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水平滚动的文字

水平滚动的文字

作者: 王学岗 | 来源:发表于2019-08-16 15:35 被阅读0次

    可以自由拖拽的水平滚动的文字,按下后暂停两秒钟继续滚动

    package com.ds.uilib.scrollview;
    
    /**
     * Created by dapeng on 2017/6/14.
     */
    
    import android.content.Context;
    import android.content.res.TypedArray;
    import android.graphics.Canvas;
    import android.graphics.Color;
    import android.graphics.Paint;
    import android.graphics.Paint.FontMetrics;
    import android.graphics.PixelFormat;
    import android.graphics.PorterDuff;
    import android.graphics.PorterDuff.Mode;
    import android.graphics.PorterDuffXfermode;
    import android.os.Handler;
    import android.os.Message;
    import android.util.AttributeSet;
    import android.util.Log;
    import android.view.MotionEvent;
    import android.view.SurfaceHolder;
    import android.view.SurfaceView;
    
    import androidx.annotation.NonNull;
    
    import com.ds.uilib.R;
    
    import java.util.concurrent.Executors;
    import java.util.concurrent.ScheduledExecutorService;
    import java.util.concurrent.TimeUnit;
    
    public class CustomScrollBar extends SurfaceView implements
            SurfaceHolder.Callback {
    
        private final String TAG = "CustomScrollBar";
    
        private SurfaceHolder holder;
        private Paint paint = null;// 画笔
        private boolean bStop = false; // 停止滚动
    
        private boolean clickEnable = false; // 可以点击
        private boolean isHorizontal = true; // 水平|垂直
        private int speed = 1; // 滚动速度
        private String text = "";// 文本内容
        private float textSize = 15f; // 字号
        private int textColor = Color.BLACK; // 文字颜色
        private int times = Integer.MAX_VALUE; // 滚动次数
    
        private int viewWidth = 0;// 控件的长度
        private int viewHeight = 0; // 控件的高度
        private float textWidth = 0f;// 水平滚动时的文本长度
        private float textHeight = 0f; // 垂直滚动时的文本高度
    
        private float textX = 0f;// 文字的横坐标
        private float textY = 0f;// 文字的纵坐标
        private float viewWidth_plus_textLength = 0.0f;// 显示总长度
        private int time = 0; // 已滚动次数
    
        private ScheduledExecutorService scheduledExecutorService; // 执行滚动线程
        private boolean isMoveLeft;
        private boolean isUp;
        private float moveX;
        private float upX;
        private float textXDown;
        private float downX;
        private float donwTextX;
        Handler handler = new Handler(){
            @Override
            public void handleMessage(@NonNull Message msg) {
                super.handleMessage(msg);
                bStop=false;
            }
        };
    
        public CustomScrollBar(Context context) {
            super(context);
        }
    
        public CustomScrollBar(Context context, AttributeSet attrs) {
            //---------1
            super(context, attrs);
            holder = this.getHolder();
            holder.addCallback(this);
            paint = new Paint();
    
            //获取布局文件中的值
            TypedArray arr = getContext().obtainStyledAttributes(attrs,
                    R.styleable.CustomScrollBar);
            clickEnable = arr.getBoolean(R.styleable.CustomScrollBar_clickEnable,
                    clickEnable);
            isHorizontal = arr.getBoolean(R.styleable.CustomScrollBar_isHorizontal,
                    isHorizontal);
            speed = arr.getInteger(R.styleable.CustomScrollBar_speed, speed);
            text = arr.getString(R.styleable.CustomScrollBar_text3);
            textColor = arr.getColor(R.styleable.CustomScrollBar_textColor3, textColor);
            textSize = arr.getDimension(R.styleable.CustomScrollBar_textSize3, textSize);
            times = arr.getInteger(R.styleable.CustomScrollBar_times, times);
    
            time = times;
            paint.setColor(textColor);
            paint.setTextSize(textSize);
    
            /*
             * 下面两行代码配合draw()方法中的canvas.drawColor(Color.TRANSPARENT,Mode.CLEAR);
             * 将画布填充为透明
             */
            setZOrderOnTop(true);
            getHolder().setFormat(PixelFormat.TRANSLUCENT);
    
            setFocusable(true); // 设置焦点
        }
    
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            //----------2
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            viewWidth = MeasureSpec.getSize(widthMeasureSpec);//得到控件的宽度
            viewHeight = MeasureSpec.getSize(heightMeasureSpec);//得到控件的高度
            if (isHorizontal) { // 水平滚动
                textWidth = paint.measureText(text);// 获取text的长度
                viewWidth_plus_textLength = viewWidth + textWidth;
                textY = (viewHeight - getFontHeight(textSize)) / 2
                        + getPaddingTop() - getPaddingBottom();
            } else { // 垂直滚动
                textHeight = getFontHeight(textSize) * text.length();// 获取text的长度
                viewWidth_plus_textLength = viewHeight + textHeight;
                textX = (viewWidth - textSize) / 2 + getPaddingLeft()
                        - getPaddingRight();
            }
    
