I've tried again to write a GUI app with Lazarus and I'm having some problems.

First, I have a form where every time I load the project, the IDE resets the form's position to -200. Every time. I've tried changing it, saving the project and cleaning the entire project's directories, but every time I load the project, the form's top position is always set back to -200. Ironically, I've never set to anything like that or moved the form while designing to that position.

Secondly, The form consists of 2 panels. One aligned left, the other aligned client. There are a total of 6 TListView's on the form, sited on these panels and the amount of flicker with the app is atrocious. Setting DoubleBuffered to true for the panels helped some, but is still unacceptable to me.

Vista32/rev.25961

Any hints?

Thanks,

Use less listviews ? I can't imagine why you'd need 6 Listviews ??

Michael.

Sorry. Actually there are 3 listviews on the form. 1 on the left aligned panel and 2 which are sited on a TPageControl on separate Tabsheets. The TPageControl is sited on the client aligned Panel.

No worries. All of my lazarus development has mostly been with non-gui applications, but against my judgment I figured I'd give lazarus another go for a GUI app which was a mistake apparently. The same exact GUI works perfectly compiled with Delphi. No flicker, no
Warm Regards,

Lee

Hello Lazarus-List,

you wrote

> Vista32/rev.25961 > > Any hints?

MVC> Use less listviews ? I can't imagine why you'd need 6 Listviews ??

Some times they are needed ;) In the other hand there is some uneeded repaints in ListView but I was unable to found the root of the problem. One form that I have since 0.9.27 without almost not flicker since added the BeginUpdate to LCL now is flickering like no BeginUpdate :-?

I hope to have sometime tomorrow to try to catch the root of the problem (Win32/XP). The effect looks like BeginUpdate is not used for insertions or deletions, but used for updates :-?

Populating the listview is ok for me. Once they are populated and I minimize and then restore the app is where I get all the flicker.

Hello Lazarus-List,

you wrote

> I hope to have sometime tomorrow to try to catch the root of the > problem (Win32/XP). The effect looks like BeginUpdate is not used for > insertions or deletions, but used for updates :-?

LJ> Populating the listview is ok for me. Once they are populated and I minimize LJ> and then restore the app is where I get all the flicker.

I do not have that problem, minimize/maximize no problem, but I had found the culprit in my case, it could be or not a "bug", maybe a windows listview strange thing or a missunderstood by my side.

I had write a little test project and compiled also in Delphi 7. The test add 6000 entries, updates them, scroll from first to last, and delete them.

The scroll flickers a bit more in Lazarus than in Delphi. My problem was the beginupdate/endupdate which many times only one line is updated/added/deleted and the endupdate forces a repaint which inserts more flickering than not using them.

Op 2010-11-16 17:32, Michael Van Canneyt het geskryf:

Use less listviews ? I can't imagine why you'd need 6 Listviews ??

What do you keep telling me, use cases vary. :-)
I have a form with 6 StringGrid components - all working in sync and displaying various parts of the same data. Why so many? Bottom grids display totals, middle grids allow for scrollable data. Top grids allows for customizable multi line titles and sorting.

Regards,
- Graeme -