net.archenemy.archenemyapp.view.SlidingTabLayout.java Source code

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Here is the source code for net.archenemy.archenemyapp.view.SlidingTabLayout.java

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/**
 * Copyright 2014-present Chilja Gossow.
 *
 * 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 net.archenemy.archenemyapp.view;

import net.archenemy.archenemyapp.presenter.BaseFragmentPagerAdapter;

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;

/**
 * Layout with tabs and a sliding indicator
 * 
 */
public class SlidingTabLayout extends HorizontalScrollView {

    private class InternalViewPagerListener implements ViewPager.OnPageChangeListener {
        private int scrollState;

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            int tabStripChildCount = tabStrip.getChildCount();
            if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
                return;
            }

            tabStrip.onViewPagerPageChanged(position, positionOffset);

            View selectedTab = tabStrip.getChildAt(position);

            int extraOffset = (selectedTab != null) ? (int) (positionOffset * selectedTab.getWidth()) : 0;

            scrollToTab(position, extraOffset);

            if (viewPagerPageChangeListener != null) {
                viewPagerPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }

        @Override
        public void onPageScrollStateChanged(int state) {
            scrollState = state;

            if (viewPagerPageChangeListener != null) {
                viewPagerPageChangeListener.onPageScrollStateChanged(state);
            }
        }

        @Override
        public void onPageSelected(int position) {
            if (scrollState == ViewPager.SCROLL_STATE_IDLE) {
                tabStrip.onViewPagerPageChanged(position, 0f);
                scrollToTab(position, 0);
                setTabSelection(position);
            }

            if (viewPagerPageChangeListener != null) {
                viewPagerPageChangeListener.onPageSelected(position);
            }
        }

    }

    private class TabClickListener implements View.OnClickListener {
        @Override
        public void onClick(View view) {
            setTabSelection(view);
            setPageSelection(view);
        }
    }

    private int tabViewLayoutId;
    private int tabViewImageViewId;

    private ViewPager viewPager;

    private ViewPager.OnPageChangeListener viewPagerPageChangeListener;

    private final SlidingTabStrip tabStrip;

    public SlidingTabLayout(Context context) {
        this(context, null);
    }

    public SlidingTabLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SlidingTabLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        setHorizontalScrollBarEnabled(false);
        setFillViewport(true);

        tabStrip = new SlidingTabStrip(context);
        addView(tabStrip, android.view.ViewGroup.LayoutParams.MATCH_PARENT,
                android.view.ViewGroup.LayoutParams.WRAP_CONTENT);
    }

    public void setCustomTabView(int layoutResId, int imageViewId) {
        tabViewLayoutId = layoutResId;
        tabViewImageViewId = imageViewId;
    }

    public void setIndicatorColor(int color) {
        tabStrip.setIndicatorColor(color);
    }

    public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
        viewPagerPageChangeListener = listener;
    }

    public void setViewPager(ViewPager viewPager) {
        tabStrip.removeAllViews();

        this.viewPager = viewPager;
        if (viewPager != null) {
            viewPager.setOnPageChangeListener(new InternalViewPagerListener());
            populateTabStrip();
        }
    }

    private void populateTabStrip() {
        final PagerAdapter adapter = viewPager.getAdapter();
        final View.OnClickListener tabClickListener = new TabClickListener();
        if (adapter.getCount() > 0) {
            int width = getResources().getDisplayMetrics().widthPixels;
            int tabWidth = width / adapter.getCount();
            for (int i = 0; i < adapter.getCount(); i++) {
                ViewGroup tabView = null;
                ImageView tabIcon = null;

                if (tabViewLayoutId != 0) {
                    // If there is a custom tab view layout id set, try and inflate it
                    tabView = (ViewGroup) LayoutInflater.from(getContext()).inflate(tabViewLayoutId, tabStrip,
                            false);
                    tabIcon = (ImageView) tabView.findViewById(tabViewImageViewId);
                }

                tabIcon.setImageResource(((BaseFragmentPagerAdapter) adapter).getIconResId(i));
                tabView.setOnClickListener(tabClickListener);
                tabStrip.addView(tabView, tabWidth, android.view.ViewGroup.LayoutParams.MATCH_PARENT);
            }
        }
    }

    private void scrollToTab(int tabIndex, int positionOffset) {
        final int tabStripChildCount = tabStrip.getChildCount();
        if ((tabStripChildCount == 0) || (tabIndex < 0) || (tabIndex >= tabStripChildCount)) {
            return;
        }

        View selectedTab = tabStrip.getChildAt(tabIndex);
        if (selectedTab != null) {
            int targetScrollX = selectedTab.getLeft() + positionOffset;
            scrollTo(targetScrollX, 0);
            if (positionOffset == 0) {
                setTabSelection(tabIndex);
            }
        }
    }

    private void setPageSelection(View selectedTabView) {
        for (int i = 0; i < tabStrip.getChildCount(); i++) {
            View tabView = tabStrip.getChildAt(i);
            if (selectedTabView == tabView) {
                viewPager.setCurrentItem(i);
                return;
            }
        }
    }

    private void setTabSelected(View tab) {
        ImageView tabIcon = (ImageView) tab.findViewById(tabViewImageViewId);
        tabIcon.setAlpha(1f);
    }

    private void setTabSelection(int position) {
        setTabSelection(tabStrip.getChildAt(position));
    }

    private void setTabSelection(View selectedTabView) {
        for (int i = 0; i < tabStrip.getChildCount(); i++) {
            View tabView = tabStrip.getChildAt(i);
            if (selectedTabView == tabView) {
                setTabSelected(tabView);
            } else {
                setTabUnselected(tabView);
            }
        }
    }

    private void setTabUnselected(View tab) {
        ImageView tabIcon = (ImageView) tab.findViewById(tabViewImageViewId);
        tabIcon.setAlpha(0.54f);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();

        if (viewPager != null) {
            scrollToTab(viewPager.getCurrentItem(), 0);
        }
    }
}