首页 > 代码库 > ViewGroup实现可以上下、左右滚动跑马灯效果
ViewGroup实现可以上下、左右滚动跑马灯效果
先上效果图:
动画效果有点差.....
代码:
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; @Override public void run() { // TODO Auto-generated method stub while(enabled) { try { Thread.sleep(4000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } setNextView(); enabled = mIndex + 1 < mAdapter.getCount(); } } }); @Override protected 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); else data[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() { @Override public 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 views Iterator<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); } } @Override protected 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()ed int 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); } } } } }
使用:
String temp = getResources().getString(R.string.info); ScrollTextView switcher1 = (ScrollTextView) findViewById(R.id.switcher1); switcher1.setText(temp); switcher1.beginScroll();
唉,我觉得我真是懒....
还是直接给工程吧!
源码下载
ViewGroup实现可以上下、左右滚动跑马灯效果
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