SnakeLayout源码

声明：这款SnakeLayout确实强大，膜拜中……

转自：http://wallage.blog.163.com/blog/static/1738962420108211120850/

import java.util.ArrayList;import java.util.Date;import java.util.List;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.Rect;import android.util.AttributeSet;import android.util.Log;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.View;import android.view.GestureDetector.OnGestureListener;import android.widget.FrameLayout;import android.widget.ImageView;public class SnakeLayout extends FrameLayout {private static final String LOG_TAG = "SnakeLayout";private GestureDetector mGestureDetector;private SnakeOnGestureListener mGestureListener;private List<View> ViewHolder;private int selectImg;private int totalViewNum;private View mContentView;private SnakeView ScrollView;private Context mContext;private enum State {ABOUT_TO_ANIMATE, ANIMATING, ANIMATE_END, READY, TRACKING};private State mState;private double aniStartPos;// Value = scrollNum + percent*direction;private double aniStopPos;// Value = scrollNum + percent*direction;private Date aniStartTime;private long aniTime = 1000;private double aniSpeed = 500;private double aniDefG = 5;private int mContentWidth = 0;private int mContentHeight = 0;private int clickItem = -1;private int direction = 0;private int movDirection = 0;private double percent = 0;private int scrollNum = 0;private PathScale myPathViews;private List<Bitmap> BmpRecViews;private OnSelectListener selectListener;private OnClickListener clickListener;private int currentIndex = 0;public SnakeLayout(Context context, AttributeSet attrs) {super(context, attrs);Log.d(LOG_TAG, "Init Snake Layout");mContext = context;TypedArray a = context.obtainStyledAttributes(attrs,R.styleable.SnakeLayout);selectImg = a.getInteger(R.styleable.SnakeLayout_selectImg, -1);a.recycle();mGestureListener = new SnakeOnGestureListener();mGestureDetector = new GestureDetector(mGestureListener);mGestureDetector.setIsLongpressEnabled(false);BmpRecViews = new ArrayList<Bitmap>();myPathViews = new PathScale();mState = State.READY;}public void Init() {for (int i = 0; i < totalViewNum; i++) {ImageView v = (ImageView) ViewHolder.get(i);v.setScaleType(ImageView.ScaleType.FIT_XY);v.setImageBitmap(BmpRecViews.get((i + currentIndex)% BmpRecViews.size()));}}public void addBitmap(Bitmap b) {if (b != null)BmpRecViews.add(b);}public void addBitmap(Bitmap b, int position) {if (b != null)BmpRecViews.add(position, b);}public void addRec(int rec) {Bitmap b = BitmapFactory.decodeResource(this.getResources(), rec);if (b != null)BmpRecViews.add(b);}public void addRec(int rec, int position) {Bitmap b = BitmapFactory.decodeResource(this.getResources(), rec);if (b != null)BmpRecViews.add(position, b);}private class PathScale {private int totalNum;List<Double> myLen;List<Rect> myRect;int recentScrollNum = 0;double RecentPercent = 0;public PathScale() {totalNum = 0;myLen = new ArrayList<Double>();myRect = new ArrayList<Rect>();}public double getAverageLen() {double len = 0;if (totalNum < 2)return len;for (int i = 0; i < totalNum - 2; i++) {len += myLen.get(i);}return len / (totalNum - 1);}public int size() {return totalNum;}public void addPointView(int left, int top, int right, int bottom) {totalNum++;Log.d(LOG_TAG, "total num : " + totalNum);Rect r = new Rect(left, top, right, bottom);myRect.add(r);if (totalNum > 1) {Rect r0 = myRect.get(totalNum - 2);int dx = r0.centerX() - r.centerX();int dy = r0.centerY() - r.centerY();double len = Math.sqrt(dx * dx + dy * dy);myLen.add(len);}}public int getRecentScrollNum() {return recentScrollNum;}public double getPercent() {return RecentPercent;}public void computeScroll(int clickNum, int dir, double len) {double remain = len;recentScrollNum = 0;RecentPercent = 0;if (dir == 1) {for (int i = clickNum;; i++) {if (i > totalNum - 2)i = totalNum - 2;if (i < 0)i = 0;double tmp = myLen.get(i);if (remain >= tmp) {recentScrollNum++;remain -= tmp;} else {RecentPercent = remain / tmp;break;}}} else if (dir == -1) {for (int i = clickNum;; i--) {if (i - 1 > totalNum - 2)i = totalNum - 1;if (i - 1 < 0)i = 1;double tmp = myLen.get(i - 1);if (remain >= tmp) {recentScrollNum--;remain -= tmp;} else {RecentPercent = remain / tmp;break;}}}}public Rect getMoveRect(int selectNum) {if (direction == 1) {int newIndex = selectNum + scrollNum;if (newIndex >= totalNum - 1) {Rect r0 = myRect.get(totalNum - 1);Rect r1 = myRect.get(totalNum - 2);int nx = (int) (r0.centerX() - (r1.centerX() - r0.centerX())* percent);int ny = (int) (r0.centerY() - (r1.centerY() - r0.centerY())* percent);int nw = (int) (r0.width() - (r1.width() - r0.width())* percent);int nh = (int) (r0.height() - (r1.height() - r0.height())* percent);return new Rect(nx - nw / 2, ny - nh / 2, nx + nw / 2, ny+ nh / 2);} else if (newIndex == -1) {Rect r0 = myRect.get(0);Rect r1 = myRect.get(1);int nx = (int) (r0.centerX() - (r1.centerX() - r0.centerX())* (1 - percent));int ny = (int) (r0.centerY() - (r1.centerY() - r0.centerY())* (1 - percent));int nw = (int) (r0.width() - (r1.width() - r0.width())* (1 - percent));int nh = (int) (r0.height() - (r1.height() - r0.height())* (1 - percent));return new Rect(nx - nw / 2, ny - nh / 2, nx + nw / 2, ny+ nh / 2);} else if (newIndex > totalNum - 1 || newIndex < -1) {return null;} else {Rect r0 = myRect.get(newIndex);Rect r1 = myRect.get(newIndex + 1);int nx = (int) (r0.centerX() + (r1.centerX() - r0.centerX())* percent);int ny = (int) (r0.centerY() + (r1.centerY() - r0.centerY())* percent);int nw = (int) (r0.width() + (r1.width() - r0.width())* percent);int nh = (int) (r0.height() + (r1.height() - r0.height())* percent);return new Rect(nx - nw / 2, ny - nh / 2, nx + nw / 2, ny+ nh / 2);}} else if (direction == -1) {int newIndex = selectNum + scrollNum;if (newIndex == 0) {Rect r0 = myRect.get(0);Rect r1 = myRect.get(1);int nx = (int) (r0.centerX() - (r1.centerX() - r0.centerX())* percent);int ny = (int) (r0.centerY() - (r1.centerY() - r0.centerY())* percent);int nw = (int) (r0.width() - (r1.width() - r0.width())* percent);int nh = (int) (r0.height() - (r1.height() - r0.height())* percent);return new Rect(nx - nw / 2, ny - nh / 2, nx + nw / 2, ny+ nh / 2);} else if (newIndex == totalNum) {Rect r0 = myRect.get(totalNum - 1);Rect r1 = myRect.get(totalNum - 2);int nx = (int) (r0.centerX() - (r1.centerX() - r0.centerX())* (1 - percent));int ny = (int) (r0.centerY() - (r1.centerY() - r0.centerY())* (1 - percent));int nw = (int) (r0.width() - (r1.width() - r0.width())* (1 - percent));int nh = (int) (r0.height() - (r1.height() - r0.height())* (1 - percent));return new Rect(nx - nw / 2, ny - nh / 2, nx + nw / 2, ny+ nh / 2);} else if (newIndex > totalNum || newIndex < 0) {return null;} else {Rect r0 = myRect.get(newIndex);Rect r1 = myRect.get(newIndex - 1);int nx = (int) (r0.centerX() + (r1.centerX() - r0.centerX())* percent);int ny = (int) (r0.centerY() + (r1.centerY() - r0.centerY())* percent);int nw = (int) (r0.width() + (r1.width() - r0.width())* percent);int nh = (int) (r0.height() + (r1.height() - r0.height())* percent);return new Rect(nx - nw / 2, ny - nh / 2, nx + nw / 2, ny+ nh / 2);}} else {return null;}}}public static interface OnSelectListener {public void onSelected(int position);}public void setOnSelectListener(OnSelectListener l) {selectListener = l;}public static interface OnClickListener {public void onClicked(int position);}public void setOnClickListener(OnClickListener l) {clickListener = l;}protected void onFinishInflate() {super.onFinishInflate();Log.d(LOG_TAG, "onFinishInflate");ViewHolder = new ArrayList<View>();View v = findViewById(R.id.snakeImg0);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg1);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg2);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg3);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg4);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg5);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg6);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg7);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg8);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg9);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg10);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg11);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg12);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg13);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg14);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg15);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg16);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg17);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg18);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg19);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg20);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg21);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg22);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg23);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg24);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg25);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg26);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg27);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg28);if (v != null)ViewHolder.add(v);v = findViewById(R.id.snakeImg29);if (v != null)ViewHolder.add(v);mContentView = findViewById(R.id.snakeContent);totalViewNum = ViewHolder.size();if (totalViewNum < 3) {throw new RuntimeException("Please confirm that there are more than Three "+ "ImageViews with id snakeImg* in your xml file, * is a interger");}if (selectImg == -1)selectImg = totalViewNum / 2;this.setOnTouchListener(touchListener);this.setLongClickable(true);}protected void onLayout(boolean changed, int l, int t, int r, int b) {super.onLayout(changed, l, t, r, b);if (mContentView != null) {mContentWidth = mContentView.getWidth();mContentHeight = mContentView.getHeight();}if (myPathViews.size() == 0) {for (int i = 0; i < totalViewNum; i++) {View v = ViewHolder.get(i);int left = getLeft(v), top = getTop(v);int right = getRight(v), bottom = getBottom(v);myPathViews.addPointView(left, top, right, bottom);}}Log.d(LOG_TAG, "onLayout mContentWidth:" + mContentWidth+ " mContentHeight:" + mContentHeight);}protected void dispatchDraw(Canvas canvas) {Log.d(LOG_TAG, "dispatchDraw");if (ScrollView == null) {ScrollView = new SnakeView(mContext);ScrollView.setLayoutParams(new LayoutParams(mContentWidth,mContentHeight));addView(ScrollView);}super.dispatchDraw(canvas);}public void getGlobalLocation(View v, int location[]) {int v_location[] = new int[2], p_location[] = new int[2];v.getLocationOnScreen(v_location);mContentView.getLocationOnScreen(p_location);location[0] = v_location[0] - p_location[0];location[1] = v_location[1] - p_location[1];}public int getLeft(View v) {int v_location[] = new int[2], p_location[] = new int[2];v.getLocationOnScreen(v_location);int l = ((ImageView) v).getPaddingLeft();mContentView.getLocationOnScreen(p_location);return l + v_location[0] - p_location[0];}public int getRight(View v) {int v_location[] = new int[2], p_location[] = new int[2];v.getLocationOnScreen(v_location);int r = ((ImageView) v).getPaddingRight();mContentView.getLocationOnScreen(p_location);return v.getWidth() - r + v_location[0] - p_location[0];}public int getTop(View v) {int v_location[] = new int[2], p_location[] = new int[2];v.getLocationOnScreen(v_location);int t = ((ImageView) v).getPaddingTop();mContentView.getLocationOnScreen(p_location);return t + v_location[1] - p_location[1];}public int getBottom(View v) {int v_location[] = new int[2], p_location[] = new int[2];v.getLocationOnScreen(v_location);int b = ((ImageView) v).getPaddingBottom();mContentView.getLocationOnScreen(p_location);return v.getHeight() - b + v_location[1] - p_location[1];}OnTouchListener