TweetFollow Us on Twitter

Window Structures
Volume Number:5
Issue Number:6
Column Tag:abC

Related Info: Window Manager

Window Structures

By Bob Gordon, Minneapolis, MN

Welcome to the second incarnation of the MacTutor intro column. The column is called abC because of its introductory nature (the “abc’s”), and it uses the C language (the “C”). What I propose to do is to continue in the spirit of the previous set of articles, but focus less on C and more on the Mac.

I also will not attempt to present a complete program each time. Since an introduction by its very nature tends to be a bit repetitive, I found the last time that the same code would appear for months at a time. This took up a lot of space in the magazine, and made it difficult to focus on one issue as we were always carrying around a large amount of other code just to make an application work. This means that the articles will tend to be shorter, which will likely make it more possible for me to get them done.

One other point before we start. I found that one of the most useful things in writing for MacTutor is getting mail. Feel free to write; comments are much appreciated; and include your phone number.

Making a Window

One of the first steps in a Mac application is putting a window on the screen, typically in response to a request from the user. This method developed here is done entirely in code (as opposed to using resources). This has some limits, but offers the ability to easily add some features to ease the maintenance of windows.

There are two points: First a window consists of the window stuff and the application specific stuff. From the Mac’s point of view, the window stuff consists of only the frame and does not even include the scroll bars (if any). On the other hand the application probably does not want to be concerned with such things as the scroll bars, zoom boxes, sizing, et cetera.

Second, it is good programming practice to separate the application specific code from the more generic user-interface code. This eases maintenance and debugging and modification. To this end I created a file, shell.c which handles many of the generic properties, helper files (e.g. windowhelp.c) to add the capabilities I wanted, and the file app.c, which actually contains the parts of the application. In the snippets of code that follow, you will notice an occasional call to a function like appxxx(). This is a call in the shell part of the program to the app.c file. It is here, after, for example, preparation has been made for updating a window (appupdate() ), that the application must update the application portion.

windowhelp.h

The windowhelp functions work because the WindowRecord defined in the ToolBox is a fixed length object. What I did is add some additional data structures on the end. This simply makes the object a little longer, but all the toolbox window and QuickDraw functions will work correctly. The advantage of doing this is that I can now keep additional information, which I think should be attached to a window in a safe place where I can always find it, and the application parts of the code need to concern themselves with it.

One might suggest that the WRefCon (a field in the WindowRecord specifically for the application’s own use) field is the proper place for this. This is probably true, but so much of this stuff seemed to either be more part of the window than the application (scroll bars) or likely to be part of any application (knowing whether the contents had changed or not), that it seemed a Good Idea to put it all together in one place. In this way much of the Mac user interface is handled for us each time we start a project. I use the WRefCon field to store the reference to the applications information proper.

Now, I make have no pretenses that this is the optimal way of doing things. In fact, I know there are additions and changes I am going to make, but if we wait to get all that worked out, we’ll never get this written.

A few comments about the fields:

The first four are what I call window margins. I noticed that many applications place various graphic objects around the edges of the window. There are scroll bars to the bottom and right, rulers on the top and tools on the left. Whatever it is, it brings in the edge of the window as far where the application can write. The window margins are sizes, in pixels of the areas reserved by things around the edges. The application can change them (if the user asks to see the rulers, for example).

The next field, cursrt, is the rectangle defined by the window and the margins. I called it cursrt because outside the rectangle the cursor is typically the 11 o’clock arrow, and inside the cursor is whatever the application would like.

The zoomrt is the rectangle to hold the size to zoom to if the user clicks the zoom box. Frankly, I haven’t implemented zooming yet. It may be that we’ll want two rectangles for zooming: one to hold the maximum size and one to hold the small (user set) size.

mouser is a code for the mouse cursor. I made it a char simply because I couldn’t imagine anyone wanting more than 255 cursors and because the built-in cursors are numbered one through four. If you want to add a cursor resource, simply start the numbers at five and everything will work fine. And if you want more cursors or want to use bigger numbers, make it a short.

