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
    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.

virtual pascal void
    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

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*
    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
    if ( gPictureOrnamentServer == NULL )
        gPictureOrnamentServer = new TPictureOrnamentServer;

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

Tweetbot 2.1 - Popular Twitter client. (...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
MacPilot 8.0 - Enable over 1,200 hidden...
MacPilot gives you the power of UNIX and the simplicity of Macintosh, which means a phenomenal amount of untapped power in your hands! Use MacPilot to unlock over 1,200 features, and access them all... Read more
Typinator 6.7 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
Adobe Lightroom 6.2 - Import, develop, a...
Adobe Lightroom is available as part of Adobe Creative Cloud for as little as $9.99/month bundled with Photoshop CC as part of the photography package. Lightroom 6 is also available for purchase as a... Read more
ForeverSave 2.1.4 - Universal auto-save...
ForeverSave auto-saves all documents you're working on while simultaneously doing backup versioning in the background. Lost data can be quickly restored at any time. Losing data, caused by... Read more
VueScan 9.5.27 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
AirPort Utility 6.3.6 - Set up and manag...
Note: Most recent release available only within OS X 10.11 El Capitan update. Use AirPort Utility to set up and manage your Wi-Fi network and AirPort base stations, including AirPort Express, AirPort... Read more
Quicksilver 1.3.1 - Application launcher...
Quicksilver is a light, fast and free Mac application that gives you the power to control your Mac with keystrokes alone. Quicksilver allows you to find what you need quickly and easily, then act... Read more
Tidy Up (Five Users) 4.1.5 - Find duplic...
Tidy Up is a complete duplicate finder and disk-tidiness utility. With Tidy Up you can search for duplicate files and packages by the owner application, content, type, creator, extension, time... Read more
Mellel 3.4.3 - The word processor of cho...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more

Swords & Crossbones: An Epic Pirate...
Swords & Crossbones: An Epic Pirate Story 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
Camel Up (Games)
Camel Up 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: | Read more »
The Martian: Bring Him Home (Games)
The Martian: Bring Him Home 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Based on the best selling novel and critically acclaimed film, THE MARTIAN tells the story of Astronaut Mark... | Read more »
This Week at 148Apps: September 21-30, 2...
Leap Into Fall With 148Apps How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out above... | Read more »
Tweetbot 4 for Twitter (Social Networki...
Tweetbot 4 for Twitter 4.0 Device: iOS Universal Category: Social Networking Price: $4.99, Version: 4.0 (iTunes) Description: *** 50% off for a limited time. *** | Read more »
Mori (Games)
Mori 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Stop, rewind and unwind with Mori. Time is always running, take a moment to take control. Mori is an action puzzle game about infinitely... | Read more »
100 Years' War (Games)
100 Years' War 1.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: | Read more »
Tower in the Sky (Games)
Tower in the Sky 0.0.60 Device: iOS Universal Category: Games Price: $1.99, Version: 0.0.60 (iTunes) Description: | Read more »
hocus. (Games)
hocus. 1.0.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0.0 (iTunes) Description: New, polished, mind-bending, minimal puzzle game with dozens of levels and extra-ordinary design Features:- Beautifully crafted... | Read more »
Mos Speedrun 2 (Games)
Mos Speedrun 2 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Mos is back, in her biggest and most exciting adventure ever! Wall-jump to victory through 30 mysterious, action packed levels... | Read more »

Price Scanner via

13-inch 2.5GHz MacBook Pro (refurbished) avai...
Apple has 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″ 2.5GHz MacBook Pros... Read more
27-inch 3.2GHz iMac on sale for $1689, save $...
Adorama has the 27″ 3.2GHz iMac on sale for $1689 including free shipping plus NY & NJ sales tax only. Their price is $110 off MSRP. Read more
12-inch Retina MacBooks on sale for up to $12...
B&H Photo has 12″ Retina MacBooks in stock today and on sale for up to $120 off MSRP. B&H will include free shipping, and there is NY sales tax only: - 12″ 1.1GHz Gray Retina MacBook: $1224 $... Read more
Tablets Shaping Up for Growth in 2016 – Strat...
Observing that Apple, Samsung, and Microsoft have refocused what tablet computers can do, market analysis firm Strategy Analytics believes there is immense opportunity for new and replacement sales... Read more
Apple Interbrand’s Number One Most Valuable G...
Apple and Google hold aced #1 and #2 spots respectively in Interbrand’s 2015 Best Global Brands Report, leading all tech brands that now comprise more than a third of the entire rankings value.... Read more
Apple offering refurbished 2015 13-inch Retin...
Apple is offering Certified Refurbished 2015 13″ Retina MacBook Pros for up to $270 (15%) off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: -... Read more
Apple refurbished 2015 MacBook Airs available...
Apple has Certified Refurbished 2015 11″ and 13″ MacBook Airs (the latest models), available for up to $180 off the cost of new models. An Apple one-year warranty is included with each MacBook, and... Read more
Adobe Photoshop Elements 14 Gets Haze Removal...
The latest iteration of Adobe’s powerful consumer image editing appliction Photoshop Elements 14 analyzes your photo and removes background haze, so your shot looks sharp all the way to the horizon... Read more
Apple refurbished 15-inch Retina MacBook Pros...
Apple has Certified Refurbished 2015 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2... Read more
21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $100 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1029.99 $70 off - 21″ 2.7GHz iMac: $1229 $70 off - 21″ 2.9GHz iMac: $... Read more

Jobs Board

Touch Validation Design (EE) - *Apple* Watc...
**Job Summary** Help launch next-generation Touch Technologies in Apple products. The Touch Technology team develops cutting-edge Touch solutions and technologies that Read more
WW Sales Strategy & Program Manager, *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
*Apple* TV Product Design Internship (Spring...
…the mechanical design effort associated with creating world-class products with the Apple TV PD Group. Responsibilities will include working closely with manufacturing, Read more
Product Design Engineer - *Apple* Watch - A...
**Job Summary** Product Design Engineer - WATCH ( Apple Watch) Be an integral part of a small and visible team of world-class Mechanical Engineers making Apple 's Read more
Senior Software System App Engineer, *Apple*...
**Job Summary** The Apple Watch system application team is looking for great software engineers who are comfortable working across all levels of the software stack. From Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.