touchListener = new OnTouchListener() {public boolean onTouch(View v, MotionEvent event) {Log.d(LOG_TAG,"onTouch " + " x: " + event.getX() + " y: " + event.getY());int action = event.getAction();if (action == MotionEvent.ACTION_UP) {Log.d(LOG_TAG, "ACTION_UP " + percent);if (mState == State.TRACKING) {aniStartPos = 1.0 * scrollNum + direction * percent;aniStopPos = scrollNum;if (percent > 0.5) {aniStopPos += direction;}aniTime = (long) (1000 * percent);mState = State.ABOUT_TO_ANIMATE;aniStartTime = new Date();ScrollView.invalidate();}}mGestureDetector.onTouchEvent(event);return false;}};public void moveView() {Log.d(LOG_TAG, "move View");if (direction != 0) {if (percent > 1)percent = 1;if (direction == -1) {int size = BmpRecViews.size();for (int i = 0; i < totalViewNum + 1; i++) {Rect r = myPathViews.getMoveRect(i - scrollNum);if (r == null)continue;int bmpIndex = (i - scrollNum + currentIndex) % size;while (bmpIndex < 0)bmpIndex += size;Bitmap b = BmpRecViews.get(bmpIndex);if (b != null) {ScrollView.addView(b, r.left, r.top, r.width(),r.height());}}} else if (direction == 1) {int size = BmpRecViews.size();for (int i = -1; i < totalViewNum; i++) {Rect r = myPathViews.getMoveRect(i - scrollNum);if (r == null)continue;int bmpIndex = (i - scrollNum + currentIndex) % size;while (bmpIndex < 0)bmpIndex += size;Bitmap b = BmpRecViews.get(bmpIndex);if (b != null) {ScrollView.addView(b, r.left, r.top, r.width(),r.height());}}}}}class SnakeOnGestureListener implements OnGestureListener {int initX;int initY;int scrollView;int mClickView = -1;public boolean onDown(MotionEvent event) {Log.d(LOG_TAG, "onDown");initX = (int) event.getX();initY = (int) event.getY();if (mState == State.ANIMATING) {mState = State.TRACKING;} else {direction = 0;percent = 0;scrollNum = 0;aniSpeed = 0;for (int i = 0; i < totalViewNum; i++) {ImageView tempView = (ImageView) ViewHolder.get(i);int local[] = new int[2];getGlobalLocation(tempView, local);int l = getLeft(tempView);int t = getTop(tempView);int w = getRight(tempView) - l;int h = getBottom(tempView) - t;tempView.setVisibility(View.INVISIBLE);int newIndex = i + currentIndex;int size = BmpRecViews.size();while (newIndex < 0) {newIndex += size;}newIndex = newIndex % size;Bitmap b = BmpRecViews.get(newIndex);if (b != null) {ScrollView.addView(b, l, t, w, h);}}}return false;}public boolean onFling(MotionEvent e1, MotionEvent e2, float vx,float vy) {aniSpeed = Math.sqrt(vx * vx + vy * vy);double len = myPathViews.getAverageLen();double v = aniSpeed / (2 * len);aniTime = (long) (v * 1000 / aniDefG);double s = v * v / (2 * aniDefG);Log.d(LOG_TAG, "onFling,velocityX:" + vx + " velocityY:" + vy+ " aniTime:" + aniTime + " Fling s:" + s);aniStartPos = 1.0 * scrollNum + direction * percent;aniStopPos = aniStartPos + direction * s;aniStopPos = Math.round(aniStopPos);mState = State.ABOUT_TO_ANIMATE;aniStartTime = new Date();ScrollView.invalidate();return false;}public void onLongPress(MotionEvent e) {Log.d(LOG_TAG, "onLongPress");}public boolean onScroll(MotionEvent e1, MotionEvent e2,float distanceX, float distanceY) {Log.d(LOG_TAG, "onScroll, distanceX:" + distanceX + "distanceY:"+ distanceY);mState = State.TRACKING;scrollView = getNearClickView(initX, initY);double dx = e2.getX() - initX;double dy = e2.getY() - initY;initX = (int) e2.getX();initY = (int) e2.getY();// compute the directionif (scrollView != 0 && scrollView != totalViewNum - 1) {View v0 = ViewHolder.get(scrollView);View v1 = ViewHolder.get(scrollView - 1);View v2 = ViewHolder.get(scrollView + 1);double len1, len2;double x0 = (getLeft(v0) + getRight(v0)) * 1.0 / 2;double y0 = (getTop(v0) + getBottom(v0)) * 1.0 / 2;double x1 = (getLeft(v1) + getRight(v1)) * 1.0 / 2;double y1 = (getTop(v1) + getBottom(v1)) * 1.0 / 2;double x2 = (getLeft(v2) + getRight(v2)) * 1.0 / 2;double y2 = (getTop(v2) + getBottom(v2)) * 1.0 / 2;double dx1 = x1 - x0, dy1 = y1 - y0;double dx2 = x2 - x0, dy2 = y2 - y0;len1 = Math.sqrt(dx1 * dx1 + dy1 * dy1);len2 = Math.sqrt(dx2 * dx2 + dy2 * dy2);double r1 = (dx1 * dx + dy1 * dy) / len1, r2 = (dx2 * dx + dy2* dy)/ len2;if (r1 > r2 && r1 > 0) {movDirection = -1;myPathViews.computeScroll(scrollView, movDirection, r1);} else if (r2 > r1 && r2 > 0) {movDirection = 1;myPathViews.computeScroll(scrollView, movDirection, r2);}} else if (scrollView == 0) {View v0 = ViewHolder.get(scrollView);View v1 = ViewHolder.get(scrollView + 1);double len1;double x0 = (getLeft(v0) + getRight(v0)) * 1.0 / 2;double y0 = (getTop(v0) + getBottom(v0)) * 1.0 / 2;double x1 = (getLeft(v1) + getRight(v1)) * 1.0 / 2;double y1 = (getTop(v1) + getBottom(v1)) * 1.0 / 2;double dx1 = x1 - x0, dy1 = y1 - y0;len1 = Math.sqrt(dx1 * dx1 + dy1 * dy1);double r1 = (dx1 * dx + dy1 * dy) / len1;if (r1 > 0) {movDirection = 1;myPathViews.computeScroll(scrollView, movDirection, r1);} else {movDirection = -1;myPathViews.computeScroll(scrollView, movDirection, -r1);}} else if (scrollView == totalViewNum - 1) {View v0 = ViewHolder.get(scrollView);View v1 = ViewHolder.get(scrollView - 1);double len1;double x0 = (getLeft(v0) + getRight(v0)) * 1.0 / 2;double y0 = (getTop(v0) + getBottom(v0)) * 1.0 / 2;double x1 = (getLeft(v1) + getRight(v1)) * 1.0 / 2;double y1 = (getTop(v1) + getBottom(v1)) * 1.0 / 2;double dx1 = x1 - x0, dy1 = y1 - y0;len1 = Math.sqrt(dx1 * dx1 + dy1 * dy1);double r1 = (dx1 * dx + dy1 * dy) / len1;if (r1 > 0) {movDirection = -1;myPathViews.computeScroll(scrollView, movDirection, r1);} else {movDirection = 1;myPathViews.computeScroll(scrollView, movDirection, -r1);}}if (direction == 0)direction = movDirection;double pos = scrollNum * 1.0 + percent * direction+ myPathViews.getPercent() * movDirection+ myPathViews.getRecentScrollNum() * 1.0;if (pos > 0)direction = 1;elsedirection = -1;scrollNum = (int) pos;percent = Math.abs(pos - 1.0 * scrollNum);Log.d(LOG_TAG, "pos:" + pos + " scrollNum:" + scrollNum+ " percent:" + percent + " direction = " + direction);// move the viewScrollView.clear();moveView();ScrollView.invalidate();return false;}public void onShowPress(MotionEvent e) {Log.d(LOG_TAG, "onShowPress");}public boolean onSingleTapUp(MotionEvent e) {Log.d(LOG_TAG, "onSingleTapUp");if (mState == State.ANIMATING) {mState = State.TRACKING;} else if (mState == State.READY) {mClickView = getClickView((int) e.getX(), (int) e.getY());Log.d(LOG_TAG, "View " + mClickView + " is clicked!");clickItem = mClickView;if (clickListener != null) {int s = currentIndex + clickItem, size = BmpRecViews.size();s %= size;if (s < 0)s += size;clickListener.onClicked(s);}if (mClickView != -1) {aniStopPos = selectImg - mClickView;if (aniStopPos == 0)return false;if (aniStopPos > 0)direction = 1;elsedirection = -1;aniStartPos = 0;aniTime = (long) Math.abs(500 * aniStopPos);mState = State.ABOUT_TO_ANIMATE;aniStartTime = new Date();ScrollView.invalidate();}}return false;}}public void setSelected(int position) {currentIndex = position - selectImg;}public void setSelectedWithAnimation(int position) {int size = BmpRecViews.size();currentIndex %= size;if (currentIndex < 0)currentIndex += size;aniStopPos = position - selectImg - currentIndex;if (aniStopPos == 0)return;if (aniStopPos > 0)direction = 1;elsedirection = -1;aniStartPos = 0;aniTime = 1000;mState = State.ABOUT_TO_ANIMATE;aniStartTime = new Date();ScrollView.invalidate();}private int getClickView(int x, int y) {int cn = -1;View v;for (int i = 0; i < totalViewNum; i++) {v = ViewHolder.get(i);if (v == null)continue;int l = getLeft(v), r = getRight(v);int t = getTop(v), b = getBottom(v);if (l < x && x < r && t < y && y < b) {cn = i;}}return cn;}public int getNearClickView(int x, int y) {int minLen = 10000, cn = -1;View v;for (int i = 0; i < totalViewNum; i++) {v = ViewHolder.get(i);if (v == null)continue;int vx = (getLeft(v) + getRight(v)) / 2;int vy = (getTop(v) + getBottom(v)) / 2;int len = (int) Math.sqrt((x - vx) * (x - vx) + (y - vy) * (y - vy));if (len < minLen) {minLen = len;cn = i;}}return cn;}public boolean getAnimateData() {long time = aniTime;Date date = new Date();long t = date.getTime() - aniStartTime.getTime();if (t < 0 || t > time) {mState = State.ANIMATE_END;return false;} else {mState = State.ANIMATING;double s = aniStopPos - aniStartPos;double g = 2 * s / (time * time);double mScroll = 0;mScroll = g * time * t - g * t * t / 2;scrollNum = (int) (mScroll + aniStartPos);percent = Math.abs(mScroll + aniStartPos - 1.0 * scrollNum);ScrollView.clear();moveView();return true;}}public void handleAniEnd() {int size = BmpRecViews.size();currentIndex -= aniStopPos;clickItem = -1;for (int i = 0; i < totalViewNum; i++) {int newIndex = i + currentIndex;while (newIndex < 0) {newIndex += size;}newIndex = newIndex % size;ImageView myView = (ImageView) ViewHolder.get(i);myView.setVisibility(View.VISIBLE);myView.setImageBitmap(BmpRecViews.get(newIndex));}invalidate();mState = State.READY;if (selectListener != null) {int s = currentIndex + selectImg;s %= size;if (s < 0)s += size;selectListener.onSelected(s);}}public class SnakeView extends View {private List<MyView> mListView;public int test = 0;public SnakeView(Context context) {super(context);mListView = new ArrayList<MyView>();}private class MyView {Bitmap bitmap;int left;int top;int width;int height;public MyView(Bitmap b, int l, int t, int w, int h) {bitmap = b;left = l;top = t;width = w;height = h;}}public void addView(Bitmap b, int left, int top, int width, int height) {if (b != null) {MyView v = new MyView(b, left, top, width, height);mListView.add(v);}}public void clear() {mListView.clear();}protected void onDraw(Canvas canvas) {Paint defaultPaint = new Paint();defaultPaint.setAlpha(0);defaultPaint.setAntiAlias(true);int num = mListView.size();if (num == 0)canvas.drawRect(0, 0, mContentWidth, mContentHeight,defaultPaint);Log.d(LOG_TAG, "Num need to show : " + num);if (selectImg >= 0 && selectImg < num) {for (int i = 0; i <= selectImg; i++) {canvas.save();MyView v = mListView.get(i);Matrix m = new Matrix();int bw = v.bitmap.getWidth(), bh = v.bitmap.getHeight();m.postScale((float) v.width / bw, (float) v.height / bh);Bitmap dstbmp = Bitmap.createBitmap(v.bitmap, 0, 0, bw, bh,m, true);canvas.drawBitmap(dstbmp, v.left, v.top, null);}for (int i = num - 1; i > selectImg; i--) {canvas.save();MyView v = mListView.get(i);Matrix m = new Matrix();int bw = v.bitmap.getWidth(), bh = v.bitmap.getHeight();m.postScale((float) v.width / bw, (float) v.height / bh);Bitmap dstbmp = Bitmap.createBitmap(v.bitmap, 0, 0, bw, bh,m, true);canvas.drawBitmap(dstbmp, v.left, v.top, null);}}if (mState == State.ABOUT_TO_ANIMATE || mState == State.ANIMATING) {getAnimateData();if (mState == State.ANIMATE_END) {mListView.clear();handleAniEnd();}this.invalidate();}}}}

main.xml文件：

<?xml version = "1.0" encoding = "utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:snake=" http://schemas.android.com/apk/res/com.Snake "    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <com.xxx.test.SnakeLayout        android:id="@+id/my_snake"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:layout_weight="1"        snake:selectImg="7" >        <LinearLayout            android:id="@+id/snakeContent"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:orientation="vertical" >            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content"                android:paddingTop="70dip" >                <TextView                    android:layout_width="270dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg0"                    android:layout_width="40dip"                    android:layout_height="40dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="300dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg1"                    android:layout_width="60dip"                    android:layout_height="60dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="295dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg2"                    