Agenda & Assignment 11, March 17

CSC 101/IMM 120

Spring 2009

Summary of Class Activities:

You will need a folder of examples for this exercise.
(you can also find this folder on the front page as "Programming Examples"

Processing Code Sharing: put your Processing project from last week up on a computer and then walk around the room looking at the code others have written.

Three big topics today focus in HUMAN INTERFACE

1. Typography - is remarkably like images, but the bits mean something different!
2. Strings of characters. An ancient form of human expression
3. Mouse & keyboard input: simple communication

	Wolz Examples	Book Pages	Processing Examples	Reference page commands
Typography	_01BasicTypography _02AnimatedTypography _30MouseTypography	737-740	Basics/Typography	Pfont, loadFont, textFont, text, textAlign,textSize, textLeading, textWidth
Strings	_04CharAndString _05OperationsOnCharAndString _06EqualsString _07Tickertape	679-682	Nothing simple enough	char, String, "+" operator concatenates.
Keyboard events	_08KeyEventMethods _09KeyVariables _10KeyMovement	603-612	Input	key, keyCode,keyPressed, keyPressed(),keyReleased()
Mouse events	_11MouseExample	564-603	Input	mouseDragged(),mouseMoved(),mouseButton,mouseX,mouseReleased(),pmouseX,mousePressed(),mouseY,mousePressed,pmouseY

 

A Brief Summary of "Written" communication:

• Human beings communicate via voice and gesture: this is LANGUAGE
• WRITEN language was invented thousands of years ago as a means of PERSISTANCE over distance and time.
• SYMBOLS evolved into CHARACTERS that are combined into sequences of STRINGS
• Until the 1980's human computer communication was via STRINGS of CHARACTERS (and numbers) and the human and computer TOOK TURNS
• GRAPHICAL USER INTERFACES (GUIs) changed the nature of the dialog and required the notion of an EVENT.

Typography:

Same idea as images: a class of objects called "PFont" holds the data representation of the fonts.

Review of the notion of the "data" file attached to the folder where the Processing project is stored.
Like an image, the Pfont file is stored here. You create the Pfont file using the "Tools" pulldown menu. (You can also programmatically use "createFont" but we won't.

The steps are:

1. Load the font (loadFont). This just prepares it.
2. Specify the font to use for subsequent text (textFont).
3. Optionally specify the text alignment. (textAlign)
4. Color the text (fill).
5. Place the text on the screen (text).

Strings:

A symbolic "character" is one of the oldest ideas in programming.
You might want to look up "ASCII" or "UNICODE" on the internet....

char is a primitive datatype (like int, float, color)
To specify a character surround it with single quotation marks: 'a'.

String is a composite datatype (like Array). It holds a sequence of characters.
To specify a string surround it with double quotations marks: "hello"
A String is also a "class" and has methods! Look them up in the reference

Important String methods and operations:

+ concatenates two strings: "hi " + "there" becomes "hi there". (note the space in the first string!)

length() is very helpful and determines the length of the string

equals() determines whether two strings have the same characters. Don't use "==" for strings. (Long story, not now.)

Others: charAt(), indexOf(), substring(), toLowerCase(), toUpperCase()

Keyboard & Mouse Input

Keyboard input is based on the idea of an event. You've seen events in Scratch.
Event METHODS are like event SCRIPTS in Scratch, they are called by the operating system when an event such as a key press occurs.

You can also use the keypress variable but this isn't as useful.

Detecting particular keys is done with the "key" and "keyCode" variables.

Mouse detection acts pretty much the same way.

Detecting other kinds of sensors also works this way.......

 

HOMEWORK

Reading: (Due March 24) Read Chapters 9 & 10. But read for your own pleasure and edification, not like this was a textbook where you have to remember EVERYTHING for the multiple choice test. Make notes on what is interesting and what you might find useful in the future. Pick one example and try running it. Or run all the examples.....or some of them.

Programming Assignment: (Due Tuesday, March 24)

Once again you will be asked to create a simple sketch of your own based on the examples presented this week. Begin by working through the questions in the set of sketches presented in class. If you have trouble figuring something out, work with a classmate, post a question on the wiki, bring the question to class on Friday or email Dr. Wolz. Your sketch this week should include two of the following: typogrpahy, string manipulation and keyboard input.

Journal Assignment: (Due Tuesday, March 10) Events are a big deal in user interactivity. Contrast the way events are implemented in Scratch and Processing.