Do not update adapter again

library/build.gradle

@@ -19,6 +19,7 @@ android {
       proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
     }
   }
+  namespace 'com.ogaclejapan.smarttablayout'
 }
 
 dependencies {
@@ -27,13 +28,3 @@ dependencies {
   implementation deps.androidx.fragment.lib
 }
 
-license {
-
-  sourceSets {
-    main.java.srcDirs = android.sourceSets.main.java.srcDirs
-    main.resources.srcDirs = android.sourceSets.main.resources.srcDirs
-  }
-
-  excludes(["**/*.xml"])
-
-}

library/src/main/java/com/ogaclejapan/smarttablayout/SmartTabLayout2.java

@@ -89,10 +89,14 @@ public class SmartTabLayout2 extends HorizontalScrollView {
   private OnScrollChangeListener onScrollChangeListener;
   private TabProvider tabProvider;
   private InternalTabClickListener internalTabClickListener;
+  private InternalTabLongClickListener internalTabLongClickListener;
   private OnTabClickListener onTabClickListener;
+  private OnTabLongClickListener onTabLongClickListener;
   private boolean distributeEvenly;
   private int textAppearance;
 
+  private int childCountCache = 0;
+
   public SmartTabLayout2(Context context) {
     this(context, null);
   }
@@ -161,6 +165,7 @@ public SmartTabLayout2(Context context, AttributeSet attrs, int defStyle) {
     this.tabViewTextHorizontalPadding = textHorizontalPadding;
     this.tabViewTextMinWidth = textMinWidth;
     this.internalTabClickListener = clickable ? new InternalTabClickListener() : null;
+    this.internalTabLongClickListener = clickable ? new InternalTabLongClickListener() : null;
     this.distributeEvenly = distributeEvenly;
     this.textAppearance = textStyle;
 
@@ -193,15 +198,19 @@ protected void onScrollChanged(int l, int t, int oldl, int oldt) {
   @Override
   protected void onSizeChanged(int w, int h, int oldw, int oldh) {
     super.onSizeChanged(w, h, oldw, oldh);
-    if (tabStrip.isIndicatorAlwaysInCenter() && tabStrip.getChildCount() > 0) {
-      View firstTab = tabStrip.getChildAt(0);
-      View lastTab = tabStrip.getChildAt(tabStrip.getChildCount() - 1);
-      int start = (w - Utils.getMeasuredWidth(firstTab)) / 2 - Utils.getMarginStart(firstTab);
-      int end = (w - Utils.getMeasuredWidth(lastTab)) / 2 - Utils.getMarginEnd(lastTab);
-      tabStrip.setMinimumWidth(tabStrip.getMeasuredWidth());
-      ViewCompat.setPaddingRelative(this, start, getPaddingTop(), end, getPaddingBottom());
-      setClipToPadding(false);
-    }
+    adjustForIndicatorAlwaysInCenter(w, h);
+  }
+
+  private void adjustForIndicatorAlwaysInCenter(int w, int h) {
+      if (tabStrip.isIndicatorAlwaysInCenter() && tabStrip.getChildCount() > 0) {
+          View firstTab = tabStrip.getChildAt(0);
+          View lastTab = tabStrip.getChildAt(tabStrip.getChildCount() - 1);
+          int start = (w - Utils.getMeasuredWidth(firstTab)) / 2 - Utils.getMarginStart(firstTab);
+          int end = (w - Utils.getMeasuredWidth(lastTab)) / 2 - Utils.getMarginEnd(lastTab);
+          tabStrip.setMinimumWidth(tabStrip.getMeasuredWidth());
+          ViewCompat.setPaddingRelative(this, start, getPaddingTop(), end, getPaddingBottom());
+          setClipToPadding(false);
+      }
   }
 
   @Override
@@ -211,6 +220,10 @@ protected void onLayout(boolean changed, int l, int t, int r, int b) {
     if (changed && viewPager != null) {
       scrollToTab(viewPager.getCurrentItem(), 0);
     }
+    if (childCountCache != tabStrip.getChildCount()) {
+        adjustForIndicatorAlwaysInCenter(getMeasuredWidth(), getMeasuredHeight());
+    }
+    childCountCache = tabStrip.getChildCount();
   }
 
   /**
@@ -305,6 +318,10 @@ public void setOnTabClickListener(OnTabClickListener listener) {
     onTabClickListener = listener;
   }
 
+  public void setOnTabLongClickListener(OnTabLongClickListener listener) {
+      onTabLongClickListener = listener;
+  }
+
   /**
    * Set the custom layout to be inflated for the tab views.
    *
@@ -333,7 +350,9 @@ public void setViewPager(@NonNull ViewPager2 viewPager, @NonNull RecyclerView.Ad
     tabStrip.removeAllViews();
 
     this.viewPager = viewPager;
-    this.viewPager.setAdapter(adapter);
+    if (this.viewPager.getAdapter() != adapter){
+      this.viewPager.setAdapter(adapter);
+    }
     this.tabTitleProvider = titleProvider;
     if (viewPager != null && viewPager.getAdapter() != null) {
       viewPager.registerOnPageChangeCallback(new InternalViewPagerListener());
@@ -422,6 +441,9 @@ private void populateTabStrip() {
       if (internalTabClickListener != null) {
         tabView.setOnClickListener(internalTabClickListener);
       }
+      if (internalTabLongClickListener != null) {
+          tabView.setOnLongClickListener(internalTabLongClickListener);
+      }
 
       tabStrip.addView(tabView);
 
@@ -538,6 +560,19 @@ public interface OnTabClickListener {
     void onTabClicked(int position);
   }
 
+    /**
+     * Interface definition for a callback to be invoked when a tab is long clicked.
+     */
+    public interface OnTabLongClickListener {
+
+        /**
+         * Called when a tab is clicked.
+         *
+         * @param position tab's position
+         */
+        void onTabLongClicked(int position);
+    }
+
   /**
    * Create the custom tabs in the tab layout. Set with
    * {@link #setCustomTabView(SmartTabLayout2.TabProvider)}
@@ -650,4 +685,19 @@ public void onClick(View v) {
       }
     }
   }
+
+    private class InternalTabLongClickListener implements OnLongClickListener {
+        @Override
+        public boolean onLongClick(View v) {
+            for (int i = 0; i < tabStrip.getChildCount(); i++) {
+                if (v == tabStrip.getChildAt(i)) {
+                    if (onTabLongClickListener != null) {
+                        onTabLongClickListener.onTabLongClicked(i);
+                    }
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
 }

utils-v4/build.gradle

@@ -18,6 +18,7 @@ android {
       proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
     }
   }
+  namespace 'com.ogaclejapan.smarttablayout.utils'
 }
 
 dependencies {