Support sdk 19 where possible and add image picker (#10)3.0

* Fix plural

* Switch to long

* Test plural again

* Comment

* Major update to image picker and view utils

* Make image activity full screen

* Update min sdk and prefix

* Lower sdk requirement and make string private

* Bring kpref activity to sdk 19

11 files changed, 197 insertions, 85 deletions

diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt
index 7f4399d..1474c1a 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt
@@ -1,5 +1,6 @@
 package ca.allanwang.kau.swipe
 
+import android.annotation.SuppressLint
 import android.app.Activity
 import android.content.Context
 import android.graphics.Canvas
@@ -37,6 +38,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
         }
 
     var activity: Activity? = null
+        @SuppressLint("NewApi")
         set(value) {
             field = value
             if (value != null) {
@@ -81,6 +83,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
 
     val chromeFadeListener: SwipeListener by lazy {
         object : SwipeListener {
+            @SuppressLint("NewApi")
             override fun onScroll(percent: Float, px: Int, edgeFlag: Int) {
                 if (!transitionSystemBars) return
                 activity?.apply {
diff --git a/core/src/main/kotlin/ca/allanwang/kau/ui/SimpleRippleDrawable.kt b/core/src/main/kotlin/ca/allanwang/kau/ui/SimpleRippleDrawable.kt
index 30c8edd..b92b222 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/ui/SimpleRippleDrawable.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/ui/SimpleRippleDrawable.kt
@@ -3,7 +3,9 @@ package ca.allanwang.kau.ui
 import android.content.res.ColorStateList
 import android.graphics.drawable.ColorDrawable
 import android.graphics.drawable.RippleDrawable
+import android.os.Build
 import android.support.annotation.ColorInt
+import android.support.annotation.RequiresApi
 import ca.allanwang.kau.utils.adjustAlpha
 
 /**
@@ -11,6 +13,7 @@ import ca.allanwang.kau.utils.adjustAlpha
  *
  * Tries to mimic a standard ripple, given the foreground and background colors
  */
+@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
 fun createSimpleRippleDrawable(@ColorInt foregroundColor: Int, @ColorInt backgroundColor: Int): RippleDrawable {
     val states = ColorStateList(arrayOf(intArrayOf()), intArrayOf(foregroundColor))
     val content = ColorDrawable(backgroundColor)
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt
index cd6e089..54aeaff 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt
@@ -39,13 +39,17 @@ fun Activity.finishSlideOut() {
 }
 
 inline var Activity.navigationBarColor: Int
+    @SuppressLint("NewApi")
     get() = if (buildIsLollipopAndUp) window.navigationBarColor else Color.BLACK
+    @SuppressLint("NewApi")
     set(value) {
         if (buildIsLollipopAndUp) window.navigationBarColor = value
     }
 
 inline var Activity.statusBarColor: Int
+    @SuppressLint("NewApi")
     get() = if (buildIsLollipopAndUp) window.statusBarColor else Color.BLACK
+    @SuppressLint("NewApi")
     set(value) {
         if (buildIsLollipopAndUp) window.statusBarColor = value
     }
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/AnimHolder.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/AnimHolder.kt
index 3db8b9c..2767f04 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/AnimHolder.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/AnimHolder.kt
@@ -1,5 +1,7 @@
 package ca.allanwang.kau.utils
 
+import android.os.Build
+import android.support.annotation.RequiresApi
 import ca.allanwang.kau.kotlin.lazyInterpolator
 
 /**
@@ -9,6 +11,7 @@ import ca.allanwang.kau.kotlin.lazyInterpolator
  */
 object AnimHolder {
 
+    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
     val fastOutSlowInInterpolator = lazyInterpolator(android.R.interpolator.fast_out_linear_in)
     val decelerateInterpolator = lazyInterpolator(android.R.interpolator.decelerate_cubic)
 
