add layoutAlignment, offsetX for barStyle;

AHCategoryView/Classes/AHCategoryNavBar.swift

@@ -29,6 +29,9 @@ public class AHCategoryNavBar: UIView {
 
     fileprivate lazy var buttons = [UIButton]()
 
+    /// The paddings stuck before/after a AHCategoryItem
+    fileprivate var itemPadding: CGFloat = 8.0
+
     // each key is the index from categories or buttons
     fileprivate lazy var badgeDict = [Int : BadgeInfo]()
 
@@ -230,9 +233,7 @@ fileprivate extension AHCategoryNavBar {
     }
     func setupScrollView(){
         scrollView.showsHorizontalScrollIndicator = false
-        if !barStyle.isScrollabel {
-            scrollView.isScrollEnabled = false
-        }
+        scrollView.isScrollEnabled = barStyle.isScrollabel
         addSubview(scrollView)
     }
 
@@ -272,21 +273,32 @@ fileprivate extension AHCategoryNavBar {
 
             if barStyle.isScrollabel {
                 // scrollabel, each label has its own width according to its text
-                width = textWidth
+                width = textWidth + itemPadding * 2
                 if i > 0 {
                     let previousBtn = buttons[i - 1]
-                    x = previousBtn.frame.maxX + barStyle.interItemSpace
+                    x = previousBtn.frame.maxX + barStyle.interItemSpace + barStyle.offsetX
                 }
                 // special adjustment for the default button
                 if i == barStyle.defaultCategoryIndex {
                     x = barStyle.interItemSpace * 0.5
                 }
             }else{
-                // not scrollabel, then divide width equally for all labels
-                width = self.bounds.width / CGFloat(categories.count)
-
-                if i > 0 {
-                    x = width * CGFloat(i)
+                if barStyle.layoutAlignment == .left {
+                    width = textWidth + itemPadding * 2
+                    if i > 0 {
+                        let previousBtn = buttons[i - 1]
+                        x = previousBtn.frame.maxX + barStyle.interItemSpace + barStyle.offsetX
+                    }
+                    // special adjustment for the default button
+                    if i == barStyle.defaultCategoryIndex {
+                        x = barStyle.interItemSpace * 0.5
+                    }
+                }else {
+                    width = self.bounds.width / CGFloat(categories.count)
+
+                    if i > 0 {
+                        x = width * CGFloat(i) + barStyle.offsetX
+                    }
                 }
             }
 

AHCategoryView/Classes/AHCategoryNavBarStyle.swift

@@ -8,9 +8,21 @@
 
 import UIKit
 
+public enum AHCategoryNavBarAlignment {
+    case left
+    case center
+}
+
 public struct AHCategoryNavBarStyle {
     public var height: CGFloat = 44.0
 
+    /// The x offset for the navBar in its superView
+    public var offsetX: CGFloat = 0.0
+
+    /// Laying out category items from left to right, or from center to both sides.
+    /// Note: This attribute only works with when isScrollabel=false.
+    public var layoutAlignment: AHCategoryNavBarAlignment = .left
+
     /// if set to true, all items will have equal spacing.
     public var isScrollabel = false
     public var fontSize: CGFloat = 15.0

Example/AHCategoryView/Base.lproj/Main.storyboard

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12120" systemVersion="16E195" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="vXZ-lx-hvc">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12120" systemVersion="16E195" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="q1P-tN-qDe">
     <device id="retina4_7" orientation="portrait">
         <adaptation id="fullscreen"/>
     </device>
@@ -22,9 +22,29 @@
                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
                         <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                     </view>
+                    <navigationItem key="navigationItem" id="i5a-3M-EQJ"/>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="x5A-6p-PRh" sceneMemberID="firstResponder"/>
             </objects>
+            <point key="canvasLocation" x="1076" y="138.98050974512745"/>
+        </scene>
+        <!--Navigation Controller-->
+        <scene sceneID="Nhb-nz-86g">
+            <objects>
+                <navigationController automaticallyAdjustsScrollViewInsets="NO" id="q1P-tN-qDe" sceneMemberID="viewController">
+                    <toolbarItems/>
+                    <navigationBar key="navigationBar" contentMode="scaleToFill" id="gjJ-zB-8cg">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="44"/>
+                        <autoresizingMask key="autoresizingMask"/>
+                    </navigationBar>
+                    <nil name="viewControllers"/>
+                    <connections>
+                        <segue destination="vXZ-lx-hvc" kind="relationship" relationship="rootViewController" id="PTU-4V-SCv"/>
+                    </connections>
+                </navigationController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="V2b-1r-aaW" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="244" y="-543.77811094452773"/>
         </scene>
     </scenes>
 </document>

