安卓折叠视图

桃扇骨 2022-08-22 15:25 56阅读 0赞

# 安卓折叠视图 #

[上一篇博][Link 1]客写的是侧滑菜单,这篇就写个会折叠的菜单,先上效果图:  
![这里写图片描述][20160601160027369]  
![这里写图片描述][20160601160044166]  
![这里写图片描述][20160601160056666]  
好骚是不是= =

package xiaolin.widget;
    
    import android.content.Context;
    import android.graphics.Bitmap;
    import android.graphics.Canvas;
    import android.graphics.Color;
    import android.graphics.Matrix;
    import android.graphics.Paint;
    import android.graphics.PaintFlagsDrawFilter;
    import android.graphics.Rect;
    import android.util.AttributeSet;
    import android.view.KeyEvent;
    import android.view.MotionEvent;
    import android.view.VelocityTracker;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.Scroller;
    
    import xiaolin.utils.Utils;
    
    /** * Created by Administrator on 2016/1/14. */
    public class AFoldingPaneLayer extends ViewGroup { 
    
        public static final String TAG = "AFoldingPaneLayer";
        public static final int MININERCEPTXVILOCITY = 8;   // 最小拦截速度（dp）
        public static final int MINTOUCHVILOCITY = 300;     // 最小触发速度（dp）
        private static final int drawerTime = 400;          // 动画时间
    
        private Scroller mScroller = null;
        private VelocityTracker velocity = null;
        private Paint paint = new Paint();
        private Paint mPaintShadow = new Paint();
        private Bitmap bitmapFull = null;
        private AFoldingListener listener = null;
    
        private int menuWidth = 0;        // 菜单宽度
        private boolean mIsOpenFolding = false;     // 是否显示抽屉
        private boolean isTouchRight = false;
        private boolean isBeingDragged = false;
        private boolean isUnableToDrad = false;
        private boolean mIsUpdateBitmap = true;
        private float lastInerceptX = 0;
        private float lastInerceptY = 0;
        private float lastTouchX = 0;
        private float firstTouchX= 0;
        private int mNumberOfFolds = 2;
    
        public AFoldingPaneLayer(Context context) {
            super(context);
            init(context);
        }
    
        public AFoldingPaneLayer(Context context, AttributeSet attrs) {
            super(context, attrs);
            init(context);
        }
    
        public AFoldingPaneLayer(Context context, AttributeSet attrs, int defStyleAttr) {
            super(context, attrs, defStyleAttr);
            init(context);
        }
    
        private void init(Context context){
            mScroller = new Scroller(context);
            paint.setAntiAlias(true);
            paint.setDither(true);
    
            mPaintShadow.setColor(Color.BLACK);
            mPaintShadow.setStyle(Paint.Style.FILL);
        }
    
        @Override
        // 布局测量
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            int width = MeasureSpec.getSize(widthMeasureSpec);
            int height = MeasureSpec.getSize(heightMeasureSpec);
            setMeasuredDimension(width, height);
            menuWidth= (int)(width*0.75f);         // 菜单宽度
            if(bitmapFull != null){
                bitmapFull.recycle();
                bitmapFull = null;
            }
            bitmapFull = Bitmap.createBitmap(width+menuWidth, height, Bitmap.Config.ARGB_8888);
            mIsUpdateBitmap = true;
            int childCount = getChildCount();
            if(childCount < 1){
                return;
            }
            View menuView = getChildAt(0);
            // 合成菜单的测量宽度
            int menuWidthSpec = MeasureSpec.makeMeasureSpec(menuWidth, MeasureSpec.EXACTLY);
            menuView.measure(menuWidthSpec, heightMeasureSpec);
            for(int i=1; i<childCount; i++){
                View childView1 = getChildAt(i);
                childView1.measure(widthMeasureSpec, heightMeasureSpec);
            }
        }
    
