[Solved] Questions about Thumbviewer
lazarus / 39-Graphics

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madepabloh · 2014-10-10 22:16

I am using Thumbviewer component to see thumbnail of images in a
directory. However, i explored the code of this component, but i don´t
see how to figure out some issues. So, i have some questions may be
you could help me to solve.

On the first hand, I would like to capture the image name of the
selected thumbnail. This name is showed in the caption of each image,
but i dont know how to capture it as string to be used in other
procedures.

Thanks!

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wp · 2014-10-10 22:29

I suppose you refer to theo's ThumbViewer
(https://github.com/theo222/lazarus-thumbviewer).

The Thumbviewer has put all info on loaded images into the
"ImageLoaderManager" which is accessible by the equally-named
property. Call its method "ItemFromImage(AImageIndex)" to get to an
image at a specific index. This image is type TThreadedImage which
exposes the filename in property "URL".

Just navigate through the thumbcontrol and threadedimageloader units
and look at the properties and public methods and you'll easily find
what you need. The structure of this component is relatively easily
understood.

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madepabloh · 2014-10-10 22:34

Thanks @wp

Yes i am talking about this component.
Thanks for point me toward this imageloadermanager. I will explore it
with more detail.
 Cheers,

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madepabloh · 2014-10-11 09:24

I solved the issue to extract the name of the thumbnail based on what
@wp explained.

I made this code, to search for the thumbnail code, and to search for
the image name into an stringlist, to select that line. May beit could
be interesting for others:

Code: [Select]procedure TMain.ThumbControl1SelectItem(Sender: TObject;
Item: TThreadedImage);
var
 pic2: string;
 i: integer
 item1: integer;
begin
  thumbcontrol1.LoadSelectedBitmap(Image1.Picture.Bitmap);
  if ToolButton22.Down = true then  // this button show/hide the
stringgrid. If hided, the next setfocus returns and error
    begin
      pic2 :=
ExtractFileNameOnly(thumbcontrol1.ImageLoaderManager.ActiveItem.URL);
      for i:= 0 to PicturesGrid.RowCount-1 do
        begin
          if PicturesGrid.Cells[1,i] = pic2 + '.jpg' then  // this is
because it is case sensitive.
            begin
              item1 := i;
              PicturesGrid.Options := PicturesGrid.Options +
[goRowSelect];
              break; // I only expect to have one file with the same
name, so, once the image is located, it is not necessary to continue
the loop
            end
          else
            begin
              item1 := 0;
              PicturesGrid.Options := PicturesGrid.Options -
[goRowSelect];
            end;
        end;
      PicturesGrid.Row:= item1;
      PicturesGrid.SetFocus;
    end;
end;

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madepabloh · 2014-10-11 09:38

I also prepared a code to search and select an image of the
thumbcontrol based on a file name located into a selected row of a
stringgrid.

Code: [Select]procedure TMain.PicturesGridSelection(Sender: TObject;
aCol, aRow: Integer);
var
  pic1: string;
begin
  pic1 := ExtractFileNameOnly(PicturesGrid.Cells[1,aRow]);
  for i:= 0 to Thumbcontrol1.ImageLoaderManager.CountItems-1 do
    begin
      Thumbcontrol1.ImageLoaderManager.ActiveIndex := i;
      Thumbcontrol1.ImageLoaderManager.ItemFromIndex(i);
      if
AnsiContainsStr(Thumbcontrol1.ImageLoaderManager.ActiveItem.URL, pic1)
= true then
        begin
          Thumbcontrol1.ImageLoaderManager.ActiveIndex := i;
          thumbcontrol1.LoadSelectedBitmap(Image1.Picture.Bitmap);
          break;
        end
      else
        begin
           Thumbcontrol1.ImageLoaderManager.ActiveIndex := 0;
        end;
    end;
end; 
I hope those things could help others to work with that component.

Thanks Werner for your explanations because they pointed me to the
correct path.
Cheers,