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/AnimUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/AnimUtils.kt
index bbde077..ed4b7bd 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/AnimUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/AnimUtils.kt
@@ -2,12 +2,12 @@ package ca.allanwang.kau.utils
 
 import android.animation.Animator
 import android.animation.AnimatorListenerAdapter
+import android.annotation.SuppressLint
 import android.support.annotation.StringRes
 import android.view.View
 import android.view.ViewAnimationUtils
 import android.view.animation.Animation
 import android.view.animation.AnimationUtils
-import android.view.animation.DecelerateInterpolator
 import android.widget.TextView
 
 /**
@@ -15,33 +15,8 @@ import android.widget.TextView
  *
  * Animation extension functions for Views
  */
-@KauUtils fun View.rootCircularReveal(x: Int = 0, y: Int = 0, duration: Long = 500L, onStart: (() -> Unit)? = null, onFinish: (() -> Unit)? = null) {
-    this.addOnLayoutChangeListener(object : View.OnLayoutChangeListener {
-        override @KauUtils fun onLayoutChange(v: View, left: Int, top: Int, right: Int, bottom: Int, oldLeft: Int, oldTop: Int,
-                                              oldRight: Int, oldBottom: Int) {
-            v.removeOnLayoutChangeListener(this)
-            var x2 = x
-            var y2 = y
-            if (x2 > right) x2 = 0
-            if (y2 > bottom) y2 = 0
-            val radius = Math.hypot(Math.max(x2, right - x2).toDouble(), Math.max(y2, bottom - y2).toDouble()).toInt()
-            val reveal = ViewAnimationUtils.createCircularReveal(v, x2, y2, 0f, radius.toFloat())
-            reveal.interpolator = DecelerateInterpolator(1f)
-            reveal.duration = duration
-            reveal.addListener(object : AnimatorListenerAdapter() {
-                override @KauUtils fun onAnimationStart(animation: Animator?) {
-                    visible()
-                    onStart?.invoke()
-                }
-
-                override @KauUtils fun onAnimationEnd(animation: Animator?) = onFinish?.invoke() ?: Unit
-                override @KauUtils fun onAnimationCancel(animation: Animator?) = onFinish?.invoke() ?: Unit
-            })
-            reveal.start()
-        }
-    })
-}
 
+@SuppressLint("NewApi")
 @KauUtils fun View.circularReveal(x: Int = 0, y: Int = 0, offset: Long = 0L, radius: Float = -1.0f, duration: Long = 500L, onStart: (() -> Unit)? = null, onFinish: (() -> Unit)? = null) {
     if (!isAttachedToWindow) {
         onStart?.invoke()
@@ -49,10 +24,11 @@ import android.widget.TextView
         onFinish?.invoke()
         return
     }
-    var r = radius
-    if (r < 0.0f) {
-        r = Math.max(Math.hypot(x.toDouble(), y.toDouble()), Math.hypot((width - x.toDouble()), (height - y.toDouble()))).toFloat()
-    }
+    if (!buildIsLollipopAndUp) return fadeIn(offset, duration, onStart, onFinish)
+
+    val r = if (radius >= 0) radius
+    else Math.max(Math.hypot(x.toDouble(), y.toDouble()), Math.hypot((width - x.toDouble()), (height - y.toDouble()))).toFloat()
+
     val anim = ViewAnimationUtils.createCircularReveal(this, x, y, 0f, r).setDuration(duration)
     anim.startDelay = offset
     anim.addListener(object : AnimatorListenerAdapter() {
@@ -67,6 +43,7 @@ import android.widget.TextView
     anim.start()
 }
 