        }
    
        @Override
        public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
            //----------4
            Log.d(TAG, "surfaceChanged: ");
        }
    
        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            //-----------3
            bStop = false;
            scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
            scheduledExecutorService.scheduleAtFixedRate(new ScrollThread(), 1000,
                    10, TimeUnit.MILLISECONDS);
            Log.d(TAG, "surfaceCreated: ");
    
        }
    
        @Override
        public void surfaceDestroyed(SurfaceHolder arg0) {
            bStop = true;
            scheduledExecutorService.shutdown();
            Log.d(TAG, "surfaceDestroyed: ");
        }
    
        // 获取字体高度
        private int getFontHeight(float fontSize) {
            Paint paint = new Paint();
            paint.setTextSize(fontSize);
            FontMetrics fm = paint.getFontMetrics();
            return (int) Math.ceil(fm.descent - fm.ascent);
        }
    
        private void setTimes(int times) {
            if (times <= 0) {
                this.times = Integer.MAX_VALUE;
            } else {
                this.times = times;
                time = times;
            }
        }
    
        public void setText(String text) {
            this.text = text;
        }
    
        private void setSpeed(int speed) {
            if (speed > 10 || speed < 0) {
                throw new IllegalArgumentException("Speed was invalid integer, it must between 0 and 10");
            } else {
                this.speed = speed;
            }
        }
    
        /**
         * 当屏幕被触摸时调用
         */
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            if (!clickEnable) {
                return true;
            }
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    bStop = true;
    //                if (!bStop && time == 0) {
    //                    time = times;
    //                }
                    downX = event.getX();
                    donwTextX =viewWidth- textX;
                    break;
                case MotionEvent.ACTION_MOVE:
    
                    Canvas canvas = holder.lockCanvas();
                    canvas.drawColor(Color.TRANSPARENT, Mode.CLEAR);// 通过清屏把画布填充为透明
                    isMoveLeft = true;
                    moveX = event.getRawX();
                    canvas.drawText(text, moveX+viewWidth-textX-downX, textY, paint);
    
                    postInvalidate();
                    holder.unlockCanvasAndPost(canvas);// 解锁画布,提交画好的图像
                    break;
                case MotionEvent.ACTION_UP:
                    isUp = true;
                    upX=event.getRawX();
                    textX = donwTextX - downX+upX;
                    textX = viewWidth -textX;
                    if(textX<0){
                        textX=0;
                    }
                    isMoveLeft = false;
    //                bStop = false;
                    handler.sendEmptyMessageDelayed(0, 2000);
                    break;
            }
            return true;
        }
    
        private synchronized void draw(float X, float Y) {
            Canvas canvas = holder.lockCanvas();//获取画布
            canvas.drawColor(Color.TRANSPARENT, Mode.CLEAR);// 通过清屏把画布填充为透明
            if (isHorizontal) { // 水平滚动
                canvas.drawText(text, X, Y, paint);
            }
    //        else { // 垂直滚动
    //            for (int i = 0; i < text.length(); i++) {
    //                canvas.drawText(text.charAt(i) + "", X, Y + (i + 1)
    //                        * getFontHeight(textSize), paint);
    //            }
    //        }
            holder.unlockCanvasAndPost(canvas);// 解锁画布,提交画好的图像
        }
    
        class ScrollThread implements Runnable {
    
            @Override
            public void run() {
    
                while (!bStop) {
                    if (isHorizontal) {
                            draw(viewWidth - textX, textY);
                             Log.i("machao",textX+"");
                            textX += speed;// 速度设置:1-10
    
                        if (textX > viewWidth_plus_textLength) {
                                textX = 0;
                                --time;
                        }
    
                        //垂直不做处理
    //                else {
    //                    draw(textX, viewHeight - textY);
    //                    textY += speed;
    //                    if (textY > viewWidth_plus_textLength) {
    //                        textY = 0;
    //                        --time;
    //                    }
    //                }
                        if (time <= 0) {
    //                        bStop = true;
                        }
                    }
                }
            }
        }
    }
    

    属性文件中配置

      <declare-styleable name="CustomScrollBar">
            <attr name="clickEnable" format="boolean" />
            <attr name="isHorizontal" format="boolean" />
            <attr name="speed" format="integer" />
            <attr name="text3" format="string" />
            <attr name="textColor3" format="color" />
            <attr name="textSize3" format="dimension" />
            <attr name="times" format="integer" />
        </declare-styleable>
    

    代码中使用

    
     <com.ds.uilib.scrollview.CustomScrollBar
                android:id="@+id/customscrollBar"
                android:layout_width="match_parent"
                android:layout_height="50dp"
                android:layout_alignParentTop="true"
                android:layout_marginTop="22dp"
                app:clickEnable="true"
                app:isHorizontal="true"
                app:speed="2"
                app:textColor3="@color/color666666"
                app:textSize3="14sp"
                app:times="3" />
    

    参考文章https://blog.csdn.net/u012604745/article/details/73277245

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