triangle.cxx File Reference

Detailed Description

User class with custom JavaScript painter in the web canvas.

Custom class is just triangle which drawn on the frame with NDC coordinates triangle.mjs provides JavaScript code for object painting and interactivity It is also possible to use such "simple" class without loading of custom JS code, but then it requires appropriate Paint() method and will miss interactivity in browser

This macro must be executed with ACLiC like 'root –web triangle.cxx+'

 
#include <iostream>
 
#include "TNamed.h"
#include "TAttLine.h"
#include "TAttFill.h"
#include "TWebCanvas.h"
#include "TCanvas.h"
#include "TROOT.h"
 
#include "ROOT/RWebWindowsManager.hxx"
 
class TTriangle : public TNamed, public TAttLine, public TAttFill {
   double fX[3] = {0, 0, 0};
   double fY[3] = {0, 0, 0};
 
public:
   TTriangle() {} // =default not allowed !!!
 
   TTriangle(const char *name, const char *title = "") : TNamed(name, title) {}
 
   void SetPoints(double x1, double y1, double x2, double y2, double x3, double y3)
   {
      fX[0] = x1;
      fY[0] = y1;
      fX[1] = x2;
      fY[1] = y2;
      fX[2] = x3;
      fY[2] = y3;
   }
 
   /** In old graphics just provide line drawing */
   void Paint(Option_t *opt) override
   {
      if (!gPad)
         return;
      TAttLine::Modify(); // Change line attributes only if necessary
      TAttFill::Modify(); // Change fill area attributes only if necessary
 
      if (*opt == 'f')
         gPad->PaintFillAreaNDC(3, fX, fY, opt);
      else
         gPad->PaintPolyLineNDC(3, fX, fY, opt);
   }
 
   ClassDefOverride(TTriangle, 1); // Example of triangle drawing in web canvas
};
 
void triangle(bool ignore_jsmodule = false)
{
   if (ignore_jsmodule) {
      printf("Custom JS module will NOT be provided for TTriangle class\n");
      printf("No interactive features will be available\n");
      printf("TTriangle::Paint() method will be used for object painting - also in web case\n");
   } else {
#ifdef __CLING__
      printf("Please run this script in compiled mode by running \".x triangle.cxx+\"\n");
      printf("Requires to properly generate dictionary for TTriangle class\n");
      return;
#endif
 
      std::string fdir = __FILE__;
      auto pos = fdir.find("triangle.cxx");
      if (pos != std::string::npos)
         fdir.resize(pos);
      else
         fdir = gROOT->GetTutorialsDir() + std::string("/webcanv/");
 
      // location required to load files
      // also it is name of modules path used in importmap
      ROOT::RWebWindowsManager::AddServerLocation("tutorials_webcanv", fdir);
 
      // mark TTriangle as supported on the client
      TWebCanvas::AddCustomClass("TTriangle");
 
      // specify which extra module should be loaded,
      // "tutorials_webcanv/" is registered path from server locations
      TWebCanvas::SetCustomScripts("modules:tutorials_webcanv/triangle.mjs");
   }
 
   auto tr1 = new TTriangle("tr1", "first triangle");
   tr1->SetPoints(0.4, 0.5, 0.8, 0.3, 0.8, 0.7);
   tr1->SetLineColor(kRed);
   tr1->SetLineWidth(3);
   tr1->SetFillColor(kBlue);
 
   auto tr2 = new TTriangle("tr2", "second triangle");
   tr2->SetPoints(0.2, 0.2, 0.2, 0.6, 0.5, 0.4);
   tr2->SetLineColor(kGreen);
   tr2->SetLineStyle(kDashed);
   tr2->SetFillColor(kYellow);
 
   auto tr3 = new TTriangle("tr3", "third triangle");
   tr3->SetPoints(0.4, 0.8, 0.6, 0.8, 0.5, 0.2);
   tr3->SetLineColor(kCyan);
   tr3->SetFillColor(kMagenta);
 
   auto c1 = new TCanvas("c1", "Triangles");
   c1->Add(tr1, "f");
   c1->Add(tr2, "f");
   c1->Add(tr3, "f");
 
   // test image saving with web browser, chrome or firefox are required
   // c1->SaveAs("triangle.png");
   // c1->SaveAs("triangle.pdf");
}

Author

Sergey Linev

Definition in file triangle.cxx.