在Android中动态添加Panel框架的实现代码

这里说是框架，说的大了点，其实没有那么复杂，只是一个容易扩展的基类而已。不过至少算是框架类的代码。
复制代码代码如下:
package arui;

import android.app.Activity;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewManager;
import android.widget.FrameLayout;

/**
* Base class for panel.
*
*/
public abstract class BasePanel {

    /**
     * left up position
     */
    public static final int LEFT_UP = 1;

    /**
     * right up position
     */
    public static final int RIGHT_UP = 2;

    /**
     * left bottom position
     */
    public static final int LEFT_BOTTOM = 3;

    /**
     * right bottom position
     */
    public static final int RIGHT_BOTTOM = 4;

    private static final int DEFAULT_MARGIN = 10;

    private static final int SHOW_PANEL = 0;

    private Activity activity;

    private LayoutParams parameters;

    private View view = null;

    private int layoutId;

    /**
     * constructor.
     *
     * @param activity
     *            this panel will be attached to the activity
     * @param layoutId
     *            the panel"s layout id
     */
    public BasePanel（Activity activity, int layoutId） {
        this.activity = activity;
        this.layoutId = layoutId;
    }

    /**
     * The developer can use this method to add the panel to the Activity.
     *
     * @param act
     *            Activity
     * @param params
     *            LayoutParams
     */
    public void attach（LayoutParams params） {
        parameters = params;
        mHandler.sendMessage（mHandler.obtainMessage（SHOW_PANEL））;

    }

    /**
     * The developer can use this method to add the panel to the Activity.
     *
     * @param act
     *            Activity
     * @param position
     *            int. You can use BasePanel.LEFT_UP,BasePanel.RIGHT_UP,
     *            BasePanel.RIGHT_BOTTOM or BasePanel.LEFT_BOTTOM.
     */
    public void attach（int position） {
        attach（position, DEFAULT_MARGIN, DEFAULT_MARGIN, DEFAULT_MARGIN,
                DEFAULT_MARGIN）;
    }

    /**
     * The developer can use this method to add the panel to the Activity.
     *
     * @param act
     *            Activity
     * @param position
     *            int. You can use BasePanel.LEFT_UP,BasePanel.RIGHT_UP,
     *            BasePanel.RIGHT_BOTTOM or BasePanel.LEFT_BOTTOM.
     * @param leftMargin
     *            int, left margin.
     * @param topMargin
     *            int, top margin.
     * @param rightMargin
     *            int, right margin.
     * @param bottomMargin
     *            int, bottom margin.
     *
     */
    public void attach（int position, int leftMargin, int topMargin,
            int rightMargin, int bottomMargin） {
        FrameLayout.LayoutParams params = null;
        params = new FrameLayout.LayoutParams（LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT）;
        params.setMargins（leftMargin, topMargin, rightMargin, bottomMargin）;
        switch （position） {
        case LEFT_UP:
            params.gravity = Gravity.LEFT;
            break;
        case RIGHT_UP:
            params.gravity = Gravity.RIGHT;
            break;
        case LEFT_BOTTOM:
            params.gravity = Gravity.LEFT | Gravity.BOTTOM;
            break;
        case RIGHT_BOTTOM:
            params.gravity = Gravity.RIGHT | Gravity.BOTTOM;
            break;
        default:
            break;
        }
        attach（params）;
    }

    /**
     * The developer can use this method to remove the panel from the Activity.
     *
     */
    public void remove（） {
        if （view ！= null） {
            ViewManager mViewManager = （ViewManager） view.getParent（）;
            if （mViewManager ！= null） {
                mViewManager.removeView（view）;
            }
        }
    }

    private Handler mHandler = new Handler（Looper.getMainLooper（）） {

        @Override
        public void handleMessage（Message msg） {
            switch （msg.what） {
            case SHOW_PANEL:
                if （view == null） {
                    LayoutInflater factory = LayoutInflater.from（activity）;
                    view = factory.inflate（layoutId, null）;
                }
                dealwithPanel（view）;
                remove（）;
                activity.addContentView（view, parameters）;
                break;
            }
        }

    };

    /**
     * do something with this panel.
     *
     * @param view
     *            View of the panel
     */
    public abstract void dealwithPanel（View view）;
}