Default value of type-report not possible?

ModsCentral · **Posted:** Thu Mar 29, 2012 4:53 pm

I am trying to finish off this TextArea module that I am having a great deal of success with, now I've run into 1 minor issue.
Currently whoever uses my module can simply create a TextArea using the following

Turing:

import TextArea

var TestField : TextArea
TextArea.setDefault(TestField) %Without calling this, unless setting every property, program will crash due to "variable has no value"

TestField.x := 20
TestField.y := 300 %Loads of properties to be modified

TextArea.create (TestField) %From here on out, you can modify properties and the field will be updated oncall.

As you can see above, my issue is that the user must call "setDefault(nameOfField)" in order for this program to actually work.
This is because I'm using a type - report as a collection for the properties, and so when the module goes to initiate the textarea using the properties, there is no default value. What I need is a way to simple set a default value to the type variables like so.

Turing:

%What I currently have which I need to replace
type TextArea : record
text : string
x : real
y : real
end record
%What I need basically, but is not supported...
type TextArea : record
text : string := ""
x : real := 10
y : real := 10
end record

So, does anyone have any ideas on how I can go about this? Without having to create a procedure to call to set the default values (Currently what I'm doing)

ALSO
I am also trying to find a way to change the cursor to the text selection cursor for this module, as far I know there is no way to remove the cursor.
I'm thinking of creating a set of vb programs to change the mouse cursor as a process, maybe that should do it.

Thanks in advance

Tony · **Posted:** Thu Mar 29, 2012 5:02 pm

if you make TextArea be a class instead of a record, then it can contain all the same fields + methods (procedures). Some of those methods (a constructor) will run by default, whenever a new instance (variable) is created, so it can set the defaults on its own.

ModsCentral · **Posted:** Thu Mar 29, 2012 5:07 pm

How would I go about creating a procedure to run when a new variable of that type is instantiated?

Tony · **Posted:** Thu Mar 29, 2012 5:12 pm

a constructor is automatically executed on creation. It can be used to trigger any other actions that need to take place.

ModsCentral · **Posted:** Thu Mar 29, 2012 5:25 pm

My apologies but I'm still lost, how can I create a constructor? If I were to use this would it automatically call my procedure to set default values and create the filed as I want?

Tony · **Posted:** Thu Mar 29, 2012 5:31 pm

see class and new

ModsCentral · **Posted:** Thu Mar 29, 2012 5:32 pm

OK I'm trying to get my head wrapped around the differences between classes and modules. So if I use a class, and I create a textarea, should I use new, and if so will this then make the defined variables within the class unique to that specific variable? It's hard for me to explain this, but if this is the case then I can simply just remove type and have a list of variables with initial values without the type record, yes?

ModsCentral · **Posted:** Thu Mar 29, 2012 5:43 pm

Ok basically what I'm doing is using a module, with a type within it, and in my main program, I'm creating a new variable of that datatype, however there is no default value, what would you suggest (Can you provide sample code?)

Tony · **Posted:** Thu Mar 29, 2012 5:53 pm

I would suggest picking up some OOP concepts. http://en.wikipedia.org/wiki/Object-oriented_programming

Raknarg · **Posted:** Thu Mar 29, 2012 6:56 pm

Well, I like to use this example for explaining the difference.

Lets say you're going to make a module to control the movement of a character in an RPG. This would be good for a module, because you have a bunch of procedures and functions that relate to a general task, and it doesnt need to act differently upon different situations. Your character movement (in functionality) will never change.

Classes, on the other hand, are fairly different because you are actually creating a new object with different properties, and it will act differently than other objects even if they are from the same class, because they will complete a different task.

This is the reason you would not create a button module, because you want to create many buttons that do different things. Or, in your case, a text area that will act independantly from other text areas.

Idk if that makes sense to you, but I think about it sort of that way. Generalization vs specific tasks.

