Android 如何通过代码绘制小票单据

package com.jarwen.scanner.scanner;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.os.Environment;
import android.widget.ImageView;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.jarwen.scanner.R;
import com.jarwen.scanner.ScannerApplication;
import com.jarwen.scanner.data.model.PrintInfo;
import com.jarwen.scanner.util.Hardware;
import com.jarwen.scanner.util.Logger;
import com.jarwen.scanner.util.ToastManager;

import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;

public abstract class Scanner{

    private static final String TAG = "Scanner";

    protected Context context;
    protected ToastManager tm;

    protected Scanner(Context context, ToastManager tm){
        this.context = context;
        this.tm = tm;
    }

    /*
     * 把订单信息排版成打印纸形式。
     * chorm,2020-01-27 16:54 / 2020-01-29 19:14
     * */
    protected Bitmap makePrintImage(PrintInfo pi){
        Logger.v(TAG, "makePrintImage()");
        try{
            List<PrintInfo.Order> poders = pi.getWaybills();
            if(poders == null || poders.size() == 0) {
                tm.toast(false, context.getString(R.string.activity_main_cdjh_print_no_waybill));
                return null;
            }

            //订单信息头画笔。
            Paint commonPaint = new Paint();
            commonPaint.setColor(Color.BLACK);
            commonPaint.setAntiAlias(true);

            //运单信息列表货物重量画笔。
            Paint goodsWeightPaint = new Paint();
            goodsWeightPaint.setColor(Color.BLACK);
            goodsWeightPaint.setTextSize(14);
            goodsWeightPaint.setTypeface(Typeface.DEFAULT_BOLD);
            goodsWeightPaint.setAntiAlias(true);

            final int BOTTOM_WHITE_PADDING = 80; //打印纸底部的留白，为了方便打印完后直接撕打印纸而做的留白。
            final int BORDER_PADDING = 2; //留一点边距。
            final int IMG_WIDTH = 380; // max 380pix
            final int HEADER_TEXT_LEFT_PADDING = 20;
            final int HEADER_TEXT_MAX_LENGTH_PER_LINE = IMG_WIDTH - HEADER_TEXT_LEFT_PADDING - HEADER_TEXT_LEFT_PADDING; //小票信息头一行文本最大显示长度。
            final int WAYBILL_LIST_LEFT_PADDING = 10;

            //转发地址高度计算。
            int forwardAddrHeight = 0;
            if(pi.getForwardAddr() == null || pi.getForwardAddr().isEmpty()) {
                Logger.d(TAG, "No forward address found.");
            }else{
                commonPaint.setTextSize(15);
                int faw = getTextWidth(commonPaint, pi.getForwardAddr());
                if(faw > HEADER_TEXT_MAX_LENGTH_PER_LINE){
                    //转发地址一行放不下。
                    forwardAddrHeight = (int) Math.ceil(((float)faw / (float)HEADER_TEXT_MAX_LENGTH_PER_LINE));
                    forwardAddrHeight = forwardAddrHeight > 3 ? 3 : forwardAddrHeight; //最大不超过 3 行。
                    Logger.d(TAG, "Forward address can be divide into " + forwardAddrHeight + " lines.");
                }else{
                    //转发地址比较短，一行就能放下了。
                    Logger.d(TAG, "Forward address only need 1 line to display.");
                    forwardAddrHeight = 1;
                }
                commonPaint.setTextSize(15);
                forwardAddrHeight = (int) (forwardAddrHeight * (commonPaint.descent() - commonPaint.ascent()));
                forwardAddrHeight += 10;
                Logger.d(TAG, "Forward address display height:" + forwardAddrHeight);
            }

