 11:45 anudedeus Note Added: 0010209
2006-09-28 11:56 anudedeus Note Edited: 0010209
2006-09-29 07:20 obones Note Added: 0010245
2006-09-29 07:20 obones Status new => confirmed
2006-09-29 07:56 ZENsan Note Added: 0010253
2006-09-29 08:07 obones Note Added: 0010256
2006-09-29 08:42 ZENsan File Added:
2006-09-29 08:44 anudedeus Note Added: 0010258
2006-09-29 08:45 ZENsan Note Added: 0010259
2006-09-29 10:00 anudedeus Note Added: 0010260
2006-10-06 03:01 obones Note Added: 0010304
2006-10-10 05:40 anudedeus File Added:
2006-10-10 05:44 anudedeus Note Added: 0010339
2006-10-23 10:41 anudedeus Note Added: 0010383
2006-11-01 06:52 obones Note Added: 0010402
2006-11-01 07:49 anudedeus File Added:
2006-11-01 07:51 anudedeus Note Added: 0010405
2006-11-16 07:46 ZENsan Note Added: 0010438
2007-06-19 03:53 obones Status confirmed => resolved
2007-06-19 03:53 obones Fixed in Version => Daily / SVN
2007-06-19 03:53 obones Resolution open => fixed
2007-06-19 03:53 obones Assigned To => obones
2007-06-19 03:53 obones Note Added: 0013400