Viewgroup enables you to scroll up or down or up or down

First:

Poor animation effect .....

Code:

package com.example.scrolltextview;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Paint;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.LinearLayout;import android.widget.Scroller;import android.widget.SpinnerAdapter;import android.widget.TextView;public class ScrollTextView extends ViewGroup {private static final int SCROLL = 0;private static final int JUSTIFY = 1;private static final int ANIMATION_DURATION = 3000;private int mOrientation;private int mSize;private int mIndex;private int mPosition;private Scroller mScroller;private Map<View, Integer> mViews;private SpinnerAdapter mAdapter;private int mPackedViews;private int mAnimationDuration;private float measuredWidth = 0;private float textSize = 0;private float measuredHeight = 0;private String text= null;private String[] data;private boolean flag = true;public ScrollTextView(Context context, AttributeSet attrs) {super(context, attrs);int[] linerarLayoutAttrs = {android.R.attr.orientation,};TypedArray a = context.obtainStyledAttributes(attrs, linerarLayoutAttrs);mOrientation = a.getInteger(0, LinearLayout.HORIZONTAL);a.recycle();mAnimationDuration = ANIMATION_DURATION;mScroller = new Scroller(context);mIndex = -1;mPosition = -1;mPackedViews = -1;mViews = new HashMap<View, Integer>();setFocusable(true);setFocusableInTouchMode(true);}public float getCharacterWidth(String text, float size){if(null == text || "".equals(text))return 0;float width = 0;Paint paint = new Paint();paint.setTextSize(size);float text_width = paint.measureText(text);//得到总体长度width = text_width/text.length();//字符的长度return width;}public void setText(String text){this.text = text;data  = new String[]{this.text};LayoutInflater inflater= (LayoutInflater) getContext().getSystemService(getContext().LAYOUT_INFLATER_SERVICE);TextView view = (TextView) inflater.inflate(R.layout.scroll_text_view, null);textSize = view.getTextSize();measuredHeight = textSize;textSize = getCharacterWidth(text,textSize);}public void beginScroll(){thread.start();}Thread thread = new Thread(new Runnable() {boolean enabled = true;@Overridepublic void run() {// TODO Auto-generated method stubwhile(enabled){try {Thread.sleep(4000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}setNextView();enabled = mIndex + 1 < mAdapter.getCount();}}});@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);measuredWidth = getMeasuredWidth();mSize = mOrientation == LinearLayout.HORIZONTAL? getMeasuredWidth() : getMeasuredHeight();if(flag && text!=null){int length = text.length();Log.i("AAA", "length*textSize:"+length*textSize+" measuredWidth:"+measuredWidth);if(length*textSize >= measuredWidth){int textCountInOneLine = (int) (measuredWidth/textSize -1);int lineCount =(int) ((length%textCountInOneLine==0)? (length/textCountInOneLine):(length/textCountInOneLine+1));Log.i("AAA", "length:"+length+" textCountInOneLine:"+textCountInOneLine+" lineCount:"+lineCount);data = new String[lineCount];for(int i=0;i<lineCount;i++){if((i+1)*textCountInOneLine<length)data[i] =  text.substring(i*textCountInOneLine, (i+1)*textCountInOneLine);elsedata[i] =  text.substring(i*textCountInOneLine, length);Log.i("AAA", "data:"+data[i]);}}else{data = new String[]{text};}ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(), R.layout.scroll_text_view, data);setAdapter(adapter);flag = false;}View view = getChildAt(0);if(view!=null){measureChild(view, widthMeasureSpec, widthMeasureSpec);measuredHeight = view.getMeasuredHeight();}setMeasuredDimension((int)measuredWidth, (int)measuredHeight);}private int getPackedViews(int offset) {int size = mSize;int start = offset / size;int numViews = offset % size != 0? 1 : 0;return start << 1 | numViews;}Handler handler = new Handler() {@Overridepublic void handleMessage(Message msg) {mScroller.computeScrollOffset();int currX = mScroller.getCurrX();int delta = mPosition - currX;mPosition = currX;int packed = getPackedViews(mPosition);manageViews(packed);scroll(delta);if (!mScroller.isFinished()) {handler.sendEmptyMessage(msg.what);} else {if (msg.what == SCROLL) {justify();} else {mIndex = mPosition / mSize;}}}};private void justify() {int offset = mPosition % mSize;if (offset != 0) {int endPosition = mPosition - offset;if (offset > mSize / 2) {endPosition += mSize;}mScroller.startScroll(mPosition, 0, endPosition - mPosition, 0, mAnimationDuration);handler.sendEmptyMessage(JUSTIFY);} else {mIndex = mPosition / mSize;}}private void scroll(int offset) {if (mOrientation == LinearLayout.HORIZONTAL) {for (View view : mViews.keySet()) {view.offsetLeftAndRight(offset);}} else {for (View view : mViews.keySet()) {view.offsetTopAndBottom(offset);}}invalidate();}public void setSelection(int index, boolean animate) {if (index == mIndex) {return;}int endPosition = index * mSize;int diff = Math.abs(index - mIndex);int sign = index > mIndex? 1 : -1;mIndex = index;if (diff > 1) {mPosition = endPosition - sign * mSize;}if (animate) {mScroller.startScroll(mPosition, 0, endPosition - mPosition, 0, mAnimationDuration);handler.removeMessages(JUSTIFY);handler.removeMessages(SCROLL);handler.sendEmptyMessage(JUSTIFY);} else {mPosition = endPosition;manageViews(index << 1);invalidate();}}private void manageViews(int packedViews) {if (packedViews == mPackedViews) {return;}mPackedViews = packedViews;int startIdx = packedViews >> 1;int endIdx = startIdx + (packedViews & 1);int viewIdx = startIdx;while (viewIdx <= endIdx) {if (!mViews.containsValue(viewIdx)) {if (viewIdx >= 0 && viewIdx < mAdapter.getCount()) {View view = mAdapter.getView(viewIdx, null, this);mViews.put(view, viewIdx);addView(view);}}viewIdx++;}// remove not visible viewsIterator<View> iterator = mViews.keySet().iterator();while (iterator.hasNext()) {View view = iterator.next();int idx = mViews.get(view);if (idx < startIdx || idx > endIdx) {iterator.remove();removeView(view);}}}public int getSelection() {return mIndex;}public void setPreviousView() {if (mAdapter != null && mIndex > 0) {setSelection(mIndex-1, true);}}public void setNextView() {if (mAdapter != null && mIndex + 1 < mAdapter.getCount()) {setSelection(mIndex+1, true);}}public void setAdapter(SpinnerAdapter adapter) {mAdapter = adapter;if (mAdapter != null) {setSelection(0, false);}}@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {for (View view : mViews.keySet()) {if (view.getWidth() == 0) {// new View: not layout()edint idx = mViews.get(view);if (mOrientation == LinearLayout.HORIZONTAL) {int left = mSize * idx - mPosition;view.layout(left, 0, left+r-l, b-t);} else {int top = mSize * idx - mPosition;view.layout(0, top, r-l, top+b-t);}}}}}

Usage:

String temp = getResources().getString(R.string.info);    ScrollTextView switcher1 = (ScrollTextView) findViewById(R.id.switcher1);switcher1.setText(temp);switcher1.beginScroll();

Alas, I think I'm really lazy ....

Or directly to the project!

Source code download

Viewgroup enables you to scroll up or down or up or down