+@SuppressLint("NewApi")
 @KauUtils fun View.circularHide(x: Int = 0, y: Int = 0, offset: Long = 0L, radius: Float = -1.0f, duration: Long = 500L, onStart: (() -> Unit)? = null, onFinish: (() -> Unit)? = null) {
     if (!isAttachedToWindow) {
         onStart?.invoke()
@@ -74,10 +51,11 @@ import android.widget.TextView
         onFinish?.invoke()
         return
     }
-    var r = radius
-    if (r < 0.0f) {
-        r = Math.max(Math.hypot(x.toDouble(), y.toDouble()), Math.hypot((width - x.toDouble()), (height - y.toDouble()))).toFloat()
-    }
+    if (!buildIsLollipopAndUp) return fadeOut(offset, duration, onStart, onFinish)
+
+    val r = if (radius >= 0) radius
+    else Math.max(Math.hypot(x.toDouble(), y.toDouble()), Math.hypot((width - x.toDouble()), (height - y.toDouble()))).toFloat()
+
     val anim = ViewAnimationUtils.createCircularReveal(this, x, y, r, 0f).setDuration(duration)
     anim.startDelay = offset
     anim.addListener(object : AnimatorListenerAdapter() {
@@ -100,20 +78,18 @@ import android.widget.TextView
         onFinish?.invoke()
         return
     }
-    if (isAttachedToWindow) {
-        val anim = AnimationUtils.loadAnimation(context, android.R.anim.fade_in)
-        anim.startOffset = offset
-        anim.duration = duration
-        anim.setAnimationListener(object : Animation.AnimationListener {
-            override @KauUtils fun onAnimationRepeat(animation: Animation?) {}
-            override @KauUtils fun onAnimationEnd(animation: Animation?) = onFinish?.invoke() ?: Unit
-            override @KauUtils fun onAnimationStart(animation: Animation?) {
-                visible()
-                onStart?.invoke()
-            }
-        })
-        startAnimation(anim)
-    }
+    val anim = AnimationUtils.loadAnimation(context, android.R.anim.fade_in)
+    anim.startOffset = offset
+    anim.duration = duration
+    anim.setAnimationListener(object : Animation.AnimationListener {
+        override @KauUtils fun onAnimationRepeat(animation: Animation?) {}
+        override @KauUtils fun onAnimationEnd(animation: Animation?) = onFinish?.invoke() ?: Unit
+        override @KauUtils fun onAnimationStart(animation: Animation?) {
+            visible()
+            onStart?.invoke()
+        }
+    })
+    startAnimation(anim)
 }
 
 @KauUtils fun View.fadeOut(offset: Long = 0L, duration: Long = 200L, onStart: (() -> Unit)? = null, onFinish: (() -> Unit)? = null) {
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt
index 9fcc7e7..f267a60 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt
@@ -8,4 +8,7 @@ const val ANDROID_NAMESPACE = "http://schemas.android.com/apk/res/android"
 const val KAU_LEFT = 1
 const val KAU_TOP = 2
 const val KAU_RIGHT = 4
-const val KAU_BOTTOM = 8
\ No newline at end of file
+const val KAU_BOTTOM = 8
+const val KAU_HORIZONTAL = KAU_LEFT and KAU_RIGHT
+const val KAU_VERTICAL = KAU_TOP and KAU_BOTTOM
+const val KAU_ALL = KAU_HORIZONTAL and KAU_VERTICAL
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt
index a8e0715..bf30a91 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt
@@ -1,5 +1,6 @@
 package ca.allanwang.kau.utils
 
+import android.annotation.SuppressLint
 import android.app.Activity
 import android.app.ActivityOptions
 import android.content.ClipData
@@ -25,6 +26,7 @@ import com.afollestad.materialdialogs.MaterialDialog
 /**
  * Created by Allan Wang on 2017-06-03.
  */
+@SuppressLint("NewApi")
 fun Context.startActivity(
         clazz: Class<out Activity>,
         clearStack: Boolean = false,
@@ -34,7 +36,9 @@ fun Context.startActivity(
     val intent = (Intent(this, clazz))
     if (clearStack) intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK)
     intent.intentBuilder()
-    val fullBundle = if (transition && this is Activity) ActivityOptions.makeSceneTransitionAnimation(this).toBundle() else Bundle()
+    val fullBundle = if (transition && this is Activity && buildIsLollipopAndUp)
+        ActivityOptions.makeSceneTransitionAnimation(this).toBundle()
+    else Bundle()
     if (transition && this !is Activity) KL.d("Cannot make scene transition when context is not an instance of an Activity")
     if (bundle != null) fullBundle.putAll(bundle)
     ContextCompat.startActivity(this, intent, if (fullBundle.isEmpty) null else fullBundle)
@@ -97,7 +101,11 @@ inline fun Context.drawable(@DrawableRes id: Int): Drawable = ContextCompat.getD
 inline fun Context.drawable(@DrawableRes id: Int, fallback: Drawable?): Drawable? = if (id > 0) drawable(id) else fallback
 inline fun Context.interpolator(@InterpolatorRes id: Int) = AnimationUtils.loadInterpolator(this, id)
 inline fun Context.animation(@AnimRes id: Int) = AnimationUtils.loadAnimation(this, id)
-inline fun Context.plural(@PluralsRes id: Int, quantity: Number) = resources.getQuantityString(id, quantity.toInt())
+/**
+ * Returns plural form of res. The quantity is also passed to the formatter as an int
+ */
+inline fun Context.plural(@PluralsRes id: Int, quantity: Number)
+        = resources.getQuantityString(id, quantity.toInt(), quantity.toInt())
 
