ViewPager,ActionBar,Fragment應用--模仿通訊錄滑動效果

最近由Android2.3切換到Android4.0的開發，一下子居然有點不適應，Android4.0新增了一些功能模塊如ActionBar,Fragment等其實在Android3.0就有了，但一直沒有做過平板上的開發，所以對這些模塊非常陌生，一下子感覺Android4.0的開發難度甚大，經過十來天的努力，終於略微有所悟，在看通訊錄的時候，感覺如果將其效果模仿出來豈不是初步達到掌握這些模塊。

先看圖，再列舉出代碼：

按住左右滑動時會自動切換。

源代碼下載：http://download.csdn.net/detail/hjj0212/5023509

主要代碼如下：

package com.example.testtabactionbar;

import android.net.Uri;
import android.os.Bundle;
import android.os.Parcelable;
import android.provider.ContactsContract.Contacts;
import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.app.ListFragment;
import android.app.ActionBar.Tab;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.text.TextUtils;
import android.util.Log;
import android.view.ContextMenu;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
import android.widget.SearchView.OnQueryTextListener;

public class MainActivity extends Activity {
	private ActionBar mActionBar;
	private static final TabState DEFAULT_TAB = TabState.GROUPS;
    private TabState mCurrentTab = DEFAULT_TAB;
    private final MyTabListener mTabListener = new MyTabListener();
    private ArraListFragment mArrayFragment;
    private CursorLoaderFragment mCursorFragment;
    private ContextMenuFragment mContextMenuFragment;
    private ViewPager mTabPager;
    private TabPagerAdapter mTabPagerAdapter;	
    private final TabPagerListener mTabPagerListener = new TabPagerListener();
    
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.tab_view_pager);
		initActionBar();
		createViewAndFragment();
	}
	
	private void createViewAndFragment(){
		final FragmentManager fragmentManager = getFragmentManager();
		final FragmentTransaction transaction = fragmentManager.beginTransaction();
		
        mTabPager = getView(R.id.tab_pager);
        mTabPagerAdapter = new TabPagerAdapter();
        mTabPager.setAdapter(mTabPagerAdapter);
        mTabPager.setOnPageChangeListener(mTabPagerListener);

        final String FAVORITE_TAG = "tab-pager-favorite";
        final String ALL_TAG = "tab-pager-all";
        final String GROUPS_TAG = "tab-pager-groups";

        // Create the fragments and add as children of the view pager.
        // The pager adapter will only change the visibility; it'll never create/destroy
        // fragments.
        // However, if it's after screen rotation, the fragments have been re-created by
        // the fragment manager, so first see if there're already the target fragments
        // existing.
		mContextMenuFragment = (ContextMenuFragment) fragmentManager
				.findFragmentByTag(FAVORITE_TAG);
		mArrayFragment = (ArraListFragment) fragmentManager
				.findFragmentByTag(ALL_TAG);
		mCursorFragment = (CursorLoaderFragment) fragmentManager
				.findFragmentByTag(GROUPS_TAG);

		if (mContextMenuFragment == null) {
			Log.e("HJJ", "ContextMenuFragmentd == null");
			mContextMenuFragment = new ContextMenuFragment();
			mArrayFragment = new ArraListFragment();
			mCursorFragment = new CursorLoaderFragment();

			transaction.add(R.id.tab_pager, mContextMenuFragment, FAVORITE_TAG);
			transaction.add(R.id.tab_pager, mArrayFragment, ALL_TAG);
			transaction.add(R.id.tab_pager, mCursorFragment, GROUPS_TAG);
		}

		// Hide all fragments for now. We adjust visibility when we get
		// onSelectedTabChanged()
		// from ActionBarAdapter.
		transaction.hide(mContextMenuFragment);
		transaction.hide(mArrayFragment);
		transaction.hide(mCursorFragment);
		
        transaction.commitAllowingStateLoss();
        fragmentManager.executePendingTransactions();
	}
	
    private class TabPagerListener implements ViewPager.OnPageChangeListener {
        @Override
        public void onPageScrollStateChanged(int state) {
        }

