TLMDDBGrid record selection problem

STUDIO CENTRO SRL

TLMDDBGrid shows various problems when selecting records using the mouse. All of them seems to appear when the user drags the mouse under the grid's bottom border.

See the very simple attached demo program and this video :

- at the very beginning you can see an empty grid, this is caused by another problem I've already filed a request for (the grid should contain 10 records).

- after disabling opEditing you can see the inserted records and the range selection without rowselect (this is just to show normal behaviour).

- then I've disabled opRangeSelect and here you can see that dragging the mouse under the grid's bottom border, it scrolls up and the last record shown is actually the first one (contains Test 1), then moving the mouse up you can see a sort of range selection that's completely weird.

- at the end, I've enabled opRowSelect and again very strange behaviour can be seen when dragging the mouse down and up again.

Moreover, in another test I've done after recording the video, strange effects are visible also with the default settings (opRowSelect unchecked and opRangeSelect checked) if you drag the mouse down and up, so the problem isn't caused by row select or range select, it's here anyway.

Eugene Balabuev (LMD)

Confirmed. But fixing this will take considerable time.

Eugene Balabuev (LMD)

Bug will be moved to LMD 2018 issue tracker (https://git.lmd.de/customer/lmdvcl/issues/2). 

If you have LMD Git-access, you can follow up progress there, otherwise please wait for the next minor release.

STUDIO CENTRO SRL

Hello, I've tested the last release but nothing changes.

Any news on this bugs? 

Thank you.

Eugene Balabuev (LMD)

Hi,

Its unfortunately impossible to support multi-select in data-aware version of the grid; I've forgot to remove this possibility. Please use our new feature - row checking instead:

- Row checking feature added. Row checks are shown directly inside indicator column.

- New opShowRowChecks option for showing hiding row check-boxes.

- New CheckIndicatorWidth, CheckedCellBgColor, CheckedCellTextColor properties in Grid.Style object. Color properties can be set to clNone to preserve default cell colors.

- New IsRowChecked[Index: Integer] property for simple (non db-aware) grid. Row checks are stored internally in default data store.

- New OnGetRowChecked/OnSetRowChecked events for db-aware grid. Row checks should be stored externally (dictionary can be used in user's code, for example).

STUDIO CENTRO SRL

Hello, 

as mentioned before :

"then I've disabled opRangeSelect and here you can see that dragging the mouse under the grid's bottom border, it scrolls up and the last record shown is actually the first one (contains Test 1), then moving the mouse up you can see a sort of range selection that's completely weird."

This problem persists.

Thank you.

STUDIO CENTRO SRL

Hi.

The new opShowRowChecks option gives an error as soon as I try to check it. Try new VCL project, new TLMDDBGrid, try to check opShowRowChecks, this is what I get:

What's going wrong here?

Thank you.

Eugene Balabuev (LMD)

Hi,

The issue "The new opShowRowChecks option gives an error as soon as I try to check it." is fixed.

STUDIO CENTRO SRL

Hi,

The opShowRowChecks now works, thanks. But there's another problem now, the event OnDblClick on the grid doesn't fire anymore. I want to use double click to select the row (my users are used to this practice).

Can you investigate this please?

Thank you.

Eugene Balabuev (LMD)

DblClick activates inplace editor. How you used it to select row?

STUDIO CENTRO SRL

By setting the grid's option opEditing to False. In LMD 2017 (as in delphi's own TDBGrid) this way a double click fires the OnDblClick event.

Eugene Balabuev (LMD)

Ok, I'll look.

STUDIO CENTRO SRL

Thank you. I've just compared the sources between 2017 and 2018, it seems you've eliminated the "inherited" from the new code, there's a comment saying it caused problems. However this way other mechanisms in the ancestor are inhibited, among these is the double click handling.

Eugene Balabuev (LMD)

I've reverted the possibility to use OnDblClick.

STUDIO CENTRO SRL

Thank you, it seems ok now.

STUDIO CENTRO SRL

Just as a reminder, there is still the problem with selection:

"then I've disabled opRangeSelect and here you can see that dragging the mouse under the grid's bottom border, it scrolls up and the last record shown is actually the first one (contains Test 1), then moving the mouse up you can see a sort of range selection that's completely weird."

Thank you.

Eugene Balabuev (LMD)

I thinking, may be just disable dragging mouse effect when opRangeSelect  is not specified in options?

STUDIO CENTRO SRL

Maybe. Actually delphi's DBGrid doesn't scroll if you drag the mouse on the grid. Whould you implement this fix? I'll be glad to test it.

By the way, if I've understood correctly, opRangeSelect shouldn't be available for TLMDDBGrid, right?

Eugene Balabuev (LMD)

> Whould you implement this fix? I'll be glad to test it.

Yes, I"ll try.

> By the way, if I've understood correctly, opRangeSelect shouldn't be available for TLMDDBGrid, right?

There no technical ways to implement it correctly on the top of Delphi's abstract TDataSet functionality.

STUDIO CENTRO SRL

>> By the way, if I've understood correctly, opRangeSelect shouldn't be available for TLMDDBGrid, right?

>There no technical ways to implement it correctly on the top of Delphi's abstract TDataSet functionality.

Sorry, maybe I said that badly. I meant, shouldn't the opRangeSelect option be REMOVED from the list of options available on the TLMDDBGrid, in order to prevent others from using it?

Eugene Balabuev (LMD)

Yes, you right. I will disable it in some way. May be the simplest way is raising exception on attempt to actiavate the option.

Eugene Balabuev (LMD)

Done.