The changed field simply states whether or not the window contents have changed.

The next field, ckind (contents kind) I used to indicate the kind of window. Currently this is either text or a object drawing. Whether this will stay this way or not I don’t know. Currently I use this in the functions that handle update and activation events to determine what to do.

The last field is a handle to the current TextEdit record. A window may have more than one. This is needed because when a window is activated, the blinking cursor needs to be placed in whichever edit record the user left it in.

As you can see, much of this information falls somewhere between what is strictly application specific and what is part of the window. Much of it, however, the application either need not be concerned with or is needed for almost all applications.

Following the WindowStruct definition are several groups of #defines. The most interesting of these are the WDOC/WGROW/WZOOM. By using these when you define a window (simply add together the ones you want), you can specify whether you want a simple document window to have a grow box or a zoom box. You can also add in the codes for the vertical or horizontal scroll bars.

/* 1 */

/*windowhelp.h */
#include “TextEdit.h”
 
#ifndef WINDOWHELP_H
#define WINDOWHELP_H

/* window add-on structure */

#define WindowStruct struct w_struct
WindowStruct
 {
 WindowRecord  wr; /* the original window record */
 uchar  mtop;    /* margin indents */
 uchar  mleft;
 uchar  mbottom;
 uchar  mright;
 Rect   cursrt;  /* rectangle used for cursor control */
 Rect   zoomrt;  /* rectangle for zoom operation */
 char   mouser;  /* mouse pointer id (cursor shape) */
 char   changed; /*if window contents havebeen changed */
 short  ckind;   /* kind of contents */
 TEHandle curtext; /* handle current te rec for window */
 };
 

#define Woffset  18
#define SBarWidth15

/* these definitions allow easy generation of the four square
 * cornered titled windows. The basic (simplest) window is the
 * WDOC (NoGrowDocProc). To this optionally add WGROW to add a 
 * grow box and/or WZOOM to add a zoom box.
 */
#define WDOC4
#define WGROW    -4
#define WZOOM    8
#define WVBAR    16
#define WHBAR    32

/* specify the content of the window */
#define CDRAW    1
#define CTEXT    2

/* Value in windowKind field of WindowRecord by WindowNew
 * if the window has a grow box. This is used by routines that
 * redraw the window to decide whether to draw the grow box
 * or not 
 */
#define HASGROW  9

#endif

WindowHelp.c

WindowHelp.c consists mainly of two functions, WindowNew() and WindowClose().

WindowNew() opens a window after creating a WindowStruct as shown above (no check for memory yet). Note that it only gets four arguments. The title (which can be a null string in which case the window is named “Untitled”), a percentage (the window is opened as a certain percentage of the monitor size), the windowkind (WDOC/WGROW/WZOOM), and the content kind.

A few other notes: The call to AppPage() is a kludge. It is supposed to return the page size. Currently some numbers are just hard coded in AppPage(). The page size is needed for scrolling. Just put in sizes for an 8.5 by 11 piece of paper (in pixels) or whatever size page you want. The call to AppNew() is where the application does the initialization of its own data for a new window and places a reference to it (typically a handle) in the WRefCon.

WindowClose() closes a window. After checking to see if the window is a desk accessory (and handling that), it calls AppClose() to allow the application to close its own structures. Then is closes the window and frees the memory. It is in here that we would check to see if the window contents had changed (and had not been saved) and ask the user if we were to save the file.

