Java Code Examples for android.text.Layout#getLineCount()

/**
 * Performs a scroll down action.
 * Scrolls down by the specified number of lines.
 *
 * @param widget The text view.
 * @param buffer The text buffer.
 * @param amount The number of lines to scroll by.  Must be at least 1.
 * @return True if the event was handled.
 * @hide
 */
protected boolean scrollDown(TextView widget, Spannable buffer, int amount) {
    final Layout layout = widget.getLayout();
    final int innerHeight = getInnerHeight(widget);
    final int bottom = widget.getScrollY() + innerHeight;
    int bottomLine = layout.getLineForVertical(bottom);
    if (layout.getLineTop(bottomLine + 1) < bottom + 1) {
        // Less than a pixel of this line is out of view,
        // so we must have tried to make it entirely in view
        // and now want the next line to be in view instead.
        bottomLine += 1;
    }
    final int limit = layout.getLineCount() - 1;
    if (bottomLine <= limit) {
        bottomLine = Math.min(bottomLine + amount - 1, limit);
        Touch.scrollTo(widget, layout, widget.getScrollX(),
                layout.getLineTop(bottomLine + 1) - innerHeight);
        return true;
    }
    return false;
}
 

/**
 * 按行分割文本
 */
private void spliteLineData(Layout layout,String text){
    mLineDataList.clear();
    int lineCount = layout.getLineCount();
    Log.d("hyh", "AutomaticEditText: spliteLineData: text="+text+" ,lineCount="+lineCount);
    for (int i = 0; i < lineCount; i++) {
        int start = layout.getLineStart(i);
        int end = layout.getLineEnd(i);
        String rowStr = text.substring(start,end);
        //去除掉换行符
        if(rowStr.contains(SYM_CHANGE_LINE)){
            rowStr = rowStr.replace(SYM_CHANGE_LINE,"");
        }
        CustomSpanData customTextSpanData = new CustomSpanData.Builder(start,end)
            .setSpanType(TYPE_ABS_SIZE_SPAN)
            .setTextSize(UNIT_PX,mLayoutHelper.getFontSize())
            .build();
        LineData lineData = new LineData(rowStr,customTextSpanData);
        Log.d("hyh", "AutomaticEditText: spliteLineData: lineData="+lineData.toString());
        mLineDataList.add(lineData);
    }
}
 

@Override
protected void drawFrame(Canvas canvas) {
    Layout layout = mHTextView.getLayout();
    int gapIndex = 0;
    for (int i = 0; i < layout.getLineCount(); i++) {
        int lineStart = layout.getLineStart(i);
        int lineEnd = layout.getLineEnd(i);
        float lineLeft = layout.getLineLeft(i);
        float lineBaseline = layout.getLineBaseline(i);
        String lineText = mText.subSequence(lineStart, lineEnd).toString();
        for (int c = 0; c < lineText.length(); c++) {
            int alpha = alphaList.get(gapIndex);
            mPaint.setAlpha((int) ((255 - alpha) * progress + alpha));
            canvas.drawText(String.valueOf(lineText.charAt(c)), lineLeft, lineBaseline, mPaint);
            lineLeft += gapList.get(gapIndex++);
        }
    }
}
 

/**
 * 裁剪文本至固定行数
 * @param text                  源文本
 * @return                      字符串
 */
private String tailorText(String text){
    String destStr = text + ELLIPSIS + getUnfoldText();
    Layout layout = makeTextLayout(destStr);
    //如果行数大于固定行数
    if(layout.getLineCount() > getFoldLine()){
        int index = layout.getLineEnd(getFoldLine());
        if(text.length() < index){
            index = text.length();
        }
        //从最后一位逐渐试错至固定行数
        String subText = text.substring(0, index-1); 
        return tailorText(subText);
    }else{
        return destStr;
    }
}
 

/**
 * Returns the width of the layout.
 *
 * @param layout The layout.
 * @return The width of the layout.
 */
public static int getWidth(Layout layout) {
  if (layout == null) {
    return 0;
  }

