Added a UI for the Interests Prototype.

chrome/android/java/src/org/chromium/chrome/browser/ntp/InterestsItemView.java

+// Copyright 2015 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.ntp;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.content.res.TypedArray;
+import android.graphics.Color;
+import android.graphics.Rect;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
+import android.os.AsyncTask;
+import android.support.v4.graphics.drawable.RoundedBitmapDrawable;
+import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory;
+import android.support.v7.widget.AppCompatTextView;
+import android.text.TextUtils;
+import android.util.LruCache;
+import android.util.TypedValue;
+import android.view.Gravity;
+import android.view.View;
+import android.view.View.OnClickListener;
+
+import org.chromium.base.Log;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ntp.InterestsPage.InterestsClickListener;
+import org.chromium.chrome.browser.ntp.InterestsService.Interest;
+import org.chromium.chrome.browser.widget.RoundedIconGenerator;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+
+/**
+ * Displays the interest name along with an image of it. This item can be clicked.
+ */
+class InterestsItemView extends AppCompatTextView implements OnClickListener {
+
+    private static final String TAG = "interests_item_view";

[knn, 2015/12/02 14:18:59]

CamelCase

[PEConn, 2015/12/08 17:27:49]

Done.

+
+    /**
+     * Drawing-related values that can be shared between instances of InterestsItemView.
+     */
+    static final class DrawingData {
+
+        private final int mPadding;
+        private final int mMinHeight;
+        private final int mImageSize;
+        private final int mTextSize;
+        private final int mImageTextSize;
+
+        /**
+         * Initialize shared values used for drawing the image.
+         *
+         * @param context The view context in which the InterestsItemView will be drawn.
+         */
+        DrawingData(Context context) {
+            Resources res = context.getResources();
+            mPadding = res.getDimensionPixelOffset(R.dimen.ntp_list_item_padding);
+            mMinHeight = res.getDimensionPixelSize(R.dimen.ntp_interest_item_min_height);
+            mTextSize = res.getDimensionPixelSize(R.dimen.ntp_interest_item_text_size);
+            mImageSize = res.getDimensionPixelSize(R.dimen.ntp_interest_item_image_size);
+            mImageTextSize = res.getDimensionPixelSize(R.dimen.ntp_interest_item_image_text_size);
+        }
+    }
+
+    private Interest mInterest;
+    private DownloadImageTask mDownloadTask;
+
+    private final Context mContext;
+    private final DrawingData mDrawingData;
+    private final LruCache<String, Drawable> mImageCache;
+    private final InterestsClickListener mListener;
+    private final RoundedIconGenerator mIconGenerator;
+
+    /**
+     * @param context The view context in which this item will be shown.
+     * @param interest The interest to display.
+     * @param listener Callback object for when a view is pressed.
+     * @param imageCache A cache to store downloaded images.
+     * @param drawingData Information about the view size.
+     */
+    InterestsItemView(Context context, Interest interest, InterestsClickListener listener,
+            LruCache<String, Drawable> imageCache, DrawingData drawingData) {
+        super(context);
+
+        mContext = context;
+        mListener = listener;
+        mImageCache = imageCache;
+        mDrawingData = drawingData;
+
+        setTextSize(TypedValue.COMPLEX_UNIT_PX, mDrawingData.mTextSize);
+        setMinimumHeight(mDrawingData.mMinHeight);
+        setGravity(Gravity.CENTER);
+        setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
+
+        mIconGenerator = new RoundedIconGenerator(
+                mDrawingData.mImageSize,
+                mDrawingData.mImageSize,
+                mDrawingData.mImageSize / 2,
+                Color.GRAY,
+                mDrawingData.mImageTextSize);
+
+        setOnClickListener(this);
+
+        reset(interest);
+    }
+
+    /**
+     * Resets the view contents so that it can be reused in the grid view.
+     *
+     * @param interest The interest to display.
+     */
+    public void reset(Interest interest) {
+        // Reset Drawable state so ripples don't continue when the View is reused.
+        jumpDrawablesToCurrentState();
+
+        // Exit early if this View is already displaying the Interest given.
+        if (mInterest != null
+                && TextUtils.equals(interest.getName(), mInterest.getName())
+                && TextUtils.equals(interest.getImageUrl(), mInterest.getImageUrl())) {
+            mInterest = interest;
+            return;
+        }
+
+        mInterest = interest;
+
+        setText(mInterest.getName());
+
+        Drawable image = mImageCache.get(mInterest.getImageUrl());
+        if (image == null) {
+            // Cache miss, download the image and use a temporary in the meantime.

[Bernhard Bauer, 2015/12/02 14:09:47]

Hm... if we are called for the same interest several times in a row, we will
start multiple downloads. Could we collapse those somehow?

[Bernhard Bauer, 2015/12/02 14:10:39]

(I suspect this will eventually boil down to something equivalent to promises. I
really wonder why we don't have that yet...)

[PEConn, 2015/12/08 17:27:49]

Done.

+            mDownloadTask = new DownloadImageTask(mInterest.getImageUrl());
+            mDownloadTask.execute();
+
+            mIconGenerator.setBackgroundColor(getTileColor(mInterest.getName()));
+            image = new BitmapDrawable(mContext.getResources(),
+                                       mIconGenerator.generateIconForText(mInterest.getName()));
+        }
+        setImage(image);
+    }
+
+    /**
+     * @return The image URL for the interest.
+     */
+    public String getImageUrl() {
+        return mInterest.getImageUrl();
+    }
+
+    /**
+     * @return The name of the interest.
+     */
+    public String getName() {
+        return mInterest.getName();
+    }
+
+    private void setImage(Drawable image) {
+        image.setBounds(new Rect(0, 0, mDrawingData.mImageSize, mDrawingData.mImageSize));
+        setCompoundDrawables(null, image, null, null);
+    }
+
+    private int getTileColor(String str) {
+        // Rough copy of LetterTileDrawable.pickColor.
+        // TODO(peconn): Move this to a more general class.
+        TypedArray colors = mContext.getResources().obtainTypedArray(R.array.letter_tile_colors);
+        return colors.getColor(Math.abs(str.hashCode() % colors.length()), Color.DKGRAY);
+    }
+
+    @Override
+    public void onClick(View v) {
+        mListener.onInterestClicked(getName());
+    }
+
+    private void onImageDownloaded(Drawable image, String url) {
+        if (image == null) {
+            return;
+        }
+
+        mImageCache.put(url, image);
+
+        // If the Interest this View is displaying has changed while downloading, do not update
+        // the image.
+        if (url == mInterest.getImageUrl()) {
+            setImage(image);
+        }
+    }
+
+    private class DownloadImageTask extends AsyncTask<Void, Void, Drawable> {
+
+        private final String mUrl;
+
+        public DownloadImageTask(String url) {
+            mUrl = url;
+        }
+
+        @Override
+        protected Drawable doInBackground(Void... voids) {
+            // This is run on a background thread.
+            try {
+                // TODO(peconn): Replace this with something from the C++ Chrome stack.
+                URL imageUrl = new URL(mUrl);
+                InputStream in = imageUrl.openStream();
+                RoundedBitmapDrawable img =
+                        RoundedBitmapDrawableFactory.create(getResources(), in);
+
+                // TODO(peconn): Modify image so it does not get stretched.
+                img.setCircular(true);
+                return img;
+            } catch (IOException e) {
+                Log.e(TAG, "Error downloading image: " + e.toString());
+            }
+            return null;
+        }
+
+        @Override
+        protected void onPostExecute(Drawable image) {
+            // This is run on the main thread.
+            onImageDownloaded(image, mUrl);
+        }
+    }
+}