TweetFollow Us on Twitter

Selective Color
Volume Number:10
Issue Number:1
Column Tag:C Workshop

Related Info: Dialog Manager

Selective Color

Using custom color buttons on color and black and white Macs

By Mark W. Batten, Washington, D.C.

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

Custom color buttons enliven any application, but if the programmer is writing software that must run on both black-and-white and color machines (as most of us are), it may seem daunting to write code that will draw the button different ways on differently configured machines. This article demonstrates a simple scheme to create buttons that are smart enough to be custom-drawn on color machines, and as regular Toolbox buttons on black-and-white machines.

The key to the technique is the Toolbox routine SetDItem. Although generally used only to change a dialog item’s rectangle, SetDItem is actually quite powerful; it lets you change just about everything associated with a dialog item. In this example, we’ll use it to point the Mac to our own CDEF to draw the button on color machines.

Setting Up The Resources

First, you need to create the CDEF that draws the color button. At the end of this article is source code for a sample button with a nice 3-D appearance.

(This particular CDEF uses an “auxiliary control record” (as described in Inside Macintosh, Vol. 5, pp. 216-18) to tell it what colors to draw the control in. If you’ve never encountered these arcane things, don’t worry; you don’t need to understand them to implement the scheme described in the article).

Second, create a dialog (DLOG) and a dialog item list (DITL) for your application as you normally would. Be sure that your DLOG will not be displayed when it’s loaded (in ResEdit, be sure the “Initially visible” box is unchecked). The DITL should use normal, vanilla buttons for OK and Cancel. That way, the resource is all set up to run normally on black-and-white machine, without any more work.

For this example, you also need to create two other resources: a dialog color table (‘dctb’) and a control color table (‘cctb’). (The correct values for the sample are listed at the end of this article). The ‘dctb’ serves two functions here: first, when you call GetNewDialog to read in a dialog, the Mac will automatically make it a color dialog, based on a CGrafPort, if the Mac finds a ‘dctb’ with the same ID as the DLOG resource. Second, the ‘dctb’ colors the content area of the dialog, which makes our button look better. The CDEF uses the ‘cctb’ resource to determine what colors to use when drawing the custom button.

Making The Switch

On a black-and-white Mac, the dialog will perform as it’s supposed to, without any special code in your application. To do something fancier on color machines, your application just has to alert the Dialog Manager to use our custom CDEF instead of the standard one. Here are the necessary steps.

1. In your application’s initialization routines, load the CDEF resource and the cctb color table into variables, like this:


/* 1 */

 Handle myCDEF;  /* handle to our custom CDEF */
 CTabHandle CtrlCTab;/* handle to colors for our control */

 myCDEF=GetResource('CDEF',32); 
 CtrlCTab=(CTabHandle)GetResource('cctb',128);

2. When you’re ready to create the dialog, load it with GetNewDialog (or build it from scratch with NewDialog). Then call the following routine, which uses SetDItem to tell the Mac where to find our custom code. Pass the DialogPtr in d and the item number of the button you want to convert in i:

/* 2 */

ConvertToColorButtons(d,i)
DialogPtr d;
int i; 
{
 int j; 
 Handle tItem; 
 Rect box; 
 char n[31];

 GetDItem(d,i,&j,&tItem,&box);
 if(j==ctrlItem+btnCtrl || 
 j==ctrlItem+btnCtrl+itemDisable){
 SetCtlColor(tItem,CtrlCTab);
 (**((ControlHandle)tItem)).contrlDefProc=myCDEF;
 j&=127;
 SetDItem(d,i,j,tItem,&box); 
 }
}
 Here's the CDEF code.

pascal long main(var,CH,msg,par)
int msg,var;
ControlHandle CH;
long par;
{
 long l;

 l=0L;
 switch(msg){
 case 0: 
 doDraw(CH); 
 break;
 case 1: 
 l=(long)doTest(par,CH); 
 break;
 case 2: 
 doCalc(par,CH); 
 break;
 }
 return l;
}

doTest(par,CH)
long par;
ControlHandle CH;
{
 Point pt;

 pt.v=HiWord(par); 
 pt.h=LoWord(par);
 return (int)PtInRect(pt,&((**CH).contrlRect));
}

doCalc(par,CH)
RgnHandle par;
ControlHandle CH;
{
 par=(RgnHandle)((long)par&0x7FFFFFFF);
 RectRgn(par,&((**CH).contrlRect));
}

doDraw(CH)
ControlHandle CH;
{
 int j,k,*p;
 Handle tItem;
 Rect r;
 RGBColor rgb,rgb1,rgb2; 
 AuxCtlHandle ax;
 FontInfo inf;
 
 r=(**CH).contrlRect; 
 j=StringWidth((**CH).contrlTitle); 
 GetFontInfo(&inf); 
 k=inf.ascent+inf.descent;
 k=(r.top+r.bottom+k)/2;
 MoveTo((r.left+r.right-j)/2,k-inf.descent);
 DrawString((**CH).contrlTitle);
 GetAuxCtl(CH,&ax);
 
 p=(int *)&(**(**ax).acCTable).ctTable[0].rgb.red; 
 rgb.red=p[0];   /* 21845, 0x5555*/
 rgb.green=p[1]; /* 21845, 0x5555*/
 rgb.blue=p[2];  /* 21845, 0x5555*/
 rgb1.red=p[4];  /* 34952, 0x8888*/
 rgb1.green=p[5];/* 34952, 0x8888*/
 rgb1.blue=p[6]; /* 34952, 0x8888*/
 rgb2.red=rgb2.green=rgb2.blue=0xFFFF;
 
 PenSize(2,2);
 RGBForeColor(&rgb);
 MoveTo(r.right-2,r.top); 
 LineTo(r.left,r.top);
 LineTo(r.left,r.bottom-2); 
 RGBForeColor(&rgb2);
 MoveTo(r.right-2,r.top+1);
 LineTo(r.right-2,r.bottom-2);
 LineTo(r.left,r.bottom-2); 
 rgb2.red=rgb2.green=rgb2.blue=0;
 RGBForeColor(&rgb2);
 InsetRect(&r,2,2);
 FrameRect(&r);

 InsetRect(&r,2,2);
 if(!(**CH).contrlHilite){
 PenSize(1,1);
 RGBForeColor(&rgb);
 MoveTo(r.left,r.top);
 LineTo(r.left,r.bottom-2);
 PenSize(2,2); 
 LineTo(r.right-2,r.bottom-2);
 Move(0,-1);
 PenSize(1,1);
 RGBForeColor(&rgb1);
 LineTo(r.left+1,r.bottom-3);
 LineTo(r.left+1,r.top);
 LineTo(r.right-1,r.top);
 Move(0,1);
 rgb2.red=rgb2.green=rgb2.blue=0xFFFF; 
 RGBForeColor(&rgb2);
 LineTo(r.left+2,r.top+1);
 }
 else {
 MoveTo(r.right-2,r.top);
 RGBForeColor(&rgb);
 LineTo(r.left,r.top);
 PenSize(1,1);
 LineTo(r.left,r.bottom-3);
 PenSize(3,3);
 LineTo(r.right-3,r.bottom-3); 
 PenSize(1,1);
 Move(2,-1);
 RGBForeColor(&rgb1); 
 LineTo(r.left+1,r.bottom-4);
 LineTo(r.left+1,r.top+2);
 LineTo(r.right-1,r.top+2);
 }
 rgb2.red=rgb2.green=rgb2.blue=0;
 RGBForeColor(&rgb2); 
}

The values for the color table resources for the example are as follows:

The control color table (type 'cctb') has two entries. The part codes are just 0 and 1 (the CDEF doesn't really use these) and the colors are { 0x5555,0x5555,0x5555 } and { 0x8888,0x8888,0x8888 }.

The dialog color table (type 'dctb') must have five entries, with part codes of 0-4, and colors as follows: { 0xAAAA,0xAAAA,0xAAAA }, { 0x5555,0x5555, 0x5555 }, { 0,0,0 }, { 0,0,0 }, { 0,0,0 }.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Air Video Server HD 2.1.0 - Stream video...
Air Video Server HD streams videos instantly from your computer on your iPhone, iPad, iPod touch or Apple TV. No need to worry about converting or transferring files. We took everything that was... Read more
Duplicate Annihilator 5.7.5 - Find and d...
Duplicate Annihilator takes on the time-consuming task of comparing the images in your iPhoto library using effective algorithms to make sure that no duplicate escapes. Duplicate Annihilator... Read more
BusyContacts 1.0.2 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
Capture One Pro 8.2.0.82 - RAW workflow...
Capture One Pro 8 is a professional RAW converter offering you ultimate image quality with accurate colors and incredible detail from more than 300 high-end cameras -- straight out of the box. It... Read more
Backblaze 4.0.0.872 - Online backup serv...
Backblaze is an online backup service designed from the ground-up for the Mac.With unlimited storage available for $5 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more
Little Snitch 3.5.2 - 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
Monolingual 1.6.4 - Remove unwanted OS X...
Monolingual is a program for removing unnecesary language resources from OS X, in order to reclaim several hundred megabytes of disk space. If you use your computer in only one (human) language, you... Read more
CleanApp 5.0 - Application deinstaller a...
CleanApp is an application deinstaller and archiver.... Your hard drive gets fuller day by day, but do you know why? CleanApp 5 provides you with insights how to reclaim disk space. There are... Read more
Fantastical 2.0 - Create calendar events...
Fantastical is the Mac calendar you'll actually enjoy using. Creating an event with Fantastical is quick, easy, and fun: Open Fantastical with a single click or keystroke Type in your event details... Read more
Cocktail 8.2 - General maintenance and o...
Cocktail is a general purpose utility for OS X that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more

