侧滑菜单

来源：互联网发布：网络手机号码编辑：程序博客网时间：2024/05/06 03:44
本博客为: http://www.imooc.com/video/4386/0 笔记
public class SlidingMenu extends HorizontalScrollView {    private ViewGroup mWapper;    private ViewGroup mMenu;    private ViewGroup mContent;    //屏幕的宽度    private int mScreenWidth;    //菜单右边距    private int mMenuRightPadding;    //是否已经测量    private boolean isOnce=true;    //菜单的宽度    private int mWidth=0;    public SlidingMenu(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        // 获取我们定义的属性        TypedArray a = context.getTheme().obtainStyledAttributes(attrs,                R.styleable.SlidingMenu, defStyle, 0);        int n = a.getIndexCount();        for (int i = 0; i < n; i++)        {            int attr = a.getIndex(i);            switch (attr)            {            case R.styleable.SlidingMenu_rightPadding:                mMenuRightPadding = a.getDimensionPixelSize(attr,                        (int) TypedValue.applyDimension(                                TypedValue.COMPLEX_UNIT_DIP, 50, context                                        .getResources().getDisplayMetrics()));                break;            }        }        a.recycle();        //获取手机屏幕的宽度        WindowManager wm = (WindowManager) context                .getSystemService(Context.WINDOW_SERVICE);        DisplayMetrics outMetrics = new DisplayMetrics();        wm.getDefaultDisplay().getMetrics(outMetrics);        mScreenWidth = outMetrics.widthPixels;    }    public SlidingMenu(Context context, AttributeSet attrs) {        this(context, attrs,0);    }    public SlidingMenu(Context context) {        this(context,null);    }    /**     * 指定子控件与自身的宽高     */    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        if(isOnce){             mWapper=(ViewGroup) getChildAt(0);             mMenu=(ViewGroup) mWapper.getChildAt(0);             mContent=(ViewGroup) mWapper.getChildAt(1);             mWidth=mMenu.getLayoutParams().width=mScreenWidth-mMenuRightPadding;             mContent.getLayoutParams().width=mScreenWidth;             isOnce=false;        }         super.onMeasure(widthMeasureSpec, heightMeasureSpec);    }    /**     * 初始化菜单的位置为隐藏     */    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        // TODO 自动生成的方法存根        super.onLayout(changed, l, t, r, b);        if(changed){            this.scrollTo(mWidth, 0);        }    }    /**     * 监听滑动的判断        * 当偏移量达到临界点之时的处理     */    @Override    public boolean onTouchEvent(MotionEvent ev) {        switch(ev.getAction()){         case MotionEvent.ACTION_UP:             //获取偏移量             int scrollX=this.getScrollX();             if(scrollX>=mWidth/2){                 //平滑的滚动                      this.smoothScrollTo(mWidth, 0);             }else{                //平滑的滚动                 this.smoothScrollTo(0, 0);             }            return true;        }        return super.onTouchEvent(ev);    }    /**     * 通过滑动过程中各种的梯度来实现动画效果     */    @Override    protected void onScrollChanged(int l, int t, int oldl, int oldt) {        // TODO 自动生成的方法存根        super.onScrollChanged(l, t, oldl, oldt);        //获取变化的梯度        float scale=l*1.0f/mWidth;// 1--0        /**         * 内容区域缩放的动画         */        float rightScale = 0.7f + 0.3f * scale;        //设置缩放的中心点        ViewHelper.setPivotX(mContent, 0);        ViewHelper.setPivotY(mContent, mContent.getHeight() / 2);        ViewHelper.setScaleX(mContent, rightScale);        ViewHelper.setScaleY(mContent, rightScale);        //设置菜单滑动时的偏移量        ViewHelper.setTranslationX(mMenu, mWidth*scale*0.8f);        /**         * 菜单缩放与透明度的变化         */        float leftScale = 1.0f - scale * 0.3f;        float leftAlpha = 0.6f + 0.4f * (1 - scale);        ViewHelper.setScaleX(mMenu, leftScale);        ViewHelper.setScaleY(mMenu, leftScale);        ViewHelper.setAlpha(mMenu, leftAlpha);    }}
0 0