android:layout_width="50dip"                    android:layout_height="50dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="290dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg3"                    android:layout_width="35dip"                    android:layout_height="35dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="290dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg4"                    android:layout_width="35dip"                    android:layout_height="35dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="292dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg5"                    android:layout_width="40dip"                    android:layout_height="40dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="320dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg6"                    android:layout_width="40dip"                    android:layout_height="40dip" />                <ImageView                    android:id="@+id/snakeImg7"                    android:layout_width="50dip"                    android:layout_height="55dip"                    android:paddingLeft="10dip"                    android:paddingTop="15dip" />                <ImageView                    android:id="@+id/snakeImg8"                    android:layout_width="50dip"                    android:layout_height="55dip"                    android:paddingLeft="10dip"                    android:paddingTop="15dip" />                <ImageView                    android:id="@+id/snakeImg9"                    android:layout_width="50dip"                    android:layout_height="55dip"                    android:paddingLeft="10dip"                    android:paddingTop="15dip" />                <ImageView                    android:id="@+id/snakeImg10"                    android:layout_width="50dip"                    android:layout_height="50dip"                    android:paddingLeft="10dip"                    android:paddingTop="10dip" />                <ImageView                    android:id="@+id/snakeImg11"                    android:layout_width="50dip"                    android:layout_height="40dip"                    android:paddingLeft="10dip" />                <ImageView                    android:id="@+id/snakeImg12"                    android:layout_width="50dip"                    android:layout_height="40dip"                    android:paddingLeft="10dip" />                <ImageView                    android:id="@+id/snakeImg13"                    android:layout_width="50dip"                    android:layout_height="50dip"                    android:paddingLeft="10dip"                    android:paddingTop="10dip" />            </LinearLayout>            <LinearLayout                android:layout_width="fill_parent"                android:layout_height="wrap_content" >                <TextView                    android:layout_width="260dip"                    android:layout_height="1dip" />                <ImageView                    android:id="@+id/snakeImg21"                    android:layout_width="50dip"                    android:layout_height="25dip"                    android:paddingLeft="25dip" />                <ImageView                    android:id="@+id/snakeImg20"                    android:layout_width="50dip"                    android:layout_height="55dip"                    android:paddingLeft="15dip"                    android:paddingTop="20dip" />                <ImageView                    android:id="@+id/snakeImg19"                    android:layout_width="50dip"                    android:layout_height="65dip"                    android:paddingLeft="10dip"                    android:paddingTop="25dip" />                <ImageView                    android:id="@+id/snakeImg18"                    android:layout_width="50dip"                    