 //Attr retrievers
 fun Context.resolveColor(@AttrRes attr: Int, fallback: Int = 0): Int {
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/IIconUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/IIconUtils.kt
index 03a1605..4c71945 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/IIconUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/IIconUtils.kt
@@ -13,8 +13,7 @@ import com.mikepenz.iconics.typeface.IIcon
  */
 @KauUtils fun IIcon.toDrawable(c: Context, sizeDp: Int = 24, @ColorInt color: Int = Color.WHITE, builder: IconicsDrawable.() -> Unit = {}): Drawable {
     val state = ColorStateList.valueOf(color)
-    val icon = IconicsDrawable(c).icon(this).sizeDp(sizeDp)
-    icon.setTintList(state)
+    val icon = IconicsDrawable(c).icon(this).sizeDp(sizeDp).color(state)
     icon.builder()
     return icon
 }
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt
index 89d64e5..36bcc93 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt
@@ -30,12 +30,14 @@ import android.os.Build
     }
 }
 
-inline val buildIsLollipopAndUp: Boolean
-    get() = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
-
 inline val buildIsMarshmallowAndUp: Boolean
+
     get() = Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
 
+inline val buildIsLollipopAndUp: Boolean
+    @SuppressWarnings("NewApi")
+    get() = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
+
 inline val buildIsNougatAndUp: Boolean
     get() = Build.VERSION.SDK_INT >= Build.VERSION_CODES.N
 
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt
index 9e668d0..fa062f7 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt
@@ -1,11 +1,19 @@
 package ca.allanwang.kau.utils
 
-import android.support.transition.Transition
-import android.support.transition.TransitionSet
+import android.os.Build
+import android.support.annotation.RequiresApi
+import android.support.annotation.TransitionRes
+import android.support.transition.AutoTransition
+import android.support.transition.TransitionInflater
+import android.support.transition.TransitionManager
+import android.support.transition.Transition as SupportTransition
+import android.transition.Transition
+import android.view.ViewGroup
 
 /**
  * Created by Allan Wang on 2017-06-24.
  */
+@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
 class TransitionEndListener(val onEnd: (transition: Transition) -> Unit) : Transition.TransitionListener {
     override fun onTransitionEnd(transition: Transition) = onEnd(transition)
     override fun onTransitionResume(transition: Transition) {}
@@ -14,6 +22,35 @@ class TransitionEndListener(val onEnd: (transition: Transition) -> Unit) : Trans
     override fun onTransitionStart(transition: Transition) {}
 }
 