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

        @Override
        public void onPageSelected(int position) {
            // Make sure not in the search mode, in which case position != TabState.ordinal().
            TabState selectedTab = TabState.fromInt(position);
            setCurrentTab(selectedTab, false);
            invalidateOptionsMenu();
        }
    }
    
	private void initActionBar(){
    	mActionBar = getActionBar();
    	mActionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
    	// 去掉默認標題欄
    	mActionBar.setDisplayShowHomeEnabled(false);  
    	mActionBar.setDisplayShowTitleEnabled(false); 
        // Set up tabs
        addTab(TabState.GROUPS, R.drawable.ic_tab_groups);
        addTab(TabState.ALL, R.drawable.ic_tab_all);
        addTab(TabState.FAVORITES, R.drawable.ic_tab_starred);
	}
	
    private class TabPagerAdapter extends PagerAdapter {
        private final FragmentManager mFragmentManager;
        private FragmentTransaction mCurTransaction = null;

        private boolean mTabPagerAdapterSearchMode;

        private Fragment mCurrentPrimaryItem;

        public TabPagerAdapter() {
            mFragmentManager = getFragmentManager();
        }

        @Override
        public int getCount() {
            return mTabPagerAdapterSearchMode ? 1 : TabState.values().length;
        }

        /** Gets called when the number of items changes. */
        @Override
        public int getItemPosition(Object object) {
            if (mTabPagerAdapterSearchMode) {
                if (object == mArrayFragment) {
                    return 0; // Only 1 page in search mode
                }
            } else {
                if (object == mContextMenuFragment) {
                    return TabState.FAVORITES.ordinal();
                }
                if (object == mArrayFragment) {
                    return TabState.ALL.ordinal();
                }
                if (object == mCursorFragment) {
                    return TabState.GROUPS.ordinal();
                }
            }
            return POSITION_NONE;
        }

        @Override
        public void startUpdate(View container) {
        }

        private Fragment getFragment(int position) {
			if (position == TabState.FAVORITES.ordinal()) {
				return mContextMenuFragment;
			} else if (position == TabState.ALL.ordinal()) {
				return mArrayFragment;
			} else if (position == TabState.GROUPS.ordinal()) {
				return mCursorFragment;
			}
            throw new IllegalArgumentException("position: " + position);
        }

        @Override
        public Object instantiateItem(View container, int position) {
            if (mCurTransaction == null) {
                mCurTransaction = mFragmentManager.beginTransaction();
            }
            Fragment f = getFragment(position);
            mCurTransaction.show(f);

            // Non primary pages are not visible.
            //f.setUserVisibleHint(f == mCurrentPrimaryItem);
            return f;
        }

        @Override
        public void destroyItem(View container, int position, Object object) {
            if (mCurTransaction == null) {
                mCurTransaction = mFragmentManager.beginTransaction();
            }
            mCurTransaction.hide((Fragment) object);
        }

        @Override
        public void finishUpdate(View container) {
            if (mCurTransaction != null) {
                mCurTransaction.commitAllowingStateLoss();
                mCurTransaction = null;
                mFragmentManager.executePendingTransactions();
            }
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return ((Fragment) object).getView() == view;
        }

        @Override
        public void setPrimaryItem(View container, int position, Object object) {
            Fragment fragment = (Fragment) object;
            if (mCurrentPrimaryItem != fragment) {
                if (mCurrentPrimaryItem != null) {
                    //mCurrentPrimaryItem.setUserVisibleHint(false);
                }
                if (fragment != null) {
                    //fragment.setUserVisibleHint(true);
                }
                mCurrentPrimaryItem = fragment;
            }
        }

        @Override
        public Parcelable saveState() {
            return null;
        }

        @Override
        public void restoreState(Parcelable state, ClassLoader loader) {
        }
    }
    
    @SuppressWarnings("unchecked")
    public <T extends View> T getView(int id) {
        T result = (T)findViewById(id);
        if (result == null) {
            throw new IllegalArgumentException("view 0x" + Integer.toHexString(id)
                    + " doesn't exist");
        }
        return result;
    }
    
    protected static void showFragment(FragmentTransaction ft, Fragment f) {
        if ((f != null) && f.isHidden()) ft.show(f);
    }

    protected static void hideFragment(FragmentTransaction ft, Fragment f) {
        if ((f != null) && !f.isHidden()) ft.hide(f);
    }
    
	private void addTab(TabState tabState, int icon) {
		final Tab tab = mActionBar.newTab();
		tab.setTag(tabState);
		tab.setTabListener(mTabListener);
		tab.setIcon(icon);
		mActionBar.addTab(tab);
	}

	public enum TabState {
		GROUPS, ALL, FAVORITES;

		public static TabState fromInt(int value) {
			if (GROUPS.ordinal() == value) {
				return GROUPS;
			}
			if (ALL.ordinal() == value) {
				return ALL;
			}
			if (FAVORITES.ordinal() == value) {
				return FAVORITES;
			}
			throw new IllegalArgumentException("Invalid value: " + value);
		}
	}
	
    private class MyTabListener implements ActionBar.TabListener {
        /**
         * If true, it won't call {@link #setCurrentTab} in {@link #onTabSelected}.
         * This flag is used when we want to programmatically update the current tab without
         * {@link #onTabSelected} getting called.
         */
        public boolean mIgnoreTabSelected;

