Android自定义组件系列【四】——自定义ViewGroup实现双侧滑动
Android自定义组件系列【4】——自定义ViewGroup实现双侧滑动
在上一篇文章《Android自定义组件系列【3】——自定义ViewGroup实现侧滑》中实现了仿Facebook和人人网的侧滑效果，这一篇我们将接着上一篇来实现双面滑动的效果。
1、布局示意图：
2、核心代码
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mWidth = MeasureSpec.getSize(widthMeasureSpec); //获取MyScrollView的宽度
mHeight = MeasureSpec.getSize(heightMeasureSpec); //获取MyScrollView的高度
if(!isLocked){
initX = getScrollX();
isLocked = true;
}
}
在该方法中获取到初始的视图坐标偏移量getScrollX()
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
System.out.println("ACTION_DOWN");
mDownX = x; //记录按下时的x坐标
break;
case MotionEvent.ACTION_UP:
System.out.println("ACTION_UP");
int dis = (int) (x - mDownX); //滑动的距离
if(Math.abs(dis) > (mWidth * mMenuWeight / 2)){
if(dis > 0){ //如果>0则是向右滑动
toRightMove();
}else{ //如果<0则是向左滑动
toLeftMove();
}
}
break;
default:
break;
}
return true;
}
监听函数记录下按下和移动的屏幕坐标，求差计算出移动距离，如果这个距离大于阀值 （mWidth * mMenuWeight / 2)则滑动 public void toRightMove(){
System.out.println("maxRight = " + maxRight);
System.out.println("X = " + getScrollX());
if(getScrollX() >= initX){
int dx = (int)(mWidth * mMenuWeight);
mScroller.startScroll(getScrollX(), 0, -dx, 0, 500);
if(mListener != null){
mListener.onChanged();
}
invalidate();
}
}
如果是向右滑动则，如果当前是初始位置（centerView在中间）则可以向右滑动（getScrollX == initX），或者当前左边View可以看见，则可以向右滑动将centerView移动到中间（getScrollX > initX).同理有向左滑动的方法。 public void toLeftMove(){
System.out.println("maxLeft = " + maxLeft);
System.out.println("X = " + getScrollX());
if(getScrollX() <= initX){
int dx = (int)(mWidth * mMenuWeight);
mScroller.startScroll(getScrollX(), 0, dx, 0, 500);
if(mListener != null){
mListener.onChanged();
}
invalidate();
}
}
3、全部代码MyScrollView.java
package com.example.testscrollto;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.Scroller;
public class MyScrollView extends LinearLayout{
private Context mContext;
private int mWidth;
private int mHeight;
private float mMenuWeight = 3.0f / 5; //菜单界面比例
private View mMenuView; //菜单界面
private View mPriView; //内容界面
private View mRightView; //右边界面
private int maxLeft;
private int maxRight;
private int initX;
private boolean isLocked = false;
private Scroller mScroller;
private OnMenuChangedListener mListener;
public MyScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
mScroller = new Scroller(mContext);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
mMenuView.layout(-(int)(mWidth * mMenuWeight), 0, 0, mHeight);
mPriView.layout(0, 0, mWidth, mHeight);
mRightView.layout(mWidth, 0, mWidth + (int)(mWidth * mMenuWeight), mHeight);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mWidth = MeasureSpec.getSize(widthMeasureSpec); //获取MyScrollView的宽度
mHeight = MeasureSpec.getSize(heightMeasureSpec); //获取MyScrollView的高度
if(!isLocked){
initX = getScrollX();
isLocked = true;
}
}
/**设置右滑的菜单View*/
public void setMenu(View menu){
mMenuView = menu;
addView(mMenuView);
}
/**
* 设置主界面View
*/
public void setPrimary(View primary){
mPriView = primary;
addView(mPriView);
}
public void setRightView(View rightview){
mRightView = rightview;
addView(mRightView);
}
private float mDownX;
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
System.out.println("ACTION_DOWN");
mDownX = x; //记录按下时的x坐标
break;
case MotionEvent.ACTION_UP:
System.out.println("ACTION_UP");
int dis = (int) (x - mDownX); //滑动的距离
if(Math.abs(dis) > (mWidth * mMenuWeight / 2)){
if(dis > 0){ //如果>0则是向右滑动
toRightMove();
}else{ //如果<0则是向左滑动
toLeftMove();
}
}
break;
default:
break;
}
return true;
}
@Override
public void computeScroll() {
super.computeScroll();
if(mScroller.computeScrollOffset()){
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
postInvalidate();
}
}
public void toRightMove(){
System.out.println("maxRight = " + maxRight);
System.out.println("X = " + getScrollX());
if(getScrollX() >= initX){
int dx = (int)(mWidth * mMenuWeight);
mScroller.startScroll(getScrollX(), 0, -dx, 0, 500);
if(mListener != null){
mListener.onChanged();
}
invalidate();
}
}
public void toLeftMove(){
System.out.println("maxLeft = " + maxLeft);
System.out.println("X = " + getScrollX());
if(getScrollX() <= initX){
int dx = (int)(mWidth * mMenuWeight);
mScroller.startScroll(getScrollX(), 0, dx, 0, 500);
if(mListener != null){
mListener.onChanged();
}
invalidate();
}
}
public interface OnMenuChangedListener{
public void onChanged();
}
public void setOnMenuChangedListener(OnMenuChangedListener listener){
mListener = listener;
}
}
MainActivity.javapackage com.example.testscrollto;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import com.example.testscrollto.MyScrollView.OnMenuChangedListener;
public class MainActivity extends Activity {
private MyScrollView mScrollView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mScrollView = (MyScrollView)findViewById(R.id.rightscrollview);
final View menu = getLayoutInflater().inflate(R.layout.rightscrollview_menu, null);
final View primary = getLayoutInflater().inflate(R.layout.rightscrollview_primary, null);
final View rightview = getLayoutInflater().inflate(R.layout.rightscrollview_right_menu, null);
mScrollView.setMenu(menu);
mScrollView.setPrimary(primary);
mScrollView.setRightView(rightview);
mScrollView.setOnMenuChangedListener(new OnMenuChangedListener() {
@Override
public void onChanged() {
System.out.println("窗口切换了一次");
}
});
}
}
activity_main.xml<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<com.example.testscrollto.MyScrollView
android:id="@+id/rightscrollview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
其余三个视图界面无限制，可以*定义，这里就不贴出来了。4、运行效果：
源代码下载：http://download.csdn.net/detail/lxq_xsyu/7232701