-@KauUtils fun TransitionSet.addEndListener(onEnd: (transition: Transition) -> Unit) {
+@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
+@KauUtils fun Transition.addEndListener(onEnd: (transition: Transition) -> Unit) {
     addListener(TransitionEndListener(onEnd))
+}
+
+@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
+class SupportTransitionEndListener(val onEnd: (transition: SupportTransition) -> Unit) : SupportTransition.TransitionListener {
+    override fun onTransitionEnd(transition: SupportTransition) = onEnd(transition)
+    override fun onTransitionResume(transition: SupportTransition) {}
+    override fun onTransitionPause(transition: SupportTransition) {}
+    override fun onTransitionCancel(transition: SupportTransition) {}
+    override fun onTransitionStart(transition: SupportTransition) {}
+}
+
+@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
+@KauUtils fun SupportTransition.addEndListener(onEnd: (transition: SupportTransition) -> Unit) {
+    addListener(SupportTransitionEndListener(onEnd))
+}
+
+@KauUtils fun ViewGroup.transitionAuto(builder: AutoTransition.() -> Unit = {}) {
+    if (!buildIsLollipopAndUp) return
+    val transition = AutoTransition()
+    transition.builder()
+    TransitionManager.beginDelayedTransition(this, transition)
+}
+
+@KauUtils fun ViewGroup.transitionDelayed(@TransitionRes id: Int, builder: android.support.transition.Transition.() -> Unit = {}) {
+    if (!buildIsLollipopAndUp) return
+    val transition = TransitionInflater.from(context).inflateTransition(id)
+    transition.builder()
+    TransitionManager.beginDelayedTransition(this, transition)
 }
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/ViewUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/ViewUtils.kt
index 59ae204..ead2cb7 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/ViewUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/ViewUtils.kt
@@ -5,10 +5,8 @@ package ca.allanwang.kau.utils
 import android.animation.ValueAnimator
 import android.content.Context
 import android.graphics.Color
-import android.support.annotation.ColorInt
-import android.support.annotation.ColorRes
-import android.support.annotation.StringRes
-import android.support.annotation.TransitionRes
+import android.os.Build
+import android.support.annotation.*
 import android.support.design.widget.FloatingActionButton
 import android.support.design.widget.Snackbar
 import android.support.design.widget.TextInputEditText
@@ -93,30 +91,98 @@ fun FloatingActionButton.hideIf(hide: Boolean) = if (hide) hide() else show()
 /**
  * Set left margin to a value in px
  */
-@KauUtils fun View.updateLeftMargin(margin: Int) = updateMargins(margin, KAU_LEFT)
+@KauUtils fun View.setMarginLeft(margin: Int) = setMargins(margin, KAU_LEFT)
 
 /**
  * Set top margin to a value in px
  */
-@KauUtils fun View.updateTopMargin(margin: Int) = updateMargins(margin, KAU_TOP)
+@KauUtils fun View.setMarginTop(margin: Int) = setMargins(margin, KAU_TOP)
 
 /**
  * Set right margin to a value in px
  */
-@KauUtils fun View.updateRightMargin(margin: Int) = updateMargins(margin, KAU_RIGHT)
+@KauUtils fun View.setMarginRight(margin: Int) = setMargins(margin, KAU_RIGHT)
 
 /**
  * Set bottom margin to a value in px
  */
-@KauUtils fun View.updateBottomMargin(margin: Int) = updateMargins(margin, KAU_BOTTOM)
+@KauUtils fun View.setMarginBottom(margin: Int) = setMargins(margin, KAU_BOTTOM)
 
