BindView - VerstSiu/kotlin_extension GitHub Wiki

package com.ijoic.ktx.widget.bind

/*
 * Bind once
 */
fun<T: View> Fragment.bindOnce(@IdRes id: Int): ReadOnlyProperty<Fragment, T>
fun<T: View> Fragment.bindOnceOptional(@IdRes id: Int): ReadOnlyProperty<Fragment, T?>

fun<T: View> Activity.bindOnce(@IdRes id: Int): ReadOnlyProperty<Activity, T>
fun<T: View> Activity.bindOnceOptional(@IdRes id: Int): ReadOnlyProperty<Activity, T?>

fun<T: View> ViewHolder.bindOnce(@IdRes id: Int): ReadOnlyProperty<ViewHolder, T>
fun<T: View> ViewHolder.bindOnceOptional(@IdRes id: Int): ReadOnlyProperty<ViewHolder, T?>

/*
 * Bind view
 */
interface ViewSource {
  fun<T: View> findViewById(@IdRes id: Int): T?
}

interface FragmentViewSource: ViewSource {
  val view: View?
}

fun<T: View> ViewSource.bindView(@IdRes id: Int): ReadOnlyProperty<ViewSource, T>
fun<T: View> ViewSource.bindViewOptional(@IdRes id: Int): ReadOnlyProperty<ViewSource, T?>

fun ViewSource.releaseBindViews()

class MyFragment: Fragment() {
  private val messageView: TextView by bindOnce(R.id.message_text)

  override fun onActivityCreated() {
    super.onActivityCreated()
    messageView.text = "Hello world!"
  }
}

class MyFragment: Fragment(), FragmentViewSource {
  private val messageView: TextView by bindView(R.id.message_text)

  override fun onActivityCreated() {
    super.onActivityCreated()
    // reset view binding when root view is destroyed/recreated
    releaseBindViews()

    messageView.text = "Hello world!"
  }
}