EMonitorLockException at FMX.SVGIconImageList unit's PaintToBitmap procedure

[birbilis]

The errors fires at CheckOwningThread after the following sequence (continuing from the place shown in the screenshot):

procedure TCanvas.EndScene;
begin
  try
    if FBeginSceneCount = 1 then
      DoEndScene;
    Dec(FBeginSceneCount);
  finally
    Unlock;
  end;
end;

class procedure TCanvas.Unlock;
begin
  TMonitor.Exit(FLock);
end;

class procedure TMonitor.Exit(const AObject: TObject);
begin
  CheckMonitorSupport;
  GetMonitor(AObject).Exit;
end;

procedure TMonitor.Exit;
var
  LockCount: Integer;
begin
  CheckOwningThread;
  Dec(FRecursionCount);
  if FRecursionCount = 0 then
  begin
    FOwningThread := 0;
    while True do
    begin
      LockCount := FLockCount;
      if AtomicCmpExchange(FLockCount, LockCount - 1, LockCount) = LockCount then
      begin
        // if LockCount is <> 0 after we dropped our lock, there were waiters, so signal them
        if LockCount and not 1 <> 0 then
          MonitorSupport.WaitOrSignalObject(GetEvent, nil, 0);
        Break;
      end;
    end;
  end;
end;

function TMonitor.CheckOwningThread: TThreadID;
begin
  Result := FOwningThread;
  if Result <> GetCurrentThreadId then
    Error(reMonitorNotLocked)
end;

[birbilis]

the whole callstack is here:

[birbilis]

There is a TSelection holding in it a TSVGIconImage (which has Align:=Contents) and the TSelection has Align:=Scale and is inside a TFrame (descendent) which is inside another such TSelection which is in turn inside a TFrame which is inside a TScrollBox which is inside a TForm (the idea is you have items that allow to manipulate [via control points of tselection] their contents and can nest infinitely).

Probably just placing the TSVGIconImage inside a TSelection on an FMX TForm and dragging arround the selection corners will cause that (think what I did was make one dimension of the selection too small, not sure if I hit zero there when it failed.

[carloBarazzetta]

I'm sorry but I have little experience with FMX, what I tried to do with these components was to try to provide an easy way to manage scalable icons, keeping source and destination "in sync", but I don't know if this is the cause of your problem... You would need some help from some more experienced FMX developer than me ..

[carloBarazzetta]

Did you find any solution or the cause of this problem?

[birbilis]

didn't happen again, but didn't try that case I mention above extensively (placing the TSVGIconImage inside a TSelection on an FMX TForm and dragging arround the selection corners), if I see it occuring again I will note it here (and for what version)

[carloBarazzetta]

Ok, thanks.