com.my.math_quiz.views.ViewPagerWithCustomSpeedOfSwitchingPages.java Source code

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Here is the source code for com.my.math_quiz.views.ViewPagerWithCustomSpeedOfSwitchingPages.java

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/*
    
Copyright 2014 Joe Kulovic
    
This file is part of Math-quiz.
    
Math-quiz is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
Math-quiz is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with Math-quiz.  If not, see http://www.gnu.org/licenses
    
*/
package com.my.math_quiz.views;

import java.lang.reflect.Field;

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Interpolator;
import android.widget.Scroller;

public class ViewPagerWithCustomSpeedOfSwitchingPages extends ViewPager {

    private final int fastSpeed = 80;
    private int mDuration = fastSpeed;
    private boolean isEnablePageSwiping = true;

    public void setSlowSpeed() {
        mDuration = 200;
    }

    public ViewPagerWithCustomSpeedOfSwitchingPages(Context context) {
        super(context);
        init(context);
    }

    public ViewPagerWithCustomSpeedOfSwitchingPages(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    private void init(Context context) {
        Interpolator sInterpolator = new AccelerateInterpolator();
        try {
            Field mScroller;
            mScroller = ViewPager.class.getDeclaredField("mScroller");
            mScroller.setAccessible(true);
            FixedSpeedScroller scroller = new FixedSpeedScroller(this.getContext(), sInterpolator);
            // scroller.setFixedDuration(5000);
            mScroller.set(this, scroller);
        } catch (NoSuchFieldException e) {
            Log.d("exception", e + "");
        } catch (IllegalArgumentException e) {
            Log.d("exception", e + "");
        } catch (IllegalAccessException e) {
            Log.d("exception", e + "");
        }
    }

    /**This method disable switching pages on view pager with finger. It is only done programmatically*/
    public void disablePageSwitchingWithFinger() {
        isEnablePageSwiping = false;
    }

    /**This method disable switching pages on view pager with finger. Programmatically option steal can be used*/
    public void enablePageSwitchingWithFinger() {
        isEnablePageSwiping = true;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        if (isEnablePageSwiping)
            return super.onInterceptHoverEvent(event);
        // Never allow swiping to switch between pages
        return false;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (isEnablePageSwiping)
            return super.onTouchEvent(event);
        // Never allow swiping to switch between pages
        return false;
    }

    class FixedSpeedScroller extends Scroller {

        public FixedSpeedScroller(Context context) {
            super(context);
        }

        public FixedSpeedScroller(Context context, Interpolator interpolator) {
            super(context, interpolator);
        }

        @Override
        public void startScroll(int startX, int startY, int dx, int dy, int duration) {
            // Ignore received duration, use fixed one instead
            super.startScroll(startX, startY, dx, dy, mDuration);
            mDuration = fastSpeed;
        }

        @Override
        public void startScroll(int startX, int startY, int dx, int dy) {
            // Ignore received duration, use fixed one instead
            super.startScroll(startX, startY, dx, dy, mDuration);
            mDuration = fastSpeed;
        }
    }

}