Creating an array of objects

[geowizard]

Hi, i am trying to make an array that creates a 6 slot grid of squares that i can reference and change the colours.

EasyGraphics class creates a graphics window and it has two methods setColour that changes the shape colour and fillRectangle that creates the shape.

I tried this, but i does not work properly! I think i need to pass a reference to the grpahics window to the method in the array ?? Please Help:)


EasyGraphics[]grid=new EasyGraphics[6];

grid[0] = new EasyGraphics(400,400);
grid[1].setColour(0,0,255);
grid[1].fillRectangle(20,20,50,50);
grid[2].setColour(255,255,100);
grid[2].fillRectangle(80,20,50,50);
grid[3].setColour(255,0,0);
grid[3].fillRectangle(140,20,50,50);

[Fubarable]

You must initialize each item in the array before you can use it. Here you only call new EasyGraphics once on the item in array position [0], so this is the only array item that has been constructed. The other array items will all be null, and trying to use them will generate a NullPointerException.

[geowizard]

Thanks

I actually need to only create one EasyGraphics window and put rectangles into that window, if i initialise each dataitem it creates numerous graphics windows with rectangles within them. I think i need to reference the original graphics window and call methods to put a new rectangle into each data item location in the array.

I appreciate your help, i have been confused all weekend over this and would love to resolve the problem.

[Fubarable]

Then you most definitely don't want to use an array of EasyGraphics if you only will use one EasyGraphics object, that's for sure.

You probably should create a Square class that holds all the information necessary to draw a Square including it's location, size, and color. Then create an array of 6 of these.

[geowizard]

Sounds tricky,

If i create graphics window like this

EasyGraphics g = new EasyGraphics(400,400);

it creates a 400x400 graphics window, i would like to create an array of rectangles in this graphics window using a method of the EasyGraphics class which is FillRectangle. How is this done....

one object (EasyGraphics)needs to be referenced in each array location and a different rectangle needs to be created using fillRectangle method

I think it should be simpler than creating a new class for rectangle

[Fubarable]

Seeing as how you know about this EasyGraphics library and we don't, you have us at a disadvantage. Much luck though with this project.