Add history popup when long pressing on the back key.

chrome/android/java/src/org/chromium/chrome/browser/NavigationPopup.java

Index: chrome/android/java/src/org/chromium/chrome/browser/NavigationPopup.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/NavigationPopup.java b/chrome/android/java/src/org/chromium/chrome/browser/NavigationPopup.java
new file mode 100644
index 0000000000000000000000000000000000000000..ba955616515535e0b97a58f903db19307037da8b
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/NavigationPopup.java
@@ -0,0 +1,245 @@
+// Copyright (c) 2013 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;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import android.text.TextUtils;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.AdapterView;
+import android.widget.BaseAdapter;
+import android.widget.HeaderViewListAdapter;
+import android.widget.ListPopupWindow;
+import android.widget.ListView;
+import android.widget.ListView.FixedViewInfo;
+import android.widget.PopupWindow;
+import android.widget.TextView;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.R;
+import org.chromium.content.browser.ContentViewCore;
+import org.chromium.content.browser.NavigationClient;
+import org.chromium.content.browser.NavigationEntry;
+import org.chromium.content.browser.NavigationHistory;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * A popup that handles displaying the navigation history for a given tab.
+ */
+public class NavigationPopup extends ListPopupWindow implements AdapterView.OnItemClickListener {
+
+    private static final int LIST_ITEM_HEIGHT_DP = 48;
+    private static final int FAVICON_SIZE_DP = 16;
+    private static final int PADDING_DP = 8;
+    private static final int TEXT_SIZE_SP = 18;
+
+    private static final int MAXIMUM_HISTORY_ITEMS = 8;
+
+    private final Context mContext;
+    private final NavigationPopupDelegate mDelegate;
+    private final NavigationClient mNavigationClient;
+    private final NavigationHistory mHistory;
+    private final NavigationAdapter mAdapter;
+    private final TextView mShowHistoryView;
+
+    private final int mListItemHeight;
+    private final int mFaviconSize;
+    private final int mPadding;
+
+    private int mNativeNavigationPopup;
+
+    /**
+     * Delegate functionality required to operate on the history.
+     */
+    public interface NavigationPopupDelegate {
+        /** Open the complete browser history page */
+        void openHistory();
+    }
+
+    /**
+     * Constructs a new popup with the given history information.
+     *
+     * @param context The context used for building the popup.
+     * @param delegate The delegate that handles history actions outside of the given
+     *                 {@link ContentViewCore}.
+     * @param navigationClient The owner of the history being displayed.
+     * @param isForward Whether to request forward navigation entries.
+     */
+    public NavigationPopup(
+            Context context, NavigationPopupDelegate delegate,
+            NavigationClient navigationClient, boolean isForward) {
+        super(context, null, android.R.attr.popupMenuStyle);
+        mContext = context;
+        assert delegate != null : "NavigationPopup requires non-null delegate.";
+        mDelegate = delegate;
+        mNavigationClient = navigationClient;
+        mHistory = mNavigationClient.getDirectedNavigationHistory(
+                isForward, MAXIMUM_HISTORY_ITEMS);
+        mAdapter = new NavigationAdapter();
+
+        float density = mContext.getResources().getDisplayMetrics().density;
+        mListItemHeight = (int) (density * LIST_ITEM_HEIGHT_DP);
+        mFaviconSize = (int) (density * FAVICON_SIZE_DP);
+        mPadding = (int) (density * PADDING_DP);
+
+        setModal(true);
+        setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
+        setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
+        setOnItemClickListener(this);
+
+        FixedViewInfo footerInfo = new ListView(context).new FixedViewInfo();
+        mShowHistoryView = createListItem();
+        mShowHistoryView.setText(R.string.show_history_label);
+        footerInfo.isSelectable = true;
+        footerInfo.view = mShowHistoryView;
+        ArrayList<FixedViewInfo> footerInfoList = new ArrayList<FixedViewInfo>(1);
+        footerInfoList.add(footerInfo);
+        setAdapter(new HeaderViewListAdapter(null, footerInfoList, mAdapter));
+    }
+
+    /**
+     * @return The URL of the page for managing history.
+     */
+    public static String getHistoryUrl() {
+        return nativeGetHistoryUrl();
+    }
+
+    /**
+     * @return Whether a navigation popup is valid for the given page.
