draw new line when firebase change

Author: minibugdev

app/src/main/kotlin/com/trydroid/coboard/CoBoardActivity.kt

@@ -1,12 +1,12 @@
 package com.trydroid.coboard
 
+import android.graphics.Point
 import android.os.Bundle
 import android.support.v7.app.AppCompatActivity
 import android.util.Log
 import android.view.Menu
 import android.view.MenuItem
 import com.google.firebase.database.*
-import com.trydroid.coboard.views.SimpleDrawView
 import kotlinx.android.synthetic.main.activity_main.*
 
 class CoBoardActivity : AppCompatActivity() {
@@ -26,16 +26,16 @@ class CoBoardActivity : AppCompatActivity() {
 
 	override fun onOptionsItemSelected(item: MenuItem?) =
 		when (item?.itemId) {
-			R.id.action_clear -> consumeMenuSelected { clearDrawView() }
+			R.id.action_clear -> consumeMenuSelected { removeFirebaseChild() }
 			else              -> super.onOptionsItemSelected(item)
 		}
 
 
 	override fun onStart() {
 		super.onStart()
 		mLinesReference.addChildEventListener(mLinesReferenceListener)
-		drawView.drawListener = { pointList ->
-			pointList?.let { sendToFirebase(pointList) }
+		drawView.drawListener = { lineList ->
+			lineList?.let { sendToFirebase(lineList) }
 		}
 	}
 
@@ -45,35 +45,42 @@ class CoBoardActivity : AppCompatActivity() {
 		drawView.drawListener = null
 	}
 
-	private fun sendToFirebase(pointList: List<SimpleDrawView.Point>) {
-		mLinesReference.push().setValue(pointList)
+	private fun sendToFirebase(lineList: List<Point>) {
+		mLinesReference.push().setValue(lineList)
 	}
 
-	private fun clearFirebase() {
-		mLinesReference.push().removeValue()
+	private fun removeFirebaseChild() {
+		mLinesReference.removeValue()
 	}
 
 	private fun clearDrawView() {
 		drawView.clear()
-		clearFirebase()
+	}
+
+	private fun drawLine(lineList: List<Point>) {
+		drawView.drawLine(lineList)
 	}
 
 	private val mLinesReferenceListener = object : ChildEventListener {
-		override fun onChildMoved(dataSnapshot: DataSnapshot?, p1: String?) {
+		override fun onChildAdded(dataSnapshot: DataSnapshot?, p1: String?) {
+			Log.e(TAG, "onChildAdded")
+			dataSnapshot?.children
+				?.map { children -> children.getValue<Point>(Point::class.java) }
+				?.let { lineList -> drawLine(lineList) }
 		}
 
-		override fun onChildChanged(dataSnapshot: DataSnapshot?, p1: String?) {
+		override fun onChildRemoved(dataSnapshot: DataSnapshot?) {
+			Log.e(TAG, "onChildRemoved")
+			clearDrawView()
 		}
 
-		override fun onChildAdded(dataSnapshot: DataSnapshot?, p1: String?) {
-			Log.e(TAG, "onDataChange")
+		override fun onChildMoved(dataSnapshot: DataSnapshot?, p1: String?) {
 		}
 
-		override fun onChildRemoved(dataSnapshot: DataSnapshot?) {
+		override fun onChildChanged(dataSnapshot: DataSnapshot?, p1: String?) {
 		}
 
 		override fun onCancelled(databaseError: DatabaseError) {
-			Log.w(TAG, "Lines Reference onCancelled", databaseError.toException())
 		}
 	}
 

app/src/main/kotlin/com/trydroid/coboard/views/SimpleDrawView.kt

@@ -1,23 +1,20 @@
 package com.trydroid.coboard.views
 
 import android.content.Context
-import android.graphics.Canvas
-import android.graphics.Color
-import android.graphics.Paint
-import android.graphics.Path
+import android.graphics.*
 import android.util.AttributeSet
 import android.view.MotionEvent
 import android.view.View
 
-typealias OnDrawListener = (List<SimpleDrawView.Point>?) -> Unit
+typealias OnDrawListener = (List<Point>?) -> Unit
 
 /**
  * Customize form original source
  * - https://github.com/johncarl81/androiddraw/blob/master/src/main/java/org/example/androiddraw/SimpleDrawView.java
  * - https://github.com/ByoxCode/DrawView/blob/master/drawview/src/main/java/com/byox/drawview/views/DrawView.java
  * */
 class SimpleDrawView(context: Context, attributeSet: AttributeSet) : View(context, attributeSet), View.OnTouchListener {
-	private val mPointList: MutableList<MutableList<Point>> = mutableListOf()
+	private val mLineHistoryList: MutableList<MutableList<Point>> = mutableListOf()
 	private val mPaint: Paint by lazy {
 		Paint(Paint.ANTI_ALIAS_FLAG).apply {
 			strokeWidth = STROKE_WIDTH
@@ -36,24 +33,21 @@ class SimpleDrawView(context: Context, attributeSet: AttributeSet) : View(contex
 
 	override fun onDraw(canvas: Canvas) {
 		val path = Path()
-		mPointList.forEach { pointHistory ->
-			pointHistory.forEachIndexed { index, point ->
+		mLineHistoryList.forEach { line ->
+			line.forEachIndexed { index, point ->
+				val x = point.x.toFloat()
+				val y = point.y.toFloat()
 				if (index == 0) {
-					path.moveTo(point.x, point.y)
+					path.moveTo(x, y)
 				}
 				else {
-					path.lineTo(point.x, point.y)
+					path.lineTo(x, y)
 				}
 			}
 			canvas.drawPath(path, mPaint)
 		}
 	}
 
-	fun clear() {
-		mPointList.clear()
-		invalidate()
-	}
-
 	override fun onTouch(view: View, event: MotionEvent): Boolean {
 		when (event.action) {
 			MotionEvent.ACTION_DOWN -> {
@@ -70,27 +64,31 @@ class SimpleDrawView(context: Context, attributeSet: AttributeSet) : View(contex
 		return true
 	}
 
-	private fun onTouchStart() {
-		mPointList.add(mutableListOf())
+	fun clear() {
+		mLineHistoryList.clear()
+		invalidate()
 	}
 
-	private fun onTouchMove(event: MotionEvent) {
-		mPointList.last()
-			.add(Point(x = event.x,
-					   y = event.y))
+	fun drawLine(lineList: List<Point>) {
+		mLineHistoryList.add(lineList.toMutableList())
 		invalidate()
 	}
 
-	private fun onTouchEnd() {
-		drawListener?.invoke(mPointList.lastOrNull())
+	private fun onTouchStart() {
+		mLineHistoryList.add(mutableListOf())
 	}
 
-	inner class Point(val x: Float = 0f,
-					  val y: Float = 0f) {
-
-		override fun toString(): String {
-			return "$x,$y"
+	private fun onTouchMove(event: MotionEvent) {
+		val point = Point().apply {
+			x = event.x.toInt()
+			y = event.y.toInt()
 		}
+		mLineHistoryList.last().add(point)
+		invalidate()
+	}
+
+	private fun onTouchEnd() {
+		drawListener?.invoke(mLineHistoryList.lastOrNull())
 	}
 
 	companion object {