Implement the new Photo picker, part two.

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/PickerAdapter.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.photo_picker;
+
+import android.support.v7.widget.RecyclerView.Adapter;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.chromium.chrome.R;
+
+import java.util.List;
+
+/**
+ * A data adapter for the Photo Picker.
+ */
+public class PickerAdapter extends Adapter<ViewHolder> {
+    // The category view to use to show the images.
+    private PickerCategoryView mCategoryView;
+
+    /**
+     * The PickerAdapter constructor.
+     * @param categoryView The category view to use to show the images.
+     */
+    public PickerAdapter(PickerCategoryView categoryView) {
+        mCategoryView = categoryView;
+    }
+
+    // RecyclerView.Adapter:
+
+    @Override
+    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+        View itemView = LayoutInflater.from(parent.getContext())
+                                .inflate(R.layout.picker_bitmap_view, parent, false);
+        PickerBitmapView bitmapView = (PickerBitmapView) itemView;
+        bitmapView.setCategoryView(mCategoryView);
+        return new PickerBitmapViewHolder(bitmapView);
+    }
+
+    @Override
+    public void onBindViewHolder(ViewHolder holder, int position) {
+        onBindViewHolder(holder, position, null);
+    }
+
+    @Override
+    public void onBindViewHolder(ViewHolder holder, int position, List payloads) {

[Theresa, 2017/04/05 15:48:24]

Since payloads isn't used, can you move the contents of this to the other
2-param version of the method?

[Finnur, 2017/04/06 13:22:04]

Huh... interesting. I distinctly remember relying on this function override
explicitly (think it was for selection), but now I can do without it. Weird.
Anyway. Gone.

+        if (holder instanceof PickerBitmapViewHolder) {
+            PickerBitmapViewHolder myHolder = (PickerBitmapViewHolder) holder;
+            myHolder.displayItem(mCategoryView, position);
+        }
+    }
+
+    @Override
+    public int getItemCount() {
+        return mCategoryView.getPickerBitmaps().size();
+    }
+}