Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Event dispatching thread
open-in-new
<p>The event dispatching thread (EDT) is a background <a href="/facts/Thread_(computing)/hh8WHyPd">thread</a> used in <a href="/facts/Java_(programming_language)/9ScgFyAL">Java</a> to process events from the <a href="/facts/Abstract_Window_Toolkit/QWTMvGHk">Abstract Window Toolkit</a> (AWT) <a href="/facts/Graphical_user_interface/wBlQFWDP">graphical user interface</a> <a href="/facts/Event_queue/Kq7kX86w">event queue</a>. It is an example of the generic concept of <a href="/facts/Event-driven_programming/QlGL2Fu6">event-driven programming</a>, that is popular in many other contexts than Java, for example, <a href="/facts/Web_browser/2pfyymLs">web browsers</a>, or <a href="/facts/Web_server/A4GS6thA">web servers</a>. </p><p>The events are primarily update events that cause user interface <a href="/facts/Software_componentry/eW5wvSHC">components</a> to redraw themselves, or input events from <a href="/facts/Input_device/TXYLUkux">input devices</a> such as the mouse or keyboard. The AWT uses a single-threaded painting <a href="/facts/Model_(abstract)/hgysE2kP">model</a> in which all screen updates must be performed from a single thread. The event dispatching thread is the only valid thread to update the visual state of visible user interface components. Updating visible components from other threads is the source of many common <a href="/facts/Software_bug/I1uSXySv">bugs</a> in Java <a href="/facts/Computer_program/e38jH9N9">programs</a> that use <a href="/facts/Swing_(Java)/xFbyDcjS">Swing</a>. The event dispatching thread is called the primordial worker in <a href="/facts/Adobe_Flash/3Lrp9JuH">Adobe Flash</a> and the UI thread in <a href="/facts/Standard_Widget_Toolkit/GTFSXyBV">SWT</a>, <a href="/facts/.NET_Framework/J6QDAUhP">.NET Framework</a> and <a href="/facts/Android_(operating_system)/nNyHb0xz">Android</a>. </p>