        @Override
        /*布局，设置字控件的位置*/
        protected void onLayout(boolean changed, int l, int t, int r, int b) {
            int childCount = getChildCount();
            if(childCount <1){
                return;
            }
            // 隐藏在左边的视图
            View menuView = getChildAt(0);
            // 设置子视图的位置，左上角坐标，宽高
            menuView.layout(-menuView.getMeasuredWidth(), 0, 0, menuView.getMeasuredHeight());
    
            int left = 0;
            for(int i=1; i<childCount; i++) {
                View childView = getChildAt(i);
                int w = childView.getMeasuredWidth();
                childView.layout(left, 0, left+w, childView.getMeasuredHeight());
                left += w;
            }
        }
    
        @Override
        // onDraw()函数会调用此函数
        public void computeScroll() {
            if(mScroller.computeScrollOffset()){
                int x = mScroller.getCurrX();
                scrollTo(x, 0);
                // 调用invalidate()无效
                postInvalidate();
                if(listener != null){
                    listener.progress(-x/menuWidth);
                }
            }
        }
    
        /** * 矩阵变换 * @param rect_src 源 * @param rect_dst 目标 * @param deep 深度 * @param isScaleLeft 在左边还是在右边 * @return */
        private Matrix calculate(Rect rect_src, Rect rect_dst, int deep, boolean isScaleLeft){
            float src[] = new float[]{
                    rect_src.left, rect_src.top,      // 左上
                    rect_src.right, rect_src.top,     // 右上
                    rect_src.right, rect_src.bottom,  // 右下
                    rect_src.left, rect_src.bottom    // 左下
            };
            float[] dst = null;
            if(isScaleLeft) {
                dst = new float[]{
                        rect_dst.left, rect_dst.top+deep,
                        rect_dst.right, rect_dst.top,
                        rect_dst.right, rect_dst.bottom,
                        rect_dst.left, rect_dst.bottom-deep
                };
            }else{
                dst = new float[]{
                        rect_dst.left, rect_dst.top,
                        rect_dst.right, rect_dst.top + deep,
                        rect_dst.right, rect_dst.bottom - deep,
                        rect_dst.left, rect_dst.bottom
                };
            }
            Matrix matrix = new Matrix();
            matrix.setPolyToPoly(src, 0, dst, 0, src.length >> 1);
            return matrix;
        }
    
        /*绘制子视图*/
        @Override
        protected void dispatchDraw(Canvas canvas) {
            int x = getScrollX();
            if(x >= 0 || mNumberOfFolds==0){
                super.dispatchDraw(canvas);
                return;
            }
            canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG
                    | Paint.FILTER_BITMAP_FLAG));// 画布抗锯齿
            if(-x == menuWidth || mIsUpdateBitmap){
                bitmapFull.eraseColor(Color.argb(0, 0, 0, 0));
                // 将所有像素设为透明
                Canvas canvas1 = new Canvas(bitmapFull);
                canvas1.translate(menuWidth, 0);
                // 平移到正确位团置
                super.dispatchDraw(canvas1);
                // 把视图全部画到位图上
                if(mIsUpdateBitmap){
                    mIsUpdateBitmap = false;
                    /*画上阴影*/
                }
            }
    
            int height = getHeight();
            if(-x != menuWidth) {   /*以折叠形式绘制菜单*/
                float dstX = x;
                float dstW = Math.abs((float) x / mNumberOfFolds);
                float srcX = 0;
                float srcW = Math.abs((float) menuWidth / mNumberOfFolds);
                int depth = (int)Math.sqrt(Math.pow(srcW, 2)-Math.pow(dstW, 2))/6;// 勾股定理，再缩小几倍
                for (int i = 0; i < mNumberOfFolds; i++) {
                    Rect rect_src = new Rect((int) srcX, 0, (int) (srcX + srcW), height);
                    Rect rect_dst = new Rect((int) dstX, 0, (int) (dstX + dstW), height);
                    Matrix matrix = calculate(rect_src, rect_dst, depth, i%2==1);
                    canvas.save();
                    canvas.clipRect(rect_dst);
                    canvas.concat(matrix);
                    canvas.drawBitmap(bitmapFull,0, 0, paint);
                    if(i%2==1){
                        mPaintShadow.setAlpha(128-128*-x/menuWidth);
                        canvas.drawRect(rect_src, mPaintShadow);
                    }
                    canvas.restore();
                    dstX += dstW;
                    srcX += srcW;
                }
            }else{  /*直接绘制菜单*/
                canvas.save();
                canvas.clipRect(-menuWidth, 0, 0, height);
                super.dispatchDraw(canvas);
                canvas.restore();
            }
    
