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Commit 8496ddc5 authored by Huahui Wu's avatar Huahui Wu Committed by Android (Google) Code Review
Browse files

Merge "b/3307761 Tuning two fingers pan." into honeycomb-mr1

parents 39184a08 463cc0c5

core/java/android/webkit/ZoomManager.java

+49 −1
Original line number Diff line number Diff line
@@ -16,6 +16,9 @@ 


package android.webkit;



import java.util.LinkedList;

import java.util.Queue;



import android.content.Context;

import android.content.pm.PackageManager;

import android.graphics.Canvas;
@@ -23,6 +26,7 @@ import android.graphics.Point; 
import android.graphics.Rect;

import android.os.Bundle;

import android.os.SystemClock;

import android.util.FloatMath;

import android.util.Log;

import android.view.ScaleGestureDetector;

import android.view.View;
@@ -111,6 +115,24 @@ class ZoomManager { 
    private float mZoomCenterX;

    private float mZoomCenterY;



    /*

     * Similar to mZoomCenterX(Y), these track the focus point of the scale

     * gesture. The difference is these get updated every time when onScale is

     * invoked no matter if a zooming really happens.

     */

    private float mFocusX;

    private float mFocusY;



    /*

     * mFocusMovement keeps track of the total movement that the focus point

     * has been through. Comparing to the difference of mCurrlen and mPrevLen,

     * it determines if the gesture is for panning or zooming or both.

     */

    private static final int FOCUS_QUEUE_SIZE = 5;

    private float mFocusMovementSum;

    private Queue<Float> mFocusMovementQueue;





    /*

     * These values represent the point around which the screen should be

     * centered after zooming. In other words it is used to determine the center
@@ -196,6 +218,8 @@ class ZoomManager { 
         * viewport size is.

         */

        setZoomOverviewWidth(WebView.DEFAULT_VIEWPORT_WIDTH);



        mFocusMovementQueue = new LinkedList<Float>();

    }



    /**
@@ -715,10 +739,11 @@ class ZoomManager { 
    }



    private class ScaleDetectorListener implements ScaleGestureDetector.OnScaleGestureListener {



        public boolean onScaleBegin(ScaleGestureDetector detector) {

            mInitialZoomOverview = false;

            dismissZoomPicker();

            mFocusMovementSum = 0;

            mFocusMovementQueue.clear();

            mWebView.mViewManager.startZoom();

            mWebView.onPinchToZoomAnimationStart();

            return true;
@@ -729,6 +754,29 @@ class ZoomManager { 
            float scale = Math.max(

                    computeScaleWithLimits(detector.getScaleFactor() * mActualScale),

                    getZoomOverviewScale());



            float prevFocusX = mFocusX;

            float prevFocusY = mFocusY;

            mFocusX = detector.getFocusX();

            mFocusY = detector.getFocusY();

            float focusDelta = (prevFocusX == 0 && prevFocusY == 0) ? 0 :

                    FloatMath.sqrt((mFocusX - prevFocusX) * (mFocusX - prevFocusX)

                                   + (mFocusY - prevFocusY) * (mFocusY - prevFocusY));

            mFocusMovementSum += focusDelta;

            mFocusMovementQueue.add(focusDelta);

            if (mFocusMovementQueue.size() > FOCUS_QUEUE_SIZE) {

                mFocusMovementSum -= mFocusMovementQueue.remove();

            }

            float deltaSpan = Math.abs(detector.getCurrentSpan() - detector.getPreviousSpan());



            // If the user moves the fingers but keeps the same distance between them,

            // we should do panning only.

            if (mFocusMovementSum > deltaSpan) {

                mFocusMovementSum = 0;

                mFocusMovementQueue.clear();

                return true;

            }



            if (mPinchToZoomAnimating || willScaleTriggerZoom(scale)) {

                mPinchToZoomAnimating = true;

                // limit the scale change per step