-@KauUtils private fun View.updateMargins(margin: Int, flag: Int) {
-    val p = (layoutParams as? ViewGroup.MarginLayoutParams) ?: return
+/**
+ * Set left and right margins to a value in px
+ */
+@KauUtils fun View.setMarginHorizontal(margin: Int) = setMargins(margin, KAU_HORIZONTAL)
+
+/**
+ * Set top and bottom margins to a value in px
+ */
+@KauUtils fun View.setMarginVertical(margin: Int) = setMargins(margin, KAU_VERTICAL)
+
+/**
+ * Set all margins to a value in px
+ */
+@KauUtils fun View.setMargin(margin: Int) = setMargins(margin, KAU_ALL)
+
+/**
+ * Base margin setter
+ * returns true if setting is successful, false otherwise
+ */
+@KauUtils private fun View.setMargins(margin: Int, flag: Int): Boolean {
+    val p = (layoutParams as? ViewGroup.MarginLayoutParams) ?: return false
     p.setMargins(
-            if (flag == KAU_LEFT) margin else p.leftMargin,
-            if (flag == KAU_TOP) margin else p.topMargin,
-            if (flag == KAU_RIGHT) margin else p.rightMargin,
-            if (flag == KAU_BOTTOM) margin else p.bottomMargin
+            if (flag and KAU_LEFT > 0) margin else p.leftMargin,
+            if (flag and KAU_TOP > 0) margin else p.topMargin,
+            if (flag and KAU_RIGHT > 0) margin else p.rightMargin,
+            if (flag and KAU_BOTTOM > 0) margin else p.bottomMargin
+    )
+    requestLayout()
+    return true
+}
+
+/**
+ * Set left padding to a value in px
+ */
+@KauUtils fun View.setPaddingLeft(padding: Int) = setPadding(padding, KAU_LEFT)
+
+/**
+ * Set top padding to a value in px
+ */
+@KauUtils fun View.setPaddingTop(padding: Int) = setPadding(padding, KAU_TOP)
+
+/**
+ * Set right padding to a value in px
+ */
+@KauUtils fun View.setPaddingRight(padding: Int) = setPadding(padding, KAU_RIGHT)
+
+/**
+ * Set bottom padding to a value in px
+ */
+@KauUtils fun View.setPaddingBottom(padding: Int) = setPadding(padding, KAU_BOTTOM)
+
+/**
+ * Set left and right padding to a value in px
+ */
+@KauUtils fun View.setPaddingHorizontal(padding: Int) = setPadding(padding, KAU_HORIZONTAL)
+
+/**
+ * Set top and bottom padding to a value in px
+ */
+@KauUtils fun View.setPaddingVertical(padding: Int) = setPadding(padding, KAU_VERTICAL)
+
+/**
+ * Set all padding to a value in px
+ */
+@KauUtils fun View.setPadding(padding: Int) = setPadding(padding, KAU_ALL)
+
+/**
+ * Base padding setter
+ */
+@KauUtils private fun View.setPadding(padding: Int, flag: Int) {
+    setPadding(
+            if (flag and KAU_LEFT > 0) padding else paddingLeft,
+            if (flag and KAU_TOP > 0) padding else paddingTop,
+            if (flag and KAU_RIGHT > 0) padding else paddingRight,
+            if (flag and KAU_BOTTOM > 0) padding else paddingBottom
     )
     requestLayout()
 }
@@ -131,18 +197,8 @@ fun FloatingActionButton.hideIf(hide: Boolean) = if (hide) hide() else show()
     (context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager).showSoftInput(this, InputMethodManager.SHOW_IMPLICIT)
 }
 
-@KauUtils fun ViewGroup.transitionAuto(builder: AutoTransition.() -> Unit = {}) {
-    val transition = AutoTransition()
-    transition.builder()
-    TransitionManager.beginDelayedTransition(this, transition)
-}
-
-@KauUtils fun ViewGroup.transitionDelayed(@TransitionRes id: Int, builder: Transition.() -> Unit = {}) {
-    val transition = TransitionInflater.from(context).inflateTransition(id)
-    transition.builder()
-    TransitionManager.beginDelayedTransition(this, transition)
-}
 
+@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
 @KauUtils fun View.setRippleBackground(@ColorInt foregroundColor: Int, @ColorInt backgroundColor: Int) {
     background = createSimpleRippleDrawable(foregroundColor, backgroundColor)
 }
@@ -192,4 +248,22 @@ inline fun FloatingActionButton.transition(crossinline action: FloatingActionBut
             start()
         }
     }
+}
+
+/**
+ * Attaches a listener to the recyclerview to hide the fab when it is scrolling downwards
+ * The fab will reappear when scrolling has stopped or if the user scrolls up
+ */
+fun FloatingActionButton.hideOnDownwardsScroll(recycler: RecyclerView) {
+    recycler.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+
+        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
+            if (newState == android.support.v7.widget.RecyclerView.SCROLL_STATE_IDLE && !isShown) show();
+        }
+
+        override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+            if (dy > 0 && isShown) hide()
+            else if (dy < 0 && isHidden) show()
+        }
+    })
 }
\ No newline at end of file