Merge pull request #53 from st235/feature/show_hide

implemented show and hide methods.

build.gradle

@@ -1,7 +1,7 @@
 ext {
     vers = [
-            versionCode: 36,
-            versionName: "1.2.3"
+            versionCode: 37,
+            versionName: "1.2.4"
     ]
     info = [
             name: 'expandablebottombar',

lib-expandablebottombar/src/main/java/github/com/st235/lib_expandablebottombar/ExpandableBottomBar.kt

@@ -1,5 +1,6 @@
 package github.com.st235.lib_expandablebottombar
 
+import android.animation.Animator
 import android.annotation.TargetApi
 import android.content.Context
 import android.content.res.ColorStateList
@@ -24,6 +25,8 @@ import androidx.constraintlayout.widget.ConstraintLayout
 import androidx.constraintlayout.widget.ConstraintSet
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.content.ContextCompat
+import androidx.core.view.ViewCompat
+import androidx.core.view.marginBottom
 import github.com.st235.lib_expandablebottombar.ExpandableBottomBar.ItemStyle.Companion.toItemStyle
 import github.com.st235.lib_expandablebottombar.behavior.ExpandableBottomBarBehavior
 import github.com.st235.lib_expandablebottombar.parsers.ExpandableBottomBarParser
@@ -94,6 +97,8 @@ class ExpandableBottomBar @JvmOverloads constructor(
     var onItemSelectedListener: OnItemClickListener? = null
     var onItemReselectedListener: OnItemClickListener? = null
 
+    private var animator: Animator? = null
+
     init {
         initAttrs(context, attrs, defStyleAttr)
     }
@@ -242,6 +247,38 @@ class ExpandableBottomBar @JvmOverloads constructor(
      */
     fun getSelected(): ExpandableBottomBarMenuItem = viewControllers.getValue(selectedItemId).menuItem
 
+    /**
+     * Shows the bottom bar
+     */
+    fun show() {
+        cancelRunningAnimation()
+
+        animator = AnimationHelper.translateViewTo(this, 0F)
+        animator?.start()
+    }
+
+    /**
+     * Hides the bottom bar
+     */
+    fun hide() {
+        cancelRunningAnimation()
+
+        animator = AnimationHelper.translateViewTo(this, getMaxScrollDistance())
+        animator?.start()
+    }
+
+    private fun getMaxScrollDistance(): Float {
+        val childHeight = if (ViewCompat.isLaidOut(this)) height else measuredHeight
+        return childHeight.toFloat() + marginBottom
+    }
+
+    private fun cancelRunningAnimation() {
+        if (animator?.isRunning == true) {
+            animator?.cancel()
+            animator = null
+        }
+    }
+
     private fun madeMenuItemsAccessible(items: List<ExpandableBottomBarMenuItem>) {
         for ((i, item) in items.withIndex()) {
             val prev = viewControllers[items.getOrNull(i - 1)?.itemId]

lib-expandablebottombar/src/main/java/github/com/st235/lib_expandablebottombar/behavior/ExpandableBottomBarScrollableBehavior.kt

@@ -1,15 +1,15 @@
 package github.com.st235.lib_expandablebottombar.behavior
 
-import android.animation.ValueAnimator
+import android.animation.Animator
 import android.content.Context
 import android.os.Handler
 import android.os.Looper
 import android.util.AttributeSet
 import android.view.View
-import android.view.animation.DecelerateInterpolator
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.view.ViewCompat
 import androidx.core.view.marginBottom
+import github.com.st235.lib_expandablebottombar.utils.AnimationHelper
 import github.com.st235.lib_expandablebottombar.utils.clamp
 import kotlin.math.abs
 
@@ -19,7 +19,7 @@ class ExpandableBottomBarScrollableBehavior<V: View>:
     private val handler = Handler(Looper.getMainLooper())
     private var lastKnownRunnable: Runnable? = null
 
-    private var animator: ValueAnimator? = null
+    private var animator: Animator? = null
     private var lastKnownDirection: Int? = null
 
     constructor(): super()
@@ -88,14 +88,7 @@ class ExpandableBottomBarScrollableBehavior<V: View>:
         }
 
         cancelAnimation()
-
-        animator = ValueAnimator.ofFloat(child.translationY, translation)
-        animator?.interpolator = DecelerateInterpolator()
-        animator?.addUpdateListener { animator ->
-            val animatedValue = this.animator?.animatedValue as Float
-            child.translationY = animatedValue
-        }
-
+        animator = AnimationHelper.translateViewTo(child, translation)
         animator?.start()
     }
 

lib-expandablebottombar/src/main/java/github/com/st235/lib_expandablebottombar/utils/AnimationHelper.kt

@@ -0,0 +1,21 @@
+package github.com.st235.lib_expandablebottombar.utils
+
+import android.animation.Animator
+import android.animation.ValueAnimator
+import android.view.View
+import android.view.animation.DecelerateInterpolator
+
+object AnimationHelper {
+
+    fun <T: View> translateViewTo(child: T, translation: Float): Animator {
+        val animator = ValueAnimator.ofFloat(child.translationY, translation)
+        animator.interpolator = DecelerateInterpolator()
+        animator.addUpdateListener { animator ->
+            val animatedValue = animator?.animatedValue as Float
+            child.translationY = animatedValue
+        }
+
+        return animator
+    }
+
+}