com.aniruddhc.xPlod.ui.widgets.ScrollableTabView.java Source code

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Here is the source code for com.aniruddhc.xPlod.ui.widgets.ScrollableTabView.java

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/*
 * Copyright (C) 2011 Andreas Stuetz <andreas.stuetz@gmail.com>
 *
 * 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 com.aniruddhc.xPlod.ui.widgets;

import java.util.ArrayList;

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.View;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;

import com.aniruddhc.xPlod.ui.adapters.TabAdapter;

/**
 * I'm using a custom tab view in place of ActionBarTabs entirely for the theme
 * engine.
 */
public class ScrollableTabView extends HorizontalScrollView implements ViewPager.OnPageChangeListener {

    private ViewPager mPager = null;

    private TabAdapter mAdapter = null;

    private final LinearLayout mContainer;

    private final ArrayList<View> mTabs = new ArrayList<View>();

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

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

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

        this.setHorizontalScrollBarEnabled(false);
        this.setHorizontalFadingEdgeEnabled(false);

        mContainer = new LinearLayout(context);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
                android.view.ViewGroup.LayoutParams.MATCH_PARENT, android.view.ViewGroup.LayoutParams.MATCH_PARENT);
        mContainer.setLayoutParams(params);
        mContainer.setOrientation(LinearLayout.HORIZONTAL);

        this.addView(mContainer);

    }

    public void setAdapter(TabAdapter adapter) {
        this.mAdapter = adapter;

        if (mPager != null && mAdapter != null)
            initTabs();
    }

    public void setViewPager(ViewPager pager) {
        this.mPager = pager;
        mPager.setOnPageChangeListener(this);

        if (mPager != null && mAdapter != null)
            initTabs();
    }

    private void initTabs() {

        mContainer.removeAllViews();
        mTabs.clear();

        if (mAdapter == null)
            return;

        for (int i = 0; i < mPager.getAdapter().getCount(); i++) {

            final int index = i;

            View tab = mAdapter.getView(i);
            mContainer.addView(tab);

            tab.setFocusable(true);

            mTabs.add(tab);

            tab.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (mPager.getCurrentItem() == index) {
                        selectTab(index);
                    } else {
                        mPager.setCurrentItem(index, true);
                    }
                }
            });

        }

        selectTab(mPager.getCurrentItem());
    }

    @Override
    public void onPageScrollStateChanged(int state) {
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    }

    @Override
    public void onPageSelected(int position) {
        selectTab(position);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);

        if (changed && mPager != null)
            selectTab(mPager.getCurrentItem());
    }

    private void selectTab(int position) {

        for (int i = 0, pos = 0; i < mContainer.getChildCount(); i++, pos++) {
            View tab = mContainer.getChildAt(i);
            tab.setSelected(pos == position);
        }

        View selectedTab = mContainer.getChildAt(position);

        final int w = selectedTab.getMeasuredWidth();
        final int l = selectedTab.getLeft();

        final int x = l - this.getWidth() / 2 + w / 2;

        smoothScrollTo(x, this.getScrollY());

    }

}