android:layout_height="65dip"                    android:paddingLeft="10dip"                    android:paddingTop="25dip" />                <ImageView                    android:id="@+id/snakeImg17"                    android:layout_width="50dip"                    android:layout_height="55dip"                    android:paddingLeft="10dip"                    android:paddingTop="15dip" />                <ImageView                    android:id="@+id/snakeImg16"                    android:layout_width="50dip"                    android:layout_height="45dip"                    android:paddingLeft="10dip"                    android:paddingTop="5dip" />                <ImageView                    android:id="@+id/snakeImg15"                    android:layout_width="45dip"                    android:layout_height="35dip"                    android:paddingLeft="10dip" />                <ImageView                    android:id="@+id/snakeImg14"                    android:layout_width="45dip"                    android:layout_height="35dip"                    android:paddingLeft="10dip" />            </LinearLayout>        </LinearLayout>    </com.xxx.test.SnakeLayout></LinearLayout>

SnakeLayoutActivity.java代码：

import android.app.Activity;import android.os.Bundle;public class SnakeLayoutActivity extends Activity {SnakeLayout mSnake;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);mSnake = (SnakeLayout) findViewById(R.id.my_snake);mSnake.addRec(R.drawable.png1);mSnake.addRec(R.drawable.png2);mSnake.addRec(R.drawable.png3);mSnake.addRec(R.drawable.png4);mSnake.addRec(R.drawable.png5);mSnake.addRec(R.drawable.png6);mSnake.addRec(R.drawable.png7);mSnake.addRec(R.drawable.png8);mSnake.addRec(R.drawable.png9);mSnake.addRec(R.drawable.png10);mSnake.addRec(R.drawable.png11);mSnake.addRec(R.drawable.png12);mSnake.addRec(R.drawable.png13);mSnake.addRec(R.drawable.png14);mSnake.addRec(R.drawable.png15);mSnake.addRec(R.drawable.png16);mSnake.addRec(R.drawable.png17);mSnake.addRec(R.drawable.png18);mSnake.addRec(R.drawable.png19);mSnake.addRec(R.drawable.png20);mSnake.addRec(R.drawable.png21);mSnake.addRec(R.drawable.png22);mSnake.addRec(R.drawable.png23);mSnake.addRec(R.drawable.png24);mSnake.addRec(R.drawable.png25);mSnake.addRec(R.drawable.png26);mSnake.addRec(R.drawable.png27);mSnake.addRec(R.drawable.png28);mSnake.Init();}}

ids.xml文件代码：

<?xml version = "1.0" encoding = "utf-8"?><resources>    <item name="snakeImg0" type="id"/>    <item name="snakeImg1" type="id"/>    <item name="snakeImg2" type="id"/>    <item name="snakeImg3" type="id"/>    <item name="snakeImg4" type="id"/>    <item name="snakeImg5" type="id"/>    <item name="snakeImg6" type="id"/>    <item name="snakeImg7" type="id"/>    <item name="snakeImg8" type="id"/>    <item name="snakeImg9" type="id"/>    <item name="snakeImg10" type="id"/>    <item name="snakeImg11" type="id"/>    <item name="snakeImg12" type="id"/>    <item name="snakeImg13" type="id"/>    <item name="snakeImg14" type="id"/>    <item name="snakeImg15" type="id"/>    <item name="snakeImg16" type="id"/>    <item name="snakeImg17" type="id"/>    <item name="snakeImg18" type="id"/>    <item name="snakeImg19" type="id"/>    <item name="snakeImg20" type="id"/>    <item name="snakeImg21" type="id"/>    <item name="snakeImg22" type="id"/>    <item name="snakeImg23" type="id"/>    <item name="snakeImg24" type="id"/>    <item name="snakeImg25" type="id"/>    <item name="snakeImg26" type="id"/>    <item name="snakeImg27" type="id"/>    <item name="snakeImg28" type="id"/>    <item name="snakeImg29" type="id"/>    <item name="snakeContent" type="id"/></resources>

attrs.xml文件代码：

<?xml version = "1.0" encoding = "utf-8"?><resources>    <declare-styleable name="SnakeLayout">        <!-- Defines the special selected position Image -->        <attr name="selectImg" format="integer" />    </declare-styleable></resources>

具体的效果图，可以查看作者的Blog