我们开发的是视频电话，所以既可以视频通话，可以只有音频的通话，所以底部含有两个按钮，最后一个就是删除功能，如果输入错误，我们可以删除输入的内容。

这里我们要通过重写LinearLayout来实现这部份，对应着上面的功能我们可以写一个接口来实现这些功能，如下：

 

public interface OnDialActionListener {        /**         * The make call button has been pressed         */        void placeCall();        /**         * The video button has been pressed         */        void placeVideoCall();        /**         * The delete button has been pressed         */        void deleteChar();        /**         * The delete button has been long pressed         */        void deleteAll();    }

通过回调来在主界面实现这些功能。例如在OnClick函数中

 

 

@Override    public void onClick(View v) {        if (actionListener != null) {            int viewId = v.getId();            if (viewId == R.id.dialVideoButton) {                actionListener.placeVideoCall();            }else if(viewId == R.id.dialButton) {                actionListener.placeCall();            }else if(viewId == R.id.deleteButton) {                actionListener.deleteChar();            }        }    }

我们可以通过本地的接口来实现内部函数，然后在主界面实例化这个接口并填写接口的实现方式。整体的代码如下：

 

 

package com.jwzhangjie.pjsip.widgets;import com.jwzhangjie.pjsip.R;import android.content.Context;import android.util.AttributeSet;import android.view.Gravity;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.View.OnLongClickListener;import android.widget.LinearLayout;public class DialerCallBar extends LinearLayout implements OnClickListener, OnLongClickListener {    public interface OnDialActionListener {        /**         * The make call button has been pressed         */        void placeCall();        /**         * The video button has been pressed         */        void placeVideoCall();        /**         * The delete button has been pressed         */        void deleteChar();        /**         * The delete button has been long pressed         */        void deleteAll();    }    private OnDialActionListener actionListener;        public DialerCallBar(Context context) {        this(context, null, 0);    }    public DialerCallBar(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }        public DialerCallBar(Context context, AttributeSet attrs, int style) {        super(context, attrs);        LayoutInflater inflater = LayoutInflater.from(context);        inflater.inflate(R.layout.dialpad_additional_buttons, this, true);        findViewById(R.id.dialVideoButton).setOnClickListener(this);        findViewById(R.id.dialButton).setOnClickListener(this);        findViewById(R.id.deleteButton).setOnClickListener(this);        findViewById(R.id.deleteButton).setOnLongClickListener(this);                if(getOrientation() == LinearLayout.VERTICAL) {            LayoutParams lp;            for(int i=0; i < getChildCount(); i++) {                lp = (LayoutParams) getChildAt(i).getLayoutParams();                int w = lp.width;                lp.width = lp.height;                lp.height = w;                lp.gravity = Gravity.CENTER_HORIZONTAL;                // Added for clarity but not necessary                getChildAt(i).setLayoutParams(lp);                            }        }    }    /**     * Set a listener for this widget actions     * @param l the listener called back when some user action is done on this widget     */    public void setOnDialActionListener(OnDialActionListener l) {        actionListener = l;    }        /**     * Set the action buttons enabled or not     */    public void setEnabled(boolean enabled) {        findViewById(R.id.dialButton).setEnabled(enabled);        findViewById(R.id.dialVideoButton).setEnabled(enabled);        findViewById(R.id.deleteButton).setEnabled(enabled);    }        @Override    public void onClick(View v) {        if (actionListener != null) {            int viewId = v.getId();            if (viewId == R.id.dialVideoButton) {                actionListener.placeVideoCall();            }else if(viewId == R.id.dialButton) {                actionListener.placeCall();            }else if(viewId == R.id.deleteButton) {                actionListener.deleteChar();            }        }    }    @Override    public boolean onLongClick(View v) {        if (actionListener != null) {            int viewId = v.getId();            if(viewId == R.id.deleteButton) {                actionListener.deleteAll();                v.setPressed(false);                return true;            }        }        return false;    }}