On MacOS, I encountered a warning about QuartzWindow ordered front from a non-active application

[destiny_712]

When I was running a compiler for an executable program, I encountered this error:

**2023-03-29 12:55:50.408795+0200 OTEffThreshReader[24910:250037] [Window] Warning: Window QuartzWindow 0x11b429600 ordered front from a non-active application and may order beneath the active application's windows.**

**2023-03-29 12:55:50.529725+0200 OTEffThreshReader[24910:250037] [default] CGSWindowShmemCreateWithPort failed on port 0**

I guess the reason for it was that I created Canvas and didn’t activate my application correctly.
What should I do to activate my application?

This is the code snippet I tested:

    TApplication* myApp = new TApplication("myApp", &argc, argv);
    TCanvas* thresholds_distr = new TCanvas("c1","c1",950,10,600,400);
    TH1D* h_thrs__1 = new TH1D("h1", "h1", 50, 0, 50);
    h_thrs__1->Fill(100);
    thresholds_distr->cd();
    h_thrs__1->Draw();
    thresholds_distr->Modified();
    thresholds_distr->Update();
    myApp->Run();

---

ROOT Version: ROOT Version: 6.26/06
Platform: MacOS 13.3（22E252）
Compiler: Not Provided

---

[couet]

Welcome to the ROOT forum.

What about:

File thresholds.C

void thresholds.C() {
    TCanvas* thresholds_distr = new TCanvas("c1","c1",950,10,600,400);
    TH1D* h_thrs__1 = new TH1D("h1", "h1", 50, 0, 50);
    h_thrs__1->Fill(100);
    thresholds_distr->cd();
    h_thrs__1->Draw();
}

$ root thresholds.C

does it work ?

[destiny_712]

Yes, it works well. I have tried not to use the TApplication, and it will not have a warning. It warns just because of the TApplication.

[Wile_E_Coyote]

You need the TApplication only in a standalone application (i.e., in your own “main”).

[destiny_712]

Yes. I do. I also tested it on other OS (Linux), and only macOS will cause this warning.

[Wile_E_Coyote]

Something for @Axel and/or @couet then.

@destiny_712 Can you provide a minimal “main” which reproduces your problem (and how exactly you build your application)?

[destiny_712]

main.cpp (642 位元組)
In fact, I am using Xcode to compile my program. I do not know the specific compilation settings. I chose the default option of Xcode.

//
//  main.cpp
//  TestCanvas
//
//  Created by destiny_712 on 2023/4/4.
//

#include <iostream>

#include <TApplication.h>
#include <TCanvas.h>
#include <TH1D.h>

int main(int argc, const char * argv[])
{
    // insert code here...
    TApplication* myApp = new TApplication("myApp", 0, 0);
    TCanvas* thresholds_distr = new TCanvas("c1","c1",950,10,600,400);
    TH1D* h_thrs__1 = new TH1D("h1", "h1", 50, 0, 50);
    h_thrs__1->Fill(100);
    thresholds_distr->cd();
    h_thrs__1->Draw();
    thresholds_distr->Modified();
    thresholds_distr->Update();
    myApp->Run();
    std::cout << "Hello, world!" << std::endl;
    return 0;
}

[Wile_E_Coyote]

Actually, it’s not really clear to me what you exactly do when you get these errors (what is a “non-active application”?).

Try:
$(root-config --cxx --cflags) -O2 -Wall -Wextra -o main main.cpp $(root-config --libs) ; ./main

[destiny_712]

Thank you for your solution. Doing this does remove the warnings I was encountering earlier.
But it lacks the convenience of using Run directly from Xcode to automate.
Thank you anyway. At least it is not ROOT’s problem.

[Wile_E_Coyote]

So, we need someone who works with Xcode to try to “explain” it.