Merge pull request #1961 from GOVINDDIXIT/fix#1938

[NEW] Add erase feature in drawing

draw/src/main/java/chat/rocket/android/draw/main/ui/DrawActivity.kt

@@ -53,8 +53,15 @@ class DrawingActivity : DaggerAppCompatActivity(), DrawView {
     }
 
     private fun setupDrawTools() {
-        image_draw_eraser.setOnClickListener {
+        image_draw_eraser.setOnLongClickListener{
             custom_draw_view.clearCanvas()
+            return@setOnLongClickListener true
+        }
+
+        image_draw_eraser.setOnClickListener {
+            custom_draw_view.setColor(
+                ResourcesCompat.getColor(resources, R.color.color_white, null)
+            )
             toggleDrawTools(draw_tools, false)
         }
 
@@ -111,6 +118,13 @@ class DrawingActivity : DaggerAppCompatActivity(), DrawView {
     }
 
     private fun colorSelector() {
+        image_color_black.setOnClickListener {
+            custom_draw_view.setColor(
+                    ResourcesCompat.getColor(resources, R.color.color_black, null)
+            )
+            scaleColorView(image_color_black)
+        }
+
         image_color_red.setOnClickListener {
             custom_draw_view.setColor(
                 ResourcesCompat.getColor(resources, R.color.color_red, null)

draw/src/main/java/chat/rocket/android/draw/widget/CustomDrawView.kt

@@ -42,7 +42,6 @@ class CustomDrawView(context: Context, attrs: AttributeSet) : View(context, attr
     fun undo() {
         if (mPaths.isEmpty() && mLastPaths.isNotEmpty()) {
             mPaths = mLastPaths.clone() as LinkedHashMap<MyPath, PaintOptions>
-            mLastPaths.clear()
             invalidate()
             return
         }