Path: utzoo!mnetor!uunet!husc6!bbn!rochester!PT.CS.CMU.EDU!andrew.cmu.edu!bader+
From: bader+@andrew.cmu.edu (Miles Bader)
Newsgroups: comp.windows.misc
Subject: Re: Does anyone really understand windows?
Message-ID: <sW6BGny00UhBwhM08h@andrew.cmu.edu>
Date: 16 Feb 88 23:30:59 GMT
References: <1457@sugar.UUCP>
Organization: Carnegie Mellon University
Lines: 156
In-Reply-To: <1457@sugar.UUCP>



Here's a program for the "Andrew Toolkit" that displays helloworld in a 
window...  Note that it (like the Xtk version in David Rosenthal's paper) 
isn't a good example if you want to do more than use pre-existing views & 
dataobjects or combinations thereof (but see the second version later in this 
message).

/* --------------- start file hwapp.H --------------- */
class hwapp : application{
    overrides:
	Start() returns boolean;
};
/* --------------- end file hwapp.H --------------- */

/*  --------------- start file hwapp.c --------------- */
#include <class.h>

#include "hwapp.eh"

#include "im.ih"
#include "text.ih"
#include "textview.ih"

boolean hwapp__Start(self)
struct hwapp *self;
{
    struct text *t;
    struct textview *tv;
    struct im *im;

    if(!super_Start(self))
	return FALSE;

    t=text_New();
    if(t==NULL)
	return FALSE;

    text_InsertCharacters(t,0,"Hello world!",sizeof("Hello world!")-1);

    tv=textview_New();
    if(tv==NULL){
	text_Destroy(t);
	return FALSE;
    }

    textview_SetDataObject(tv,t);

    im=im_Create(NULL);		/* an im is effectively a window */
    if(im==NULL){
	text_Destroy(t);
	textview_Destroy(tv);
	return FALSE;
    }

    im_SetView(im,tv);

    return TRUE;
}
/*  --------------- end file hwapp.c --------------- */

To compile it, I type:
	class -I/usr/andy/include/be2 hwapp.H
	cc -c -I/usr/andy/include -I/usr/andy/include/be2 hwapp.c
	makedo hwapp.o

And to run it:
	runapp hwapp

or alternatively:
	ln -s /usr/andy/bin/runapp hw
	hw


Here's the same program, but using a custom view:

First, the driver:

/*  --------------- start file hwapp.H --------------- */
class hwapp : application{
    overrides:
	Start() returns boolean;
};
/*  --------------- end file hwapp.H --------------- */

/*  --------------- start file hwapp.c --------------- */
#include <class.h>

#include "hwapp.eh"

#include "im.ih"
#include "helloworld.ih"

boolean hwapp__Start(self)
struct hwapp *self;
{
    struct helloworld *hw;
    struct im *im;

    if(!super_Start(self))
	return FALSE;

    hw=helloworld_New();
    if(hw==NULL)
	return FALSE;

    im=im_Create(NULL);
    if(im==NULL){
	helloworld_Destroy(hw);
	return FALSE;
    }

    im_SetView(im,hw);

    return TRUE;
}
/*  --------------- end file hwapp.c --------------- */

Now, the view:

/*  --------------- start file helloworld.H --------------- */
class helloworld : view {
    overrides:
        FullUpdate(enum view_UpdateType type, long left, long top, long width, 
long right);
};
/*  --------------- end file helloworld.H --------------- */

/*  --------------- start file helloworld.c --------------- */
#include <class.h>

#include "helloworld.eh"

#include "graphic.ih"

void helloworld__FullUpdate(hw, type, left, top, width, height)
struct helloworld *hw;
enum view_UpdateType type;
long left;
long top;
long width;
long height;
{
    int x,y;
    struct rectangle VisualRect;		

    helloworld_GetVisualBounds(hw,&VisualRect);
    x = rectangle_Left(&VisualRect) + rectangle_Width(&VisualRect)/2;
    y = rectangle_Top(&VisualRect) + rectangle_Height(&VisualRect)/2;

    helloworld_MoveTo(hw,x,y);
    helloworld_DrawString(hw,"hello world",
	graphic_BETWEENTOPANDBASELINE | graphic_BETWEENLEFTANDRIGHT);    
}
/*  --------------- end file helloworld.c --------------- */

-Miles