【Dialer】android6.0拨号界面分析<二>

题记

大家清明假期快乐！！！！

下面简单介绍下拨号界面运用ViewPager+Fragment实现的主界面。

ViewPager和Fragment

原生拨号应用界面的ViewPager由mViewPager+mViewPagerTabs组成。
mViewPager：ViewPager，用于与容纳fragment，并使用adapter与数据进行交互。
mViewPagerTabs：这里我认为是为了更好的定义ViewPager的Title使用。（相当于更加灵活的ViewPager的“头部”）。

代码如下：
mViewPager的初始化：

// 初始化ViewPager        mViewPager = (ViewPager) parentView.findViewById(R.id.lists_pager);        mViewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager());        // 设置Adapter，与fragment建立联系        mViewPager.setAdapter(mViewPagerAdapter);        mViewPager.setOffscreenPageLimit(TAB_COUNT_WITH_VOICEMAIL - 1);        mViewPager.setOnPageChangeListener(this);

ViewPagerAdapter代码如下：

    public class ViewPagerAdapter extends FragmentPagerAdapter {        public ViewPagerAdapter(FragmentManager fm) {            super(fm);        }        @Override        public long getItemId(int position) {            return getRtlPosition(position);        }        @Override        public Fragment getItem(int position) {            switch (getRtlPosition(position)) {                case TAB_INDEX_SPEED_DIAL:                    mSpeedDialFragment = new SpeedDialFragment();                    return mSpeedDialFragment;                case TAB_INDEX_RECENTS:                    mRecentsFragment = new CallLogFragment(CallLogQueryHandler.CALL_TYPE_ALL,                            MAX_RECENTS_ENTRIES, System.currentTimeMillis() - OLDEST_RECENTS_DATE);                    return mRecentsFragment;                case TAB_INDEX_ALL_CONTACTS:                    mAllContactsFragment = new AllContactsFragment();                    return mAllContactsFragment;                case TAB_INDEX_VOICEMAIL:                    mVoicemailFragment = new CallLogFragment(Calls.VOICEMAIL_TYPE);                    return mVoicemailFragment;            }            throw new IllegalStateException("No fragment at position " + position);        }        **//初始化Fragment； ViewPager.addNewItem() ->instantiateItem->getItem（）**        @Override        public Object instantiateItem(ViewGroup container, int position) {            // On rotation the FragmentManager handles rotation. Therefore getItem() isn't called.            // Copy the fragments that the FragmentManager finds so that we can store them in            // instance variables for later.            final Fragment fragment =                    (Fragment) super.instantiateItem(container, position);            if (fragment instanceof SpeedDialFragment) {                mSpeedDialFragment = (SpeedDialFragment) fragment;            } else if (fragment instanceof CallLogFragment && position == TAB_INDEX_RECENTS) {                mRecentsFragment = (CallLogFragment) fragment;            } else if (fragment instanceof AllContactsFragment) {                mAllContactsFragment = (AllContactsFragment) fragment;            } else if (fragment instanceof CallLogFragment && position == TAB_INDEX_VOICEMAIL) {                mVoicemailFragment = (CallLogFragment) fragment;            }            return fragment;        }        @Override        public int getCount() {            return mHasActiveVoicemailProvider ? TAB_COUNT_WITH_VOICEMAIL : TAB_COUNT_DEFAULT;        }        @Override        public CharSequence getPageTitle(int position) {            return mTabTitles[position];        }    }

在每次 ViewPager 需要一个用以显示的 Object 的时候，函数instantiateItem都会被 ViewPager.addNewItem() 调用；函数instantiateItem中判断一下要生成的 Fragment 是否已经生成过了，如果生成过了，就使用旧的，旧的将被 Fragment.attach()；如果没有，就调用 getItem() 生成一个新的，新的对象将被 FragmentTransation.add()；

上述完成了mViewPager+Fragment的布局。

ViewPagerTabs的使用

ViewPagerTabs代码定义及实现：

        //图标        mTabIcons = new int[TAB_COUNT_WITH_VOICEMAIL];        mTabIcons[TAB_INDEX_SPEED_DIAL] = R.drawable.tab_speed_dial;        mTabIcons[TAB_INDEX_RECENTS] = R.drawable.tab_recents;        mTabIcons[TAB_INDEX_ALL_CONTACTS] = R.drawable.tab_contacts;        mTabIcons[TAB_INDEX_VOICEMAIL] = R.drawable.tab_voicemail;        //初始化ViewPageTabs。        mViewPagerTabs = (ViewPagerTabs) parentView.findViewById(R.id.lists_pager_header);        mViewPagerTabs.setTabIcons(mTabIcons);        //mViewPagerTabs与ViewPager进行关联        mViewPagerTabs.setViewPager(mViewPager);

上述代码实现了mViewPagerTabs 和mViewPager关联，那么怎么实现将上方图标设置为mViewPager的Title的呢？下面分析mViewPagerTabs的实现：主要的看函数setViewPager()：

    public void setViewPager(ViewPager viewPager) {        mPager = viewPager;        //此处实现添加TAB项，并向addTabs函数传入上面的mViewPagerAdapter。        addTabs(mPager.getAdapter());    }

    private void addTabs(PagerAdapter adapter) {        mTabStrip.removeAllViews();        final int count = adapter.getCount();        for (int i = 0; i < count; i++) {            //设置Tab项            addTab(adapter.getPageTitle(i), i);        }    }

下述代码就是详细的设置mViewPager的Tab页，并设置Tab页的监听事件。

    private void addTab(CharSequence tabTitle, final int position) {        View tabView;        if (mTabIcons != null && position < mTabIcons.length) {            View iconView = new View(getContext());            iconView.setBackgroundResource(mTabIcons[position]);            iconView.setContentDescription(tabTitle);            tabView = iconView;        } else {            final TextView textView = new TextView(getContext());            textView.setText(tabTitle);            textView.setBackgroundResource(R.drawable.view_pager_tab_background);            // Assign various text appearance related attributes to child views.            if (mTextStyle > 0) {                textView.setTypeface(textView.getTypeface(), mTextStyle);            }            if (mTextSize > 0) {                textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);            }            if (mTextColor != null) {                textView.setTextColor(mTextColor);            }            textView.setAllCaps(mTextAllCaps);            textView.setGravity(Gravity.CENTER);            tabView = textView;        }        tabView.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                mPager.setCurrentItem(getRtlPosition(position));            }        });        tabView.setOnLongClickListener(new OnTabLongClickListener(position));        tabView.setPadding(mSidePadding, 0, mSidePadding, 0);        mTabStrip.addView(tabView, new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,                LayoutParams.MATCH_PARENT, 1));        // Default to the first child being selected        if (position == 0) {            mPrevSelected = 0;            tabView.setSelected(true);        }    }

至此也将mViewPagerTabs和mViewPager进行完美结合；mViewPagerTabs的作用就是讲Tab的设置独立出来，方便进行定制和复用。

后记

后续会进行通话记录页面的详细分析，也就是CallLogFragment的详细布局及数据实现。

Keep Moving！！！