Enabled Databinding

app/build.gradle

@@ -11,8 +11,8 @@ android {
         applicationId "com.opencraft.android.gradienttextview"
         minSdkVersion 15
         targetSdkVersion 27
-        versionCode 1
-        versionName "1.0.1"
+        versionCode 2
+        versionName "1.1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     buildTypes {

app/src/main/java/com/opencraft/android/gradienttextview/sample/MainActivity.kt

@@ -1,7 +1,7 @@
 package com.opencraft.android.gradienttextview.sample
 
-import android.arch.lifecycle.ViewModelProviders
 import android.databinding.DataBindingUtil
+import android.graphics.Color
 import android.os.Bundle
 import android.support.v7.app.AppCompatActivity
 import com.opencraft.android.gradienttextview.R
@@ -11,8 +11,11 @@ class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        var vm = ViewModelProviders.of(this).get(MainViewModel::class.java)
-        var binding = DataBindingUtil.setContentView<ActivityMainBinding>(this, R.layout.activity_main)
+        val vm = MainViewModel(this)
+        val binding = DataBindingUtil.setContentView<ActivityMainBinding>(this, R.layout.activity_main)
         binding.vm = vm
+//        binding.gradient.postDelayed({
+//            binding.gradient.gradientColors = intArrayOf(Color.BLUE, Color.GREEN)
+//        }, 1000)
     }
 }

app/src/main/java/com/opencraft/android/gradienttextview/sample/MainViewModel.kt

@@ -1,8 +1,10 @@
 package com.opencraft.android.gradienttextview.sample
 
-import android.arch.lifecycle.ViewModel
+import android.content.Context
 import android.databinding.ObservableField
+import com.opencraft.android.gradienttextview.R
 
-class MainViewModel : ViewModel() {
+class MainViewModel(context: Context) {
     val text = ObservableField<String>("aaaaaaaaaa\naaaaaaaaaa\naaaaaaaaaa\naaaaaaaaaa\naaaaaaaaaa")
+    val colors = context.resources.getIntArray(R.array.gradient_default)
 }

app/src/main/res/layout/activity_main.xml

@@ -24,10 +24,10 @@
             android:text="aaaaaaaaaaaaa\naaaaaaaaaaaaa\naaaaaaaaaaaaa\naaaaaaaaaaaaaa"
             android:textSize="22sp"
             android:textStyle="bold"
-            app:color_array="@array/gradient_default"
-            app:color_span_array="@array/gradient_color_span_default"
             app:gradient_end="BOTTOM_RIGHT"
-            app:gradient_start="TOP_LEFT" />
+            app:gradient_start="TOP_LEFT"
+            app:gradientColors="@{vm.colors}"
+            />
 
         <com.opencraft.library.GradientTextView
             android:id="@+id/gradient"
@@ -38,7 +38,7 @@
             android:textSize="22sp"
             android:textStyle="bold"
             app:angle="-45"
-            app:color_array="@array/gradient_default"
+            app:gradientColors="@array/gradient_default"
             app:color_span_array="@array/gradient_color_span_default" />
 
     </LinearLayout>

build.gradle

@@ -7,7 +7,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.3'
+        classpath 'com.android.tools.build:gradle:3.1.4'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong

library/src/main/java/com/opencraft/library/GradientTextView.kt

@@ -1,38 +1,28 @@
 package com.opencraft.library
 
-import android.annotation.SuppressLint
 import android.content.Context
 import android.content.res.TypedArray
-import android.databinding.InverseBindingMethod
-import android.databinding.InverseBindingMethods
-import android.graphics.Color
-import android.graphics.LinearGradient
-import android.graphics.Point
-import android.graphics.Shader
+import android.graphics.*
 import android.support.v7.widget.AppCompatTextView
 import android.util.AttributeSet
 
-@InverseBindingMethods(InverseBindingMethod(type = GradientTextView::class, attribute = "android:text"))
 class GradientTextView constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : AppCompatTextView(context, attrs, defStyleAttr) {
 
     constructor(context: Context) : this(context, null)
     constructor(context: Context, attrs: AttributeSet?) : this(context, attrs, 0)
 
-    private var gradientColors = intArrayOf(Color.BLACK, Color.WHITE)
     private var gradientColorPos = floatArrayOf(0f, 1f)
-    private var linearGradient: LinearGradient? = null
     private var angle = 0.0
     private var startOption = -1
     private var endOption = -1
+    private var changedColors = true
 
