文字滚动View
效果(无法显示效果点击这里)
项目中应用
demo
原理其实就是把文字逐行绘制出来，利用属性动画改变绘制的位置来实现滚动
代码写的有点粗糙，分享出来希望能帮到大家
使用
1.布局中添加
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<com.example.demo.TextScrollView
android:id="@+id/tsv_txt"
android:layout_width="500dp"
android:layout_height="300dp"
android:background="@color/colorPrimary" />
</LinearLayout>
2.代码中设置文字数据
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
LogUtils.getConfig().globalTag = "123456"
setContentView(R.layout.activity_main)
tsv_txt.setTextSizeDp(20)
tsv_txt.setTextColor("#000000")
val strings = arrayListOf<String>()
strings.add("1111111111111111111111111111111111111111111111111111111111111111111")
strings.add("222222222222222222222222222222222222")
strings.add("333333333333333333333333333333333")
strings.add("4444444444444444444444444444444")
strings.add("55555555555555555555555555555555555555555")
strings.add("6666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666")
strings.add("7777777777777")
strings.add("888888888888888888888888888888888888888888888888")
strings.add("99999999999999999999999999999999999999999999999999999")
strings.add("00000000000000000000000000000000000000000000000000000000")
tsv_txt.setData(strings)
}
}
直接复制下面代码或者下载Demo把文件复制到自己项目就可以
package com.example.demo;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.view.View;
import androidx.annotation.Nullable;
import java.util.ArrayList;
public class TextScrollView extends View {
private ArrayList<String> strings = new ArrayList<>();
private ArrayList<StaticLayout> mStaticLayouts = new ArrayList<>();
private TextPaint mTextPaint;
private ValueAnimator mValueAnimator;
private int mOffset;
private int mOffsetScroll;
private int mScrollPosition = 0;
private int mPosition = 0;
private int mOffsetY = 0;
private int mWidth = 0;
private int mHeight = 0;
private int mCheckSizeSum = 0;
private float spacingmult = 1;
private float spacingadd = 0;
private int mScrollDuration = 500;
private int mScrollInterval = 1500;
private boolean isDownScroll = false;
private Runnable mNextScrollRun = new Runnable() {
@Override
public void run() {
mOffsetScroll = mOffsetScroll + mOffset;
mScrollPosition++;
startScroll();
}
};
private Runnable mCheckSizeRun = () -> setData(strings);
public TextScrollView(Context context) {
super(context);
init();
}
public TextScrollView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
init();
}
public TextScrollView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
//默认文字大小颜色
mTextPaint = new TextPaint();
//文字颜色
mTextPaint.setColor(Color.parseColor("#CCFFFFFF"));
mTextPaint.setAntiAlias(true);
//文字大小dp
mTextPaint.setTextSize(dp2px(13));
}
public int dp2px(final float dpValue) {
final float scale = getContext().getResources().getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5f);
}
public void setTextSizeDp(int size) {
mTextPaint.setTextSize(dp2px(size));
}
/**
* 设置文字颜色
*
* @param color 例如 #CCFFFFFF
*/
public void setTextColor(String color) {
mTextPaint.setColor(Color.parseColor(color));
}
/**
* 设置数据
*/
public void setData(ArrayList<String> strings) {
mOffset = 0;
mOffsetScroll = 0;
mScrollPosition = 0;
mPosition = 0;
mOffsetY = 0;
removeCallbacks(mNextScrollRun);
removeCallbacks(mCheckSizeRun);
mStaticLayouts.clear();
this.strings = strings;
if (mWidth == 0) {
if (mCheckSizeSum > 3) return;
postDelayed(mCheckSizeRun, 50);
mCheckSizeSum++;
return;
}
if (mValueAnimator != null) mValueAnimator.cancel();
clearAnimation();
for (String string : this.strings) {
mStaticLayouts.add(createStaticLayout(string));
}
start();
}
public void setScrollDirection(boolean isDown) {
isDownScroll = isDown;
start();
}
private StaticLayout createStaticLayout(String text) {
return new StaticLayout(text, mTextPaint, mWidth, Layout.Alignment.ALIGN_NORMAL, spacingmult, spacingadd, true);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mWidth = MeasureSpec.getSize(widthMeasureSpec);
mHeight = MeasureSpec.getSize(heightMeasureSpec);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mStaticLayouts.size() == 0) return;
canvas.save();
int textY = mOffsetScroll;
for (int i = 0; i < strings.size(); i++) {
StaticLayout staticLayout = mStaticLayouts.get(i);
if (i == 0) {
canvas.translate(0, textY + mOffset);
} else {
canvas.translate(0, textY);
}
staticLayout.draw(canvas);
textY = staticLayout.getHeight();
}
canvas.restore();
}
private void start(){
if (mStaticLayouts.size() != 0) offsetY(mHeight);
}
private void offsetY(int viewHeight) {
if (mValueAnimator != null && mValueAnimator.isStarted()) return;
int height = 0;
for (StaticLayout staticLayout : mStaticLayouts) {
height = height + staticLayout.getHeight();
if (height > viewHeight) {
mOffsetY = height - viewHeight;
mPosition = mStaticLayouts.indexOf(staticLayout);
break;
}
}
//如果能全部显示就不滚动
if (height <= viewHeight) {
invalidate();
return;
}
mValueAnimator = ValueAnimator.ofInt(-mOffsetY);
mValueAnimator.setDuration(mScrollDuration);
mValueAnimator.removeAllUpdateListeners();
mValueAnimator.removeAllListeners();
mValueAnimator.addUpdateListener(animation -> {
Object value = animation.getAnimatedValue();
mOffset = (int) value;
invalidate();
});
mValueAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
postDelayed(mNextScrollRun, mScrollInterval);
}
});
mValueAnimator.start();
}
private void startScroll() {
if (mValueAnimator != null && mValueAnimator.isStarted()) return;
if (mScrollPosition > mStaticLayouts.size() - 1) {
mScrollPosition--;
}
if (mScrollPosition > 0) {
String txt = strings.get(0);
strings.add(txt);
mStaticLayouts.add(createStaticLayout(txt));
mOffsetScroll = mStaticLayouts.get(0).getHeight() + mOffsetScroll;
strings.remove(0);
mStaticLayouts.remove(0);
}
if (mPosition > mStaticLayouts.size() - 1) mPosition = mStaticLayouts.size() - 1;
int scrollHeight = mStaticLayouts.get(mPosition).getHeight();
mValueAnimator = ValueAnimator.ofInt(isDownScroll ? scrollHeight : -scrollHeight);
mValueAnimator.setDuration(mScrollDuration);
mValueAnimator.removeAllUpdateListeners();
mValueAnimator.removeAllListeners();
mValueAnimator.addUpdateListener(animation -> {
Object value = animation.getAnimatedValue();
mOffset = (int) value;
invalidate();
});
mValueAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
postDelayed(mNextScrollRun, mScrollInterval);
}
});
mValueAnimator.start();
}
}
