Extending javafx.animation.KeyValue public-init override problem

[Fabricio Sanchez]

Hi there,

I want to extend class javafx.animation.KeyValue so that I can attach extra information to a KeyValue animation (inside a Timeline KeyFrame).

The problem I have is that the only way I've found of instantiating a KeyValue for a KeyFrame is:

var keyFrame:KeyFrame = target => value tween interpolator;

So how can I initialise my subclass to something meaningful using the syntax above?
Solution Attempt 1:

public class MyKeyValue extends KeyValue {
    public-init var action:TimelineAction;
    public-init var frame:KeyFrame;
    public-init var node:MyImage; // The node to apply action to
    
    init {
         def tempNode = node;
         var opacity = action.opaciyy;
         tempNode.opacity => opacity tween action.interpolator; // How can I store this within this instance?
    }
}

I've also tried to generate an inner KeyValue, which I think works, however, I can't tie it in to the superclass public-init variables.
Solution Attempt 2:

public class MyKeyValue extends KeyValue {
    public-init var action:TimelineAction;
    public-init var frame:KeyFrame;
    public-init var node:MyImage; // The node to apply action to
    
    init {
         def tempNode = node;
         var opacity = action.opacity;
         var keyValue:KeyValue = tempNode.opacity => opacity tween action.interpolator;

         // Update extended variable values
         interpolate = keyValue.interpolate; // interpolate has script only (default) write access in javafx.animation.KeyValue
         target = keyValue.target; // target has script only (default) write access in javafx.animation.KeyValue
         value = keyValue.value; // value has script only (default) write access in javafx.animation.KeyValue
    }
}

For the above to work, I want to override the following variables that exist in javafx.animation.KeyValue

public-init var interpolate:Interpolator;
public-init var target:KeyValueTarget;
public-init var value:function():Object;

// I also tried on my subclass:
public-init override var interpolate; // get error: Cannot override 'interpolate' -- this instance variable must be writeable.
public override var interpolate; // get error: Cannot override 'interpolate' -- this instance variable must be writeable.
public var interpolate; // get error: 'var' overrides member 'interpolate' in 'javafx.animation.KeyValue'; use 'override'.

Any ideas?

Thank you,

Fabricio

[Jim Clarke]

This is a bug, (JFXC-3979). You cannot override a public-init variable. I don't know when it will be fixed, but the work around is to initialize the variables in the object Literal for the sub-class.

MyKeyValue {
interpolate: Interpolater.EASE_BOTH
}

[Fabricio Sanchez]

Thank you Jim,

That worked. My extension class is just a dummy class now as I have to create and initialise everything outside it and then just set the initialisation values as you suggested.
Double the work until they fix this bug, but as long as it works.

Here's a description of what I'm doing for anyone who might want to try it:

    
// Function to return an instace of MyKeyValue
public function getScaleXKeyValue(node:Node,scale:Number):MyKeyValue {
    // Create an ordinary keyValue here
    var keyValue:KeyValue = node.scaleX => scale tween Interpolator.LINEAR;
 

        return MyKeyValue {
            affectedValue: "scaleX";
            // Values required by KeyValue 
            interpolate: keyValue.interpolate
            target: keyValue.target
            value: keyValue.value
        };
  
}


public class MyKeyValue extends KeyValue {
    public-init var affectedValue:String; 
}

// So now if I want to know which type of variable is being modified I can just print out the
// affectedValue, or add any other piece of information that I might need to MyKeyValue by adding more
// variables to it.