TextView英文自动换行解决方法

public class XRTextView extends AppCompatTextView {
    private boolean mEnabled = true;

    public XRTextView(Context context) {
        super(context);
    }

    public XRTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public XRTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public void setAutoSplitEnabled(boolean enabled) {
        mEnabled = enabled;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY
                && MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY
                && getWidth() > 0
                && getHeight() > 0
                && mEnabled) {
            String newText = autoSplitText(this);
            if (!TextUtils.isEmpty(newText)) {
                setText(newText);
            }
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    private String autoSplitText(final TextView tv) {
        final String rawText = tv.getText().toString(); //原始文本
        final Paint tvPaint = tv.getPaint(); //paint，包含字体等信息
        final float tvWidth = tv.getWidth() - tv.getPaddingLeft() - tv.getPaddingRight(); //控件可用宽度

        //将原始文本按行拆分
        String[] rawTextLines = rawText.replaceAll("\r", "").split("\n");
        StringBuilder sbNewText = new StringBuilder();
        for (String rawTextLine : rawTextLines) {
            if (tvPaint.measureText(rawTextLine) <= tvWidth) {
                //如果整行宽度在控件可用宽度之内，就不处理了
                sbNewText.append(rawTextLine);
            } else {
                //如果整行宽度超过控件可用宽度，则按字符测量，在超过可用宽度的前一个字符处手动换行
                float lineWidth = 0;
                for (int cnt = 0; cnt != rawTextLine.length(); ++cnt) {
                    char ch = rawTextLine.charAt(cnt);
                    lineWidth += tvPaint.measureText(String.valueOf(ch));
                    if (lineWidth <= tvWidth) {
                        sbNewText.append(ch);
                    } else {
                        sbNewText.append("\n");
                        lineWidth = 0;
                        --cnt;
                    }
                }
            }
            sbNewText.append("\n");
        }

        //把结尾多余的\n去掉
        if (!rawText.endsWith("\n")) {
            sbNewText.deleteCharAt(sbNewText.length() - 1);
        }

        return sbNewText.toString();
    }

    public void setFont(String textFont) {
        Typeface lastTypeFace = getTypeface();
        boolean isBold = lastTypeFace != null ? lastTypeFace.isBold() : false;
        Typeface typeface = FontUtil.getTypeface(textFont, getContext());
        //使用字体
        setTypeface(typeface);
        //中文字体设置加粗
        TextPaint paint = getPaint();
        paint.setFakeBoldText(isBold);
    }
}

public class JustifyTextView extends AppCompatTextView {

    private int mLineY;
    private int mViewWidth;
    public static final String TWO_CHINESE_BLANK = "  ";

    public JustifyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        TextPaint paint = getPaint();
        paint.setColor(getCurrentTextColor());
        paint.drawableState = getDrawableState();
        mViewWidth = getMeasuredWidth();
        String text = getText().toString();
        mLineY = 0;
        mLineY += getTextSize();
        Layout layout = getLayout();

        // layout.getLayout()在4.4.3出现NullPointerException
        if (layout == null) {
            return;
        }

        Paint.FontMetrics fm = paint.getFontMetrics();

        int textHeight = (int) (Math.ceil(fm.descent - fm.ascent));
        textHeight = (int) (textHeight * layout.getSpacingMultiplier() + layout.getSpacingAdd());
        //解决了最后一行文字间距过大的问题
        for (int i = 0; i < layout.getLineCount(); i++) {
            int lineStart = layout.getLineStart(i);
            int lineEnd = layout.getLineEnd(i);
            float width = StaticLayout.getDesiredWidth(text, lineStart, lineEnd, getPaint());
            String line = text.substring(lineStart, lineEnd);

            if(i < layout.getLineCount() - 1) {
                if (needScale(line)) {
                    drawScaledText(canvas, lineStart, line, width);
                } else {
                    canvas.drawText(line, 0, mLineY, paint);
                }
            } else {
                canvas.drawText(line, 0, mLineY, paint);
            }
            mLineY += textHeight;
        }
    }

    private void drawScaledText(Canvas canvas, int lineStart, String line, float lineWidth) {
        float x = 0;
        if (isFirstLineOfParagraph(lineStart, line)) {
            String blanks = "  ";
            canvas.drawText(blanks, x, mLineY, getPaint());
            float bw = StaticLayout.getDesiredWidth(blanks, getPaint());
            x += bw;

            line = line.substring(3);
        }

        int gapCount = line.length() - 1;
        int i = 0;
        if (line.length() > 2 && line.charAt(0) == 12288 && line.charAt(1) == 12288) {
            String substring = line.substring(0, 2);
            float cw = StaticLayout.getDesiredWidth(substring, getPaint());
            canvas.drawText(substring, x, mLineY, getPaint());
            x += cw;
            i += 2;
        }

        float d = (mViewWidth - lineWidth) / gapCount;
        for (; i < line.length(); i++) {
            String c = String.valueOf(line.charAt(i));
            float cw = StaticLayout.getDesiredWidth(c, getPaint());
            canvas.drawText(c, x, mLineY, getPaint());
            x += cw + d;
        }
    }

    private boolean isFirstLineOfParagraph(int lineStart, String line) {
        return line.length() > 3 && line.charAt(0) == ' ' && line.charAt(1) == ' ';
    }

    private boolean needScale(String line) {
        if (line == null || line.length() == 0) {
            return false;
        } else {
            return line.charAt(line.length() - 1) != '\n';
        }
    }
}

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