            //收货地址高度计算。
            int revAddrHeight = 0;
            if(pi.getRevAddr() == null || pi.getRevAddr().isEmpty()) {
                Logger.d(TAG, "No receive address found.");
            }else{
                int faw = getTextWidth(commonPaint, pi.getRevAddr());
                if(faw > HEADER_TEXT_MAX_LENGTH_PER_LINE){
                    //收件地址一行放不下。
                    revAddrHeight = (int) Math.ceil(((float)faw / (float)HEADER_TEXT_MAX_LENGTH_PER_LINE));
                    revAddrHeight = revAddrHeight > 3 ? 3 : revAddrHeight; //最大不超过 3 行。
                    Logger.d(TAG, "Receive address can be divide into " + revAddrHeight + " lines.");
                }else{
                    //收件地址比较短，一行就能放下了。
                    Logger.d(TAG, "Receive address only need 1 line to display.");
                    revAddrHeight = 1;
                }
                commonPaint.setTextSize(15);
                revAddrHeight = (int) (revAddrHeight * (commonPaint.descent() - commonPaint.ascent()));
                revAddrHeight += 10;
                Logger.d(TAG, "Receive address display height:" + revAddrHeight);
            }

            commonPaint.setTextSize(14); //化身为运单列表画笔，以供计算小票高度。
            final int IMG_HEIGHT = 220 //基本信息头固定高度。
                    + (int)((commonPaint.descent() - commonPaint.ascent() + 10) * poders.size()) //运单列表所需要的高度。
                    + BOTTOM_WHITE_PADDING //尾部留白，以方便用户打印后直接撕取。
                    + forwardAddrHeight //转发地址高度。
                    + revAddrHeight; //收件地址高度。

            //创建小票空白位图，以供后续填充内容。
            Bitmap bitmap = Bitmap.createBitmap(IMG_WIDTH, IMG_HEIGHT, Bitmap.Config.ARGB_8888);
            Canvas canvas = new Canvas(bitmap);
            canvas.drawColor(Color.WHITE);

            int printHeight = BORDER_PADDING; // padding top.

            //第一行数据。
            commonPaint.setTextSize(15);
            printHeight += 5 + commonPaint.descent() - commonPaint.ascent();
            if(ScannerApplication.getInstance().getLanguageHelper().isThaiLanguage()) {
                canvas.drawText(context.getString(R.string.activity_main_cdjh_print_line1), 35, printHeight, commonPaint);
                canvas.drawText(pi.getPrintTime(), 230, printHeight, commonPaint);
            }else{
                canvas.drawText(context.getString(R.string.activity_main_cdjh_print_line1), 60, printHeight, commonPaint);
                canvas.drawText(pi.getPrintTime(), 200, printHeight, commonPaint);
            }

            //第二行数据。收件人信息
            commonPaint.setTextSize(20);
            commonPaint.setTypeface(Typeface.DEFAULT_BOLD);
            printHeight += 45;
            canvas.drawText(pi.getUsername(), HEADER_TEXT_LEFT_PADDING, printHeight, commonPaint);

            //第三行数据。提货方式。
            commonPaint.setTextSize(17);
            commonPaint.setTypeface(Typeface.DEFAULT);
            printHeight += 10 + commonPaint.descent() - commonPaint.ascent();
            canvas.drawText(pi.getRevType(), HEADER_TEXT_LEFT_PADDING, printHeight, commonPaint);

            //条形码。
            Bitmap barcodebm = makeBarcodeBitmap(pi.getOrderNo(), 260, 70);
            canvas.drawBitmap(barcodebm, 140, printHeight - 60, commonPaint);
            //条形码文字的绘制。chorm,2020-01-29 21:15
            commonPaint.setTextSize(25);
            int barcodeX = 140 + 130 - (int)(commonPaint.measureText(pi.getOrderNo()) / 2.0f);
            canvas.drawText(pi.getOrderNo(), barcodeX, printHeight + 5 + commonPaint.descent() - commonPaint.ascent(), commonPaint);

            //第四行数据。转发地址，可能有多行数据。
            printHeight += 40; //跳过条形码的高度。
            if(pi.getForwardAddr() == null || pi.getForwardAddr().isEmpty()){
                //没有转发地址。不显示也不占据空间。
            }else{
                //有转发地址，要显示。
                commonPaint.setTextSize(15);
                printHeight += commonPaint.descent() - commonPaint.ascent();
                printHeight = printMultiLinesText(canvas, commonPaint, pi.getForwardAddr(), printHeight, HEADER_TEXT_MAX_LENGTH_PER_LINE, HEADER_TEXT_LEFT_PADDING);
            }