        @Override public void onTabReselected(Tab tab, FragmentTransaction ft) { }
        @Override public void onTabUnselected(Tab tab, FragmentTransaction ft) { }

        @Override public void onTabSelected(Tab tab, FragmentTransaction ft) {
        	Log.e("HJJ", "onTabSelected..tag:" + tab.getTag());
            if (!mIgnoreTabSelected) {
                setCurrentTab((TabState)tab.getTag());
            }
        }
    }

    /**
     * Change the current tab, and notify the listener.
     */
    public void setCurrentTab(TabState tab) {
        setCurrentTab(tab, true);
    }

    /**
     * Change the current tab
     */
    public void setCurrentTab(TabState tab, boolean notifyListener) {
        if (tab == null) throw new NullPointerException();
        //實際上按照Contacts中的設計，這個是應該有效的，但在此模擬程序中，它會出現問題，因此暫時將此段去掉
//        if (tab == mCurrentTab) {
//            return;
//        }
        mCurrentTab = tab;

        int index = mCurrentTab.ordinal();
        if ((mActionBar.getNavigationMode() == ActionBar.NAVIGATION_MODE_TABS)
                && (index != mActionBar.getSelectedNavigationIndex())) {
            mActionBar.setSelectedNavigationItem(index);
        }

        if (notifyListener) onSelectedTabChanged(tab);
    }
    
    private void onSelectedTabChanged(TabState tab){
    	FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction ft = fragmentManager.beginTransaction();
        int tabIndex = tab.ordinal();
        Log.e("HJJ", "tabIndex:" + tabIndex);
        switch (tab) {
        case FAVORITES:
        	if(mContextMenuFragment!=null){
            	mTabPager.setCurrentItem(tabIndex, false);
        	}
        	showFragment(ft, mContextMenuFragment);
            hideFragment(ft, mArrayFragment);
            hideFragment(ft, mCursorFragment);
            break;
        case ALL:
        	if(mArrayFragment!=null){
        		mTabPager.setCurrentItem(tabIndex, false);
        	}
        	hideFragment(ft, mContextMenuFragment);
            hideFragment(ft, mCursorFragment);
            showFragment(ft, mArrayFragment);
            break;
        case GROUPS:
        	if(mCursorFragment!=null){
        		mTabPager.setCurrentItem(tabIndex, false);
        	}
        	hideFragment(ft, mContextMenuFragment);
            hideFragment(ft, mArrayFragment);
            showFragment(ft, mCursorFragment);
            break;
        }
    	if (!ft.isEmpty()) {
    		Log.e("HJJ", "not ft isEmpty");
            ft.commitAllowingStateLoss();
            fragmentManager.executePendingTransactions();
            // When switching tabs, we need to invalidate options menu, but executing a
            // fragment transaction does it implicitly.  We don't have to call invalidateOptionsMenu
            // manually.
        }
    }
    
    
    
	public static class ArraListFragment extends ListFragment{
		@Override
		public void onActivityCreated(Bundle savedInstanceState) {
			// TODO Auto-generated method stub
			super.onActivityCreated(savedInstanceState);
			String [] array = new String[]{"C", "C++", "Java"};
			setListAdapter(new ArrayAdapter<String>(getActivity(), 
					android.R.layout.simple_list_item_1, array));
		}
		
		@Override
		public void onListItemClick(ListView l, View v, int position, long id) {
			// TODO Auto-generated method stub
			super.onListItemClick(l, v, position, id);
		}
	}
	
	public static class CursorLoaderFragment extends ListFragment implements
			OnQueryTextListener, LoaderCallbacks<Cursor> {

		SimpleCursorAdapter mAdapter;
		String mCurFilter;

		final String[] CONTACTS_SUMMARY_PROJECTION = new String[] {
				Contacts._ID, Contacts.DISPLAY_NAME, Contacts.CONTACT_STATUS,
				Contacts.CONTACT_PRESENCE, Contacts.PHOTO_ID,
				Contacts.LOOKUP_KEY, };

