Regarding issue :
https://bugs.freepascal.org/view.php?id=30682

I added TextHint to TComboBox in r63731. QT5 now works with native TextHint, GTK2 with emulated one.
Native support for Win32 is not implemented yet. Somebody please implement it. Other widgetsets that natively support this feature for TComboBox, should also be updated.

I have a question about TextHint support of TEdit in Win32. The widgetset binding code tests EmulatedTextHintShowing and calls CreateEmulatedTextHintFont from generic LCL code.
Does it mean it actually emulates the feature inside the binding code instead of using a native feature?
It should not be needed as the emulated TextHint works purely in LCL code level. Same thing with QT4 binding code. It also uses emulated TextHint specific stuff. Is it needed?

TextHint in TMemo works only with widgetset's native support. It works with QT5 but not with GTK2.
The emulation for TMemo turned out to be tricky. It may never be implemented, unless somebody provides a patch of course.

Regards,
Juha

Juha Manninen wrote

TextHint in TMemo works only with widgetset's native support. It works with QT5 but not with GTK2. The emulation for TMemo turned out to be tricky. It may never be implemented, unless somebody provides a patch of course.

If I am not mistaken, TEdit has TextHint-emulation for WidgetSets without native support. There is no reason why the same emulation shouldn't work with TMemo.

Ondrej

PM Ondrej Pokorny wrote

If I am not mistaken, TEdit has TextHint-emulation for WidgetSets without native support. There is no reason why the same emulation shouldn't work with TMemo.

It does not. Actually it never worked. Nobody has tested it maybe because TMemo.TextHint was not published.
The native support eg. with LCL-QT5 does work.
What happened so far:
The emulated TEdit.TextHint was not updated always. I fixed it : https://bugs.freepascal.org/view.php?id=37506
Then I simplified the code in r63725 which broke TMemo's behavior : https://bugs.freepascal.org/view.php?id=37553
Then I realized that emulated TMemo.TextHint never worked and disabled it completely in r63726.
You can test by reverting it. I believe it can be fixed somehow. I will be happy if you take a r63726 ------
function TCustomMemo.CanShowEmulatedTextHint: Boolean; begin
- Result :=
- Assigned(Lines) // CM_EXIT is sent in destroy -> this function is called in destructor when Lines are already destroyed
- and (Lines.Count = 0)
- and inherited CanShowEmulatedTextHint;
+ // CM_EXIT is sent in destroy -> this is called in destructor when Lines are already destroyed
+ //Result := Assigned(Lines) and inherited CanShowEmulatedTextHint;
+ // ToDo: Make this work. The line above does not work with GTK2 at least.
+ Result := False;
end;

Juha

Emulated TMemo.TextHint (r63708) works perfectly on Win32 (Windows 10). I haven't checked your more recent changes. WinAPI doesn't support TMemo.TextHint natively.

Ondrej

PM Ondrej Pokorny wrote

Emulated TMemo.TextHint (r63708) works perfectly on Win32 (Windows 10). I haven't checked your more recent changes. WinAPI doesn't support TMemo.TextHint natively.

AFAIK it is not emulated on Windows. LCL-Win32 reports LCLCapability flag lcTextHint.
There is a related bug report :
https://bugs.freepascal.org/view.php?id=35967

I tested the emulation only with GTK2.
I should have mentioned the problem comes only when adding lines to a Memo by code when the Memo has no focus.
It is demonstrated by the example project in issue #37553.

I don't have Windows was hoping not to install it again as I don't need it for anything. Maybe I must have it for Lazarus testing anyway.

Juha

Hi,
 
something went wrong. When I open IDE Options or Project Options and I click on any item of TreeView, everything disappear. Content of the filter become "(filter)". When I change it (i.e. non-empty string), content is back. And many of the content is italic.
 
Lazarus 2.1.0 r63731M FPC 3.3.1 x86_64-linux-qt
 
Vojtěch a.k.a. Blaazen

PM Juha Manninen wrote

AFAIK it is not emulated on Windows. LCL-Win32 reports LCLCapability flag lcTextHint.

Actually it is emulated for older Windows versions.
function TWin32WidgetSet.GetLCLCapability has :
  ...
    lcTextHint:
    begin
      if (ComCtlVersion >= ComCtlVersionIE6) then
        Result := LCL_CAPABILITY_YES
      else
        Result := LCL_CAPABILITY_NO;
    end;

For Windows 10 it should report LCL_CAPABILITY_YES.

Juha

Yours is QT4 I guess.
Damn right, I can reproduce with GTK2 IDE. I mostly tested individual applications only.
I try to figure out what is going on...

Juha

Please test with r63734.
The 3-state type TEmulatedTextHintStatus and its thsChanging was needed after all.
Should have tested still more. :(
At least here it works now.

Juha

Yes, it looks fine now.
 
Thanks!

Funnily I tested with themes off, so I got LCL_CAPABILITY_NO :)

But yes, you are correct. That is not optimal. We need to split lcTextHint into lcTextHintEdit and lcTextHintMemo. Because as I wrote before WinAPI doesn't support TextHint for multi-line text boxes (TMemo):
https://docs.microsoft.com/en-us/windows/win32/api/commctrl/nf-commctrl-edit_setcuebannertext

So for TMemo we need the emulated code, which works now with a minor bug (the TextHint is not visible when the form is shown the first time). Strangely the bug is present only in a themed application, not in an unthemed one.

Ondrej

PM Ondrej Pokorny wrote

So for TMemo we need the emulated code, which works now with a minor bug (the TextHint is not visible when the form is shown the first time). Strangely the bug is present only in a themed application, not in an unthemed one.

Please test with the demo by Lagunov Aleksey in
https://bugs.freepascal.org/view.php?id=37553
adding the line
Memo1.TextHint:='My own TextHint';
as seen in my note.
Also remember to change function TCustomMemo.CanShowEmulatedTextHint. It now returns False always.
The emulation does not work with GTK2.

Juha

Why have you removed the (FTextHint '') check in CanShowEmulatedTextHint?

Why should the emulated text hint be shown if there is none?

Ondrej

AM Ondrej Pokorny wrote

Why have you removed the (FTextHint '') check in CanShowEmulatedTextHint? Why should the emulated text hint be shown if there is none?

It was restored later as I noticed the same error. First I planned to make it generic code for both TEdit and TCombobox. Then I just copied it.
The latest revision is 63734.

Juha