            //第五行数据，收件人姓名。
            commonPaint.setTextSize(18);
            printHeight += 10 + commonPaint.descent() - commonPaint.ascent();
            canvas.drawText(String.format(Locale.US, "%s        %s", pi.getReceiver(), pi.getPhone()), HEADER_TEXT_LEFT_PADDING, printHeight, commonPaint);

            //第六行数据，收货地址。
            printHeight += 10;
            if(pi.getRevAddr() == null || pi.getRevAddr().isEmpty()){
                //没有收件地址，不显示也不占据空间。
            }else{
                //有收件地址，要智能显示。
                commonPaint.setTextSize(15);
                printHeight += commonPaint.descent() - commonPaint.ascent();
                printHeight = printMultiLinesText(canvas, commonPaint, pi.getRevAddr(), printHeight, HEADER_TEXT_MAX_LENGTH_PER_LINE, HEADER_TEXT_LEFT_PADDING);
            }

            //第七行，分隔线。
            printHeight += 10;
            commonPaint.setStyle(Paint.Style.STROKE);
            commonPaint.setStrokeWidth(1);
            canvas.drawLine(10, printHeight, IMG_WIDTH - 10, printHeight, commonPaint);

            //运单数据列表区。
            commonPaint.setTextSize(14);
            commonPaint.setTypeface(Typeface.DEFAULT);
            commonPaint.setStyle(Paint.Style.FILL);
            for(PrintInfo.Order po:poders){
                printHeight += 10 + commonPaint.descent() - commonPaint.ascent();
                //第 1 列。
                canvas.drawText(po.lot, WAYBILL_LIST_LEFT_PADDING, printHeight, commonPaint);
                //第 2 列。
                canvas.drawText(po.waybillNo, 110, printHeight, commonPaint);
                //第 3 列。
                canvas.drawText(po.weight + "kg", 260, printHeight, goodsWeightPaint);
                //第 4 列。
                canvas.drawText(po.goodsType, 320, printHeight, commonPaint);
                //第 5 列。
                canvas.drawText(String.valueOf(pi.getWaybills().get(0).amount), 350, printHeight, commonPaint);
            }

            //四周边界。
            commonPaint.setStrokeWidth(1);
            commonPaint.setStyle(Paint.Style.STROKE);
            int bwhite = (int) (BOTTOM_WHITE_PADDING / 1.5f); //四周边框只围住打印内容，底部的留白不要围以方便用户撕打印纸。
            canvas.drawLine(BORDER_PADDING, BORDER_PADDING, IMG_WIDTH - BORDER_PADDING, BORDER_PADDING, commonPaint);
            canvas.drawLine(IMG_WIDTH - BORDER_PADDING, BORDER_PADDING, IMG_WIDTH - BORDER_PADDING, IMG_HEIGHT - BORDER_PADDING - bwhite, commonPaint);
            canvas.drawLine(IMG_WIDTH - BORDER_PADDING, IMG_HEIGHT - BORDER_PADDING - bwhite, BORDER_PADDING, IMG_HEIGHT - BORDER_PADDING - bwhite, commonPaint);
            canvas.drawLine(BORDER_PADDING, IMG_HEIGHT - BORDER_PADDING - bwhite, BORDER_PADDING, BORDER_PADDING, commonPaint);


            AlertDialog.Builder builder = new AlertDialog.Builder(context);
            builder.setPositiveButton("OK", null);
            ImageView iv = new ImageView(context);
            iv.setScaleType(ImageView.ScaleType.FIT_CENTER);
            iv.setImageBitmap(bitmap);
            builder.setView(iv);
            builder.setCancelable(false);
            builder.create().show();

            return bitmap;
        }catch(Exception e){
            e.printStackTrace();
        }

        return null;
    } // makePrintImage() -- end

    private Bitmap makeBarcodeBitmap(String contents, int desiredWidth, int desiredHeight) throws Exception {
        Logger.v(TAG, "makeBarcodeBitmap()");

