Printing a textView with GTK+ / C

Question

I'm working on a simple program that prints the text written in a textview using the print dialog using GTK+/Glade/C-programming language .

Here is the source :

The ui.glade file :

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <!-- interface-requires gtk+ 3.0 -->
  <object class="GtkTextBuffer" id="textbuffer1"/>
  <object class="GtkWindow" id="window1">
    <property name="width_request">440</property>
    <property name="height_request">250</property>
    <property name="can_focus">False</property>
    <child>
      <object class="GtkFixed" id="fixed1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <child>
          <object class="GtkTextView" id="textview1">
            <property name="width_request">416</property>
            <property name="height_request">186</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="buffer">textbuffer1</property>
          </object>
          <packing>
            <property name="x">13</property>
            <property name="y">13</property>
          </packing>
        </child>
        <child>
          <object class="GtkButton" id="button1">
            <property name="label" translatable="yes">Print</property>
            <property name="width_request">145</property>
            <property name="height_request">30</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
          </object>
          <packing>
            <property name="x">284</property>
            <property name="y">210</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

Main.c Source code :

#include <gtk/gtk.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

/************************ widgets variables **************************/
GtkBuilder      *builder;
GtkWidget       *window;
GtkButton       *button1;
GtkTextView     *textview1;
GtkTextBuffer   *textbuffer1;

/************************ Printing button ***************************/
void on_button1_clicked()
{
 //I'm blocked here
}

int main(int argc, char *argv[])
{
    gtk_init(&argc, &argv);

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

    /************************** Getting widgets from UI file *****************************/
    window = GTK_WIDGET(gtk_builder_get_object(builder, "window1"));
    textview1 = GTK_WIDGET(gtk_builder_get_object(builder, "textview1"));
    textbuffer1 = GTK_WIDGET(gtk_builder_get_object(builder, "textbuffer1"));
    button1 = GTK_WIDGET(gtk_builder_get_object(builder, "button1"));

    /************************** Connecting button signal **************************************/
    g_signal_connect (G_OBJECT (button1), "clicked", (GCallback)on_button1_clicked, NULL);


    gtk_builder_connect_signals(builder, NULL);
    g_object_unref(builder);

    gtk_widget_show(window);
    gtk_main();
    return 0;
}

So i'm blocked on coding the printing function , which is in this case on_button1_clicked.

I've tried to read GTK documentation about GtkPrintOperation , but that was not very helpful and not clear to me as a beginner + tutorials about this special topic using C and GTK are rare !

Answer 1

There is no super easy way to simply print some text (perhaps there are some library for it, but none that I know of). Instead you are expected to handle the graphical layout yourself. This is done using GtkPrintOperation by connecting the begin_page and draw_page signals. You will get a callback for each page so you can draw the page using Cairo. And to help with all the complicated details of text layout it is recommended that you use Pango. Then it's up to you to chose font sizes and everything based on the paper size you get told the printer uses. Exactly how complicated this needs to be depends on your needs.