कैसे घोषित तौर पर एक ढहने वाले टूलबार का वर्णन करें

class TopInfoBehavior( context: Context?, attrs: AttributeSet? ) : BehaviorByRules(context, attrs) { override fun calcAppbarHeight(child: View): Int = with(child) { return (height + pixels(R.dimen.toolbar_height)).toInt() } override fun View.provideAppbar(): AppBarLayout = ablAppbar override fun View.provideCollapsingToolbar(): CollapsingToolbarLayout = ctlToolbar override fun View.setUpViews(): List<RuledView> = listOf( RuledView( viewGroupTopDetails, BRuleYOffset( min = pixels(R.dimen.zero), max = pixels(R.dimen.toolbar_height) ) ), RuledView( textViewTopDetails, BRuleAlpha(min = 0.6f, max = 1f) .workInRange(from = appearedUntil, to = 1f), BRuleXOffset( min = 0f, max = pixels(R.dimen.big_margin), interpolator = ReverseInterpolator(AccelerateInterpolator()) ), BRuleYOffset( min = pixels(R.dimen.zero), max = pixels(R.dimen.pad), interpolator = ReverseInterpolator(LinearInterpolator()) ), BRuleAppear(0.1f), BRuleScale(min = 0.8f, max = 1f) ), RuledView( textViewPainIsTheArse, BRuleAppear(isAppearedUntil = GONE_VIEW_THRESHOLD) ), RuledView( textViewCollapsedTop, BRuleAppear(0.1f, true) ), RuledView( textViewTop, BRuleAppear(isAppearedUntil = GONE_VIEW_THRESHOLD) ), buildRuleForIcon(ivTop, LinearInterpolator()), buildRuleForIcon(ivTop2, AccelerateInterpolator(0.7f)), buildRuleForIcon(ivTop3, AccelerateInterpolator()) ) private fun View.buildRuleForIcon( view: ImageView, interpolator: Interpolator ) = RuledView( view, BRuleYOffset( min = -(ivTop3.y - tvCollapsedTop.y), max = 0f, interpolator = DecelerateInterpolator(1.5f) ), BRuleXOffset( min = 0f, max = tvCollapsedTop.width.toFloat() + pixels(R.dimen.huge_margin), interpolator = ReverseInterpolator(interpolator) ) ) companion object { const val GONE_VIEW_THRESHOLD = 0.8f } } 

 <android.support.design.widget.CoordinatorLayout> <android.support.design.widget.AppBarLayout android:layout_height="wrap_content"> <android.support.design.widget.CollapsingToolbarLayout app:layout_scrollFlags="scroll|exitUntilCollapsed"> <android.support.v7.widget.Toolbar android:layout_height="@dimen/toolbar_height" app:layout_collapseMode="pin"/> </android.support.design.widget.CollapsingToolbarLayout> </android.support.design.widget.AppBarLayout> <!--  --> <RelativeLayout android:translationZ="5dp" app:layout_behavior="TopInfoBehavior"/> <android.support.v4.widget.NestedScrollView app:layout_behavior="@string/appbar_scrolling_view_behavior"> </android.support.v4.widget.NestedScrollView> <android.support.design.widget.FloatingActionButton app:layout_anchor="@id/nesteScroll" app:layout_anchorGravity="right"/> </android.support.design.widget.CoordinatorLayout> 

 /** * [min], [max] — values in range [0, 1] */ class BRuleAlpha( override val min: Float, override val max: Float, override val interpolator: Interpolator = LinearInterpolator() ) : BaseBehaviorRule() { override fun perform(offset: Float, details: InitialViewDetails, view: View) { view.alpha = offset } } 

 abstract class BehaviorByRules( context: Context?, attrs: AttributeSet? ) : CoordinatorLayout.Behavior<View>(context, attrs) { private var views: List<RuledView> = emptyList() private var lastChildHeight = -1 private var needToUpdateHeight: Boolean = true override fun layoutDependsOn( parent: CoordinatorLayout, child: View, dependency: View ): Boolean { return dependency is AppBarLayout } override fun onDependentViewChanged( parent: CoordinatorLayout, child: View, dependency: View ): Boolean { if (views.isEmpty()) views = child.setUpViews() val progress = calcProgress(parent) views.forEach { performRules(offsetView = it, percent = progress) } tryToInitHeight(child, dependency, progress) return true } override fun onMeasureChild( parent: CoordinatorLayout, child: View, parentWidthMeasureSpec: Int, widthUsed: Int, parentHeightMeasureSpec: Int, heightUsed: Int ): Boolean { val canUpdateHeight = canUpdateHeight(calcProgress(parent)) if (canUpdateHeight) { parent.post { val newChildHeight = child.height if (newChildHeight != lastChildHeight) { lastChildHeight = newChildHeight setUpAppbarHeight(child, parent) } } } else { needToUpdateHeight = true } return super.onMeasureChild( parent, child, parentWidthMeasureSpec, widthUsed, parentHeightMeasureSpec, heightUsed ) } /** * If you use fitsSystemWindows=true in your coordinator layout, * you will have to include statusBar height in the appbarHeight */ protected abstract fun calcAppbarHeight(child: View): Int protected abstract fun View.setUpViews(): List<RuledView> protected abstract fun View.provideAppbar(): AppBarLayout protected abstract fun View.provideCollapsingToolbar(): CollapsingToolbarLayout /** * You man not want to update height, if height depends on views, that are currently invisible */ protected open fun canUpdateHeight(progress: Float): Boolean = true private fun calcProgress(parent: CoordinatorLayout): Float { val appBar = parent.provideAppbar() val scrollRange = appBar.totalScrollRange.toFloat() val scrollY = Math.abs(appBar.y) val scroll = 1 - scrollY / scrollRange return when { scroll.isNaN() -> 1f else -> scroll } } private fun setUpAppbarHeight(child: View, parent: ViewGroup) { parent.provideCollapsingToolbar().setHeight(calcAppbarHeight(child)) } private fun tryToInitHeight(child: View, dependency: View, scrollPercent: Float) { if (needToUpdateHeight && canUpdateHeight(scrollPercent)) { setUpAppbarHeight(child, dependency as ViewGroup) needToUpdateHeight = false } } private fun performRules(offsetView: RuledView, percent: Float) { val view = offsetView.view val details = offsetView.details offsetView.rules.forEach { rule -> rule.manage(percent, details, view) } } }