🏡 Show correct BottomSheetContent toolbar when contents swapped

chrome/android/java/src/org/chromium/chrome/browser/widget/BottomSheetContentController.java

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.widget;
 
 import android.content.Context;
 import android.content.res.Resources;
 import android.support.design.internal.BottomNavigationItemView;
 import android.support.design.internal.BottomNavigationMenuView;
@@ skipping 21 matching lines @@
 /**
  * Displays and controls a {@link BottomNavigationView} fixed to the bottom of the
  * {@link BottomSheet}. Also manages {@link BottomSheetContent} displayed in the BottomSheet.
  */
 public class BottomSheetContentController extends BottomNavigationView
         implements BottomSheetObserver, OnNavigationItemSelectedListener {
     private BottomSheet mBottomSheet;
     private TabModelSelector mTabModelSelector;
     private float mDistanceBelowToolbarPx;
     private int mSelectedItemId;
+    private boolean mDefaultContentInitialized;
 
     private final Map<Integer, BottomSheetContent> mBottomSheetContents = new HashMap<>();
 
     public BottomSheetContentController(Context context, AttributeSet atts) {
         super(context, atts);
     }
 
     /**
      * Initializes the {@link BottomSheetContentController}.
      * @param bottomSheet The {@link BottomSheet} associated with this bottom nav.
@@ skipping 11 matching lines @@
                 + res.getDimensionPixelOffset(R.dimen.bottom_nav_space_from_toolbar);
 
         setOnNavigationItemSelectedListener(this);
         disableShiftingMode();
     }
 
     /**
      * Initialize the default {@link BottomSheetContent}.
      */
     public void initializeDefaultContent() {
-        mBottomSheet.showContent(getSheetContentForId(R.id.action_home));
-        mSelectedItemId = R.id.action_home;
+        if (mDefaultContentInitialized) return;
+        showBottomSheetContent(R.id.action_home);
+        mDefaultContentInitialized = true;
     }
 
     @Override
     public boolean onNavigationItemSelected(MenuItem item) {
         if (mSelectedItemId == item.getItemId()) return false;
 
         showBottomSheetContent(item.getItemId());
         return true;
     }
 
     @Override
     public void onTransitionPeekToHalf(float transitionFraction) {
         float offsetY = (mBottomSheet.getMinOffset() - mBottomSheet.getSheetOffsetFromBottom())
                 + mDistanceBelowToolbarPx;
         setTranslationY((int) Math.max(offsetY, 0f));
         setVisibility(MathUtils.areFloatsEqual(transitionFraction, 0f) ? View.GONE : View.VISIBLE);
     }
 
     @Override
-    public void onSheetOpened() {}
+    public void onSheetOpened() {

[Theresa, 2017/03/14 17:12:33]

A note for myself -- mTabModelSelector.getCurrentTab() can return null if the
sheet is opened before the first tab is created -- if that's the case we should
return early rather than trying to initialize the default content to avoid
crashing.

[Theresa, 2017/03/14 20:40:02]

Done.

+        if (!mDefaultContentInitialized) initializeDefaultContent();
+    }
 
     @Override
     public void onSheetClosed() {
         Iterator<Entry<Integer, BottomSheetContent>> contentIterator =
                 mBottomSheetContents.entrySet().iterator();
         while (contentIterator.hasNext()) {
             Entry<Integer, BottomSheetContent> entry = contentIterator.next();
             if (entry.getKey() == R.id.action_home) continue;
 
             entry.getValue().destroy();
@@ skipping 57 matching lines @@
         // There are some bugs related to programatically selecting menu items that are fixed in
         // newer support library versions.
         // TODO(twellington): remove this after the support library is rolled.
         if (mSelectedItemId != 0) getMenu().findItem(mSelectedItemId).setChecked(false);
         mSelectedItemId = navItemId;
         getMenu().findItem(mSelectedItemId).setChecked(true);
 
         mBottomSheet.showContent(getSheetContentForId(mSelectedItemId));
     }
 }