From 45651efceb9cf85b23a3f0d2ee60b76baada04a8 Mon Sep 17 00:00:00 2001
From: Chahine <chahine.m@hotmail.com>
Date: Mon, 12 Feb 2018 14:01:35 -0500
Subject: [PATCH] Feature - Performance Improvements (#9)

---
 .../pageindicator/sample/MainActivity.kt      |  2 +-
 dependencies.gradle                           |  2 +-
 pageindicator/build.gradle                    |  4 +--
 .../chahinem/pageindicator/PageIndicator.kt   | 25 +++++++++++++------
 settings.gradle                               |  3 ++-
 5 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/app/src/main/java/com/chahinem/pageindicator/sample/MainActivity.kt b/app/src/main/java/com/chahinem/pageindicator/sample/MainActivity.kt
index 3371b0a..627d21d 100644
--- a/app/src/main/java/com/chahinem/pageindicator/sample/MainActivity.kt
+++ b/app/src/main/java/com/chahinem/pageindicator/sample/MainActivity.kt
@@ -34,7 +34,7 @@ class MainActivity : AppCompatActivity() {
     pagerPageIndicator.attachTo(pager)
 
     // Manual
-    manualPageIndicator.count = 4
+    manualPageIndicator.count = 777
     leftBtn.setOnClickListener { manualPageIndicator.swipePrevious() }
     rightBtn.setOnClickListener { manualPageIndicator.swipeNext() }
   }
diff --git a/dependencies.gradle b/dependencies.gradle
index 26620a5..bda8f79 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -5,7 +5,7 @@ ext {
   targetSdkVersion = 27
   buildToolsVersion = '27.0.2'
   gradleVersion = '3.0.1'
-  kotlinVersion = '1.2.20'
+  kotlinVersion = '1.2.21'
 
   supportLibraryVersion = '27.0.2'
 
diff --git a/pageindicator/build.gradle b/pageindicator/build.gradle
index 8edc59f..566b5b7 100644
--- a/pageindicator/build.gradle
+++ b/pageindicator/build.gradle
@@ -3,8 +3,8 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 apply plugin: 'com.github.dcendents.android-maven'
 
-group = 'com.github.chahinem.pageindicator'
-version = '0.2.3'
+group = 'com.github.chahinem'
+version = '0.2.4'
 
 androidExtensions { experimental = true }
 
diff --git a/pageindicator/src/main/java/com/chahinem/pageindicator/PageIndicator.kt b/pageindicator/src/main/java/com/chahinem/pageindicator/PageIndicator.kt
index d8c00ef..5500caa 100644
--- a/pageindicator/src/main/java/com/chahinem/pageindicator/PageIndicator.kt
+++ b/pageindicator/src/main/java/com/chahinem/pageindicator/PageIndicator.kt
@@ -103,13 +103,15 @@ class PageIndicator @JvmOverloads constructor(
     super.onDraw(canvas)
 
     var paddingStart = initialPadding
-    // FIXME: do not iterate on the entire list but only a subset of it
-    dotManager?.dots?.forEachIndexed { index, dot ->
+    val (start, end) = getDrawingRange()
+
+    paddingStart += (dotSize + dotSpacing) * start
+    (start until end).forEach {
       canvas?.drawCircle(
           paddingStart + dotSize / 2f - scrollAmount,
           dotSize / 2f,
-          dotSizes[index] / 2f,
-          when (dot) {
+          dotSizes[it] / 2f,
+          when (dotManager?.dots?.get(it)) {
             BYTE_6 -> selectedPaint
             else -> defaultPaint
           })
@@ -180,10 +182,10 @@ class PageIndicator @JvmOverloads constructor(
 
   private fun animateDots() {
     dotManager?.let {
-      // FIXME: do not iterate on the entire list but only a subset of it
-      it.dots.forEachIndexed { index, dot ->
+      val (start, end) = getDrawingRange()
+      (start until end).forEach { index ->
         dotAnimators[index].cancel()
-        dotAnimators[index] = ValueAnimator.ofInt(dotSizes[index], it.dotSizeFor(dot))
+        dotAnimators[index] = ValueAnimator.ofInt(dotSizes[index], it.dotSizeFor(it.dots[index]))
             .apply {
               duration = animDuration
               interpolator = DEFAULT_INTERPOLATOR
@@ -197,6 +199,14 @@ class PageIndicator @JvmOverloads constructor(
     }
   }
 
+  private fun getDrawingRange(): Pair<Int, Int> {
+    val start = Math.max(0, (dotManager?.selectedIndex ?: 0) - MOST_VISIBLE_COUNT)
+    val end = Math.min(
+        dotManager?.dots?.size ?: 0,
+        (dotManager?.selectedIndex ?: 0) + MOST_VISIBLE_COUNT)
+    return Pair(start, end)
+  }
+
   companion object {
     private const val BYTE_6 = 6.toByte()
     private const val BYTE_5 = 5.toByte()
@@ -205,6 +215,7 @@ class PageIndicator @JvmOverloads constructor(
     private const val BYTE_2 = 2.toByte()
     private const val BYTE_1 = 1.toByte()
 
+    private const val MOST_VISIBLE_COUNT = 10
     private const val DEFAULT_ANIM_DURATION = 200
 
     private val DEFAULT_INTERPOLATOR = DecelerateInterpolator()
diff --git a/settings.gradle b/settings.gradle
index b26d93a..b948c16 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1,2 +1,3 @@
 include ':app'
-include ':pageindicator'
\ No newline at end of file
+include ':pageindicator'
+project(':pageindicator').name = 'pageindicator'