Add extension functions to initialize Loupe and set listeners

[adrianolc]

Just a nice to have some extension functions to help initialize the lib and to set the listeners more in a Kotlin style.

val loupe = startLoupe(image, container) {
    useFlingToDismissGesture = !Pref.useSharedElements
    maxZoom = Pref.maxZoom
    flingAnimationDuration = Pref.flingAnimationDuration
    scaleAnimationDuration = Pref.scaleAnimationDuration
    overScaleAnimationDuration = Pref.overScaleAnimationDuration
    overScrollAnimationDuration = Pref.overScrollAnimationDuration
    dismissAnimationDuration = Pref.dismissAnimationDuration
    restoreAnimationDuration = Pref.restoreAnimationDuration
    viewDragFriction = Pref.viewDragFriction

    setOnViewTranslateListener(
        onStart = {
            hideToolbar()
        },
        onRestore = {
            showToolbar()
        },
        onDismiss = {
            finishAfterTransition()
        }
    )

    setOnScaleChangedListener { scaleFactor, focusX, focusY ->

    }
}

[igreenwood]

@adrianolc
Thank you for your nice proposal 😄
It's great to be able to write in Kotlin's style.
But I think it might be better if it wasn't an extension like View or Activity. Probably because most users will only use Loupe on a limited number of screens. 🤔

My suggestion:

• Create startLoupe() function in the companion object of Loupe ( I want to change the name startXXX to createXXX because "start" sounds like an asynchronous processing function. 🙏 )
• Add the setOnViewTranslateListener() and setOnScaleChangedListener() that you created into Loupe class.

Looks like this↓

class Loupe(imageView: ImageView, container: ViewGroup) : View.OnTouchListener,
    View.OnLayoutChangeListener {

    companion object {

        fun create(
            imageView: ImageView,
            container: ViewGroup,
            config: Loupe.() -> Unit = {}
        ): Loupe {
            return Loupe(
                imageView,
                container
            ).apply(config)
        }
    }
    
    ......

    fun setOnViewTranslateListener(
        onStart: (view: ImageView) -> Unit = {},
        onViewTranslate: (view: ImageView, amount: Float) -> Unit = { _, _ -> },
        onRestore: (view: ImageView) -> Unit = {},
        onDismiss: (view: ImageView) -> Unit = {}
    ) {
        this.onViewTranslateListener = object : OnViewTranslateListener {
            override fun onDismiss(view: ImageView) {
                onDismiss(view)
            }

            override fun onRestore(view: ImageView) {
                onRestore(view)
            }

            override fun onStart(view: ImageView) {
                onStart(view)
            }

            override fun onViewTranslate(view: ImageView, amount: Float) {
                onViewTranslate(view, amount)
            }
        }
    }

    fun setOnScaleChangedListener(onScaleChangedListener: (scaleFactor: Float, focusX: Float, focusY: Float) -> Unit) {
        this.onScaleChangedListener = object : OnScaleChangedListener {
            override fun onScaleChange(scaleFactor: Float, focusX: Float, focusY: Float) {
                onScaleChangedListener(scaleFactor, focusX, focusY)
            }
        }
    }
}

How about that? 🙏

[adrianolc]

Hi @igreenwood, thanks for your comment.

The idea of having extensions function is to not pollute the class if helper methods.

But I agree on the startLoupe method, create is a better name and also I don't see any problem with it being a method on the companion object.

What do you think? Bring the startLoupe to the companion object and rename it to only create, but let the setters as an extension function as they're only helpers and not something to include in the class.

[igreenwood]

Hi @adrianolc, I'm glad you agree with me about Loupe.create().
The extension itself is very useful and good. However, different developers have different usage preferences, so I'd like to keep the option of not using extensions.
As for the extensions, I think we could get both of our hopes up by releasing them as a separate module, what do you think? 😉
If it's OK, then this PR could be merged with only a change to Loupe.create() and I will begin to create a module for extensions 💪

[adrianolc]

All good!! I agree with you!

I can do the changes :)

[adrianolc]

Changed, so now only have the create function

val loupe = Loupe.create(image, container) {
    useFlingToDismissGesture = !Pref.useSharedElements
    maxZoom = Pref.maxZoom
    flingAnimationDuration = Pref.flingAnimationDuration
    scaleAnimationDuration = Pref.scaleAnimationDuration
    overScaleAnimationDuration = Pref.overScaleAnimationDuration
    overScrollAnimationDuration = Pref.overScrollAnimationDuration
    dismissAnimationDuration = Pref.dismissAnimationDuration
    restoreAnimationDuration = Pref.restoreAnimationDuration
    viewDragFriction = Pref.viewDragFriction
}

[igreenwood]

@adrianolc Thank youuuuuuu!!! I will release loupe: 1.0.4 and loupe-ktx:1.0.0 ASAP 💪

[adrianolc]

@igreenwood Niiiice!!!

I'm looking forward to remove the fork from our App and use the maven to implement the library!!

[igreenwood]

@adrianolc I have released com.igreenwood.loupe:loupe:1.1.0 & com.igreenwood.loupe:extensions:1.0.0 😎