ActivityFlipper.java

package com.ch_linghu.fanfoudroid.ui.module;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Gravity;
import android.widget.ImageView;
import android.widget.Toast;
import android.widget.ViewSwitcher.ViewFactory;

import com.ch_linghu.fanfoudroid.R;

/**
 * ActivityFlipper, 和 {@link ViewFactory} 类似, 只是设计用于切换activity.
 * 
 * 切换的前后顺序取决与注册时的先后顺序
 * 
 * USAGE: <code>
 *  ActivityFlipper mFlipper = new ActivityFlipper(this);
 *  mFlipper.addActivity(TwitterActivity.class);
 *  mFlipper.addActivity(MentionActivity.class);
 *  mFlipper.addActivity(DmActivity.class);
 *       
 *  // switch activity 
 *  mFlipper.setCurrentActivity(TwitterActivity.class);
 *  mFlipper.showNext();
 *  mFlipper.showPrevious();
 *       
 *  // or without set current activity
 *  mFlipper.showNextOf(TwitterActivity.class);
 *  mFlipper.showPreviousOf(TwitterActivity.class);
 * 
 *  // or auto mode, use the context as current activity
 *  mFlipper.autoShowNext();
 *  mFlipper.autoShowPrevious();
 *  
 *  // set toast
 *  mFlipper.setToastResource(new int[] {
 *       R.drawable.point_left,
 *       R.drawable.point_center,
 *       R.drawable.point_right
 *  });
 * 
 *  // set Animation
 *  mFlipper.setInAnimation(R.anim.push_left_in);
 *  mFlipper.setOutAnimation(R.anim.push_left_out);
 *  mFlipper.setPreviousInAnimation(R.anim.push_right_in);
 *  mFlipper.setPreviousOutAnimation(R.anim.push_right_out);
 * </code>
 * 
 */
public class ActivityFlipper implements IFlipper {
	private static final String TAG = "ActivityFlipper";

	private static final int SHOW_NEXT = 0;
	private static final int SHOW_PROVIOUS = 1;
	private int mDirection = SHOW_NEXT;

	private boolean mToastEnabled = false;
	private int[] mToastResourcesMap = new int[] {};

	private boolean mAnimationEnabled = false;
	private int mNextInAnimation = -1;
	private int mNextOutAnimation = -1;
	private int mPreviousInAnimation = -1;
	private int mPreviousOutAnimation = -1;

	private Activity mActivity;
	private List<Class<?>> mActivities = new ArrayList<Class<?>>();;
	private int mWhichActivity = 0;

	public ActivityFlipper() {
	}

	public ActivityFlipper(Activity activity) {
		mActivity = activity;
	}

	/**
	 * Launch Activity
	 * 
	 * @param cls
	 *            class of activity
	 */
	public void launchActivity(Class<?> cls) {
		Log.v(TAG, "launch activity :" + cls.getName());
		Intent intent = new Intent();
		intent.setClass(mActivity, cls);
		mActivity.startActivity(intent);

	}

	public void setToastResource(int[] resourceIds) {
		mToastEnabled = true;
		mToastResourcesMap = resourceIds;
	}

	private void maybeShowToast(int whichActicity) {
		if (mToastEnabled && whichActicity < mToastResourcesMap.length) {
			final Toast myToast = new Toast(mActivity);
			final ImageView myView = new ImageView(mActivity);
			myView.setImageResource(mToastResourcesMap[whichActicity]);
			myToast.setView(myView);
			myToast.setDuration(Toast.LENGTH_SHORT);
			myToast.setGravity(Gravity.BOTTOM | Gravity.CENTER, 0, 0);
			myToast.show();
		}
	}

	private void maybeShowAnimation(int whichActivity) {
		if (mAnimationEnabled) {
			boolean showPrevious = (mDirection == SHOW_PROVIOUS);
			if (showPrevious && mPreviousInAnimation != -1
					&& mPreviousOutAnimation != -1) {
				mActivity.overridePendingTransition(mPreviousInAnimation,
						mPreviousOutAnimation);
				return; // use Previous Animation
			}

			if (mNextInAnimation != -1 && mNextOutAnimation != -1) {
				mActivity.overridePendingTransition(mNextInAnimation,
						mNextOutAnimation);
			}
		}
	}