Raknarg · **Posted:** Thu Mar 29, 2012 6:58 pm

Tony, if you would like to chip in or completely negate my argument, that would be acceptable Razz

Also, I made a pretty weak example, but an example none the less

Turing:

%This module will handle movement for the used character
module movement
export all

fcn can_move

end can_move

proc move

end move

proc anyhting_else

end anyhting_else
end movement

%This class allows you to create new characters with the same functionality, but different attributes
class character
var health, power, speed, etc : something
var anythingElse : something
end character

or, in your case:

Turing:

class TextArea
export all
var text : string := ""
var x, y : real := 10
end TextArea

var newTextArea : pointer to TextArea % also can be ": ^ TextArea
new TextArea, newTextArea

put newTextArea -> x
%or, and my prefered way:
put TextArea (newTextArea).x

ModsCentral · **Posted:** Thu Mar 29, 2012 7:22 pm

That's the example I was looking for, see my issue is I'm trying to relate the coding the user will use as close to actionscript 3 (flash) as possible hereby relating the properties to this.

Turing:

import TextArea
var field : TextArea %Hoping to have a textarea instantly created with default values
field.x := 20 %Moves the field to x(20) when called (Now)
field.somthingElse %and so on

Currently I have that with the following module

Turing:

unit
module textArea
export unqualified TextArea, create, update, setDefault

type TextArea : record
text : string
x : real
y : real
width : real
height : real
backgroundColor : int
multiline : boolean
borderThickness : real
borderColor : int
borderStyle : string
font : string
bold : boolean
fontColor : int
fontSize : int
padding : real
focused : boolean
cursorSpeed : int
resetCursor : boolean
end record

procedure setDefault (var curObj : TextArea)
curObj.text := ""
curObj.width := 100
curObj.height := 14
curObj.x := maxx div 2 - (curObj.width div 2)
curObj.y := maxy div 2 - (curObj.height div 2)
curObj.backgroundColor := 0
curObj.multiline := false
curObj.borderThickness := 1
curObj.borderColor := 7
curObj.borderStyle := "solid"
curObj.font := "Arial"
curObj.bold := false
curObj.fontColor := 7
curObj.fontSize := 12
curObj.padding := 1
curObj.focused := false
curObj.cursorSpeed := 400
curObj.resetCursor := false
end setDefault

procedure updateText (passedObj : TextArea)
var curObj : TextArea := passedObj
var x : int := floor(curObj.x)
var y : int := floor(curObj.y) + 1
var width : int := floor(curObj.width)
var height : int := floor(curObj.height)
var font : int := Font.New (curObj.font + ":" + intstr(curObj.fontSize))
var bT : int := floor(curObj.borderThickness)
var padding : int := floor(curObj.padding)
Font.Draw (curObj.text, x, y, font, curObj.fontColor)
Font.Free (font)
end updateText

process flashCursor (passedObj : TextArea)
var curObj : TextArea := passedObj
%curObj.resetCursor := false
var font : int := Font.New (curObj.font + ":" + intstr(curObj.fontSize))
var fW : int := Font.Width (curObj.text, font)
var x : int := floor(curObj.x) + fW + 1
var y : int := floor(curObj.y)
var width : int := floor(curObj.width)
var height : int := floor(curObj.height)
var sP : int := 0
loop
curObj := passedObj
Draw.FillBox (x + 1, y, x + 1 + 0, y + height, black)
exit when curObj.focused = false or curObj.resetCursor = true
delay (curObj.cursorSpeed div 1.2)
Draw.FillBox (x + 1, y, x + 1 + 0, y + height, curObj.backgroundColor)
exit when curObj.focused = false or curObj.resetCursor = true
delay (curObj.cursorSpeed)
put curObj.resetCursor
exit when curObj.focused = false or curObj.resetCursor = true
end loop
Draw.FillBox (x + 1, y, x + 1 + 0, y + height, curObj.backgroundColor)
end flashCursor

procedure update (passedObj : TextArea)
var curObj : TextArea := passedObj
var x : int := floor(curObj.x)
var y : int := floor(curObj.y)
var width : int := floor(curObj.width)
var height : int := floor(curObj.height)
var bT : int := floor(curObj.borderThickness)
var padding : int := floor(curObj.padding)
Draw.FillBox (x - padding - bT, y - padding - bT, x + width + padding + bT, y + height + padding + bT, curObj.borderColor)
Draw.FillBox (x - padding, y - padding, x + width + padding, y + height + padding, curObj.backgroundColor)
updateText (curObj)
curObj.resetCursor := true
%fork flashCursor (curObj)
end update

process getKeyDown (passedObj : TextArea)
var curObj : TextArea := passedObj
var curLetter : string (1)
loop
if hasch then
getch (curLetter)
if ord(curLetter) = 8 then
curObj.text := curObj.text (1 .. length (curObj.text) - 1)
elsif ord(curLetter) >= 32 and ord(curLetter) <= 126 then
curObj.text := curObj.text + curLetter
end if
update (curObj)
end if

