Time Driven & Event driven handlers by Lewis Sainsbury

What is time driven mostly used for?

g_purvis — 2015-02-13 12:37:10 UTC

In real-life or safety driven programs, this is because the program is executed by the computer clock.

No external events are allowed to affect the program.

Keywords:

lewissainsbury — 2015-02-13 12:37:12 UTC

Time Driven:

lewissainsbury — 2015-02-13 12:39:21 UTC

Time driven is a type of programming that is used in real time computing. This means that they carry out a set of tasks that are activated depending on the time of a computer clock. The events are recorded in a dispatch table where the rules are given to schedule the running of the tasks.

What is the purpose of a dispatch table?

g_purvis — 2015-02-13 12:39:31 UTC

To make writing code simpler as you only have to write a shorted version of the statement, this then pulls this from the long version to execute it.

How is it controlled?

radasley — 2015-02-13 12:42:37 UTC

The code execution of time driven programming is controlled by the computer clock

Event handler:

lewissainsbury — 2015-02-13 12:47:08 UTC

This is the code that runs when an event occurs.

Real-time:

lewissainsbury — 2015-02-13 12:47:40 UTC

Real time in computing is when a program carried out tasks using a computer clock and the events will happen instantly when a certain time is reached.

Two possible events

g_purvis — 2015-02-13 12:48:14 UTC

Mouse clicks
Double clicks

Can external events affect the program?

radasley — 2015-02-13 12:48:18 UTC

No external events are allowed to affect the program which is running and rules in the dispatch table will run time an time again?

How is an event handler triggered

g_purvis — 2015-02-13 12:50:31 UTC

The events appropriate for the text box are not the same as the events for a button, as they are used in very different ways. An event triggers the appropriate event handler.

Controls

lewissainsbury — 2015-02-13 12:53:05 UTC

Controls are within event driven programming and are a visual object such as a buttons or combo box which can be interfered with.

Controls:

lewissainsbury — 2015-02-13 12:53:12 UTC

Can different objects use the same event?

radasley — 2015-02-13 12:53:51 UTC

Different types of objects can have different collections of events. The events that are appropriate for a text box are no the same as the events for a button, this is because they are used in different ways

Subroutine

lewissainsbury — 2015-02-13 12:54:52 UTC

This is a separate part of the program in its own section, similar to a function.

Subroutine use

g_purvis — 2015-02-13 12:56:09 UTC

for event handling, with the name of the object followed by an underscore then the name of the event.

Activation pattern:

lewissainsbury — 2015-02-13 13:00:25 UTC

The recordings of the time driven program.

Dispatch table:

lewissainsbury — 2015-02-13 13:02:59 UTC

Contains all of the activation patterns and contains the rules that are used to schedule running the tasks.