/*2 */


/* windowhelp.c
 * provides some routines to aid in opening and closing 
 * windows
 */
 
#include“abc.h”
#include“Quickdraw.h”
#include“EventMgr.h”
#include“WindowMgr.h”
#include“MenuMgr.h”
#include“windowhelp.h” 
#include“controlhelp.h”
#include“cursorhelp.h”

short w_total = 0; /* counts total number of windows opened*/
short w_count  = 0;
 /* counts number of windows actually open */

WindowNew(title,percentsz,windkind,contkind)
 char *title;
 short  percentsz;
 short  windkind;
 short  contkind;
{
 char   *thetitle;
 Rect   boundsrt;
 WindowRecord  *w;
 WindowStruct  *ws;
 short  width;
 short  depth;
 short  leftedge;
 short  topedge;
 Rect   pagesz;
 short  hasscroll;
 
 hasscroll = windkind & WVBAR + WHBAR; 
 /* mask out scroll bar options */
 windkind &= 8;
 if (title)
 thetitle = title;
 else
 thetitle = “Untitled”;
 SetRect(&boundsrt,screenBits.bounds.left + 4,
 screenBits.bounds.top + 24,
 screenBits.bounds.right - 4,
 screenBits.bounds.bottom - 4);
 width = boundsrt.right - boundsrt.left;
 depth = boundsrt.bottom - boundsrt.top;
 AdjustRect(&boundsrt,
 topedge = 30 + Woffset * w_total,
 leftedge = 30 + Woffset * w_total,
 ((depth * percentsz) / 100) - topedge,
 ((width * percentsz) / 100) - leftedge);
 ws = (WindowStruct *)NewPtr(sizeof (WindowStruct));
 w = (WindowRecord *)NewWindow(ws,&boundsrt,CtoPstr(thetitle),True,
 windkind,(WindowPtr)-1,True,0);
 ws = (WindowStruct *)w;
 switch (windkind)
 {
 case documentProc : 
 case zoomDocProc :
 w->windowKind = HASGROW;
 break;
 };
 if (w->windowKind == HASGROW)  /* set window margins */
 {
 ws->mright = ws->mbottom = SBarWidth;
 AppPage(&pagesz);
 if (hasscroll == WHBAR)
 ScrollNew(w,0,0,pagesz.right,HORZ);
 if (hasscroll == WVBAR)
 ScrollNew(w,0,0,pagesz.bottom,VERT);
 DrawControls(w);
 DrawGrowIcon(w);
 }
 else
 ws->mright = ws->mbottom = 0;
 ws->mtop = ws->mleft = 0;
 ws->changed = FALSE;
 ws->ckind = contkind;
 ws->curtext = NIL;
 SetCursorRect(w); /* set cursor rect for cursor control */
 AppNew(w); /* function to open application structure */
 w_count++;
 w_total++;
 PtoCstr(thetitle);
}

/* WindowClose()
 * Closes the window passed to it. Assumes window was opened 
 * with WindowNew(). If window is a desk accessory, it will 
 *  be closed correctly. If it is an application window, prior 
 *  to the window close there is a call to AppClose() (which 
 * the application must supply) to allow any application 
 * specific closing.
 */
WindowClose(w)
 WindowRecord  *w;
{
 WindowStruct  *ws;
 short  refnum;
 
 if (ws = (WindowStruct *)w)
 if ((refnum = w->windowKind) < 0)
 CloseDeskAcc(refnum);
 else 
 {
 AppClose(w);    /* close app storage, must do before */
   CloseWindow(w); /*    CloseWindow */
   DisposPtr(w);
   w_count--;    /* decrement the window count */
   if (w_count == 0) 
 /* if the number of windows on screen goes to */
   w_total = 0;  
 /*  zero, set total to zero so next time we */
   }    /* open a window it will start at the original */
}/*   window position */

/* AdjustRect
 * adjusts coordinates of a rectangle by four separate 
 * amounts. adjustment is in (towards center) if amounts are 
 * positive and out if amounts are negative);
 */
AdjustRect(rec,t,l,b,r)
 Rect *rec;
 short  t,l,b,r; /* values to adjust rectangle by */
{
 rec->top +=t;
 rec->left += l;
 rec->bottom -= b;
 rec->right -= r;
}

/* RtGlobalToLocal
 * Adjusts a rectangle to local coordinates
 */
RtGlobalToLocal(rt)
 Rect *rt;
{
 Point  *pt;
 
 pt = (Point *)rt;
 GlobalToLocal(pt);
 pt++;
 GlobalToLocal(pt);
}

The last little piece of code illustrates how these functions are called from the shell program.dofile() is part of the code that responds to menus.

