From 7957a2d8aaa4435eee184324cc4ecaefd7595374 Mon Sep 17 00:00:00 2001
From: gauthams <gauthams@google.com>
Date: Fri, 5 May 2017 16:17:27 -0700
Subject: [PATCH] Update shifting BottomNavigationView behavior to size active
 view width based on label size, rather than defaulting to maxWidth.

PiperOrigin-RevId: 155252923
---
 .../layout/design_bottom_navigation_item.xml  | 60 ++++++++++---------
 lib/res/values/dimens.xml                     |  1 +
 .../internal/BottomNavigationMenuView.java    | 18 +++++-
 3 files changed, 49 insertions(+), 30 deletions(-)

diff --git a/lib/res/layout/design_bottom_navigation_item.xml b/lib/res/layout/design_bottom_navigation_item.xml
index 4b73c09e1..345586619 100644
--- a/lib/res/layout/design_bottom_navigation_item.xml
+++ b/lib/res/layout/design_bottom_navigation_item.xml
@@ -15,35 +15,37 @@
   ~ limitations under the License.
   -->
 <merge xmlns:android="http://schemas.android.com/apk/res/android">
-    <ImageView
-        android:id="@+id/icon"
-        android:layout_width="24dp"
-        android:layout_height="24dp"
-        android:layout_gravity="center_horizontal"
-        android:layout_marginTop="@dimen/design_bottom_navigation_margin"
-        android:layout_marginBottom="@dimen/design_bottom_navigation_margin"
-        android:duplicateParentState="true" />
-    <android.support.design.internal.BaselineLayout
+  <ImageView
+      android:id="@+id/icon"
+      android:layout_width="24dp"
+      android:layout_height="24dp"
+      android:layout_marginTop="@dimen/design_bottom_navigation_margin"
+      android:layout_marginBottom="@dimen/design_bottom_navigation_margin"
+      android:layout_gravity="center_horizontal"
+      android:duplicateParentState="true"/>
+  <android.support.design.internal.BaselineLayout
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
+      android:layout_gravity="bottom|center_horizontal"
+      android:paddingBottom="10dp"
+      android:clipToPadding="false"
+      android:duplicateParentState="true">
+    <TextView
+        android:id="@+id/smallLabel"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_gravity="bottom|center_horizontal"
-        android:paddingBottom="10dp"
-        android:clipToPadding="false"
-        android:duplicateParentState="true">
-        <TextView
-            android:id="@+id/smallLabel"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:textSize="@dimen/design_bottom_navigation_text_size"
-            android:singleLine="true"
-            android:duplicateParentState="true" />
-        <TextView
-            android:id="@+id/largeLabel"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:visibility="invisible"
-            android:textSize="@dimen/design_bottom_navigation_active_text_size"
-            android:singleLine="true"
-            android:duplicateParentState="true" />
-    </android.support.design.internal.BaselineLayout>
+        android:duplicateParentState="true"
+        android:singleLine="true"
+        android:textSize="@dimen/design_bottom_navigation_text_size"/>
+    <TextView
+        android:id="@+id/largeLabel"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:paddingLeft="8dp"
+        android:paddingRight="8dp"
+        android:duplicateParentState="true"
+        android:singleLine="true"
+        android:textSize="@dimen/design_bottom_navigation_active_text_size"
+        android:visibility="invisible"/>
+  </android.support.design.internal.BaselineLayout>
 </merge>
diff --git a/lib/res/values/dimens.xml b/lib/res/values/dimens.xml
index de715ce8a..2343a7edd 100644
--- a/lib/res/values/dimens.xml
+++ b/lib/res/values/dimens.xml
@@ -67,5 +67,6 @@
     <dimen name="design_bottom_navigation_item_min_width">56dp</dimen>
     <dimen name="design_bottom_navigation_item_max_width">96dp</dimen>
     <dimen name="design_bottom_navigation_active_item_max_width">168dp</dimen>
+    <dimen name="design_bottom_navigation_active_item_min_width">96dp</dimen>
 
 </resources>
diff --git a/lib/src/android/support/design/internal/BottomNavigationMenuView.java b/lib/src/android/support/design/internal/BottomNavigationMenuView.java
index b0ebbba63..700432381 100644
--- a/lib/src/android/support/design/internal/BottomNavigationMenuView.java
+++ b/lib/src/android/support/design/internal/BottomNavigationMenuView.java
@@ -47,6 +47,7 @@ public class BottomNavigationMenuView extends ViewGroup implements MenuView {
   private final int mInactiveItemMaxWidth;
   private final int mInactiveItemMinWidth;
   private final int mActiveItemMaxWidth;
+  private final int mActiveItemMinWidth;
   private final int mItemHeight;
   private final OnClickListener mOnClickListener;
   private final Pools.Pool<BottomNavigationItemView> mItemPool = new Pools.SynchronizedPool<>(5);
@@ -77,6 +78,8 @@ public class BottomNavigationMenuView extends ViewGroup implements MenuView {
         res.getDimensionPixelSize(R.dimen.design_bottom_navigation_item_min_width);
     mActiveItemMaxWidth =
         res.getDimensionPixelSize(R.dimen.design_bottom_navigation_active_item_max_width);
+    mActiveItemMinWidth =
+        res.getDimensionPixelSize(R.dimen.design_bottom_navigation_active_item_min_width);
     mItemHeight = res.getDimensionPixelSize(R.dimen.design_bottom_navigation_height);
 
     mSet = new AutoTransition();
@@ -112,14 +115,27 @@ public class BottomNavigationMenuView extends ViewGroup implements MenuView {
     final int heightSpec = MeasureSpec.makeMeasureSpec(mItemHeight, MeasureSpec.EXACTLY);
 
     if (mShiftingMode) {
+      final View child = getChildAt(mSelectedItemPosition);
+      int activeItemWidth = mActiveItemMinWidth;
+      if (child.getVisibility() != View.GONE) {
+        // Do an AT_MOST measure pass on the active child to get its desired width, and resize the
+        // active child view based on that width
+        child.measure(
+            MeasureSpec.makeMeasureSpec(mActiveItemMaxWidth, MeasureSpec.AT_MOST), heightSpec);
+        activeItemWidth = Math.max(activeItemWidth, child.getMeasuredWidth());
+      }
       final int inactiveCount = count - 1;
       final int activeMaxAvailable = width - inactiveCount * mInactiveItemMinWidth;
-      final int activeWidth = Math.min(activeMaxAvailable, mActiveItemMaxWidth);
+      final int activeWidth =
+          Math.min(activeMaxAvailable, Math.min(activeItemWidth, mActiveItemMaxWidth));
       final int inactiveMaxAvailable = (width - activeWidth) / inactiveCount;
       final int inactiveWidth = Math.min(inactiveMaxAvailable, mInactiveItemMaxWidth);
       int extra = width - activeWidth - inactiveWidth * inactiveCount;
       for (int i = 0; i < count; i++) {
         mTempChildWidths[i] = (i == mSelectedItemPosition) ? activeWidth : inactiveWidth;
+        // Account for integer division which sometimes leaves some extra pixel spaces.
+        // e.g. If the nav was 10px wide, and 3 children were measured to be 3px-3px-3px, there
+        // would be a 1px gap somewhere, which this fills in.
         if (extra > 0) {
           mTempChildWidths[i]++;
           extra--;