MyFragmentPagerAdapter.java

package com.mfh.comna.comn.logic;

import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TabHost;
import android.widget.TabWidget;

import com.mfh.comna.view.BaseFragmentActive;
/**
 * 支持tabhost、viewPager和fragment组合的adapter
 * 既可以通过tab点击切换，也可以通过翻屏切换。
 * @author zhangyz created on 2013-4-17
 * @since Framework 1.0
 */
public class MyFragmentPagerAdapter extends FragmentPagerAdapter 
    implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
    private final BaseFragmentActive mContext;
    private final TabHost mTabHost;
    private final ViewPager mViewPager;
    private final List<TabInfo> mTabs = new ArrayList<TabInfo>();

    static final class TabInfo {
        public final TabHost.TabSpec tabSpec;
        public final String tag;
        public final Class<?> clss;
        public final Bundle args;

//        public TabInfo(Class<?> _class, Bundle _args) {
//            clss = _class;
//            args = _args;
//        }

        public TabInfo(TabHost.TabSpec _tabSpec, String _tag, Class<?> _class, Bundle _args) {
            tabSpec = _tabSpec;
            tag = _tag;
            clss = _class;
            args = _args;
        }
//
//        public String getTag() {
//            return tag;
//        }
//
//        public Class<?> getClss() {
//            return clss;
//        }
//
//        public Bundle getArgs() {
//            return args;
//        }
    }

    static class DummyTabFactory implements TabHost.TabContentFactory {

        private final Context mContext;

        public DummyTabFactory(Context context) {
            mContext = context;
        }

        @Override
        public View createTabContent(String tag) {
            View v = new View(mContext);
            v.setMinimumWidth(0);
            v.setMinimumHeight(0);
            return v;
        }
    }

    public MyFragmentPagerAdapter(BaseFragmentActive activity, TabHost tabHost, ViewPager pager) {
        super(activity.getSupportFragmentManager());
        mContext = activity;
        mTabHost = tabHost;
        mViewPager = pager;
        mTabHost.setOnTabChangedListener(this);
        // mViewPager.setOffscreenPageLimit(2);
        mViewPager.setAdapter(this);
        mViewPager.setOnPageChangeListener(this);
    }

    public void addTab(TabHost.TabSpec tabSpec,  String tag, Class<?> clss, Bundle args) {
        tabSpec.setContent(new DummyTabFactory(mContext));
        TabInfo info = new TabInfo(tabSpec, tag, clss, args);

        addFragment(info);
    }
    private void addFragment(TabInfo info){
        if (info == null) {
            return;
        }

        mTabHost.addTab(info.tabSpec);
        mTabs.add(info);
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return mTabs.size();
    }

    @Override
    public Fragment getItem(int position) {
        TabInfo info = mTabs.get(position);
//        Fragment fmt = (Fragment) info.tag;
//        if (fmt == null) {
//            fmt = Fragment.instantiate(mContext, info.clss.getName(), info.args);
//            info.tag = fmt;
//        }
//        return fmt;
        return Fragment.instantiate(mContext, info.clss.getName(), info.args);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        // TabInfo info = mTabs.get(position);
        return "";
    }

    @Override
    public void onTabChanged(String tabId) {
        int position = mTabHost.getCurrentTab();
        mViewPager.setCurrentItem(position);
        mContext.OnFragmentSelected(getItem(position));
    }

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

    @Override
    public void onPageSelected(int position) {
        // Unfortunately when TabHost changes the current tab, it kindly
        // also takes care of putting focus on it when not in touch mode.
        // The jerk.
        // This hack tries to prevent this from pulling focus out of our
        // ViewPager.
        TabWidget widget = mTabHost.getTabWidget();
        int oldFocusability = widget.getDescendantFocusability();
        widget.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
        mTabHost.setCurrentTab(position);
        widget.setDescendantFocusability(oldFocusability);

        mContext.OnFragmentSelected(getItem(position));
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
}