Archives by ALB42

More Lazarus

hmm seems I opened Pandoras Box with compiling Lazarus. Of course its very unstable and buggy, so many bugs that its hard to decide where to start. So I started with the crashes on start and some redrawing issues I noticed.
 
Not sure whats wrong but the non-buffered drawing does not work well. For example the SynEdit looks nice with buffered drawing… when non buffered Drawing happen the upper quarter of the picture is empty. So it would be nice to always used buffered drawing (as long it does flicker less and is faster) But sadly with native MUI Widgets I can not use Buffered drawing. The reason is that the MUI drawing of the children only draws directly to the window and not to the buffer. So when the buffer is drawn to the window the MUI Objects are overpainted. So I first clip the buffer to window and then call the Childs to do a redraw, works nicely so now I alsways can use buffered drawing. I think LAter I should ckeck if some more optimizations can be done here (turn off the background drawing of MUI for example).
 
An other big part of the was the file handling and Text sizing. There this bad behaviour of lazarus showed up again, they implemented all the RTL functions for file handling again. For example found again a System: -> System:/ conversation, instead of using IncludeTrailingPathDelimiter(). I guess I have to recheck all the file utils again.
 
The Text Width/Height function is often called, even there is no RastPort available (outside paint event or even before the window is open). The height one can get directly from the Font, which solved the issue. The Width is a little bit more difficult, especially for not fixed width fonts. But even so I get some problem with the Toolbar buttons, the complete Window does not redraw anymore :-O if the Textwidth is bigger than 0 very strange, but I guess this I can also debug outside Lazarus with a little test application.
 

A Tree on the backyard

The Treeviews are working in principle, just the scrollbars are not in place, The position of them is set too early, before they are created. Besides this the Trees work rather nicely also the shelltreeview. But the Edit has the same problem as in the stringgrid or valueedit. It draws not right, I didn’t find out whats wrong there the edit is completely with text on white background, only at the cursor/selection you can read the char. I still have no idea why MUI paint this in the wrong way, especially because the scrollbars are painted in the right way… very strange.

One Font dialog please

Worked on the Font Dialog and ToolBar, the toolbar needed some addition work on the theming engine… I’m not completely sure how this theming engine work. Needs some more linux debugging I guess.
The fontdialog is just directly assigned to the ASL works very nicely.

Smile Screen

Implemented Screenshot possiblity for AROS, works very nice. Also found a source, how to make a screenshot
without the windows, the application.Minimize and Restore was long time implemented already but I never tried.

so here the source to create a screenshot:

procedure TForm1.Button1Click(Sender: TObject);
var
  MyBitmap: TBitmap;
  ScreenDC: HDC;
  WrkJpg: TJpegImage;
begin
  Application.Minimize;
  Application.ProcessMessages;

  Sleep(32);

  MyBitmap := TBitmap.Create;
  ScreenDC := GetDC(0);
  MyBitmap.LoadFromDevice(ScreenDC);

  Application.Restore;
  Application.BringToFront;

  WrkJpg := TJpegImage.Create;
  try
    WrkJpg.CompressionQuality := 80;
    WrkJpg.Assign(MyBitmap);
    WrkJpg.SaveToFile('test.jpg');
  finally
    FreeAndNil(WrkJpg);
  end;
  ReleaseDC(0, ScreenDC);
  FreeAndNil(MyBitmap);
end;

and the resulting Image:

Tabs n Pages

Worked at my idea for the visible Tabs at the Pagecontrol. As I found out before the Register at MUI can not be changed on runtime, so hard to use it directly for the LCL Pagecontrol. But now I just add a second MUI Object above the Pages which only contains the Register. Rather the same schema I used for the Caption of Checkboxes.