  // Supplying VERY_WIDE will make layout.getWidth() return a very large value.
  int count = layout.getLineCount();
  int maxWidth = 0;

  for (int i = 0; i < count; i++) {
    maxWidth = Math.max(maxWidth, (int) layout.getLineRight(i));
  }

  return maxWidth;
}
 

public static WritableArray getFontMetrics(CharSequence text, Layout layout, TextPaint paint, Context context) {
  DisplayMetrics dm = context.getResources().getDisplayMetrics();
  WritableArray lines = Arguments.createArray();
  // To calculate xHeight and capHeight we have to render an "x" and "T" and manually measure their height.
  // In order to get more precision than Android offers, we blow up the text size by 100 and measure it.
  // Luckily, text size affects rendering linearly, so we can do this trick.
  TextPaint paintCopy = new TextPaint(paint);
  paintCopy.setTextSize(paintCopy.getTextSize() * AMPLIFICATION_FACTOR);
  Rect capHeightBounds = new Rect();
  paintCopy.getTextBounds(CAP_HEIGHT_MEASUREMENT_TEXT, 0, CAP_HEIGHT_MEASUREMENT_TEXT.length(), capHeightBounds);
  double capHeight = capHeightBounds.height() / AMPLIFICATION_FACTOR / dm.density;
  Rect xHeightBounds = new Rect();
  paintCopy.getTextBounds(X_HEIGHT_MEASUREMENT_TEXT, 0, X_HEIGHT_MEASUREMENT_TEXT.length(), xHeightBounds);
  double xHeight = xHeightBounds.height() / AMPLIFICATION_FACTOR / dm.density;
  for (int i = 0; i < layout.getLineCount(); i++) {
    Rect bounds = new Rect();
    layout.getLineBounds(i, bounds);
    WritableMap line = Arguments.createMap();
    line.putDouble("x", layout.getLineLeft(i) / dm.density);
    line.putDouble("y", bounds.top / dm.density);
    line.putDouble("width", layout.getLineWidth(i) / dm.density);
    line.putDouble("height", bounds.height() / dm.density);
    line.putDouble("descender", layout.getLineDescent(i) / dm.density);
    line.putDouble("ascender", -layout.getLineAscent(i) / dm.density);
    line.putDouble("baseline", layout.getLineBaseline(i) / dm.density);
    line.putDouble("capHeight", capHeight);
    line.putDouble("xHeight", xHeight);
    line.putString(
        "text", text.subSequence(layout.getLineStart(i), layout.getLineEnd(i)).toString());
    lines.pushMap(line);
  }
  return lines;
}
 

/**
 * Calculates the maximum width line in a text layout.
 *
 * @param textLayout The text layout
 * @return The maximum length line
 */
public static float calculateMaxTextWidth(@Nullable final Layout textLayout)
{
    float maxTextWidth = 0f;
    if (textLayout != null)
    {
        for (int i = 0, count = textLayout.getLineCount(); i < count; i++)
        {
            maxTextWidth = Math.max(maxTextWidth, textLayout.getLineWidth(i));
        }
    }
    return maxTextWidth;
}
 

/**
 * Find the number of lines of text which must be shown in order to display the character at
 * a given index.
 */
private int getLineForIndex(int index) {
    Layout layout = getLayout();
    int endLine = 0;
    while (endLine < layout.getLineCount() && layout.getLineEnd(endLine) < index) {
        endLine++;
    }
    // Since endLine is an index, add 1 to get the number of lines.
    return endLine + 1;
}
 

/**
 * 判断是否需要更新文本
 * @return
 */
private boolean isUpdateText(Layout layout,String text){
    boolean update = false;
    if(!mLastText.equals(text)) {
        update = true;
    }else{
        int lineCount = layout.getLineCount();
        int size = mLineDataList.size();
        if(lineCount != size){
            update = true;
        }else{
            for (int i = 0; i < lineCount; i++) {
                int start = layout.getLineStart(i);
                int end =layout.getLineEnd(i);
                String rowStr = text.substring(start, end);
                //去除掉换行符
                if(rowStr.contains(SYM_CHANGE_LINE)){
                    rowStr = rowStr.replace(SYM_CHANGE_LINE,"");
                }
                LineData lineData = mLineDataList.get(i);
                String lineText = lineData.getLineText();
                if (!rowStr.equals(lineText)) {
                    //原本的每行文字跟现在的每行文字不相同，说明排版变了，需要重新更新文本
                    update = true;
                    break;
                }
            }
        }
    }
    return  update;
}
 

public static boolean isEllipsed(@NonNull TextView textView) {
    Layout layout = textView.getLayout();
    if (layout != null) {
        int lines = layout.getLineCount();
        if (lines > 0) {
            return IntStream.range(0, lines).anyMatch(line -> layout.getEllipsisCount(line) > 0);
        }
    }
    return false;
}
 

