[Lazarus] Memo.Lines.Add seems to be slow with Lazarus 1.6

[Ondrej Pokorny]

On 04.11.2016 16:18, zeljko wrote:
> On 11/04/2016 03:32 PM, Ondrej Pokorny via Lazarus wrote:
>> On 04.11.2016 13:16, Luiz Americo Pereira Camara via Lazarus wrote:
>>> In the last trunk, the slow issue is fixed regardless of usage of
>>> TextHint in TMemo or not. Fixed also not being reset after text
>>> changed / added
>>
>> I see that r53292, r53293 and r53296 are all about TextHint - all this
>> code will be removed if we decide to rewrite TextHint, so it was just a
>> waste of time :( That's why I said better to wait, just to save your
>> energy.
>
> No it's not. It's pure LCL implementation and I guess that we won't be 
> able to get it handled on WS side for all widgetsets. In that case 
> Bart's implementation will be used.

The current implementation opened many issues and bugs. You probably 
won't be able to solve some of them at all or at a reasonable effort 
(both for development and maintenance). E.g. try to set the edit font 
color while the text hint is shown:
   Edit1.Font.Color := clRed; // << execute when TextHint is visible

I remember from last year that the TextHint sometimes even wasn't 
correctly hidden. From that point I have never used it.

My opinion is that the current implementation of TextHint should be 
completely removed. Even if TextHint won't be supported on all 
widgetsets. Sometimes it's better to have nothing than to have a bad 
solution. You said Qt5 has native support, so has WinAPI, Qt4 can be 
solved with custom painting -> not a bad start at all.

Then there is the question about using the native TextHint. E.g. WinAPI 
supports it but doesn't support custom TextHintFontColor and 
TextHintFontStyle - so what to do if we decide to use native TextHint 
support? My opinion is to keep things simple and both TextHintFontColor 
and TextHintFontStyle should be removed because they are superfluous. Is 
TextHintFontColor and TextHintFontStyle supported natively on Qt5?

Using Text and Font properties for an informative-only and inessential 
feature is just a rape of that properties. I mean everybody can do it in 
his own programs but to have such a solution on LCL level is not 
acceptable, in my eyes. In any case: if the TextHint property doesn't 
work, your programs won't stop working.


On 04.11.2016 14:28, Bart via Lazarus wrote:
> The Windows API provides a nice interface to set TextHint (and the 
> possibility to display it if control has focus, but Text is empty). At 
> the time I implemented it, I saw no API in GTK/QT for a TextHint-like 
> feature.

I see all you say. It was still a bad idea :)

Ondrej
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