		@Override
		public void onActivityCreated(Bundle savedInstanceState) {
			// TODO Auto-generated method stub
			super.onActivityCreated(savedInstanceState);

			setEmptyText("No phone numbers");
			setHasOptionsMenu(true);

			mAdapter = new SimpleCursorAdapter(getActivity(),
					android.R.layout.simple_list_item_2, null, new String[] {
							Contacts.DISPLAY_NAME, Contacts.CONTACT_STATUS },
					new int[] { android.R.id.text1, android.R.id.text2 }, 0);
			setListAdapter(mAdapter);
			setListShown(false);
			getLoaderManager().initLoader(0, null, this);
		}

//		@Override
//		public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
//			// TODO Auto-generated method stub
//			MenuItem item = menu.add("Search");
//			item.setIcon(android.R.drawable.ic_menu_search);
//			item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM
//					| MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);
//			SearchView sv = new SearchView(getActivity());
//			sv.setOnQueryTextListener(this);
//			item.setActionView(sv);
//		}

		@Override
		public boolean onQueryTextChange(String newText) {
			// TODO Auto-generated method stub
			String newFilter = !TextUtils.isEmpty(newText) ? newText : null;
			if (mCurFilter == null && newFilter == null) {
				return true;
			}
			if (mCurFilter != null && mCurFilter.equals(newFilter)) {
				return true;
			}

			mCurFilter = newFilter;
			getLoaderManager().restartLoader(0, null, this);
			return true;
		}

		@Override
		public boolean onQueryTextSubmit(String query) {
			// TODO Auto-generated method stub
			return true;
		}

		@Override
		public void onListItemClick(ListView l, View v, int position, long id) {
			// TODO Auto-generated method stub
			super.onListItemClick(l, v, position, id);
			Cursor c = (Cursor) mAdapter.getItem(position);
			String name = c.getString(0);
			Toast.makeText(getActivity(), "name:" + name, Toast.LENGTH_SHORT)
					.show();
		}

		@Override
		public Loader<Cursor> onCreateLoader(int id, Bundle args) {
			// TODO Auto-generated method stub
			Uri baseUri;
			if (mCurFilter != null) {
				baseUri = Uri.withAppendedPath(Contacts.CONTENT_FILTER_URI,
						Uri.encode(mCurFilter));
			} else {
				baseUri = Contacts.CONTENT_URI;
			}
			String select = "((" + Contacts.DISPLAY_NAME + " NOTNULL) AND ("
					+ Contacts.HAS_PHONE_NUMBER + "=1) AND ("
					+ Contacts.DISPLAY_NAME + " != '' ))";
			return new CursorLoader(getActivity(), baseUri,
					CONTACTS_SUMMARY_PROJECTION, select, null,
					Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
		}

		@Override
		public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
			// TODO Auto-generated method stub
			mAdapter.swapCursor(data);
			if (isResumed()) {
				setListShown(true);
			} else {
				setListShownNoAnimation(true);
			}
		}

		@Override
		public void onLoaderReset(Loader<Cursor> arg0) {
			// TODO Auto-generated method stub
			mAdapter.swapCursor(null);
		}
	}
	
	public static class ContextMenuFragment extends Fragment{
		@Override
		public View onCreateView(LayoutInflater inflater, ViewGroup container,
				Bundle savedInstanceState) {
			// TODO Auto-generated method stub
			View root = inflater.inflate(R.layout.fragment_context_menu, container, false);
			registerForContextMenu(root.findViewById(R.id.long_press));
			return root;
		}
		
		@Override
		public void onCreateContextMenu(ContextMenu menu, View v,
				ContextMenuInfo menuInfo) {
			// TODO Auto-generated method stub
			super.onCreateContextMenu(menu, v, menuInfo);
			menu.add(Menu.NONE, R.id.a_item, Menu.NONE, "Menu A");
			menu.add(Menu.NONE, R.id.b_item, Menu.NONE, "Menu B");
		}
		
		@Override
		public boolean onContextItemSelected(MenuItem item) {
			// TODO Auto-generated method stub
			switch (item.getItemId()) {
			case R.id.a_item:
				Toast.makeText(getActivity(), "a_item...", Toast.LENGTH_SHORT).show();
				break;
			case R.id.b_item:
				Toast.makeText(getActivity(), "b_item...", Toast.LENGTH_SHORT).show();
				break;
			default:
				break;
			}
			return super.onContextItemSelected(item);
		}
	}
    
}