larry.baby.rain.common.view.TabPageIndicator.java Source code

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Here is the source code for larry.baby.rain.common.view.TabPageIndicator.java

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/*
 * Copyright (C) 2011 The Android Open Source Project
 * Copyright (C) 2011 Jake Wharton
 *
 * 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 larry.baby.rain.common.view;

import larry.baby.rain.R;
import android.content.Context;
import android.graphics.Typeface;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * This widget implements the dynamic action bar tab behavior that can change
 * across different configurations or circumstances.
 */
public class TabPageIndicator extends HorizontalScrollView
        implements ViewPager.OnPageChangeListener, View.OnClickListener {
    Runnable mTabSelector;

    private final LinearLayout mTabLayout;
    private ViewPager mViewPager;
    private ViewPager.OnPageChangeListener mListener;

    private int mSelectedTabIndex;

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

    public TabPageIndicator(Context context, AttributeSet attrs) {
        super(context, attrs);
        setHorizontalScrollBarEnabled(false);

        mTabLayout = new LinearLayout(getContext());
        addView(mTabLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.MATCH_PARENT));
    }

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY;
        setFillViewport(lockedExpanded);

        final int oldWidth = getMeasuredWidth();
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        final int newWidth = getMeasuredWidth();

        if (lockedExpanded && oldWidth != newWidth) {
            // Recenter the tab display if we're at a new (scrollable) size.
            setCurrentItem(mSelectedTabIndex);
        }
    }

    private void animateToTab(final int position) {
        final View tabView = mTabLayout.getChildAt(position);
        if (mTabSelector != null) {
            removeCallbacks(mTabSelector);
        }
        mTabSelector = new Runnable() {
            @Override
            public void run() {
                final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;
                smoothScrollTo(scrollPos, 0);
                mTabSelector = null;
            }
        };
        post(mTabSelector);
    }

    @Override
    public void onAttachedToWindow() {
        super.onAttachedToWindow();
        if (mTabSelector != null) {
            // Re-post the selector we saved
            post(mTabSelector);
        }
    }

    @Override
    public void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (mTabSelector != null) {
            removeCallbacks(mTabSelector);
        }
    }

    private void addTab(CharSequence text, int index) {
        Context context = getContext();
        DisplayMetrics dm = context.getResources().getDisplayMetrics();

        int padX = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 22, dm);
        int padY = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 12, dm);

        TextView tabView = new TextView(context);
        tabView.setBackgroundResource(R.drawable.vpi__tab_indicator);
        tabView.setPadding(padX, padY, padX, padY);
        tabView.setGravity(Gravity.CENTER);
        tabView.setTextColor(0xfff3f3f3);
        tabView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 12);
        tabView.setTypeface(tabView.getTypeface(), Typeface.BOLD);
        tabView.setSingleLine();
        tabView.setTag(index);
        tabView.setFocusable(true);
        tabView.setOnClickListener(this);
        tabView.setText(text);

        mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0, LayoutParams.MATCH_PARENT, 1));
    }

    @Override
    public void onPageScrollStateChanged(int arg0) {
        if (mListener != null) {
            mListener.onPageScrollStateChanged(arg0);
        }
    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
        if (mListener != null) {
            mListener.onPageScrolled(arg0, arg1, arg2);
        }
    }

    @Override
    public void onPageSelected(int arg0) {
        setCurrentItem(arg0);
        if (mListener != null) {
            mListener.onPageSelected(arg0);
        }
    }

    public void setViewPager(ViewPager view) {
        final PagerAdapter adapter = view.getAdapter();
        if (adapter == null) {
            throw new IllegalStateException("ViewPager does not have adapter instance.");
        }
        mViewPager = view;
        view.setOnPageChangeListener(this);
        notifyDataSetChanged();
    }

    public void notifyDataSetChanged() {
        mTabLayout.removeAllViews();
        PagerAdapter adapter = mViewPager.getAdapter();
        final int count = adapter.getCount();
        for (int i = 0; i < count; i++) {
            addTab(adapter.getPageTitle(i), i);
        }
        if (mSelectedTabIndex > count) {
            mSelectedTabIndex = count - 1;
        }
        setCurrentItem(mSelectedTabIndex);
        requestLayout();
    }

    public void setCurrentItem(int item) {
        if (mViewPager == null) {
            throw new IllegalStateException("ViewPager has not been bound.");
        }
        mSelectedTabIndex = item;
        final int tabCount = mTabLayout.getChildCount();
        for (int i = 0; i < tabCount; i++) {
            final View child = mTabLayout.getChildAt(i);
            final boolean isSelected = i == item;
            child.setSelected(isSelected);
            if (isSelected) {
                animateToTab(item);
            }
        }
    }

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

    @Override
    public void onClick(View view) {
        mViewPager.setCurrentItem((Integer) view.getTag());
    }
}