Hello World Sample

Compiling

To compile the example:

Launch EiffelStudio.
Select Use existing Ace (control file) and click OK.
Browse to Eiffel52\examples\wel\hello\.
Choose Ace.ace
Choose the directory where the project will be compiled, by default the same directory containing the Ace file.
Click OK.

Running

After you launch the sample, You should see a window displayed as illustrated above. You will have full control over the window, and the program will quit when you close the window.

Under the Hood

MAIN_WINDOW inherits WEL_FRAME_WINDOW. In this example, we have redefined on_paint as shown below:


		on_paint (paint_dc:
	        WEL_PAINT_DC; invalid_rect: WEL_RECT) is

		      --Draw a centered text

		   is

		      paint_dc.draw_centered_text("Hello, World!", client_rect)

		   end

Note: If you look at MAIN_WINDOW, you will see that it contains many features. However, nearly all of these are features are inherited from WEL_FRAME_WINDOW.

This sample contains the following classes: