TweetFollow Us on Twitter

January 92 - UOrnaments: Half-price Icons

UOrnaments: Half-price Icons

Thomas E. Burns

What if you want to display a bunch of icons, but find that TIcons are too big and slow? This type of situation calls for a class of objects that know how to draw themselves, but don't process events. To minimize memory usage, it's nice if these classes require only one instance per icon, no matter how many places an icon appears within a view.

I developed two classes for this purpose, TOrnament and TOrnamentServer, have proven useful. TOrnament is a simple abstract class that defines objects that know how to draw themselves within a view, but do not respond to events. Because of their simplicity, ornaments are about twice as fast at drawing and consume far less memory than similar views. TOrnamentServers make using ornaments easy and efficient by managing their creation and imaging.

Using ornaments

Adding ornaments to a view is straight-forward. First, by modifying your ISomeView and IRes methods, ask the appropriate OrnamentServer, gPictureOrnamentServer for pictures or gIconOrnamentServer for icons, to load the ornament. The AddOrnament method will either create and initialize the ornament, if it hasn't already been created, or increment the ornament's reference count.
gPictureOrnamentServer->AddOrnament( kTestPicture );

Then add code to your view's Draw method that draws the ornament. This example draws the ornament kTestPicture in your view(this) at location where with highlighting hlOff:

gPictureOrnamentServer->Draw( this, kTestPicture, where, hlOff );

The final step is to delete the ornament in the view's free method. DeleteOrnament will decrement the ornament's reference count and, if the reference count is zero, free the ornament.

gPictureOrnamentServer->DeleteOrnament( kTestPicture );

Even though ornaments do a lot of work for you, only four methods are needed to implement a new subclass. I will stroll through the implementation of TPictureOrnament and TPictureOrnamentServer to demonstrate the creation of new ornament subclasses.

Implementing TPictureOrnament

Subclasses of TOrnament are used to implement specific, resource-based images, such as pictures and icons. Because TOrnament implements the methods used for reference counting, Add and Delete, its subclasses need to implement only three methods: IPictureOrnament, Draw and GetExtent.

The IPictureOrnament calls IOrnament and then loads the picture resource. IOrnament merely calls IObject, sets the reference count to zero and sets fRsrcId to rsrcId. The essential code (without failure handling) for the IPictureOrnament method is:

virtual pascal void
TPictureOrnament::IPictureOrnament
(
    short   rsrcId
)
{
    this->IOrnament( pictureRsrcId );
    fPicture = GetPicture( fRsrcId );   // fPicture holds the
                                        // picture
    FailNILResource( (Handle)fPicture );
}

The Draw method is the core of an ornament. Its implementation will, of course, vary greatly for different classes of ornaments. Typically, a Draw method will call inherited::Draw (which calls PenNormal()), load and make unpurgeable the ornament's resource, and then draw with the appropriate highlighting. Because the code for drawing pictures is rather long and specific for 'PICT' resources, I will only show the definition for the method.

UOrnaments
virtual pascal void
Draw
(
    TView*              theView,    // view to draw in
    const VPoint&       where,      // top,left corner to draw at
    HLState             hilite      // the hilite to use
);

The next method, GetExtent, returns an ornament's size in a Point. This method is usually very similar to Draw. It must load and make unpurgeable the ornament's resource and then calculate its extent. Here's TOrnament's definition of this method:

virtual pascal Point
GetExtent
(
    void
);

The next step for creating a new ornament is to make a subclass of TOrnamentServer that overrides the DoMakeOrnament method. The function of TOrnamentServers is to manage the interactions between views and ornaments. A view never needs to refer to an ornament directly; it always uses an ornaments resource number instead. The advantages of this setup are:

  • A view can assume that it always needs to load and unload an ornament because TOrnamentServer will only do what is necessary. TOrnamentServer loads an ornament only once and then unloads it only after all views are finished with it.
  • There is no need for a view to add instance variables just to keep track of all the ornaments it is using.
  • Memory is saved because an ornament is loaded only once, no matter how many views are using it.

TOrnamentServers need to create ornaments when a new one is added to its list. To maintain the "object-oriented" nature of this unit, I didn't want to make TOrnamentServer know about all the possible types of ornaments. Therefore, TOrnamentServer has a DoMakeOrnament method that returns a new TOrnament of the appropriate subclass. This method for TPictureOrnamentServer is:

pascal TOrnament*
TPictureOrnamentServer::DoMakeOrnament
(
    short       rsrcId
)
{
    TPictureOrnament*       pictureOrnament;

    pictureOrnament = new TPictureOrnament;
    pictureOrnament->IPictureOrnament( rsrcId );
    return( pictureOrnament );
}

As an optional last step, write the InitPictureOrnamentServer function. This function creates and initializes an instance of the TPictureOrnamentServer class.

pascal void
InitPictureOrnamentServer
(
    void
)
{
    if ( gPictureOrnamentServer == NULL )
    {
        gPictureOrnamentServer = new TPictureOrnamentServer;
        gPictureOrnamentServer->IPictureOrnamentServer();
    }
}

Good indications

While it only required a couple of hours to write the original UOrnaments unit, it has proven to be a useful tool. The project I was working on when creating this unit, a robot controller, requires frequent use of indicators that can appear many, many times within a view. Full fledged views would be too big and slow to be practical. I hope ornaments prove to be as useful for you.
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

BBEdit 11.0.3 - 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
Microsoft Office Preview 15.8 - Popular...
Welcome to the new and modern Microsoft Office for Mac. You will receive regular updates automatically until the official release in the second half of 2015. With the redesigned Ribbon and your... Read more
Yosemite Cache Cleaner 9.0.5 - Clear cac...
Yosemite Cache Cleaner is an award-winning general purpose tool for OS X. YCC makes system maintenance simple with an easy point-and-click interface to many OS X functions. Novice and expert users... Read more
ExpanDrive 4.3.2 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
RapidWeaver 6.0.8 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
Artlantis Studio 5.1.2.7 - 3D rendering...
Artlantis Studio is a unique and ideal tool for performing very high resolution rendering easily and in real time. The new FastRadiosity engine now lets you compute images in radiosity-even in... Read more
MacUpdate Desktop 6.0.5 - Search and ins...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
BitTorrent Sync 2.0.82 - Sync files secu...
BitTorrent Sync allows you to sync unlimited files between your own devices, or share a folder with friends and family to automatically sync anything. File transfers are encrypted. Your information... Read more
Google Drive 1.20 - File backup and shar...
Google Drive is a place where you can create, share, collaborate, and keep all of your stuff. Whether you're working with a friend on a joint research project, planning a wedding with your fiancé, or... Read more
Simon 4.0.3 - Monitor changes and crashe...
Simon monitors websites and alerts you of crashes and changes. Select pages to monitor, choose your alert options, and customize your settings. Simon does the rest. Keep a watchful eye on your... Read more

New Publisher Allstar Games Heads West w...
Allstar Games has announced its first mobile title designed for western audiences, Allstar Heroes. The game will be a massive online battle arena (MOBA) that offers dozens of heroes for you to collect and pit against your opponents. As each hero has... | Read more »
RAD Boarding Review
RAD Boarding Review By Jennifer Allen on March 5th, 2015 Our Rating: :: NEARLY RADUniversal App - Designed for iPhone and iPad RAD Boarding isn’t quite one of the greats, but it has potential.   | Read more »
Presenting the International Mobile Gami...
11th Annual International Mobile Gaming Awards ceremony, hosted by actress Allison Haislip, gathered mobile game developers and publishers from around the world. They chose 13 winners out of the 93 nominations. British studio USTWO won the the Grand... | Read more »
AG Drive Review
AG Drive Review By Tre Lawrence on March 5th, 2015 Our Rating: :: FUTURISTIC STREET RACING.Universal App - Designed for iPhone and iPad Futuristic racing… interstellar style.   | Read more »
GDC 2015 – Nightmare Guardians is an Int...
GDC 2015 – Nightmare Guardians is an Interesting Hybrid of MOBA and Lane Defense Posted by Rob Rich on March 5th, 2015 [ permalink ] I have to say that lane defense (i.e. | Read more »
Overkill 3 Review
Overkill 3 Review By Tre Lawrence on March 5th, 2015 Our Rating: :: WHO'S NEXT?Universal App - Designed for iPhone and iPad Cover system gameplay in the third-person.   Developer: Craneballs Price: Free Version Reviewed: 1.1.6... | Read more »
Warner Bros. Interactive Entertainment A...
Warner Bros. has some exciting games coming down the pipe! | Read more »
GDC 2015 – Star Trek Timelines will Prob...
GDC 2015 – Star Trek Timelines will Probably Make Your Inner Trekkie Squeal With Glee Posted by Rob Rich on March 4th, 2015 [ permalink ] Any popular fictional universe has its fair share of fan fiction – where belo | Read more »
Protect Yourself from an Onslaught of Ca...
Surprise Attack Games has announced a Cat-astrophic new physics puzzler called Fort Meow! In the game, a young girl named Nia finds her grandfather’s journal which triggers an all mighty feline attack! Why do the cats want the journal? Who knows,... | Read more »
GDC 2015 – Jelly Reef will be Game Oven’...
GDC 2015 – Jelly Reef will be Game Oven’s Last Hurrah, and it Seems like a Good Note to Go Out on Posted by Rob Rich on March 4th, 2015 [ permalink ] It’s sad knowing that Game Oven ( | Read more »

Price Scanner via MacPrices.net

Roundup of MacBook Air sale prices, models up...
B&H Photo has MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 128GB MacBook Air: $799 100 off MSRP - 11″ 256GB MacBook Air: $999 $100... Read more
New Firstrade Mobile App Enables On-The-Go Tr...
Firstrade Securities Inc. has announced its new mobile app, which gives investors immediate access to the company’s trading platform on all mobile devices. The app was developed in-house and was... Read more
Sonnet Introduces USB 3.0 + eSATA Thunderbolt...
Sonnet has announced the launch of its new USB 3.0 + eSATA Thunderbolt Adapter for easy connectivity to USB 3.0 devices and eSATA storage, and USB 3.0 + Gigabit Ethernet Thunderbolt Adapter for easy... Read more
Apple restocks refurbished 27-inch 5K iMacs f...
The Apple Store has restocked Apple Certified Refurbished 27″ 3.5GHz 5K iMacs for $2119 including free shipping. Their price is $380 off the cost of new models, and it’s the lowest price available... Read more
Free Clean Reader Mobile App Hides Swear Word...
The new Clean Reader app, now available in the Apple App Store and Google Play, delivers the opportunity of reading any book without being exposed to profanity. By selecting how clean they want their... Read more
Kinsa Launches “Groups” App to Monitor Illnes...
Kinsa, makers of the first FDA approved app-enabled smartphone thermometer thst won the 2013 Cleveland Clinic Medical Innovation Grand Prize and recently appeared in Apple’s “Parenthood” TV... Read more
iPad: A More Positive Outlook – The ‘Book Mys...
It’s good to hear someone saying positive things about the iPad. I’ve been trying to bend my mind around how Apple’s tablet could have gone from zero to bestselling personal computing device on the... Read more
Mac Pros on sale for up to $279 off MSRP
Amazon has Mac Pros in stock and on sale for up to $279 off MSRP. Shipping is free: - 4-Core Mac Pro: $2725.87, $273 off MSRP (9%) - 6-Core Mac Pro: $3719.99, $279 off MSRP (7%) Read more
Sale! 13-inch Retina MacBook Pros for up to $...
B&H Photo has 13″ Retina MacBook Pros on sale for up to $205 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.6GHz/128GB Retina MacBook Pro: $1219.99 save $80 - 13″ 2.... Read more
Another Tranche Of IBM MobileFirst For iOS Ap...
IBM has announced the next expansion phase for  its IBM MobileFirst for iOS portfolio, with a troika of new apps to address key priorities for the Banking and Financial Services, Airline and Retail... Read more

Jobs Board

*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
*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
Position Opening at *Apple* - Apple (United...
…Summary** As a Specialist, you help create the energy and excitement around Apple products, providing the right solutions and getting products into customers' hands. You Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** The Apple Store is a retail environment like no other - uniquely focused on delivering amazing customer experiences. As an Expert, you introduce people 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.