            /*绘制右边的主内容*/
            Rect rect_src = new Rect(0, 0, this.getWidth(), height);
            Rect rect_dst = new Rect(0, 0, this.getWidth()+x, height);
            Matrix m = calculate(rect_src, rect_dst, -x / 8, false);
            m.preTranslate(-menuWidth, 0);
            canvas.save();
            canvas.clipRect(rect_src);
            canvas.drawBitmap(bitmapFull, m, paint);
            canvas.restore();
        }
    
        /** * 只要您在onInterceptTouchEvent方法中返回false, * 每个后续的事件(从当前事件到最后ACTION_UP事件)将会先分发到onInterceptTouchEvent中， * 然后再交给目标子控件的onTouchEvent处理 （前提是子控件的onTouchEvent返回是true ）。 * * 如果在onInterceptTouchEvent返回true， * onInterceptTouchEvent方法中将不会收到后续的任何事件， * 目标子控件中除了ACTION_CANCEL外也不会接收所有这些后续事件， * 所有的后续事件将会被交付到你自己的onTouchEvent()方法中。 * @param event * @return */
        @Override
        public boolean onInterceptTouchEvent(MotionEvent event) {
            int action = event.getAction();
            if(action != 0){
                if(isBeingDragged){
                    return true;
                }
                if(isUnableToDrad){
                    return false;
                }
            }
            if(action == MotionEvent.ACTION_DOWN){
                lastInerceptX = event.getX();
                lastInerceptY = event.getY();
                isBeingDragged = false;
                isUnableToDrad = false;
                if(!mScroller.isFinished()){
                    mScroller.abortAnimation();
                    return true;
                }else if(mIsOpenFolding){
                    if(event.getX()>menuWidth){
                        isBeingDragged = true;
                    }
                }
            }else if(action == MotionEvent.ACTION_MOVE) {
                float x = event.getX();
                float y = event.getY();
                float dx = Math.abs(x-lastInerceptX);
                float dy = Math.abs(y-lastInerceptY);
                if(dy>dx) {  // 上下滑动
                    isUnableToDrad = true;
                }else if(x<lastInerceptX && !mIsOpenFolding) { // 往左滑动&&已关窗
                    isUnableToDrad = true;
                }else if(x>lastInerceptX && mIsOpenFolding){    // 往右滑动&&已开窗
                    isUnableToDrad = true;
                }else if(dx>dy && dx> Utils.dpToPx(MININERCEPTXVILOCITY, getResources())){  // 往右并且大于一定速度
                    isBeingDragged = true;
                }
                lastInerceptX = x;
                lastInerceptY = y;
            }
            return isBeingDragged;
        }
    
        // 触摸事件
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            int action = event.getAction();
            float x = event.getX();
            if(velocity == null){
                mIsUpdateBitmap = true;
                velocity = VelocityTracker.obtain();
                lastTouchX = x;
                if(mIsOpenFolding && x>menuWidth){
                    isTouchRight = true;
                    firstTouchX = x;
                }else{
                    isTouchRight = false;
                }
            }
            velocity.addMovement(event);
            if(action == MotionEvent.ACTION_DOWN){
       // 可能无此动作
    
            }else if(action == MotionEvent.ACTION_MOVE){ // 正在滑动
                float dx = x-lastTouchX;
                drawerViewBy((int)dx);
                lastTouchX = x;
            }else if(action == MotionEvent.ACTION_UP){
                if(isTouchRight && firstTouchX==x){
                    closeFolding();
                    velocity.recycle();
                    velocity = null;
                    return true;
                }else{
                    velocity.computeCurrentVelocity(1000);
                    if(velocity.getXVelocity() < -Utils.dpToPx(MINTOUCHVILOCITY, getResources())){
                        closeFolding();
                    }else if(velocity.getXVelocity() > Utils.dpToPx(MININERCEPTXVILOCITY, getResources())){
                        openFolding();
                    }else{
                        if(-getScrollX()>menuWidth/2){
                            openFolding();
                        }else{
                            closeFolding();
                        }
                    }
                    velocity.recycle();
                    velocity = null;
                }
            }
            return true;
        }
    