Pie In The Sky: A Pizza Odyssey (Games)
Pie In The Sky: A Pizza Odyssey 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: A game about delivering pizza. In space. | Read more »
Chosen Gives Hopeful Singers, Songwriter...
If YouTube videos and reality TV shows like The Voice have taught us one thing, it’s that there are a lot of people out there who are anxious to show the world their talents. And if they’ve taught us a second thing, it’s that there’s an almost... | Read more »
Android's Popular OfficeSuite Now A...
Once only available for Android devices, OfficeSuite has finally landed on the app store. The Mobile Systems app lets you view, edit, create, and share Word, Excel, and PowerPoint documents as well as convert them to/from PDFs. It's touted as being... | Read more »
Warhammer: Arcane Magic is Coming Soon,...
Turbo Tape Games has announced that they're joining forces with Games Workshop to bring the turn-based strategy board game, Warhammer: Arcane Magic, to life on the iOS. | Read more »
Fast & Furious: Legacy's Creati...
| Read more »
N-Fusion and 505's Ember is Totally...
| Read more »
These are All the Apple Watch Apps and G...
The Apple Watch is less than a month from hitting store shelves, and once you get your hands on it you're probably going to want some apps and games to install. Fear not! We've compiled a list of all the Apple Watch apps and games we've been able to... | Read more »
Appy to Have Known You - Lee Hamlet Look...
Being at 148Apps these past 2 years has been an awesome experience that has taught me a great deal, and working with such a great team has been a privilege. Thank you to Rob Rich, and to both Rob LeFebvre and Jeff Scott before him, for helping me... | Read more »
Hands-On With Allstar Heroes - A Promisi...
Let’s get this out of the way quickly. Allstar Heroes looks a lot like a certain other recent action RPG release, but it turns out that while it’s not yet available here, Allstar Heroes has been around for much longer than that other title. Now that... | Read more »
Macho Man and Steve Austin Join the Rank...
WWE Immortals, by Warner Bros. Interactive Entertainment and WWE, has gotten a superstar update. You'll now have access to Macho Man Randy Savage and Steve Austin. Both characters have two different versions: Macho Man Randy Savage Renegade or Macho... | Read more »

Price Scanner via MacPrices.net

Apple offering refurbished 27-inch 5K iMacs f...
The Apple Store is offering Apple Certified Refurbished 27″ 3.5GHz 5K iMacs for $2119 including free shipping. Their price is $380 off the price of new models, and it’s the lowest price available for... Read more
16GB iPad mini on sale for $199, save $50
Walmart has 16GB iPad minis (1st generation) available for $199.99 on their online store, including free shipping. Their price is $50 off MSRP. Online orders only. Read more
New 128GB MacBook Airs on sale for $50 off MS...
 B&H Photo has 128GB 11″ and 13″ 2015 MacBook Airs on sale today for $50 off MSRP including free shipping plus NY sales tax only: - 11″ 1.6GHz/128GB MacBook Air (Model #MJVM2LL/A): $849 $50 off... Read more
13-inch 2.6GHz Retina MacBook Pro (refurbishe...
The Apple Store has Apple Certified Refurbished 13″ 2.6GHz/128GB Retina MacBook Pros available for $979 including free shipping. Original MSRP for this model was $1299. Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store is offering Apple Certified Refurbished Mac Pros for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more
Samsung Galaxy S 6 and Galaxy S 6 edge U.S. P...
Samsung Electronics America, Inc. has announced the Galaxy S 6 and Galaxy S 6 edge will be available in the U.S. beginning April 10, with pre-orders being accepted now. “We have completely reimagined... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
The Apple Store has Apple Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.... Read more
Save up to $80 on iPad Air 2s, NY tax only, f...
 B&H Photo has iPad Air 2s on sale for $80 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469.99 $30 off - 64GB iPad Air 2 WiFi: $549.99 $50 off - 128GB iPad... Read more
iMacs on sale for up to $205 off MSRP
B&H Photo has 21″ and 27″ iMacs on sale for up to $205 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1019 $80 off - 21″ 2.7GHz iMac: $1189 $110 off - 21″ 2.9GHz... Read more
Färbe Technik Offers iPhone Battery Charge LI...
Färbe Technik, which manufactures and markets of mobile accessories for Apple, Blackberry and Samsung mobile devices, is offering tips on how to keep your iPhone charged while in the field: •... Read more

Jobs Board

DevOps Software Engineer - *Apple* Pay, iOS...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Sr. Technical Services Consultant, *Apple*...
**Job Summary** Apple Professional Services (APS) has an opening for a senior technical position that contributes to Apple 's efforts for strategic and transactional Read more
Lead *Apple* Solutions Consultant - Retail...
**Job Summary** Job Summary The Lead ASC is an Apple employee who serves as the Apple business manager and influencer in a hyper-business critical Reseller's store Read more
*Apple* Pay - Site Reliability Engineer - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.