Copy metafiles to clipboard?
lazarus / 55-TAChart

----------------------------------------------------------------------
ironphil · 2014-09-30 02:04

Now that the metafile format is right, would that be difficult to have
something like the existing procedure "Chart1.CopyToClipboardBitmap"
but for metafiles? Something like "Chart1.CopyToClipboardMetafile".
Even if it is specific to Windows.

----------------------------------------------------------------------
wp · 2014-09-30 18:35

Metafile are not supported offcially by Lazarus/FPC. What we have in
in TAChart in a windows-only workaround for this package without full
integration in the graphics infrastructure. On the other hand from
what I saw with the other image formats today, I get the feeling that
it should be possible to add clipboard support for meta files, at
least for windows. Give me some time and some quite moments to
understand how the clipboard formats work.

----------------------------------------------------------------------
wp · 2014-10-01 10:27

I found a solution - as always when you know it, it was not that
difficult.

Before adding it to trunk I'd ask you to test it. Please copy the
attached TADrawerCanvas unit over the original one (it is in
(lazarus)\components\tachart); you may want to make a copy of the
original one in case you want to switch back again. Recompile the
TAChart package. That should be all.

In order to copy a chart to the clipboard as a metafile use the same
code as for saving to file, but leave the file name empty:

Code: [Select]procedure TForm1.btnCopyToClipboardClick(Sender:
TObject);
begin
  with Chart1 do
    Draw(TWindowsMetafileDrawer.Create(''), Rect(0, 0, Width,
Height));
    // Setting the file name to an empty string results in copying the
chart to
    // the clipboard.
end;

Not really straightforward, but I cannot add a CopyToClipboardMetafile
method (like CopyToClipboardBitmap) to TChart because the wmf stuff is
in a separate package (for good reasons...)

Note that this code runs only under Windows.

----------------------------------------------------------------------
ironphil · 2014-10-01 20:31

It looks perfect to me. I tested it with my own project just like you
instructed and it just worked as expected. Many thanks.

----------------------------------------------------------------------
wp · 2014-10-01 21:31

It's in trunk, r48396. The wmfdemo contains a button "Copy to
clipboard" now. See also the wiki
http://wiki.lazarus.freepascal.org/TAChart_Demos#wmf

----------------------------------------------------------------------
wp · 2014-10-02 15:01

Quote I cannot add a CopyToClipboardMetafile method (like
CopyToClipboardBitmap) to TChart because the wmf stuff is in a
separate packageBut I did not think of the magnificent class helpers!
Today I added "CopyToClipboardMetaFile" and "SaveAsMethod" to TChart
by using a class helper implemented in the wmf unit (--> r46404).
These identifiers are much easier to remember. Just have a look at the
wmfdemo which shows the new syntax now:

Code: [Select]  // copy a chart to clipboard as a windows metafile
  Chart.CopyToClipboardMetafile;

  // save a chart to a windows metafile
  Chart.SaveAsWMF('c:\temp\chart.wmf');