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。

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); 
}