Added layout behavior to dismiss toolbars when scrolling

app/src/main/java/com/topjohnwu/magisk/redesign/MainActivity.kt

@@ -3,8 +3,11 @@ package com.topjohnwu.magisk.redesign
 import android.graphics.Insets
 import android.os.Bundle
 import android.view.ViewTreeObserver
+import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.view.setPadding
+import androidx.core.view.updateLayoutParams
 import androidx.fragment.app.Fragment
+import com.google.android.material.card.MaterialCardView
 import com.ncapdevi.fragnav.FragNavController
 import com.topjohnwu.magisk.Const
 import com.topjohnwu.magisk.R
@@ -16,6 +19,7 @@ import com.topjohnwu.magisk.ui.log.LogFragment
 import com.topjohnwu.magisk.ui.module.ModulesFragment
 import com.topjohnwu.magisk.ui.settings.SettingsFragment
 import com.topjohnwu.magisk.ui.superuser.SuperuserFragment
+import com.topjohnwu.magisk.utils.HideTopViewOnScrollBehavior
 import com.topjohnwu.superuser.Shell
 import org.koin.androidx.viewmodel.ext.android.viewModel
 import kotlin.reflect.KClass
@@ -48,6 +52,9 @@ open class MainActivity : CompatActivity<MainViewModel, ActivityMainMd2Binding>(
 
         setSupportActionBar(binding.mainToolbar)
 
+        binding.mainToolbarWrapper.updateLayoutParams<CoordinatorLayout.LayoutParams> {
+            behavior = HideTopViewOnScrollBehavior<MaterialCardView>()
+        }
         binding.mainNavigation.setOnNavigationItemSelectedListener {
             when (it.itemId) {
                 R.id.homeFragment -> Navigation.home()

app/src/main/java/com/topjohnwu/magisk/utils/HideTopViewOnScrollBehavior.kt

@@ -0,0 +1,130 @@
+package com.topjohnwu.magisk.utils
+
+import android.animation.TimeInterpolator
+import android.view.View
+import android.view.ViewGroup
+import android.view.ViewPropertyAnimator
+import androidx.annotation.Dimension
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import androidx.core.view.ViewCompat
+import com.google.android.material.animation.AnimationUtils
+import com.google.android.material.behavior.HideBottomViewOnScrollBehavior
+
+class HideTopViewOnScrollBehavior<V : View> : HideBottomViewOnScrollBehavior<V>() {
+
+    companion object {
+        private const val STATE_SCROLLED_DOWN = 1
+        private const val STATE_SCROLLED_UP = 2
+    }
+
+    private var height = 0
+    private var currentState = STATE_SCROLLED_UP
+    private var additionalHiddenOffsetY = 0
+    private var currentAnimator: ViewPropertyAnimator? = null
+
+    override fun onLayoutChild(
+        parent: CoordinatorLayout,
+        child: V,
+        layoutDirection: Int
+    ): Boolean {
+        val paramsCompat = child.layoutParams as ViewGroup.MarginLayoutParams
+        height = child.measuredHeight + paramsCompat.topMargin
+        return super.onLayoutChild(parent, child, layoutDirection)
+    }
+
+    /**
+     * Sets an additional offset for the y position used to hide the view.
+     *
+     * @param child the child view that is hidden by this behavior
+     * @param offset the additional offset in pixels that should be added when the view slides away
+     */
+    override fun setAdditionalHiddenOffsetY(child: V, @Dimension offset: Int) {
+        additionalHiddenOffsetY = offset
+
+        if (currentState == STATE_SCROLLED_DOWN) {
+            child.translationY = (height + additionalHiddenOffsetY).toFloat()
+        }
+    }
+
+    override fun onStartNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: V,
+        directTargetChild: View,
+        target: View,
+        nestedScrollAxes: Int
+    ) = nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
+
+    override fun onNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: V,
+        target: View,
+        dxConsumed: Int,
+        dyConsumed: Int,
+        dxUnconsumed: Int,
+        dyUnconsumed: Int
+    ) {
+        when {
+            dyConsumed > 0 -> slideUp(child)
+            dyConsumed < 0 -> slideDown(child)
+        }
+    }
+
+    /**
+     * Perform an animation that will slide the child from it's current position to be totally on the
+     * screen.
+     */
+    override fun slideDown(child: V) {
+        if (currentState == STATE_SCROLLED_UP) {
+            return
+        }
+
+        currentAnimator?.let {
+            it.cancel()
+            child.clearAnimation()
+        }
+
+        currentState = STATE_SCROLLED_UP
+        animateChildTo(
+            child,
+            0,
+            ENTER_ANIMATION_DURATION.toLong(),
+            AnimationUtils.LINEAR_OUT_SLOW_IN_INTERPOLATOR
+        )
+    }
+
+    /**
+     * Perform an animation that will slide the child from it's current position to be totally off the
+     * screen.
+     */
+    override fun slideUp(child: V) {
+        if (currentState == STATE_SCROLLED_DOWN) {
+            return
+        }
+
+        currentAnimator?.let {
+            it.cancel()
+            child.clearAnimation()
+        }
+
+        currentState = STATE_SCROLLED_DOWN
+        animateChildTo(
+            child,
+            -(height + additionalHiddenOffsetY),
+            EXIT_ANIMATION_DURATION.toLong(),
+            AnimationUtils.FAST_OUT_LINEAR_IN_INTERPOLATOR
+        )
+    }
+
+    private fun animateChildTo(
+        child: V,
+        targetY: Int,
+        duration: Long,
+        interpolator: TimeInterpolator
+    ) = child
+        .animate()
+        .translationY(targetY.toFloat())
+        .setInterpolator(interpolator)
+        .setDuration(duration)
+        .withEndAction { currentAnimator = null }
+        .let { currentAnimator = it }
+}

app/src/main/res/layout/activity_main_md2.xml

@@ -28,6 +28,7 @@
             style="?styleCardElevated"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:id="@+id/main_toolbar_wrapper"
             android:layout_marginStart="@dimen/l1"
             android:layout_marginTop="@{(int) @dimen/l1 + viewModel.insets.top}"
             android:layout_marginEnd="@dimen/l1"
@@ -55,6 +56,7 @@
             style="?styleCardElevated"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
             android:layout_gravity="bottom"
             android:layout_marginStart="@dimen/l1"
             android:layout_marginEnd="@dimen/l1"

app/src/main/res/layout/fragment_home_md2.xml

@@ -22,7 +22,7 @@
         android:layout_height="match_parent"
         android:clipToPadding="false"
         android:paddingTop="@{viewModel.insets.top + (int) @dimen/internal_action_bar_size + (int) @dimen/l2}"
-        android:paddingBottom="@{viewModel.insets.bottom + (int) @dimen/margin_fab + (int) @dimen/l1}"
+        android:paddingBottom="@{viewModel.insets.bottom + (int) @dimen/l1}"
         tools:layout_marginTop="24dp">
 
         <LinearLayout