private void translateText(Layout layout, BufferType type) {
    originalLineCount = layout.getLineCount();
    if (layout.getLineCount() > mShowMaxLine) {
        isOverMaxLine = true;
        SpannableStringBuilder span = new SpannableStringBuilder();
        int start = layout.getLineStart(mShowMaxLine - 1);
        int end = layout.getLineEnd(mShowMaxLine - 1);
        if (mTipGravity == END) {
            TextPaint paint = getPaint();
            StringBuilder builder = new StringBuilder(ELLIPSIZE_END).append(mFoldText);
            end -= paint.breakText(mOriginalText, start, end, false, paint.measureText(builder.toString()), null);
            float x = getWidth() - getPaddingLeft() - getPaddingRight() - getTextWidth(mFoldText);
            while (layout.getPrimaryHorizontal(end - 1) + getTextWidth(mOriginalText.subSequence(end - 1, end).toString()) < x) {
                end++;
            }
            end--;
        } else {
            end--;
        }
        CharSequence ellipsize = mOriginalText.subSequence(0, end);
        span.append(ellipsize);
        span.append(ELLIPSIZE_END);
        if (mTipGravity != END) {
            span.append("\n");
        }
        super.setText(span, type);
    } else {
        isOverMaxLine = false;
    }
}
 

private boolean isContentEllipsised(TextView textView) {
  Layout layout = textView.getLayout();
  if (layout != null) {
    int lineCount = layout.getLineCount();
    for (int i = 0; i < lineCount; i++) {
      if (layout.getEllipsisCount(i) > 0) {
        return true;
      }
    }
  }
  return false;
}
 

@Nullable
protected CharSequence getNextLine(Editable editable, Layout layout, int currentLine) {
    if (currentLine + 1 > layout.getLineCount() - 1) return null;
    int lineStart = layout.getLineStart(currentLine + 1);
    int lineEnd = layout.getLineEnd(currentLine + 1);
    return editable.subSequence(lineStart, lineEnd);
}
 

@VisibleForTesting
public static int resolveWidth(
    int widthSpec, Layout layout, boolean minimallyWide, int minimallyWideThreshold) {
  final int fullWidth = SizeSpec.resolveSize(widthSpec, layout.getWidth());

  if (minimallyWide && layout.getLineCount() > 1) {
    final int minimalWidth = SizeSpec.resolveSize(widthSpec, LayoutMeasureUtil.getWidth(layout));

    if (fullWidth - minimalWidth > minimallyWideThreshold) {
      return minimalWidth;
    }
  }

  return fullWidth;
}
 

@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());

	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 (needScale(line)) {
			drawScaledText(canvas, lineStart, line, width);
		} else {
			canvas.drawText(line, 0, mLineY, paint);
		}
		mLineY += textHeight;
	}
}
 

/**
 * Performs a scroll page up action.
 * Scrolls down by one page.
 *
 * @param widget The text view.
 * @param buffer The text buffer.
 * @return True if the event was handled.
 * @hide
 */
protected boolean scrollPageDown(TextView widget, Spannable buffer) {
    final Layout layout = widget.getLayout();
    final int innerHeight = getInnerHeight(widget);
    final int bottom = widget.getScrollY() + innerHeight + innerHeight;
    int bottomLine = layout.getLineForVertical(bottom);
    if (bottomLine <= layout.getLineCount() - 1) {
        Touch.scrollTo(widget, layout, widget.getScrollX(),
                layout.getLineTop(bottomLine + 1) - innerHeight);
        return true;
    }
    return false;
}
 

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    if (needCheckDevice && isVivoApi22()) {

        int width = getMeasuredWidth();
        CharSequence charSequence = getText();
        Layout layout = createWorkingLayout(charSequence, getPaint(), width);
        float dotWidth = getPaint().measureText(DOT_SUFFIX);
        int lineCount = layout.getLineCount();
        Log.d(TAG, "onMeasure , lineCount : " + lineCount);
        // 多行且第一行未占满
        if (lineCount > 1 && Math.abs(width - layout.getLineWidth(0)) > dotWidth) {
            Log.d(TAG, "onMeasure , firstLineEndIndex : " + layout.getLineEnd(0));
            int index = layout.getLineEnd(1);
            while (true) {
                index--;
                charSequence = charSequence.subSequence(0, index);
                charSequence = SpannableStringBuilder.valueOf(charSequence).append(DOT_SUFFIX);
                layout = createWorkingLayout(charSequence, getPaint(), width);
                if (layout.getLineCount() == 1 && (width - layout.getLineWidth(0) <= dotWidth || index <= 10)) {
                    mLayout = layout;
                    break;
                }
            }
        }
        needCheckDevice = false;
    }
}
 

