Web-canvas

[barao]

Dears,

I’m running 6.31.01 version which uses web-canvas and I built ROOT on apple M1.

We can select either web or graphic canvas using rootrc property: Canvas.Name (respectively TWebCanvas or TRootCanvas).

I figured out that TPad::WaitPrimitive() do not act as expected (waiting for a user interaction) when displaying in the TWebCanvas. Is that normal?

Thanks

[linev]

Hi,

Can you provide macro which demonstrates expected behavior?

Up to now I did not test this method with web-based canvas.

Regards,
Sergey

[barao]

The very simple macro to test was this one:

#include "TCanvas.h"
#include "TF1.h"
#include "TApplication.h"

#include <iostream>
using namespace std;

int main() {

  auto A = new TApplication("a", 0,0);
  auto c = new TCanvas("c","",1400,1200);
  auto f = new TF1("f","sin(x)/x", 0., 4.);
  f->Draw();
  c->Modified();
  c->Update();
  cout << "aqui" << endl;
  c->Print("a.png");
  c->WaitPrimitive();
}

[linev]

Hi,

In your macro one just waits when some (not any) action performed on the pad.
For instance - click on axis returns from waiting but click on the frame or title not.
But method WaitPrimitive potentially can do much more.

I will try to implement something with correspondent behavior on web canvas - but not identical.

Regards,
Sergey

[linev]

And even worse - if one tries to activate edit mode like:

auto obj = c->WaitPrimitive("","PolyLine");

method never returns - also after stop of creation of polyline.

One need to fix method itself.

[linev]

Hi,

I have simple PR with the fix for c->WaitPrimitive() call for ROOT 6.30. It will wait until double click on the frame.

More complex functionality with real edit mode will be implemented later.

Regards,
Sergey

[barao]

Hi Sergey,
Just to be sure I understood:

• you implemented a correction on version 6.30?
• what about the master? I just dit a pull, cmake, recompiled it and the web canvas just flashes and disappear (doesn’t stop waiting for an action…)

Thanks a lot
fernando

[linev]

I did not merge my changes yet.

But after applying PR c->WaitPrimitive() will block until double click in the frame.

Same fix will be applied to master and 6.30 branch.

Real editing mode I will implement later - after my vacations.