GTK+ 3 Glade C Programming Template Files

A set of template files for starting new GTK+ 3 C programming language projects using Glade for the GUI. The structure of the template directory separates the C source code and Glade files into their own sub-directories with a makefile in the main directory.

These template files make it easier to manage a project by separating the C source code and the Glade files. The makefile allows source code files to be added to the project easily as the project grows.

This article extends simple GTK+ 3 C programming using Glade and compiling by entering compile commands manually, to a better structured project and using a makefile.

Part 4 of GTK 3 Programming with C and Glade Tutorial
See the full GTK3 tutorial index

Structure of the GTK+ 3 Glade Template Directory

The template has a src directory that contains the C source files for the project, and a glade directory that contains the Glade files. The makefile is found in the root directory of the template as shown in the image below.

GTK+ 3 and Glade Template Source Code

The template directory contains the following source code that can be copied to create a set of template files for your own projects.

The Makefile

Below is the contents of the file called makefile which must be placed in the root directory of the project.

# change application name here (executable output name)
TARGET=template_app

# compiler
CC=gcc
# debug
DEBUG=-g
# optimisation
OPT=-O0
# warnings
WARN=-Wall

PTHREAD=-pthread

CCFLAGS=$(DEBUG) $(OPT) $(WARN) $(PTHREAD) -pipe

GTKLIB=`pkg-config --cflags --libs gtk+-3.0`

# linker
LD=gcc
LDFLAGS=$(PTHREAD) $(GTKLIB) -export-dynamic

OBJS=    main.o

all: $(OBJS)
    $(LD) -o $(TARGET) $(OBJS) $(LDFLAGS)
    
main.o: src/main.c
    $(CC) -c $(CCFLAGS) src/main.c $(GTKLIB) -o main.o
    
clean:
    rm -f *.o $(TARGET)

Change the name template_app at the top of the file to the name of your project. This will be the name of the executable file that is generated after compiling.

Modify the makefile when new C source code files are added to the project so that the new files are compiled and linked.

Main C Source Code File

In the src directory, create a file called main.c and copy the following code to it.

#include <gtk/gtk.h>

int main(int argc, char *argv[])
{
    GtkBuilder      *builder; 
    GtkWidget       *window;

    gtk_init(&argc, &argv);

    // builder = gtk_builder_new();
    // gtk_builder_add_from_file (builder, "glade/window_main.glade", NULL);
    // Update October 2019: The line below replaces the 2 lines above
    builder = gtk_builder_new_from_file("glade/window_main.glade");

    window = GTK_WIDGET(gtk_builder_get_object(builder, "window_main"));
    gtk_builder_connect_signals(builder, NULL);

    g_object_unref(builder);

    gtk_widget_show(window);                
    gtk_main();

    return 0;
}

// called when window is closed
void on_window_main_destroy()
{
    gtk_main_quit();
}

All C source code files that are added to the project can be placed in the src directory. Glade files that are used in the project are placed in the glade directory and accessed as such in the C source code as the following line of code from above shows.

 gtk_builder_add_from_file (builder, "glade/window_main.glade", NULL);

Update October 2019: the code has been simplified by replacing these two lines of code:

builder = gtk_builder_new();
gtk_builder_add_from_file (builder, "glade/window_main.glade", NULL);

With this single line of code:

builder = gtk_builder_new_from_file("glade/window_main.glade");

Glade File

A new glade file can be created in the Glade editor or the code below can be copied to a file called window_main.glade in the glade directory.

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.16.1 -->
<interface>
  <requires lib="gtk+" version="3.10"/>
  <object class="GtkWindow" id="window_main">
    <property name="can_focus">False</property>
    <property name="title" translatable="yes">Template Window</property>
    <property name="default_width">640</property>
    <property name="default_height">480</property>
    <signal name="destroy" handler="on_window_main_destroy" swapped="no"/>
    <child>
      <placeholder/>
    </child>
  </object>
</interface>

All new Glade files added to the project are to be put into the glade directory.

Building the GTK+ 3 Glade C Programming Template Project

Open a terminal window and change to the project directory. To build the project, enter make in the terminal window. This assumes that the correct software and libraries have been installed.

Build the project:

make

Clean the project — delete object and executable files:

make clean

If an error message appears when you try to build the project using make, open the make file in a text editor and be sure to replace the spaces that are used to indent text in the file with tab characters by using the Tab key. A typical error message is:

makefile:26: *** missing separator.  Stop.

This indicates that the following indented line in the make file listing is indented with spaces instead of a tab character:

all: $(OBJS)
    $(LD) -o $(TARGET) $(OBJS) $(LDFLAGS)