Demonstration how different ROOT web-based widgets can be embed into qt application

Compile on Linux

Create build directory and call:

cmake $ROOTSYS/tutorials/webgui/qtweb
make -j

ROOT should be compiled with configured -Dqt5web=ON or -Dqt6web=ON. If both are present, one can use selector -Dwithqt=5 or -Dwithqt=6 As a result, qtweb application should be created.

Compile on Windows

Run x86 native tools shell from MS VC. Configure Qt5 pathes:

set PATH=%PATH%;C:\Qt5\5.15.2\msvc2019\bin

Compile ROOT with qt5web support in Release mode:

cd C:\
mkdir root
cd C:\root
cmake -G"Visual Studio 16 2019" -A Win32 -Thost=x64 c:\git\root -Droot7=ON -DCMAKE_CXX_STANDARD=17 -Dwebgui=ON -Dqt5web=ON
cmake --build . --config Release -- /maxcpucount

Configure ROOT, create build directory and build qt5web tutorial:

call C:\root\bin\thisroot.bat
cd C:\
mkdir qt5web
cd C:\qt5web
cmake -G"Visual Studio 16 2019" -A Win32 -Thost=x64 c:\root\tutorials\webgui\qtweb
cmake --build . --config Release -- /maxcpucount

As a result, Release\qtweb.exe executable should be created.

Demo application

Application based on QTabWidget with four tabs - standard Qt widget, TCanvas, RCanvas and geometry drawing. Both canvas variants include different histograms drawing.

How to include RCanvas/TCanvas into other Qt-based project

Most easy way - just include RCanvasWidget.h and RCanvasWidget.cpp files in the project and let compile, linking with ROOT basic libraries root-config --libs plus -lROOTWebDisplay -lROOTGpadv7. RCanvasWidget is just QWidget which internally embed RCanvas drawing. See ExampleWidget.ui file how to embed such custom widget in normal qt ui file.

To let ROOT work inside Qt event loop, one should instantiate TApplication object and regularly call gSystem->ProcessEvents() - see how it is done in ExampleMain.cpp.

Author: Sergey Linev