/* 3 */

dofile(item)
 short  item;
{
 WindowRecord  *w;
 
 switch(item)
 {
 case iNew: WindowNew(“”,40,WDOC+WGROW+WVBAR,CTEXT);
   break;
 case iClose: WindowClose(FrontWindow());
   break;
 case iQuit : while (w = (WindowRecord *)FrontWindow() )
 {
 WindowClose(w);
 }
   ExitToShell();
   break;
 }
}

I hope this gives you some ideas on how to handle windows. Since it can open as many windows as you want, there should be some check for memory limits. I also hope this is suitably introductory. Again, if you have any questions or comments, please write.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

pwSafe 4.0.1 - Secure password managemen...
pwSafe provides simple and secure password management across devices and computers. pwSafe uses iCloud to keep your password databases backed-up and synced between Macs and iOS devices. It is... Read more
WALTR 1.5.4 - Drag-and-drop any media fi...
WALTR is designed to make it easy to upload and convert any music or video file to an iPad or iPhone format for native playback. It supports a huge variety of media file types, including MP3, MP4,... Read more
Audio Hijack 3.1 - Record and enhance au...
Audio Hijack (was Audio Hijack Pro) drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio... Read more
PopChar 7.1 - Floating window shows avai...
We're also selling a 5-license family pack for only $25.99! PopChar helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to... Read more
BBEdit 11.1.1 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Picasa 3.9.139 - Organize, edit, and sha...
Picasa and Picasa Web Albums allows you to organize, edit, and upload your photos to the Web from your computer in quick, simple steps. Arrange your photos into folders and albums and erase their... Read more
Mac DVDRipper Pro 5.0.5 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
NetShade 6.2 - Browse privately using an...
This promotion is for NetShade and 1 year of Proxy and VPN services NetShade is an anonymous proxy and VPN app+service for Mac. Unblock your Internet through NetShade's high-speed proxy and VPN... Read more
CrossOver 14.1.3 - Run Windows apps on y...
CrossOver can get your Windows productivity applications and PC games up and running on your Mac quickly and easily. CrossOver runs the Windows software that you need on Mac at home, in the office,... Read more
Little Snitch 3.5.3 - Alerts you about o...
Little Snitch gives you control over your private outgoing data. Track background activity As soon as your computer connects to the Internet, applications often have permission to send any... Read more

Block Fortress has a Big New Update for...
Block Fortress is a survival-style game that's as fun as it is blocky. It's also just gotten a rather sizeable update that adds a lot more cool stuff. [Read more] | Read more »
Simple and Surreal Star Base Sim rymdkap...
I really like rymdkapsel. Not just because I'm a sucker for games that are cleverly simple or highly stylisitc, but because it's fun and challenging. Actually it's extremely challenging, which is why I was excited to learn that it's getting a couple... | Read more »
Check out the anticipated Angel Stone in...
Fincon has finally revealed Angel Stone in action in the first ever official gameplay trailer for the anticipated hack and slasher. Angel Stone is set in a post-apocalyptic world in which humanity is in danger of being wiped out by the demonic... | Read more »
Moleskine Timepage is an All-New Calenda...
Moleskine Timepage is a bit of a departure for the notebook manufacturer (since it has little to do with notebooks), but it certainly carries their simple and elegant style quite well. [Read more] | Read more »
Jog on Over and Check Out the New Runtas...
Runtastic has put out a fair number of apps to help you sleep, track excercise, and train various parts of your body. Now it's time for your legs to have their own time in the spotlight with Runtastic Leg Trainer. [Read more] | Read more »
It's Lights Out in the Upcoming Pla...
Ember’s Journey is a stark puzzle platformer with a twist: the entire game is played in darkness. The only light you can see by is the one emanating from your own character. [Read more] | Read more »
MooVee - Your Movies Guru (Entertainmen...
MooVee - Your Movies Guru 1.0 Device: iOS iPhone Category: Entertainment Price: $1.99, Version: 1.0 (iTunes) Description: MooVee helps you effortlessly manage your movies, on your iPhone. | Read more »
Geometry Wars 3: Dimensions (Games)
Geometry Wars 3: Dimensions 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Enjoy the next chapter in the award-winning Geometry Wars franchise and enjoy stunning, console-quality... | Read more »
CHAOS RINGS Ⅲ (Games)
CHAOS RINGS Ⅲ 1.0.0 Device: iOS Universal Category: Games Price: $19.99, Version: 1.0.0 (iTunes) Description: The newest addition to the popular smartphone RPG series is finally here! ・CHAOS RINGS Overview | Read more »
The Popular Insight Series of Travel Gui...
Getting around in a country when you can't understand the primary language can be tough. Fortunately there are several options available to help wold travellers with the important stuff like giving directions to a cab driver or asking where the... | Read more »

