To build and install Graphal just run ./configure, make and make install commands in the top level package directory. They expect all neccessary tools are installed. The configure script processes only very basic checks, please see content of the top level Makefile for possible build options - e.g. prefix of installation directory or disable optional tools.
Open the project and click Build - Build All menu item. You can also choose between debug and release version. The project in IDE is configured to use the same Makefiles as the command line build.