%exit when curObj.focused = false
end loop
end getKeyDown

process getMouseClick (passedObj : TextArea)
var curObj : TextArea := passedObj
var x : int := floor(curObj.x) - floor(curObj.padding)
var y : int := floor(curObj.y) - floor(curObj.padding)
var width : int := floor(curObj.width) + floor(curObj.padding * 2)
var height : int := floor(curObj.height) + floor(curObj.padding * 2)
var mX, mY, mB : int

loop
Mouse.Where(mX, mY, mB)
if mX >= x and mX <= x + width and mY >= y and mY <= y + height then %MOUSE ENTERED OBJECT
if mB = 1 then %MOUSE CLICKED OBJECT, CALL SPECIFIED CALLBACK FUNCTION (For now focus textarea)
if curObj.focused = false then %OBJECT NOT ALREADY FOCUSED
curObj.focused := true
fork flashCursor (curObj)
fork getKeyDown (curObj)
end if
elsif mB = 0 then
%MOUSE UP... DO NOTHING FOR NOW
end if
else %MOUSE LEFT OBJECT
if mB = 1 then %MOUSE CLICKED AWAY FROM OBJECT... (For now unfocus textarea)
curObj.focused := false
end if
end if
end loop
end getMouseClick

procedure create (passedObj : TextArea)
var curObj : TextArea := passedObj
var x : int := floor(curObj.x)
var y : int := floor(curObj.y)
var width : int := floor(curObj.width)
var height : int := floor(curObj.height)
var bT : int := floor(curObj.borderThickness)
var padding : int := floor(curObj.padding)
Draw.FillBox (x - padding - bT, y - padding - bT, x + width + padding + bT, y + height + padding + bT, curObj.borderColor)
Draw.FillBox (x - padding, y - padding, x + width + padding, y + height + padding, curObj.backgroundColor)
fork getMouseClick (curObj)
updateText (curObj)
end create

end textArea

and the main program >>

Turing:

import textArea

View.Set("graphics:max,max,nobuttonbar,title:Test Textarea")

var testField : TextArea
textArea.setDefault(testField)
testField.backgroundColor := 30
testField.text := "awesome"
textArea.create(testField)

This works so far, except I would like to just eliminate the whole create and setdefault functions to be called.
Also I know processes are sort of deprecated but they run individually (Just having an issue with cancelling the cursor flash process)
I'll give your code a shot, thanks Smile

[/syntax]

ModsCentral · **Posted:** Thu Mar 29, 2012 7:25 pm

Also, is it possible to edit the variables outside the class?

EDIT #1 Just realized Turing throws an error "... readonly" yet if you select run anyway, the variable is hereby modified. Weird?
EDIT #2 So far what you have is what i need, except now I'm stuck with my alternate issue, trying to get the function create to get called automatically. Can I use forward's or something along with the procedure to call it within the class?

EDIT #3

Turing:

class TextArea
export unqualified all
var text : string := ""
var pervasive x, y : real := 10

procedure create

end create
create

end TextArea

var newTextArea : ^ TextArea
new newTextArea

newTextArea -> x := 2
put newTextArea -> x

Is what I have now. I don't want to call the create function manually ;/ is that required?

Raknarg · **Posted:** Thu Mar 29, 2012 7:44 pm

Yes, a class is not really a procedure. Something will have to be called for anything to work. Create, or initialize as I usually call it, will have to be called at the initial instance of the objects use.

ModsCentral · **Posted:** Thu Mar 29, 2012 7:54 pm

Alright modified my code to work with classes. This definitely makes them 100% independent with all others objects which is nice, and also you won't need to pass in the object to initiate it. However, are you saying you must call for example > textfield -> load, in order for it to show any changes made to the properties? Is there no way for the class to detect any modifications to the variables hence call the load proc itself? Maybe a process by which checks each value with a temporarily saved value, and if different then reload?

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