Event handlers and Message Passing Interface
Many programs respond to some events, such as when a user presses a button or inputs some text. A very important mechanism is event handling or the ability of a program to react to user action. If we want to handle when a user presses a button, we need to create some kind of a listener that will listen to button events, in this case a press action.
An event handler is a function that the operating system calls each time the control sends some kind of message, such as I have been pressed in the case of buttons or I received a character in the case of a textbox.
Event handlers are very important. Timers are events that trigger after a certain portion of time has elapsed. When you press a key on the keyboard, ...