Create `CustomRecyclerView` to listen to scrolling

1 files changed, 38 insertions, 0 deletions

diff --git a/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/widget/CustomRecyclerView.kt b/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/widget/CustomRecyclerView.kt
new file mode 100644
index 0000000000..710bb834d0
--- /dev/null
+++ b/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/widget/CustomRecyclerView.kt
@@ -0,0 +1,38 @@
+package net.mullvad.mullvadvpn.ui.widget
+
+import android.content.Context
+import android.support.v7.widget.RecyclerView
+import android.util.AttributeSet
+import net.mullvad.mullvadvpn.util.ListenableScrollableView
+
+class CustomRecyclerView : RecyclerView, ListenableScrollableView {
+    override var horizontalScrollOffset = 0
+    override var verticalScrollOffset = 0
+
+    override var onScrollListener: ((Int, Int, Int, Int) -> Unit)? = null
+
+    constructor(context: Context) : super(context) {}
+
+    constructor(context: Context, attributes: AttributeSet) : super(context, attributes) {}
+
+    constructor(context: Context, attributes: AttributeSet, defaultStyleAttribute: Int) :
+        super(context, attributes, defaultStyleAttribute) {
+        }
+
+    override fun onScrolled(horizontalDelta: Int, verticalDelta: Int) {
+        super.onScrolled(horizontalDelta, verticalDelta)
+
+        val oldHorizontalScrollOffset = horizontalScrollOffset
+        val oldVerticalScrollOffset = verticalScrollOffset
+
+        horizontalScrollOffset += horizontalDelta
+        verticalScrollOffset += verticalDelta
+
+        onScrollListener?.invoke(
+            horizontalScrollOffset,
+            verticalScrollOffset,
+            oldHorizontalScrollOffset,
+            oldVerticalScrollOffset
+        )
+    }
+}