DividerItemDecoration

views/src/main/AndroidManifest.xml

@@ -1,2 +1,2 @@
 <manifest
-    package="ru.touchin.roboswag.components.views"/>
+    package="ru.touchin.roboswag.views"/>

views/src/main/java/ru/touchin/roboswag/views/decorators/DividerItemDecoration.kt

@@ -0,0 +1,74 @@
+package ru.touchin.roboswag.views.decorators
+
+import android.content.Context
+import android.graphics.Canvas
+import android.graphics.Rect
+import android.graphics.drawable.Drawable
+import android.view.View
+import androidx.annotation.DrawableRes
+import androidx.core.content.res.getDrawableOrThrow
+import androidx.core.view.children
+import androidx.recyclerview.widget.RecyclerView
+import ru.touchin.roboswag.components.utils.px
+
+abstract class DividerItemDecoration(
+        context: Context,
+        @DrawableRes drawableId: Int? = null,
+        protected open val predicate: ((position: Int) -> Boolean) = { true },
+        protected open val startMargin: Int = 0,
+        protected open val endMargin: Int = 0,
+        protected open val offset: Boolean = true,
+        protected open val showOnLastItem: Boolean = false
+) : RecyclerView.ItemDecoration() {
+
+    protected val bounds = Rect()
+    protected val divider: Drawable
+
+    init {
+        if (drawableId == null) {
+            context.obtainStyledAttributes(intArrayOf(android.R.attr.listDivider)).apply {
+                divider = getDrawableOrThrow(0)
+                recycle()
+            }
+        } else {
+            divider = context.getDrawable(drawableId)!!
+        }
+    }
+
+    override fun onDraw(canvas: Canvas, parent: RecyclerView, state: RecyclerView.State) {
+        if (offset) {
+            drawDivider(canvas, parent, state)
+        }
+    }
+
+    override fun onDrawOver(canvas: Canvas, parent: RecyclerView, state: RecyclerView.State) {
+        if (!offset) {
+            drawDivider(canvas, parent, state)
+        }
+    }
+
+    private fun drawDivider(canvas: Canvas, parent: RecyclerView, state: RecyclerView.State) {
+        canvas.save()
+        parent.children.forEach { child ->
+            val position = parent.getChildAdapterPosition(child)
+            if (predicate(position) && (position != state.itemCount - 1 || showOnLastItem)) {
+                parent.getDecoratedBoundsWithMargins(child, bounds)
+                val top = getDividerTop(child)
+                val bottom = getDividerBottom(child)
+                divider.setBounds(
+                        bounds.left + startMargin,
+                        top,
+                        bounds.right - (endMargin.toFloat().px).toInt(),
+                        bottom
+                )
+                divider.draw(canvas)
+            }
+        }
+        canvas.restore()
+    }
+
+    abstract fun getDividerTop(child: View): Int
+
+    abstract fun getDividerBottom(child: View): Int
+
+}