Properties: Accessing to Properties of DALi Objects

Thread Architecture: High-Performance Multi-Threaded Architecture of DALi

GetCurrentPosition()

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A property is a value used by an object that can be modified or read via Dali::Handle::GetProperty() / SetProperty() API.

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The difference between properties and ordinary C++ member variables is that a property can be dynamically added to or removed from an existing object in runtime, which enables more flexible, script-like programming with DALi.

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Dali::Handle (in mobile and wearable) provides methods to manage properties, thus the DALi classes that inherit from Dali::Handle (most of classes that users would use) have a number of predefined properties and can have any number of user-defined custom properties. -

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Accessing to Properties

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Properties of an object usually can be accessed via two ways: by its class member functions or by property getters/setters (Dali::Handle::GetProperty() / SetProperty()).

For example, Dali::Actor has following predefined properties:

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- Table: Properties of Dali::Actor -
Property Index (enumeration)	Member Functions
Dali::Actor::POSITION	Dali::Actor::GetCurrentPosition() / SetPosition()
Dali::Actor::ORIENTATION	Dali::Actor::GetCurrentOrientation() / SetOrientation()
Dali::Actor::SIZE	Dali::Actor::GetCurrentSize() / SetSize()
Dali::Actor::COLOR	Dali::Actor::GetCurrentColor() / SetColor()
Dali::Actor::NAME	Dali::Actor::GetName() / SetName()
...	...

- - You can access them in both ways: - -

-Actor actor = Actor::New();
-actor.SetName("test actor");
-std::cout << actor.GetName() << std::endl;  // "test actor"
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-Actor actor = Actor::New();
-actor.SetProperty( Actor::Property::NAME, "test actor" );
-std::cout << actor.GetProperty( Actor::Property::NAME ) << std::endl;  // "test actor"
-std::cout << actor.GetProperty<std::string>( Actor::Property::NAME ) << std::endl;  // "test actor"
-std::cout << actor.GetProperty( Actor::Property::NAME ).Get<std::string>() << std::endl;  // "test actor"
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Usages of Properties

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Registering User-Defined Custom Properties to an Object

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Properties can be registered / unregistered in runtime, which enables script-like programming of DALi application, for example, adding custom member data to an instance of a DALi class without subclassing the class or maintaining another pool of custom data.

For example, you can set your own custom data to PushButton objects and use them later when the buttons are clicked like:

-  void Create( Application& application )
-  {
-    for( int i=0; i<5; ++i )
-    {
-      Toolkit::PushButton button = Toolkit::PushButton::New();
-      button.SetSize( 100, 100 );
-      button.SetPosition( 100*i+50, 50 );
-      button.ClickedSignal().Connect( this, OnButtonClicked );
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-      // Register a custom property having button index.
-      // Store the property index so you can look it up later.
-      // Note: This is much faster than looking the property up by property name and should always be used if possible.
-      // As all control types are the same (PushButtons) the indices to the unique custom property are all same.
-      Property::Value data( i );
-      mCustomDataIndex = button.RegisterProperty( "custom-data", data );
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-      Stage::GetCurrent().Add(button);
-    }
-  }
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-  bool OnButtonClicked(Toolkit::Button button)
-  {
-    // Look up the custom property by the stored property index.
-    // Note: If the property belongs to a control in another library, or we do not know the index, we can look the index up first with:
-    // Property::Index index = button.GetPropertyIndex( "custom-data" );
-    cout << button.GetProperty( mCustomDataIndex ) << endl;
-    return true;
-  }
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Animation

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Constraint

- - - -types - -set/get add/remove - -constraint animation +

DALi uses a multithreaded architecture in order to provide the best performance and scalability.

Event Thread: The main thread in which application code and event handling runs.
Update Thread: Updates the nodes on the scene as well as running animations and constraints.
Render Thread: OpenGL drawing, texture and geometry uploading etc.
Resource Thread: Loads images and decodes into bitmaps etc.

Figure: DALi Thread Architecture

Thread Architecture