[Android History] List item shadows and width constrained styling

chrome/android/java/src/org/chromium/chrome/browser/history/HistoryItemView.java

Index: chrome/android/java/src/org/chromium/chrome/browser/history/HistoryItemView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/history/HistoryItemView.java b/chrome/android/java/src/org/chromium/chrome/browser/history/HistoryItemView.java
index bccddaa565b56bd880473635e32cbe44c78cc218..aed4cf4c9e12af1144e8bbf9c157c324d7ec1a7b 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/history/HistoryItemView.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/history/HistoryItemView.java
@@ -21,6 +21,7 @@ import org.chromium.chrome.browser.favicon.LargeIconBridge.LargeIconCallback;
 import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.widget.RoundedIconGenerator;
 import org.chromium.chrome.browser.widget.TintedImageButton;
+import org.chromium.chrome.browser.widget.displaystyle.MarginResizer;
 import org.chromium.chrome.browser.widget.selection.SelectableItemView;
 
 /**
@@ -97,6 +98,9 @@ public class HistoryItemView extends SelectableItemView<HistoryItem> implements
             mTitle.setTextColor(
                     ApiCompatibilityUtils.getColor(getResources(), R.color.default_text_color));
         }
+
+        setBackgroundResource(
+                selectBackgroundResource(item.isLastInGroup(), item.isFirstInGroup()));
     }
 
     /**
@@ -108,6 +112,10 @@ public class HistoryItemView extends SelectableItemView<HistoryItem> implements
 
         mHistoryManager = manager;
         if (!getItem().wasBlockedVisit()) requestIcon();
+
+        MarginResizer.createWithViewAdapter(this,
+                mHistoryManager.getSelectableListLayout().getUiConfig(),
+                mHistoryManager.getDefaultLateralListItemMarginPx(), 0);
     }
 
     /**
@@ -168,4 +176,12 @@ public class HistoryItemView extends SelectableItemView<HistoryItem> implements
                 !PrefServiceBridge.getInstance().canDeleteBrowsingHistory() ? View.GONE :
                     mRemoveButtonVisible ? View.VISIBLE : View.INVISIBLE);
     }
+
+    private int selectBackgroundResource(boolean isLastInGroup, boolean isFirstInGroup) {

[Theresa, 2017/01/27 00:57:35]

The background needs to be reselected when other items in the group are removed
so that the top/bottom shadows for the group are displayed correctly.

[Theresa, 2017/01/27 23:34:45]

Done.

+        if (!isLastInGroup && !isFirstInGroup) return R.drawable.list_item_middle;

[gone, 2017/01/27 18:48:52]

might be clearer to just structure it as 

if (blah)
    return thing here
else if (blah2)
    return other thing
else if (blah3)
    return that other thing
else
    return what

alternatively

if (!isLastInGroup) {
    return isFirstInGroup ? R.drawable.list_item_middle :
R.drawable.list_item_top;
} else {
    return isFirstInGroup ? R.drawable.list_item.single :
R.drawable.list_item_bottom;
}

don't know what's cleanest

[Theresa, 2017/01/27 23:34:45]

Done.

+        if (!isLastInGroup && isFirstInGroup) return R.drawable.list_item_top;
+        if (isLastInGroup && !isFirstInGroup) return R.drawable.list_item_bottom;
+
+        return R.drawable.list_item_single;
+    }
 }