Example/AHCategoryView/Images.xcassets/search-magnifier.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "[email protected]",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "[email protected]",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "[email protected]",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

Example/AHCategoryView/ViewController.swift

@@ -8,50 +8,66 @@
 
 import UIKit
 import AHCategoryView
+
+private let ScreenSize = UIScreen.main.bounds.size
+
 class ViewController: UIViewController {
-    let categoryTitles = ["Featured", "Charts"]
-    var categoryView: AHCategoryView!
+    let categoryTitles = ["Featured", "Charts","Charts","Charts","Charts"]
+    fileprivate weak var categoryView: AHCategoryView!
+    var childVCs = [UIViewController]()
+
     override func viewDidLoad() {
         super.viewDidLoad()
-        var childVCs = [UIViewController]()
-        // the extra 1 is for the first meItem
-        for _ in 0..<(categoryTitles.count) {
-            let vc = UIViewController()
-            vc.view.backgroundColor = UIColor.random()
-            childVCs.append(vc)
-        }
+        let searchBtn = UIButton(type: .custom)
+        let searchImg = UIImage(named: "search-magnifier")
+        searchBtn.setImage(searchImg, for: .normal)
+        searchBtn.sizeToFit()
+        self.navigationItem.rightBarButtonItem = UIBarButtonItem(customView: searchBtn)
 
-        var style = AHCategoryNavBarStyle()
-        style.isScrollabel = false
-        style.showIndicator = true
-        style.normalColor = UIColor(red: 0, green: 0, blue: 0, alpha: 1.0)
-        style.selectedColor = UIColor(red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)
-        style.showBgMaskView = false
 
-        // test custom maskView
-//        let customeMask = UIView()
-//        customeMask.backgroundColor = UIColor.yellow
-//        style.bgMaskView = customeMask
+        var meItem = AHCategoryItem()
+        meItem.normalImage = UIImage(named: "me-normal")
+        meItem.selectedImage = UIImage(named: "me-selected")
+
 
+        var featureItem = AHCategoryItem()
+        featureItem.title = "Feature"
+        var chartItem = AHCategoryItem()
+        chartItem.title = "Categories"
+        var radioItem = AHCategoryItem()
+        radioItem.title = "Radio"
+        var liveItem = AHCategoryItem()
+        liveItem.title = "Live"
 
-        style.showTransitionAnimation = true
-        let frame = CGRect(x: 0, y: 64, width: view.bounds.width, height: view.bounds.height - 64)
 
+        let items = [meItem, featureItem, chartItem]
 
-        var categoryItems = [AHCategoryItem]()
-        var meItem = AHCategoryItem()
-        meItem.normalImage = UIImage(named: "me-normal")
-        meItem.selectedImage = UIImage(named: "me-selected")
-//        categoryItems.append(meItem)
-        categoryTitles.forEach { (titel) in
-            var item = AHCategoryItem()
-            item.title = titel
-            categoryItems.append(item)
+
+        for _ in 0..<3 {
+            let vc = UIViewController()
+            vc.view.backgroundColor = UIColor.red
+            childVCs.append(vc)
         }
-        categoryView = AHCategoryView(frame: frame, categories: categoryItems, childVCs: childVCs, parentVC: self, barStyle: style)
 
-        view.addSubview(categoryView)
+        let frame = CGRect(x: 0, y: 64.0, width: ScreenSize.width, height: ScreenSize.height - 64.0)
+        var style = AHCategoryNavBarStyle()
+//        style.offsetX = -16.0
+        style.isScrollabel = false
+        style.layoutAlignment = .center
+        style.isEmbedded = false
+        style.showSeparators = false
+        style.indicatorColor = UIColor(red: 1, green: 0, blue: 0, alpha: 1.0)
+        style.normalColor = UIColor(red: 0, green: 0, blue: 0, alpha: 1.0)
+        style.selectedColor = UIColor(red: 1, green: 0, blue: 0, alpha: 1.0)
+        style.defaultCategoryIndex = 1
+        self.view.backgroundColor = UIColor.white
 
+        let categoryView = AHCategoryView(frame: frame, categories: items, childVCs: childVCs, parentVC: self, barStyle: style)
+        self.view.addSubview(categoryView)
+        self.categoryView = categoryView
+        categoryView.navBar.frame = CGRect(x: 0, y: 0, width: 359.0, height: 44.0)
+        self.navigationItem.titleView = categoryView.navBar
+        self.navigationController?.navigationBar.barTintColor = UIColor.white
     }