From c5a824ac89af99017b95b0806b700f0428e198e3 Mon Sep 17 00:00:00 2001
From: Alex Ning <chineseperson5@gmail.com>
Date: Thu, 29 Aug 2019 13:22:27 +0800
Subject: Set item offset in Postfragment when using
 StaggeredGridLayoutManager. Minor UI tweaks.

---
 .../infinityforreddit/PostFragment.java            | 37 +++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

(limited to 'app/src/main/java/ml')

diff --git a/app/src/main/java/ml/docilealligator/infinityforreddit/PostFragment.java b/app/src/main/java/ml/docilealligator/infinityforreddit/PostFragment.java
index 86900902..23b24de2 100644
--- a/app/src/main/java/ml/docilealligator/infinityforreddit/PostFragment.java
+++ b/app/src/main/java/ml/docilealligator/infinityforreddit/PostFragment.java
@@ -7,11 +7,11 @@ import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.res.Configuration;
 import android.content.res.Resources;
+import android.graphics.Rect;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.CountDownTimer;
 import android.os.Handler;
-import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -22,6 +22,7 @@ import android.widget.LinearLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.DimenRes;
 import androidx.annotation.NonNull;
 import androidx.coordinatorlayout.widget.CoordinatorLayout;
 import androidx.fragment.app.Fragment;
@@ -159,6 +160,9 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
         } else {
             mStaggeredGridLayoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
             mPostRecyclerView.setLayoutManager(mStaggeredGridLayoutManager);
+            StaggeredGridLayoutManagerItemOffsetDecoration itemDecoration =
+                    new StaggeredGridLayoutManagerItemOffsetDecoration(activity, R.dimen.staggeredLayoutManagerItemOffset);
+            mPostRecyclerView.addItemDecoration(itemDecoration);
         }
 
         mGlide = Glide.with(activity);
@@ -583,4 +587,35 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
             currentPosition = -1;
         }
     }
+
+    private static class StaggeredGridLayoutManagerItemOffsetDecoration extends RecyclerView.ItemDecoration {
+
+        private int mItemOffset;
+
+        StaggeredGridLayoutManagerItemOffsetDecoration(int itemOffset) {
+            mItemOffset = itemOffset;
+        }
+
+        StaggeredGridLayoutManagerItemOffsetDecoration(@NonNull Context context, @DimenRes int itemOffsetId) {
+            this(context.getResources().getDimensionPixelSize(itemOffsetId));
+        }
+
+        @Override
+        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent,
+                                   @NonNull RecyclerView.State state) {
+            super.getItemOffsets(outRect, view, parent, state);
+
+            StaggeredGridLayoutManager.LayoutParams layoutParams = (StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams();
+
+            int spanIndex = layoutParams.getSpanIndex();
+
+            int halfOffset = mItemOffset / 2;
+
+            if(spanIndex == 0) {
+                outRect.set(0, 0, halfOffset, 0);
+            } else {
+                outRect.set(halfOffset, 0, 0, 0);
+            }
+        }
+    }
 }
\ No newline at end of file
-- 
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