Added one-click scroll to the bottom

app/src/main/java/com/topjohnwu/magisk/ui/log/LogViewModel.kt

@@ -43,6 +43,8 @@ class LogViewModel(
     private val logItem get() = items[0] as LogRvItem
     private val magiskLogItem get() = items[1] as MagiskLogRvItem
 
+    val scrollPosition = KObservableField(0)
+
     init {
         currentPage.addOnPropertyChangedCallback {
             it ?: return@addOnPropertyChangedCallback
@@ -59,6 +61,10 @@ class LogViewModel(
         else -> ""
     }
 
+    fun scrollDownPressed() {
+        scrollPosition.value = magiskLogItem.items.size - 1
+    }
+
     fun refresh() {
         fetchLogs().subscribeK { logItem.update(it) }
         fetchMagiskLog().subscribeK { magiskLogItem.update(it) }

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

@@ -11,8 +11,10 @@ import androidx.databinding.InverseBindingAdapter
 import androidx.databinding.InverseBindingListener
 import androidx.drawerlayout.widget.DrawerLayout
 import androidx.interpolator.view.animation.FastOutSlowInInterpolator
+import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import androidx.viewpager.widget.ViewPager
+import com.google.android.material.floatingactionbutton.FloatingActionButton
 import com.google.android.material.navigation.NavigationView
 import com.skoumal.teanity.extensions.subscribeK
 import com.topjohnwu.magisk.R
@@ -176,4 +178,32 @@ fun setScrollToLast(view: RecyclerView, shouldScrollToLast: Boolean) {
     } else {
         view.adapter?.removeListener()
     }
-}
+}
+
+@BindingAdapter("hide")
+fun setHidden(view: FloatingActionButton, hide: Boolean) {
+    if (hide) view.hide() else view.show()
+}
+
+@BindingAdapter("scrollPosition", "scrollPositionSmooth", requireAll = false)
+fun setScrollPosition(view: RecyclerView, position: Int, smoothScroll: Boolean) = when {
+    smoothScroll -> view.smoothScrollToPosition(position)
+    else -> view.scrollToPosition(position)
+}
+
+@BindingAdapter("recyclerScrollEvent")
+fun setScrollListener(view: RecyclerView, listener: InverseBindingListener) {
+    view.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
+            // don't change this or the recycler will stop at every line, effectively disabling smooth scroll
+            if (newState == RecyclerView.SCROLL_STATE_IDLE) {
+                listener.onChange()
+            }
+        }
+    })
+}
+
+@InverseBindingAdapter(attribute = "scrollPosition", event = "recyclerScrollEvent")
+fun getScrollPosition(view: RecyclerView) = (view.layoutManager as? LinearLayoutManager)
+    ?.findLastCompletelyVisibleItemPosition()
+    ?: -1