[RESOLVED] Class Question: Variables and this->

[Pigmaster]

Hello,

I have a class that I have been using but now I would like to modify it slightly but I am having a few problems. It is a simple image class.

Here is my working code..

class ImgClass {

function init($imgWidth,$imgHeight) {
	$this->Chart_Max_Width = $imgWidth;
	$this->Chart_Max_Height = $imgHeight;
	$this->im = imagecreatetruecolor($this->Chart_Max_Width, $this->Chart_Max_Height);
}

function preLoadColours() {
	$this->colour_Snow = ImageColorAllocate($this->im, 255, 250, 250);
	$this->colour_Snow2 = ImageColorAllocate($this->im, 238, 233, 233);
	$this->colour_Snow3 = ImageColorAllocate($this->im, 205, 201, 201);
	$this->colour_Snow4 = ImageColorAllocate($this->im, 139, 137, 137);

}

function setBG() {
	imagefilledrectangle($this->im, 0, 0, $this->Chart_Max_Width, $this->Chart_Max_Height, $this->colour_Snow4);
}
function outputimg() {
	//Output the image
	header ("Content-type: image/png");
	imagepng ($this->im,Null,0);
}
}


$g=new ImgClass;
$g->init(600,400);
$g->preLoadColours();
$g->setBG();
$g->outputimg();

So the above code will create a 600x400 image and paint the background as colour_Snow4

What I would like to do is supply the BG colour when calling the function setBG, this will give me more flexability.

I tried using $g->setBG(colour_Snow2) and $g->setBG(this->colour_Snow2) but this does not work.

Is there a way I can call the colour?

Thanks

[NogDog]

I think what you're looking for is:

$g->setBG($g->colour_Snow2);

[traq]

	function setBG($bg=FALSE) {
		$bg = $bg && !empty($this->$bg) ? $this->$bg: $this->colour_Snow4;
		imagefilledrectangle($this->im, 0, 0, $this->Chart_Max_Width, $this->Chart_Max_Height, $bg);
	}

1) added an input parameter to the setBG() function (I called it $bg). made the default value FALSE (otherwise, you'd get an error if you called the function with no parameter).

2) added the first line to the function. this checks if the $bg parameter is set, and that it refers to an existing property. If it is, we use it; otherwise, we use the default (the original value you had in the script).

3) changed the last parameter of imagefilledrectangle() to use $bg.

example:

$g = new ImgClass();
$g->init(600,400);
$g->preLoadColours();

// this sets the color to "snow2":
$g->setBG('colour_Snow2');
// not specifying would result in the script using the Snow4 color
// $g->setBG();

$g->outputimg();

[Pigmaster]

Fantastic,

Both work like a charm.

Thank you thank you.