        @Override
        // 按键监听
        public boolean dispatchKeyEvent(KeyEvent event) {
            int code = event.getKeyCode();
            int action = event.getAction();
            if(code==KeyEvent.KEYCODE_BACK && action==KeyEvent.ACTION_UP){
                if(mIsOpenFolding){
                    closeFolding();
                    return true;
                }
            }
            return super.dispatchKeyEvent(event);
        }
    
        // 滚动距离并判断范围
        private void drawerViewBy(int dx){
            dx = -dx;
            int x = getScrollX();
            if(x+dx>0){
                scrollTo(0, 0);
            }else if(x+dx < -menuWidth){
                scrollTo(-menuWidth, 0);
            }else {
                scrollTo(x + dx, 0);
            }
            if(listener != null){
                listener.progress(-getScrollX()/(float)menuWidth);
            }
        }
    
        // 设置窗格数量
        public void setNumberOfFolds(int numberOfFolds){
            this.mNumberOfFolds = numberOfFolds;
        }
    
        public int getNumberOfFolds(){
            return mNumberOfFolds;
        }
    
        // 关闭菜单
        public void closeFolding(){
            int x = getScrollX();
            mScroller.startScroll(x, 0, -x, 0, drawerTime);
            invalidate();
            mIsOpenFolding = false;
            if(listener != null) {
                listener.fold(mIsOpenFolding);
            }
        }
    
        // 打开菜单
        public void openFolding(){
            int x = getScrollX();
            mScroller.startScroll(x, 0, -menuWidth - x, 0, drawerTime);
            invalidate();
            mIsOpenFolding = true;
            if(listener != null){
                listener.fold(mIsOpenFolding);
            }
        }
    
        // 是否打开菜单
        public boolean isOpen(){
            return mIsOpenFolding;
        }
    
        // 设置监听
        public void setFoldingListener(AFoldingListener listener){
            this.listener = listener;
        }
    
        // 监听接口
        public interface AFoldingListener{ 
            public void fold(boolean isOpen);
            public void progress(float progress);// 0.0f-1.0f
        }
    
    }

package xiaolin.utils;
    
    import android.content.res.Resources;
    import android.util.TypedValue;
    
    /** * Created by Administrator on 2016/1/17. */
    public class Utils { 
    
        private Utils(){
    
        }
    
        /** * dp转为像素 * @param dp * @param resources * @return */
        public static float dpToPx(float dp, Resources resources){
            return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.getDisplayMetrics());
        }
    }

在xml里使用

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#ffffff" android:orientation="vertical">
    
        <xiaolin.widget.AFoldingPaneLayer android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/layout">
    
            
            <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:background="#ffffff" android:orientation="vertical">
    
                <ImageView android:layout_width="match_parent" android:layout_height="match_parent" android:src="@drawable/img_bg" android:scaleType="centerCrop"/>
    
            </LinearLayout>
    
            
            <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:background="@color/colorPrimary" android:orientation="vertical" android:gravity="center">
    
                <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="小林" android:textColor="#ffffff" android:textSize="20sp"/>
    
            </LinearLayout>
    
        </xiaolin.widget.AFoldingPaneLayer>
    
    </LinearLayout>

在Activity里使用

package xiaolin.widget;
    
    import android.app.Activity;
    import android.os.Bundle;
    
    public class MainActivity extends Activity { 
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            AFoldingPaneLayer layer = (AFoldingPaneLayer)findViewById(R.id.layout);
            layer.setNumberOfFolds(4);// 设置有四个窗格,默认有两个窗格
        }
    
    }

[Link 1]: http://blog.csdn.net/u010431205/article/details/51556392
[20160601160027369]: /images/20220722/c30895e645224879acb8e0c7c689c848.png
[20160601160044166]: /images/20220722/0f70de4cb9ce40629d3d7d5e69a2d4c9.png
[20160601160056666]: /images/20220722/8c4f71d0265340db92cd4847021fbbbd.png