From 2d17e1d212ed88fdeca4b27bf04c17c56bd5dee1 Mon Sep 17 00:00:00 2001
From: Grace Kloba <klobag@google.com>
Date: Tue, 9 Mar 2010 10:55:04 -0800
Subject: [PATCH] Add an api to set WebView over scroll background.

If the WebView doesn't support zoom, or WebView does
not use wide viewport and horizontal is just fit,
don't do over scroll.

Fix http://b/issue?id=2498403
Fix http://b/issue?id=2497901
---
 api/current.xml                           | 24 +++++++++++++++++++++++
 core/java/android/webkit/WebSettings.java | 18 +++++++++++++++++
 core/java/android/webkit/WebView.java     | 11 +++++++----
 3 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/api/current.xml b/api/current.xml
index 21c1c184c96c3..ed3f69659123d 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -193450,6 +193450,17 @@
  visibility="public"
 >
 </method>
+<method name="getUseSystemOverscrollBackground"
+ return="boolean"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
 <method name="getUseWideViewPort"
  return="boolean"
  abstract="false"
@@ -194029,6 +194040,19 @@
 <parameter name="use" type="boolean">
 </parameter>
 </method>
+<method name="setUseSystemOverscrollBackground"
+ return="void"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="system" type="boolean">
+</parameter>
+</method>
 <method name="setUseWideViewPort"
  return="void"
  abstract="false"
diff --git a/core/java/android/webkit/WebSettings.java b/core/java/android/webkit/WebSettings.java
index 89814196f7100..fb15f788d781c 100644
--- a/core/java/android/webkit/WebSettings.java
+++ b/core/java/android/webkit/WebSettings.java
@@ -192,6 +192,7 @@ public class WebSettings {
     private boolean         mBuiltInZoomControls = false;
     private boolean         mAllowFileAccess = true;
     private boolean         mLoadWithOverviewMode = false;
+    private boolean         mUseSystemOverscrollBackground = false;
 
     // private WebSettings, not accessible by the host activity
     static private int      mDoubleTapToastCount = 3;
@@ -469,6 +470,23 @@ public class WebSettings {
         return mLoadWithOverviewMode;
     }
 
+    /**
+     * Set whether the WebView uses system background for over scroll
+     * background. If false, it will use the WebView's background. Default is
+     * false.
+     */
+    public void setUseSystemOverscrollBackground(boolean system) {
+        mUseSystemOverscrollBackground = system;
+    }
+
+    /**
+     * Returns true if this WebView uses system background instead of WebView
+     * background for over scroll background.
+     */
+    public boolean getUseSystemOverscrollBackground() {
+        return mUseSystemOverscrollBackground;
+    }
+
     /**
      * Store whether the WebView is saving form data.
      */
diff --git a/core/java/android/webkit/WebView.java b/core/java/android/webkit/WebView.java
index 655c4c5bb3ce0..6f6ee1d11c0b0 100644
--- a/core/java/android/webkit/WebView.java
+++ b/core/java/android/webkit/WebView.java
@@ -2305,9 +2305,11 @@ public class WebView extends AbsoluteLayout
             boolean clampedY) {
         mInOverScrollMode = false;
         int maxX = computeMaxScrollX();
-        if (Math.abs(mMinZoomScale - mMaxZoomScale) < 0.01f && maxX == 0) {
-            // do not over scroll x if the page can't be zoomed and it just fits
-            // the screen
+        if (maxX == 0 && (Math.abs(mMinZoomScale - mMaxZoomScale) < 0.01f)
+                || !getSettings().supportZoom()
+                || !getSettings().getUseWideViewPort()) {
+            // do not over scroll x if the page just fits the screen and it
+            // can't zoom or the view doesn't use wide viewport
             scrollX = pinLocX(scrollX);
         } else if (scrollX < 0 || scrollX > maxX) {
             mInOverScrollMode = true;
@@ -3112,7 +3114,8 @@ public class WebView extends AbsoluteLayout
         }
 
         int saveCount = canvas.save();
-        if (mInOverScrollMode) {
+        if (mInOverScrollMode
+                && getSettings().getUseSystemOverscrollBackground()) {
             if (mOverScrollBackground == null) {
                 mOverScrollBackground = new Paint();
                 Bitmap bm = BitmapFactory.decodeResource(