	/**
	 * Launch Activity by index
	 * 
	 * @param whichActivity
	 *            the index of Activity
	 */
	private void launchActivity(int whichActivity) {
		launchActivity(mActivities.get(whichActivity));
		maybeShowToast(whichActivity);
		maybeShowAnimation(whichActivity);
	}

	/**
	 * Add Activity NOTE: 添加的顺序很重要
	 * 
	 * @param cls
	 *            class of activity
	 */
	public void addActivity(Class<?> cls) {
		mActivities.add(cls);
	}

	/**
	 * Get index of the Activity
	 * 
	 * @param cls
	 *            class of activity
	 * @return
	 */
	private int getIndexOf(Class<?> cls) {
		int index = mActivities.indexOf(cls);
		if (-1 == index) {
			Log.e(TAG, "No such activity: " + cls.getName());
		}
		return index;
	}

	@SuppressWarnings("unused")
	private Class<?> getActivityAt(int index) {
		if (index > 0 && index < mActivities.size()) {
			return mActivities.get(index);
		}
		return null;
	}

	/**
	 * Show next activity(already setCurrentActivity)
	 */
	@Override
	public void showNext() {
		mDirection = SHOW_NEXT;
		setDisplayedActivity(mWhichActivity + 1, true);
	}

	/**
	 * Show next activity of
	 * 
	 * @param cls
	 *            class of activity
	 */
	public void showNextOf(Class<?> cls) {
		setCurrentActivity(cls);
		showNext();
	}

	/**
	 * Show next activity(use current context as a activity)
	 */
	public void autoShowNext() {
		showNextOf(mActivity.getClass());
	}

	/**
	 * Show previous activity(already setCurrentActivity)
	 */
	@Override
	public void showPrevious() {
		mDirection = SHOW_PROVIOUS;
		setDisplayedActivity(mWhichActivity - 1, true);
	}

	/**
	 * Show previous activity of
	 * 
	 * @param cls
	 *            class of activity
	 */
	public void showPreviousOf(Class<?> cls) {
		setCurrentActivity(cls);
		showPrevious();
	}

	/**
	 * Show previous activity(use current context as a activity)
	 */
	public void autoShowPrevious() {
		showPreviousOf(mActivity.getClass());
	}

	/**
	 * Sets which child view will be displayed
	 * 
	 * @param whichActivity
	 *            the index of the child view to display
	 * @param display
	 *            display immediately
	 */
	public void setDisplayedActivity(int whichActivity, boolean display) {
		mWhichActivity = whichActivity;
		if (whichActivity >= getCount()) {
			mWhichActivity = 0;
		} else if (whichActivity < 0) {
			mWhichActivity = getCount() - 1;
		}

		if (display) {
			launchActivity(mWhichActivity);
		}
	}

	/**
	 * Set current Activity
	 * 
	 * @param cls
	 *            class of activity
	 */
	public void setCurrentActivity(Class<?> cls) {
		setDisplayedActivity(getIndexOf(cls), false);
	}

	public void setInAnimation(int resourceId) {
		setEnableAnimation(true);
		mNextInAnimation = resourceId;
	}

	public void setOutAnimation(int resourceId) {
		setEnableAnimation(true);
		mNextOutAnimation = resourceId;
	}

	public void setPreviousInAnimation(int resourceId) {
		mPreviousInAnimation = resourceId;
	}

	public void setPreviousOutAnimation(int resourceId) {
		mPreviousOutAnimation = resourceId;
	}

	public void setEnableAnimation(boolean enable) {
		mAnimationEnabled = enable;
	}

	/**
	 * Count activities
	 * 
	 * @return the number of activities
	 */
	public int getCount() {
		return mActivities.size();
	}
}