Price Scanner via MacPrices.net

Top Markets Saturation To Slow Global Smartph...
According to a new mobile phone forecast from the International Data Corporation (IDC) Worldwide Quarterly Mobile Phone Tracker, smartphone shipments are expected to grow 11.3% in 2015 — down from 27... Read more
Apple refurbished 2014 13-inch Retina MacBook...
The Apple Store has Apple Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and... Read more
What Would the ideal Apple Productivity Platf...
For the past four years I’ve kept a foot in both the Mac and iPad camps respectively. my daily computing hours divided about 50/50 between the two devices with remarkable consistency. However, there’... Read more
PageMeUp 1.2.1 Ten Dollar Page Layout Applica...
Paris, France-based Softobe, an OS X software development company, has announced that their PageMeUp v. 1.2.1, is available on the Mac App Store for $9.99. The license can be installed on up to 5... Read more
Eight New Products For USB Type-C Application...
Fresco Logic, specialists in advanced connectivity technologies and ICs, has introduced two new product families targeting the Type-C connector recently introduced across a number of consumer... Read more
Scripps National Spelling Bee Launches Buzzwo...
Scripps National Spelling Bee fans can monitor the action at the 2015 Spelling Bee with the new Buzzworthy app for iOS, Android and Windows mobile devices. The free Buzzworthy app provides friendly... Read more
13-inch 2.5GHz MacBook Pro on sale for $120 o...
B&H Photo has the 13″ 2.5GHz MacBook Pro on sale for $979 including free shipping plus NY sales tax only. Their price is $120 off MSRP, and it’s the lowest price for this model (except for Apple’... Read more
27-inch 3.3GHz 5K iMac on sale for $1899, $10...
B&H Photo has the new 27″ 3.3GHz 5K iMac on sale for $1899.99 including free shipping plus NY tax only. Their price is $100 off MSRP. Read more
Save up to $50 on iPad Air 2, NY tax only, fr...
B&H Photo has iPad Air 2s on sale for up to $50 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469 $30 off - 64GB iPad Air 2 WiFi: $549.99 $50 off - 128GB iPad... Read more
Updated Mac Price Trackers
We’ve updated our Mac Price Trackers with the latest information on prices, bundles, and availability on systems from Apple’s authorized internet/catalog resellers: - 15″ MacBook Pros - 13″ MacBook... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Program Manager, *Apple* Community Support...
**Job Summary** Apple Support Communities ( discussions. apple .com) helps customers get the most from their Apple products and services by providing access to Read more
Senior Data Scientist, *Apple* Retail - Onl...
**Job Summary** Apple Retail - Online sells Apple products to customers around the world. In addition to selling Apple products with unique services such as iPad Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Watch SW Application Project Manager...
**Job Summary** The Apple Watch software team is looking for an Application Engineering Project Manager to work on new projects for Apple . The successful candidate Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.