Chapter 7. Miscellaneous Widgets

Table of Contents

Label

Labels are the main method of placing non-editable text in windows, for instance to place a title next to a Entry widget. You can specify the text in the constructor, or later with the set_text() or set_markup() methods.

The width of the label will be adjusted automatically. You can produce multi-line labels by putting line breaks ("\n") in the label string.

The label text can be justified using the set_justify() method. The widget is also capable of word-wrapping, which can be activated with set_line_wrap().

Gtk::Label support some simple formatting, for instance allowing you to make some text bold, colored, or larger. You can do this by providing a string to set_markup(), using the Pango Markup syntax. For instance, <b>bold text</b> and <s>strikethrough text</s> .

Reference

Example

Below is a short example to illustrate these functions. This example makes use of the Frame widget to better demonstrate the label styles. (The Frame widget is explained in the Frame section.) It is possible that the first character in m_Label_Normal is shown underlined only when you press the Alt key.

Figure 7.1. Label

Source Code

File: examplewindow.h (For use with gtkmm 3, not gtkmm 2)

#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H

#include <gtkmm.h>

class ExampleWindow : public Gtk::Window
{
public:
  ExampleWindow();
  virtual ~ExampleWindow();

protected:

  //Child widgets:
  Gtk::Box m_HBox;
  Gtk::Box m_VBox, m_VBox2;
  Gtk::Frame m_Frame_Normal, m_Frame_Multi, m_Frame_Left, m_Frame_Right,
    m_Frame_LineWrapped, m_Frame_FilledWrapped, m_Frame_Underlined;
  Gtk::Label m_Label_Normal, m_Label_Multi, m_Label_Left, m_Label_Right,
    m_Label_LineWrapped, m_Label_FilledWrapped, m_Label_Underlined;
};

#endif //GTKMM_EXAMPLEWINDOW_H

File: main.cc (For use with gtkmm 3, not gtkmm 2)

#include "examplewindow.h"
#include <gtkmm/application.h>

int main(int argc, char *argv[])
{
  auto app = Gtk::Application::create(argc, argv, "org.gtkmm.example");

  ExampleWindow window;

  //Shows the window and returns when it is closed.
  return app->run(window);
}

File: examplewindow.cc (For use with gtkmm 3, not gtkmm 2)

#include "examplewindow.h"
#include <iostream>

ExampleWindow::ExampleWindow()
:
  m_HBox(Gtk::ORIENTATION_HORIZONTAL, 5),
  m_VBox(Gtk::ORIENTATION_VERTICAL, 5),
  m_VBox2(Gtk::ORIENTATION_VERTICAL, 5),
  m_Frame_Normal("Normal Label"),
  m_Frame_Multi("Multi-line Label"),
  m_Frame_Left("Left Justified Label"),
  m_Frame_Right("Right Justified Label"),
  m_Frame_LineWrapped("Line wrapped label"),
  m_Frame_FilledWrapped("Filled, wrapped label"),
  m_Frame_Underlined("Underlined label"),
  m_Label_Normal("_This is a Normal label", true),
  m_Label_Multi("This is a Multi-line label.\nSecond line\nThird line"),
  m_Label_Left("This is a Left-Justified\nMulti-line label.\nThird line"),
  m_Label_Right("This is a Right-Justified\nMulti-line label.\nThird line"),
  m_Label_Underlined("This label is underlined!\n"
          "This one is underlined in quite a funky fashion")
{
  set_title("Label");
  set_border_width(5);

  add(m_HBox);

  m_HBox.pack_start(m_VBox, Gtk::PACK_SHRINK);

  m_Frame_Normal.add(m_Label_Normal);
  m_VBox.pack_start(m_Frame_Normal, Gtk::PACK_SHRINK);

  m_Frame_Multi.add(m_Label_Multi);
  m_VBox.pack_start(m_Frame_Multi, Gtk::PACK_SHRINK);

  m_Label_Left.set_justify(Gtk::JUSTIFY_LEFT);
  m_Frame_Left.add(m_Label_Left);
  m_VBox.pack_start(m_Frame_Left, Gtk::PACK_SHRINK);

  m_Label_Right.set_justify(Gtk::JUSTIFY_RIGHT);
  m_Frame_Right.add(m_Label_Right);
  m_VBox.pack_start(m_Frame_Right, Gtk::PACK_SHRINK);

  m_HBox.pack_start(m_VBox2, Gtk::PACK_SHRINK);

  m_Label_LineWrapped.set_text(
          "This is an example of a line-wrapped label.  It "
          /* add a big space to the next line to test spacing */
          "should not be taking up the entire             "
          "width allocated to it, but automatically "
          "wraps the words to fit.  "
          "The time has come, for all good men, to come to "
          "the aid of their party.  "
          "The sixth sheik's six sheep's sick.\n"
          "     It supports multiple paragraphs correctly, "
          "and  correctly   adds "
          "many          extra  spaces. ");
  m_Label_LineWrapped.set_line_wrap();
  m_Frame_LineWrapped.add(m_Label_LineWrapped);
  m_VBox2.pack_start(m_Frame_LineWrapped, Gtk::PACK_SHRINK);

  m_Label_FilledWrapped.set_text(
          "This is an example of a line-wrapped, filled label.  "
          "It should be taking "
          "up the entire              width allocated to it.  "
          "Here is a sentence to prove "
          "my point.  Here is another sentence. "
          "Here comes the sun, do de do de do.\n"
          "    This is a new paragraph.\n"
          "    This is another newer, longer, better "
          "paragraph.  It is coming to an end, "
          "unfortunately.");
  m_Label_FilledWrapped.set_justify(Gtk::JUSTIFY_FILL);
  m_Label_FilledWrapped.set_line_wrap();
  m_Frame_FilledWrapped.add(m_Label_FilledWrapped);
  m_VBox2.pack_start(m_Frame_FilledWrapped, Gtk::PACK_SHRINK);

  m_Label_Underlined.set_justify(Gtk::JUSTIFY_LEFT);
  m_Label_Underlined.set_pattern (
          "_________________________ _ _________ _ ______"
          "     __ _______ ___");
  m_Frame_Underlined.add(m_Label_Underlined);
  m_VBox2.pack_start(m_Frame_Underlined, Gtk::PACK_SHRINK);

  show_all_children();
}

ExampleWindow::~ExampleWindow()
{
}


Example		Entry