Add the 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.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.util.Log;
+import android.util.LruCache;
+import android.util.TypedValue;
+import android.view.Gravity;
+import android.view.View;
+import android.view.View.OnClickListener;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ntp.InterestsPage.InterestsListener;
+import org.chromium.chrome.browser.widget.RoundedIconGenerator;
+
+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 {
+
+    /**
+     * 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 String mName;
+    private String mImageUrl;
+    private LruCache<String, Drawable> mImageCache;
+    private Context mContext;
+    private RoundedIconGenerator mIconGenerator;
+    private DrawingData mDrawingData;
+    private InterestsListener mListener;
+    private DownloadImage mDownloadTask = null;

[Marc Treib, 2015/09/18 13:26:03]

Why is (only) this one explicitly initialized to null?

[tache, 2015/09/21 15:35:54]

Done.

+
+    /**
+     * @param context The view context in which this item will be shown.
+     * @param name The name of the interest.
+     * @param imageUrl The URL for the interet's image.
+     * @param imageCache A cache to store downloaded images.
+     */
+    InterestsItemView(Context context, String name, String imageUrl,
+            InterestsListener listener,
+            LruCache<String, Drawable> imageCache) {

[Marc Treib, 2015/09/18 13:26:03]

Weird line breaks?

[tache, 2015/09/21 15:35:55]

Done.

+        super(context);
+
+        mContext = context;
+        mListener = listener;
+        mImageCache = imageCache;
+        mDrawingData = new DrawingData(mContext);

[Marc Treib, 2015/09/18 13:26:03]

Wait, when you use it like this, then nothing is actually shared, right?

[tache, 2015/09/21 15:35:54]

Now it shared in the InterestPageView and past to the item via the constructor.

+
+        mIconGenerator = new RoundedIconGenerator(
+                mDrawingData.mImageSize,
+                mDrawingData.mImageSize,
+                mDrawingData.mImageSize / 2,
+                Color.GRAY,
+                mDrawingData.mImageTextSize);
+
+        setTextSize(TypedValue.COMPLEX_UNIT_PX, mDrawingData.mTextSize);
+        setMinimumHeight(mDrawingData.mMinHeight);
+        setGravity(Gravity.CENTER);
+        setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
+
+        setOnClickListener(this);
+
+        reset(name, imageUrl);
+    }
+
+    /**
+     * Resets the view contents so that it can be reused in the list view.
+     *
+     * @param name The title of the page.
+     * @param imageUrl The URL of the page.
+     */

[Marc Treib, 2015/09/18 13:26:03]

Add @return please

[tache, 2015/09/21 15:35:54]

Removed the return value, since it was not used anywhere.

+    public boolean reset(String name, String imageUrl) {
+        // If there is an active download task for this view then it shouldn't update
+        // the view when it finishes.
+        if (mDownloadTask != null) {
+            mDownloadTask.setShouldUpdateView(false);
+            mDownloadTask = null;
+        }
+        // Reset drawable state so ripples don't continue when the view is reused.
+        jumpDrawablesToCurrentState();
+
+        if (mName != null && mName.equals(name) && mImageUrl != null
+                && mImageUrl.equals(imageUrl)) {
+            return false;
+        }
+
+        mName = name;
+        setText(mName);
+
+        mImageUrl = imageUrl;
+        Drawable image = mImageCache.get(mImageUrl);
+
+        if (image == null) {
+            // cache miss need to download the image and use a temporary image in the meantime.

[Marc Treib, 2015/09/18 13:26:03]

nit: Capitalize "Cache", also add a comma after "miss".

[tache, 2015/09/21 15:35:55]

Done.

+            mDownloadTask = new DownloadImage(this, mImageCache);
+            mDownloadTask.execute(mImageUrl);
+
+            image = new BitmapDrawable(
+                    mContext.getResources(),
+                    mIconGenerator.generateIconForText(mName));
+
+        }
+
+        setImage(image);
+
+        return true;
+    }
+
+    /**
+     * @return The image url for the interest.
+     */
+    public String getImageUrl() {
+        return mImageUrl;
+    }
+
+    /**
+     * @return The name of the interest.
+     */
+    public String getName() {
+        return mName;
+    }
+
+    /**
+     * Updates the image and triggers a redraw with the new image.
+     *
+     * @param image The new image to display. May be null.
+     */
+    public void setImage(Drawable image) {
+        if (image == null) {
+            return;
+        }
+
+        setImageBounds(image);
+
+        this.setCompoundDrawables(null, image, null, null);
+    }
+
+    private void setImageBounds(Drawable image) {
+        image.setBounds(new Rect(
+                0, 0, mDrawingData.mImageSize, mDrawingData.mImageSize));
+    }
+
+    @Override
+    public void onClick(View v) {
+        mListener.onInterestClicked(getName());
+    }
+
+    private class DownloadImage extends AsyncTask<String, Integer, Drawable> {

[Marc Treib, 2015/09/18 13:26:03]

DownloadImageTask?

[tache, 2015/09/21 15:35:55]

Done.

+
+        private InterestsItemView mView;
+        private LruCache<String, Drawable> mCache;
+        private String mUrl;
+        private boolean mShouldUpdateView;
+
+        public DownloadImage(InterestsItemView view, LruCache<String, Drawable> cache) {
+            mView = view;
+            mCache = cache;
+            mShouldUpdateView = true;
+        }
+
+        public void setShouldUpdateView(boolean shouldUpdateView) {
+            mShouldUpdateView = shouldUpdateView;
+        }
+
+        @Override
+        protected Drawable doInBackground(String... arg0) {
+            // This is done in a background thread
+            mUrl = arg0[0];
+            return downloadImage(mUrl);
+        }
+
+        /**
+         * Called after the image has been downloaded. This runs on the main thread.
+         */
+        protected void onPostExecute(Drawable image) {

[Marc Treib, 2015/09/18 13:26:03]

Should this have @Override?

[tache, 2015/09/21 15:35:55]

Done.

+            if (image != null) {
+                mCache.put(mUrl, image);
+
+                if (mShouldUpdateView) {
+                    mView.setImage(image);
+                }
+            }
+        }
+
+        private Drawable downloadImage(String url) {
+            URL imageUrl;
+            InputStream in;
+
+            try {
+                imageUrl = new URL(url);
+                in = imageUrl.openStream();
+
+                return getRoundedImage(in);
+            } catch (Exception e) {

[Marc Treib, 2015/09/18 13:26:03]

Be more specific than just "Exception" please.

[tache, 2015/09/21 15:35:54]

Done.

+                Log.e("Error downloading image: ", e.toString());
+            }
+            return null;
+        }
+
+        private Drawable getRoundedImage(InputStream in) {
+            RoundedBitmapDrawable img = RoundedBitmapDrawableFactory.create(getResources(), in);
+
+            img.setCircular(true);
+
+            return img;
+        }
+    }
+}