Android SDK开发 -- TitleBar重构 （代理模式的使用）

BaseFragment的TitleBar封装如下

public class BaseFragment extends Fragment {

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

		Log.d("fragment:onCreateView", getView());

		return null;
	}

	@Override
	public void onViewCreated(View view, Bundle savedInstanceState) {
		super.onViewCreated(view, savedInstanceState);
		Log.d("fragment:onCreateView", getView());
		findViewById();
	}

	private ViewSwitcher[] titleSwitcher;

	/**
	 * 初始化View
	 */
	protected void findViewById() {
		titleSwitcher = new ViewSwitcher[3];
		titleSwitcher[0] = (ViewSwitcher) findViewById(R.id.app_title_left_switcher);
		titleSwitcher[1] = (ViewSwitcher) findViewById(R.id.app_title_middle_switcher);
		titleSwitcher[2] = (ViewSwitcher) findViewById(R.id.app_title_right_switcher);
	}

	protected void setTitle(TitleRes leftTitle, TitleRes middleTitle, TitleRes rightTitle) {
		TitleRes[] reses = new TitleRes[] { leftTitle, middleTitle, rightTitle };
		for (int i = 0; i < reses.length; i++) {
			TitleRes res = reses[i];
			ViewSwitcher switcher = titleSwitcher[i];
			if (res == null) {
				switcher.setVisibility(View.INVISIBLE);
			} else {
				switcher.setVisibility(View.VISIBLE);
				// 触发单击事件的View
				View clickView = null;
				// 文字
				if (res.getType() == 0) {
					switcher.setDisplayedChild(0);// 显示TextView
					//
					Object resource = res.getResource();
					String title = resource instanceof Integer ? getResources().getString((Integer) resource) : String.valueOf(resource);
					((TextView) switcher.getChildAt(0)).setText(title);
					clickView = switcher.getChildAt(0);
				} else {
					switcher.setDisplayedChild(1);// 显示ImageView
					//
					int imageResource = (Integer) res.getResource();
					((ImageView) switcher.getChildAt(1)).setImageResource(imageResource);
					clickView = switcher.getChildAt(1);
				}
				// 设置title的单击事件
				clickView.setOnClickListener(res.getClickListener());
			}
		}
	}

	protected View findViewById(int id) {
		return getView().findViewById(id);
	}
}

子类调用

public class HomeFragment extends BaseFragment implements View.OnClickListener {

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
		View layout = inflater.inflate(R.layout.home, container, false);
		super.onCreateView(inflater, container, savedInstanceState);
		return layout;
	}

	@Override
	public void onViewCreated(View view, Bundle savedInstanceState) {
		super.onViewCreated(view, savedInstanceState);

		findViewById(R.id.home_title_sample).setOnClickListener(this);

		TitleRes left = null;
		TitleRes middle = new TitleRes("首页标题");
		TitleRes right = null;
		
		setTitle(left, middle, right);
	}

可以发现跟BaseActivity 中的代码实现基本上是类似的

但是BaseActivity和BaseFragment又没有共同的父类

 这个时候需要采用 组合的方式进行代码重构

/**
 * 因为Fragment和Activity没有共同的父类 ，但是他们各自的父类里又有一些TitleBar相同的业务逻辑处理

 * 所以我创建了该类
 * 
 * @author coffee 

 *         2015-12-24 下午10:26:10
 */
public class TitleMgr {

	/**
	 * TitleBar的上下文
	 */
	private Context context;
	/**
	 * TitleBar所在的顶层View容易
	 */
	private View contentView;

	/**
	 * 三个Title
	 */
	private ViewSwitcher[] titleSwitcher;

	public TitleMgr(Context context, View contenView) {
		this.context = context;
		this.contentView = contenView;
	}

	private Resources getResources() {
		return context.getResources();
	}

	private View findViewById(int id) {
		return contentView.findViewById(id);
	}

	/**
	 * 初始化title bar
	 */
	public void findViewById() {
		titleSwitcher = new ViewSwitcher[3];
		titleSwitcher[0] = (ViewSwitcher) findViewById(R.id.app_title_left_switcher);
		titleSwitcher[1] = (ViewSwitcher) findViewById(R.id.app_title_middle_switcher);
		titleSwitcher[2] = (ViewSwitcher) findViewById(R.id.app_title_right_switcher);
	}

	public void setTitle(TitleRes leftTitle, TitleRes middleTitle, TitleRes rightTitle) {
		TitleRes[] reses = new TitleRes[] { leftTitle, middleTitle, rightTitle };
		for (int i = 0; i < reses.length; i++) {
			TitleRes res = reses[i];
			ViewSwitcher switcher = titleSwitcher[i];
			if (res == null) {
				switcher.setVisibility(View.INVISIBLE);
			} else {
				switcher.setVisibility(View.VISIBLE);
				// 触发单击事件的View
				View clickView = null;
				// 文字
				if (res.getType() == 0) {
					switcher.setDisplayedChild(0);// 显示TextView
					//
					Object resource = res.getResource();
					String title = resource instanceof Integer ? getResources().getString((Integer) resource) : String.valueOf(resource);
					((TextView) switcher.getChildAt(0)).setText(title);
					clickView = switcher.getChildAt(0);
				} else {
					switcher.setDisplayedChild(1);// 显示ImageView
					//
					int imageResource = (Integer) res.getResource();
					((ImageView) switcher.getChildAt(1)).setImageResource(imageResource);
					clickView = switcher.getChildAt(1);
				}
				// 设置title的单击事件
				clickView.setOnClickListener(res.getClickListener());
			}
		}
	}
}

public class BaseFragment extends Fragment {

	private TitleMgr titleMgr;

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
		Log.d("fragment:onCreateView", getView());
		return null;
	}

	@Override
	public void onViewCreated(View view, Bundle savedInstanceState) {
		super.onViewCreated(view, savedInstanceState);
		Log.d("fragment:onCreateView", getView());
		//
		titleMgr = new TitleMgr(getActivity(), getView());
		titleMgr.findViewById();
	}

	protected void setTitle(TitleRes leftTitle, TitleRes middleTitle, TitleRes rightTitle) {
		titleMgr.setTitle(leftTitle, middleTitle, rightTitle);
	}

public abstract class BaseActivity extends Activity {

	private TitleMgr titleMgr;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		ActivityMgr.push(this);

		findViewById();
	}

	/**
	 * 初始化View
	 */
	protected void findViewById() {
		titleMgr = new TitleMgr(getContext(), findViewById(android.R.id.content));
		titleMgr.findViewById();
	}

	protected void setTitle(TitleRes leftTitle, TitleRes middleTitle, TitleRes rightTitle) {
		titleMgr.setTitle(leftTitle, middleTitle, rightTitle);
	}

我把业务逻辑抽出来放在单独写好的TitleMgr类中，然后BaseActivity和BaseFragment采用组合？也算是代理模式实现吧