private void drawLoadingMsg(Canvas canvas, String msg, float offset) {
    Layout tempLayout = new StaticLayout(msg, mTextPaint, mVisibleWidth, Layout.Alignment.ALIGN_NORMAL, 0, 0, false);
    List<String> linesData = new ArrayList<>();
    for (int i = 0; i < tempLayout.getLineCount(); i++) {
        linesData.add(msg.substring(tempLayout.getLineStart(i), tempLayout.getLineEnd(i)));
    }
    float pivotY = (mDisplayHeight - textInterval * linesData.size()) / 2f - offset;
    for (String str : linesData) {
        float textWidth = mTextPaint.measureText(str);
        float pivotX = (mDisplayWidth - textWidth) / 2;
        canvas.drawText(str, pivotX, pivotY, mTextPaint);
        pivotY += textInterval;
    }
}
 

private void drawErrorMsg(Canvas canvas, String msg, float offset) {
    Layout tempLayout = new StaticLayout(msg, mTextPaint, mVisibleWidth, Layout.Alignment.ALIGN_NORMAL, 0, 0, false);
    List<String> linesData = new ArrayList<>();
    for (int i = 0; i < tempLayout.getLineCount(); i++) {
        linesData.add(msg.substring(tempLayout.getLineStart(i), tempLayout.getLineEnd(i)));
    }
    float pivotY = (mDisplayHeight - textInterval * linesData.size()) / 3f - offset;


    for (String str : linesData) {
        float textWidth = mTextPaint.measureText(str);
        float pivotX = (mDisplayWidth - textWidth) / 2;
        if (readBookControl.getLoadingAmin() && msg.equals(mContext.getString(R.string.loading))) {
            //加载中替换为动画
        }else{
            canvas.drawText(str, pivotX, pivotY, mTextPaint);
        }

        pivotY += textInterval;

    }

    //加载中特殊绘制
    if(msg.equals(mContext.getString(R.string.loading))){
        /*
        mTextPaint.setTextSize(40);
        // 先绘制背景色文字
        mTextPaint.setColor(Color.parseColor("#808080"));
        //绘制 文字
        Rect rect = new Rect(0, 0, mDisplayWidth, mDisplayHeight);
        mTextPaint.setTextAlign(Paint.Align.CENTER);
        Paint.FontMetrics metrics = mTextPaint.getFontMetrics();
        float top = metrics.top;
        float bottom = metrics.bottom;
        int centerY = (int) (rect.centerY() - top / 2 - bottom / 2);
        canvas.drawText("搜神", rect.centerX(), centerY, mTextPaint);

        Log.d("ss","ddd");

        // 生成闭合波浪路径
       Path mPath = getActionPath(50);

        // 将Canvas按照Path的规则进行裁剪

        Paint mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setColor(Color.parseColor("#000000"));

        canvas.clipPath(mPath);
        canvas.drawCircle(mDisplayWidth / 2, mDisplayHeight / 2, mDisplayWidth / 2, mPaint);
        mTextPaint.setColor(Color.WHITE);
        canvas.drawText("搜神", rect.centerX(), centerY, mTextPaint);

        */
    }


}
 

@Override
protected void onDraw(Canvas canvas) {
    TextPaint paint = getPaint();
    paint.setColor(getCurrentTextColor());
    // 返回绘制状态的资源ID数组表示视图的当前状态
    paint.drawableState = getDrawableState();
    // 对View上的内容进行测量后得到的View内容占据的宽度
    // 前提是你必须在父布局的onLayout()方法或者此View的onDraw()方法里调用measure(0,0);
    // 否则你得到的结果和getWidth()得到的结果一样。
    mViewWidth = getMeasuredWidth();
    // 获取文本
    String text = getText().toString();
    mLineY = 0;
    mLineY += getTextSize();
    // 获取用于显示当前文本的布局
    Layout layout = getLayout();

    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());

    for (int i = 0; i < layout.getLineCount(); i++) {
        // 返回文本中的指定行开头的偏移
        int lineStart = layout.getLineStart(i);
        // 返回文本中的指定行最后一个字符的偏移
        int lineEnd = layout.getLineEnd(i);
        float width = StaticLayout.getDesiredWidth(text, lineStart, lineEnd, getPaint());
        String line = text.substring(lineStart, lineEnd);

        if (line.equals("")) {
            break;
        }

        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);
        }

        // 增加行高
        mLineY += textHeight;
    }
}