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

7.1.1. 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.)

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: 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()
{
}

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

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

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

  ExampleWindow window;

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

Label

7.1.1. Example

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