-    val TOP_LEFT = 0
-    val TOP_CENTER = 1
-    val MIDDLE_RIGHT = 2
-    val MIDDLE_LEFT = 3
-    val TOP_RIGHT = 4
-    val BOTTOM_LEFT = 5
-    val BOTTOM_CENTER = 6
-    val BOTTOM_RIGHT = 7
+    var gradientColors = intArrayOf(Color.BLACK, Color.WHITE)
+        set(value) {
+            field = value
+            changedColors = true
+            invalidate()
+        }
 
     init {
         attrs?.let {
@@ -51,6 +41,18 @@ class GradientTextView constructor(context: Context, attrs: AttributeSet?, defSt
         }
     }
 
+    private fun getLinearGradient(): LinearGradient {
+        val gradientStartPoint = getStartPoint()
+        val gradientEndPoint = getEndPoint()
+        return LinearGradient(gradientStartPoint.x.toFloat(),
+                gradientStartPoint.y.toFloat(),
+                gradientEndPoint.x.toFloat(),
+                gradientEndPoint.y.toFloat(),
+                gradientColors,
+                gradientColorPos,
+                Shader.TileMode.CLAMP)
+    }
+
     private fun loadAngle(typedArray: TypedArray) {
         angle = typedArray.getInteger(R.styleable.GradientTextView_angle, 0).toDouble()
     }
@@ -75,37 +77,23 @@ class GradientTextView constructor(context: Context, attrs: AttributeSet?, defSt
     }
 
     private fun loadColors(typedArray: TypedArray) {
-        val colors = resources.getStringArray(typedArray
-                .getResourceId(R.styleable.GradientTextView_color_array, R.array.gradient_default))
-        colors?.let {
-            gradientColors = IntArray(it.size)
-            for (i in 0 until it.size) {
-                gradientColors[i] = Color.parseColor(it[i])
-            }
-        }
+        gradientColors  = resources.getIntArray(typedArray
+                .getResourceId(R.styleable.GradientTextView_gradientColors, R.array.gradient_default))
     }
 
-    @SuppressLint("DrawAllocation")
-    override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
-        super.onLayout(changed, left, top, right, bottom)
-        if (changed) {
-
-            val startPoint = getStartPoint()
-            val endPoint = getEndPoint()
-
-            linearGradient = LinearGradient(startPoint.x.toFloat(), startPoint.y.toFloat(), endPoint.x.toFloat(), endPoint.y.toFloat(),
-                    gradientColors,
-                    gradientColorPos,
-                    Shader.TileMode.CLAMP)
-            paint.shader = linearGradient
+    override fun onDraw(canvas: Canvas?) {
+        if (changedColors) {
+            changedColors = false
+            paint.shader = getLinearGradient()
         }
+        super.onDraw(canvas)
     }
 
     private fun getEndPoint(): Point {
-        if (startOption > -1 && endOption > -1) {
-            return getPointFromEnum(endOption)
+        return if (startOption > -1 && endOption > -1) {
+            getPointFromEnum(endOption)
         } else {
-            return calcEndFromAngle()
+            calcEndFromAngle()
 
         }
     }
@@ -120,10 +108,10 @@ class GradientTextView constructor(context: Context, attrs: AttributeSet?, defSt
     }
 
     private fun getStartPoint(): Point {
-        if (startOption > -1 && endOption > -1) {
-            return getPointFromEnum(startOption)
+        return if (startOption > -1 && endOption > -1) {
+            getPointFromEnum(startOption)
         } else {
-            return calcStartFromAngle()
+            calcStartFromAngle()
         }
     }
 
@@ -151,4 +139,15 @@ class GradientTextView constructor(context: Context, attrs: AttributeSet?, defSt
         val startY = centerY + (width - centerX) * Math.sin(radians) + (centerY - centerY) * Math.cos(radians);
         return Point(startX.toInt(), startY.toInt())
     }
+
+    companion object {
+        const val TOP_LEFT = 0
+        const val TOP_CENTER = 1
+        const val MIDDLE_RIGHT = 2
+        const val MIDDLE_LEFT = 3
+        const val TOP_RIGHT = 4
+        const val BOTTOM_LEFT = 5
+        const val BOTTOM_CENTER = 6
+        const val BOTTOM_RIGHT = 7
+    }
 }

library/src/main/res/values/arrays.xml

@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <string-array name="gradient_default">
-        <item>#000000</item>
-        <item>#FFFFFF</item>
-    </string-array>
+    <integer-array name="gradient_default">
+        <item>@android:color/holo_red_dark</item>
+        <item>@android:color/holo_blue_bright</item>
+    </integer-array>
 
     <integer-array name="gradient_color_span_default">
         <item>1</item>

library/src/main/res/values/attrs.xml

@@ -2,6 +2,7 @@
 <resources>
     <declare-styleable name="GradientTextView">
         <attr name="color_array" format="reference" />
+        <attr name="gradientColors" format="reference" />
         <attr name="color_span_array" format="reference" />
         <attr name="angle" format="integer" />
         <attr name="gradient_start" format="enum">