cherry-picked bf4650ca39c9153e38c76280ceb5e9af48b67751 to froyo

According to GMail profile, almost half of WebView
init time is spent in creating the zoomControl which
is not used by them. So change to lazy initialize
the ZoomButtonControl which will be used by Browser.

Fix http://b/issue?id=2546481

diff --git a/core/java/android/webkit/WebView.java b/core/java/android/webkit/WebView.java
index f2aea1a..ff1a685 100644 (file)
--- a/core/java/android/webkit/WebView.java
+++ b/core/java/android/webkit/WebView.java
@@ -763,6 +763,8 @@ public class WebView extends AbsoluteLayout
     private ExtendedZoomControls mZoomControls;
     private Runnable mZoomControlRunnable;
 
+    // mZoomButtonsController will be lazy initialized in
+    // getZoomButtonsController() to get better performance.
     private ZoomButtonsController mZoomButtonsController;
 
     // These keep track of the center point of the zoom.  They are used to
@@ -844,18 +846,6 @@ public class WebView extends AbsoluteLayout
         mDatabase = WebViewDatabase.getInstance(context);
         mScroller = new OverScroller(context);
 
-        mZoomButtonsController = new ZoomButtonsController(this);
-        mZoomButtonsController.setOnZoomListener(mZoomListener);
-        // ZoomButtonsController positions the buttons at the bottom, but in
-        // the middle.  Change their layout parameters so they appear on the
-        // right.
-        View controls = mZoomButtonsController.getZoomControls();
-        ViewGroup.LayoutParams params = controls.getLayoutParams();
-        if (params instanceof FrameLayout.LayoutParams) {
-            FrameLayout.LayoutParams frameParams = (FrameLayout.LayoutParams)
-                    params;
-            frameParams.gravity = Gravity.RIGHT;
-        }
         updateMultiTouchSupport(context);
     }
 
@@ -875,15 +865,16 @@ public class WebView extends AbsoluteLayout
     private void updateZoomButtonsEnabled() {
         boolean canZoomIn = mActualScale < mMaxZoomScale;
         boolean canZoomOut = mActualScale > mMinZoomScale && !mInZoomOverview;
+        ZoomButtonsController controller = getZoomButtonsController();
         if (!canZoomIn && !canZoomOut) {
             // Hide the zoom in and out buttons, as well as the fit to page
             // button, if the page cannot zoom
-            mZoomButtonsController.getZoomControls().setVisibility(View.GONE);
+            controller.getZoomControls().setVisibility(View.GONE);
         } else {
             // Set each one individually, as a page may be able to zoom in
             // or out.
-            mZoomButtonsController.setZoomInEnabled(canZoomIn);
-            mZoomButtonsController.setZoomOutEnabled(canZoomOut);
+            controller.setZoomInEnabled(canZoomIn);
+            controller.setZoomOutEnabled(canZoomOut);
         }
     }
 
@@ -1760,7 +1751,7 @@ public class WebView extends AbsoluteLayout
         }
         clearTextEntry(false);
         if (getSettings().getBuiltInZoomControls()) {
-            mZoomButtonsController.setVisible(true);
+            getZoomButtonsController().setVisible(true);
         } else {
             mPrivateHandler.removeCallbacks(mZoomControlRunnable);
             mPrivateHandler.postDelayed(mZoomControlRunnable,
@@ -4072,7 +4063,7 @@ public class WebView extends AbsoluteLayout
                 // false for the first parameter
             }
         } else {
-            if (getSettings().getBuiltInZoomControls() && !mZoomButtonsController.isVisible()) {
+            if (getSettings().getBuiltInZoomControls() && !getZoomButtonsController().isVisible()) {
                 /*
                  * The zoom controls come in their own window, so our window
                  * loses focus. Our policy is to not draw the cursor ring if
@@ -5050,7 +5041,7 @@ public class WebView extends AbsoluteLayout
         WebSettings settings = getSettings();
         if (settings.supportZoom()
                 && settings.getBuiltInZoomControls()
-                && !mZoomButtonsController.isVisible()
+                && !getZoomButtonsController().isVisible()
                 && mMinZoomScale < mMaxZoomScale) {
             mZoomButtonsController.setVisible(true);
             int count = settings.getDoubleTapToastCount();
@@ -5593,6 +5584,19 @@ public class WebView extends AbsoluteLayout
      * @hide
      */
     public ZoomButtonsController getZoomButtonsController() {
+        if (mZoomButtonsController == null) {
+            mZoomButtonsController = new ZoomButtonsController(this);
+            mZoomButtonsController.setOnZoomListener(mZoomListener);
+            // ZoomButtonsController positions the buttons at the bottom, but in
+            // the middle. Change their layout parameters so they appear on the
+            // right.
+            View controls = mZoomButtonsController.getZoomControls();
+            ViewGroup.LayoutParams params = controls.getLayoutParams();
+            if (params instanceof FrameLayout.LayoutParams) {
+                FrameLayout.LayoutParams frameParams = (FrameLayout.LayoutParams) params;
+                frameParams.gravity = Gravity.RIGHT;
+            }
+        }
         return mZoomButtonsController;
     }
 
@@ -5832,7 +5836,9 @@ public class WebView extends AbsoluteLayout
         if (mWebViewCore == null) {
             // maybe called after WebView's destroy(). As we can't get settings,
             // just hide zoom control for both styles.
-            mZoomButtonsController.setVisible(false);
+            if (mZoomButtonsController != null) {
+                mZoomButtonsController.setVisible(false);
+            }
             if (mZoomControls != null) {
                 mZoomControls.hide();
             }
@@ -5840,7 +5846,7 @@ public class WebView extends AbsoluteLayout
         }
         WebSettings settings = getSettings();
         if (settings.getBuiltInZoomControls()) {
-            if (mZoomButtonsController.isVisible()) {
+            if (getZoomButtonsController().isVisible()) {
                 mZoomButtonsController.setVisible(false);
             }
         } else {