        //条形码图片
        final int WHITE = 0xFFFFFFFF;
        final int BLACK = 0xFF000000;
        HashMap<EncodeHintType, String> hints = new HashMap<>(2);
        String encoding = "UTF-8";
        hints.put(EncodeHintType.CHARACTER_SET, encoding);
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix result = writer.encode(contents, BarcodeFormat.CODE_128, desiredWidth, desiredHeight, hints);
        int width = result.getWidth();
        int height = result.getHeight();
        int[] pixels = new int[width * height];
        // All are 0, or black, by default
        for (int y = 0; y < height; y++) {
            int offset = y * width;
            for (int x = 0; x < width; x++) {
                pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
            }
        }
        Bitmap barcode = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        barcode.setPixels(pixels, 0, width, 0, 0, width, height);

        return barcode;
    }

    private int getTextWidth(Paint paint, String txt){
        Logger.v(TAG, "getTextWidth()");
        if(paint != null && txt != null) {
            return (int) Math.ceil(paint.measureText(txt));
        }

        return 0;
    } //getTextWidth() -- end

    /**
     * 根据文本长度自动将文本分行打印在小票上。
     * @return 最新的打印高度。
     * */
    private int printMultiLinesText(Canvas canvas, Paint commonPaint, String txt, int printHeight, int maxLenPerLine, int leftPadding){
        Logger.v(TAG, "printMultiLinesText()");
        //计算文本长度。
        int textWidth = getTextWidth(commonPaint, txt);
        Logger.i(TAG, "textWidth:" + textWidth + ",maxLenPerLine:" + maxLenPerLine);
        if(textWidth > maxLenPerLine){
            //文本超过一行，裁剪后显示。最大允许显示三行。
            //最长三行。超过的部分不显示。
            int lines = (int) Math.ceil((float)textWidth / (float)maxLenPerLine);
            Logger.d(TAG, "how many line can be divide? " + lines);

            if(lines == 2){
                //从尾部逐渐缩小字符串。
                int cut = 2; // 2个字符 2 个字符的裁剪。
                while(true){
                    int slen = getTextWidth(commonPaint, txt.substring(0, txt.length() - cut));
                    if(slen <= maxLenPerLine){
                        break;
                    }

                    cut += 2;
                }
                //打印第一行文本。
                canvas.drawText(txt.substring(0, txt.length() - cut), leftPadding, printHeight, commonPaint);
                //打印第二行文本。
                printHeight += 10 + commonPaint.descent() - commonPaint.ascent();
                canvas.drawText(txt.substring(txt.length() - cut), leftPadding, printHeight, commonPaint);
            }else if(lines > 2){
                int cut = 2;
                while(true){
                    int slen = getTextWidth(commonPaint, txt.substring(0, txt.length() - cut));
                    if(slen <= maxLenPerLine){
                        break;
                    }

                    cut += 2;
                }
                //打印第一行。
                canvas.drawText(txt.substring(0, txt.length() - cut), leftPadding, printHeight, commonPaint);
                //打印第二行。
                printHeight += 10 + commonPaint.descent() - commonPaint.ascent();
                canvas.drawText(txt.substring(txt.length() - cut, 2 * (txt.length() - cut)), leftPadding, printHeight, commonPaint);
                //打印第三行。
                printHeight += 10 + commonPaint.descent() - commonPaint.ascent();
                canvas.drawText(txt.substring(2 * (txt.length() - cut)), leftPadding, printHeight, commonPaint);
            }else if(lines == 1){
                Logger.w(TAG, "Single line forward address cannot be run here.");
                canvas.drawText(txt, leftPadding, printHeight, commonPaint);
            }else{
                Logger.e(TAG, "Invalid lines:" + lines);
            }
        }else{
            //只有一行，直接显示。
            canvas.drawText(txt, leftPadding, printHeight, commonPaint);
        }

        return printHeight;
    } // printMultiLinesText() -- end.

    /**
     * 将打印小票保存到 /sdcard。
     * chorm, 2020-01-29 19:21
     * */
    protected void saveTicket(Bitmap bitmap){
        Logger.v(TAG, "saveTicket()");
        try{
            SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss", Locale.US);
            FileOutputStream fos = new FileOutputStream(new File(String.format("%s%s%s%s",
                    Environment.getExternalStorageDirectory().getAbsolutePath(), "/cns_ticket", sdf.format(new Date()), ".png")));
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
            fos.flush();
            fos.close();
            tm.toast("小票已保存至SD卡");
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}