+     */
+    public boolean shouldBeShown() {
+        return mHistory.getEntryCount() > 0;
+    }
+
+    @Override
+    public void show() {
+        if (mNativeNavigationPopup == 0) initializeNative();
+        super.show();
+    }
+
+    @Override
+    public void dismiss() {
+        if (mNativeNavigationPopup != 0) {
+            nativeDestroy(mNativeNavigationPopup);
+            mNativeNavigationPopup = 0;
+        }
+        super.dismiss();
+    }
+
+    private void initializeNative() {
+        ThreadUtils.assertOnUiThread();
+        mNativeNavigationPopup = nativeInit();
+
+        Set<String> requestedUrls = new HashSet<String>();
+        for (int i = 0; i < mHistory.getEntryCount(); i++) {
+            NavigationEntry entry = mHistory.getEntryAtIndex(i);
+            if (entry.getFavicon() != null) continue;
+            String url = entry.getUrl();
+            if (!requestedUrls.contains(url)) {
+                nativeFetchFaviconForUrl(mNativeNavigationPopup, url);
+                requestedUrls.add(url);
+            }
+        }
+        nativeFetchFaviconForUrl(mNativeNavigationPopup, nativeGetHistoryUrl());
+    }
+
+    @CalledByNative
+    private void onFaviconUpdated(String url, Object favicon) {
+        for (int i = 0; i < mHistory.getEntryCount(); i++) {
+            NavigationEntry entry = mHistory.getEntryAtIndex(i);
+            if (TextUtils.equals(url, entry.getUrl())) entry.updateFavicon((Bitmap) favicon);
+        }
+        if (TextUtils.equals(url, nativeGetHistoryUrl())) {
+            updateBitmapForTextView(mShowHistoryView, (Bitmap) favicon);
+        }
+        mAdapter.notifyDataSetChanged();
+    }
+
+    @Override
+    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+        if (position == mHistory.getEntryCount()) {
+            mDelegate.openHistory();
+        } else {
+            NavigationEntry entry = (NavigationEntry) parent.getItemAtPosition(position);
+            mNavigationClient.goToNavigationIndex(entry.getIndex());
+        }
+        dismiss();
+    }
+
+    private TextView createListItem() {
+        TextView view = new TextView(mContext);
+        view.setSingleLine();
+        view.setTextSize(TEXT_SIZE_SP);
+        view.setMinimumHeight(mListItemHeight);
+        view.setGravity(Gravity.CENTER_VERTICAL);
+        view.setCompoundDrawablePadding(mPadding);
+        view.setPadding(mPadding, 0, mPadding, 0);
+        return view;
+    }
+
+    private void updateBitmapForTextView(TextView view, Bitmap bitmap) {
+        Drawable faviconDrawable = null;
+        if (bitmap != null) {
+            faviconDrawable = new BitmapDrawable(mContext.getResources(), bitmap);
+            ((BitmapDrawable) faviconDrawable).setGravity(Gravity.FILL);
+        } else {
+            faviconDrawable = new ColorDrawable(Color.TRANSPARENT);
+        }
+        faviconDrawable.setBounds(0, 0, mFaviconSize, mFaviconSize);
+        view.setCompoundDrawables(faviconDrawable, null, null, null);
+    }
+
+    private class NavigationAdapter extends BaseAdapter {
+        @Override
+        public int getCount() {
+            return mHistory.getEntryCount();
+        }
+
+        @Override
+        public Object getItem(int position) {
+            return mHistory.getEntryAtIndex(position);
+        }
+
+        @Override
+        public long getItemId(int position) {
+            return ((NavigationEntry) getItem(position)).getIndex();
+        }
+
+        @Override
+        public View getView(int position, View convertView, ViewGroup parent) {
+            TextView view;
+            if (convertView != null && convertView instanceof TextView) {
+                view = (TextView) convertView;
+            } else {
+                view = createListItem();
+            }
+            NavigationEntry entry = (NavigationEntry) getItem(position);
+
+            String entryText = entry.getTitle();
+            if (TextUtils.isEmpty(entryText)) entryText = entry.getVirtualUrl();
+            if (TextUtils.isEmpty(entryText)) entryText = entry.getUrl();
+            view.setText(entryText);
+            updateBitmapForTextView(view, entry.getFavicon());
+
+            return view;
+        }
+    }
+
+    private static native String nativeGetHistoryUrl();
+
+    private native int nativeInit();
+    private native void nativeDestroy(int nativeNavigationPopup);
+    private native void nativeFetchFaviconForUrl(int nativeNavigationPopup, String url);
+}