UI revision for tabbed browsing
     bug # http://b/issue?id=2712871

     separated tab bar from url bar
     subclassed webview for scroll listener
     added search button support

Change-Id: Ib9bd0c7e815e2ef08cdd20334daf61263cd52938
diff --git a/src/com/android/browser/ScrollWebView.java b/src/com/android/browser/ScrollWebView.java
new file mode 100644
index 0000000..16404aa
--- /dev/null
+++ b/src/com/android/browser/ScrollWebView.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.browser;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.webkit.WebView;
+
+import java.util.Map;
+
+/**
+ *  Manage WebView scroll events
+ */
+public class ScrollWebView extends WebView {
+
+    private ScrollListener mScrollListener;
+    private boolean mIsCancelled;
+    private Runnable mScrollRunnable;
+
+    /**
+     * @param context
+     * @param attrs
+     * @param defStyle
+     * @param javascriptInterfaces
+     */
+    public ScrollWebView(Context context, AttributeSet attrs, int defStyle,
+            Map<String, Object> javascriptInterfaces, boolean privateBrowsing) {
+        super(context, attrs, defStyle, javascriptInterfaces, privateBrowsing);
+    }
+
+    /**
+     * @param context
+     * @param attrs
+     * @param defStyle
+     */
+    public ScrollWebView(Context context, AttributeSet attrs, int defStyle,
+            boolean privateBrowsing) {
+        super(context, attrs, defStyle, privateBrowsing);
+    }
+
+    /**
+     * @param context
+     * @param attrs
+     */
+    public ScrollWebView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    /**
+     * @param context
+     */
+    public ScrollWebView(Context context) {
+        super(context);
+    }
+
+    @Override
+    public void setEmbeddedTitleBar(final View title) {
+        super.setEmbeddedTitleBar(title);
+        if (title != null && mScrollListener != null) {
+            // allow the scroll listener to initialize its state
+            post(new Runnable() {
+                @Override
+                public void run() {
+                    mScrollListener.onScroll((title.getHeight() == 0 ||
+                            getVisibleTitleHeight() > 0));
+                }
+            });
+        }
+    }
+
+    @Override
+    public void stopScroll() {
+        mIsCancelled = true;
+        super.stopScroll();
+    }
+
+    @Override
+    protected void onScrollChanged(int l, final int t, int ol, int ot) {
+        super.onScrollChanged(l, t, ol, ot);
+        if (!mIsCancelled) {
+            post(mScrollRunnable);
+        } else {
+            mIsCancelled = false;
+        }
+    }
+
+    void setScrollListener(ScrollListener l) {
+        mScrollListener = l;
+        if (mScrollListener != null) {
+            mScrollRunnable = new Runnable() {
+                public void run() {
+                    if (!mIsCancelled) {
+                        mScrollListener.onScroll(getVisibleTitleHeight() > 0);
+                    }
+                }
+            };
+        }
+    }
+
+    // callback for scroll events
+
+    interface ScrollListener {
+        public void onScroll(boolean titleVisible);
+    }
+
+}