TextView 自动换行,每行排满的自定义TextView

作者vip1024c交流
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return (int) (pxValue / fontScale + 0.5f); }

/**

  • 根据手机的分辨率从 dp 的单位 转成为 px(像素) */ public static int dip2px(Context context, float dpValue) { final float scale = context.getResources().getDisplayMetrics().density; return (int) (dpValue * scale + 0.5f); }

@Override public void setMaxWidth(int maxpixels) { super.setMaxWidth(maxpixels); maxWidth = maxpixels; }

@Override public void setMinHeight(int minHeight) { super.setMinHeight(minHeight); this.minHeight = minHeight; }

@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (useDefault) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); return; } int width = 0, height = 0;

int widthMode = MeasureSpec.getMode(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); int widthSize = MeasureSpec.getSize(widthMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec);

switch (widthMode) { case MeasureSpec.EXACTLY: width = widthSize; break; case MeasureSpec.AT_MOST: width = widthSize; break; case MeasureSpec.UNSPECIFIED:

((Activity) context).getWindowManager().getDefaultDisplay() .getMetrics(displayMetrics); width = displayMetrics.widthPixels; break; default: break; } if (maxWidth > 0) { width = Math.min(width, maxWidth); }

paint.setTextSize(this.getTextSize()); paint.setColor(textColor); int realHeight = measureContentHeight((int) width);

// 如果实际行宽少于预定的宽度，减少行宽以使其内容横向居中 int leftPadding = getCompoundPaddingLeft(); int rightPadding = getCompoundPaddingRight(); width = Math .min(width, (int) lineWidthMax + leftPadding + rightPadding);

if (oneLineWidth > -1) { width = oneLineWidth; } switch (heightMode) { case MeasureSpec.EXACTLY: height = heightSize; break; case MeasureSpec.AT_MOST: height = realHeight; break; case MeasureSpec.UNSPECIFIED: height = realHeight; break; default: break; }

height += getCompoundPaddingTop() + getCompoundPaddingBottom();

height = Math.max(height, minHeight);

setMeasuredDimension(width, height); }

@Override protected void onDraw(Canvas canvas) { if (useDefault) { super.onDraw(canvas); return; } if (contentList.isEmpty()) { return; } int width;

Object ob;

int leftPadding = getCompoundPaddingLeft(); int topPadding = getCompoundPaddingTop();

float height = 0 + topPadding + lineSpacing; // 只有一行时 if (oneLineWidth != -1) { height = getMeasuredHeight() / 2 - contentList.get(0).height / 2; }

for (LINE aContentList : contentList) { // 绘制一行 float realDrawedWidth = leftPadding; /** 是否换新段落 */ boolean newParagraph = false; for (int j = 0; j < aContentList.line.size(); j++) { ob = aContentList.line.get(j); width = aContentList.widthList.get(j);

paint.getFontMetrics(mFontMetrics); float x = realDrawedWidth; float y = height + aContentList.height

  • paint.getFontMetrics().descent; float top = y - aContentList.height; float bottom = y + mFontMetrics.descent; if (ob instanceof String) { canvas.drawText((String) ob, realDrawedWidth, y, paint); realDrawedWidth += width; if (((String) ob).endsWith("\n") && j == aContentList.line.size() - 1) { newParagraph = true; } } else if (ob instanceof SpanObject) { Object span = ((SpanObject) ob).span; if (span instanceof DynamicDrawableSpan) {

int start = ((Spannable) text).getSpanStart(span); int end = ((Spannable) text).getSpanEnd(span); ((DynamicDrawableSpan) span).draw(canvas, text, start, end, (int) x, (int) top, (int) y, (int) bottom, paint); realDrawedWidth += width; } else if (span instanceof BackgroundColorSpan) {

textBgColorPaint.setColor(((BackgroundColorSpan) span) .getBackgroundColor()); textBgColorPaint.setStyle(Style.FILL); textBgColorRect.left = (int) realDrawedWidth; int textHeight = (int) getTextSize(); textBgColorRect.top = (int) (height

  • aContentList.height - textHeight - mFontMetrics.descent); textBgColorRect.right = textBgColorRect.left + width; textBgColorRect.bottom = (int) (height
  • aContentList.height + lineSpacing - mFontMetrics.descent); canvas.drawRect(textBgColorRect, textBgColorPaint); canvas.drawText(((SpanObject) ob).source.toString(), realDrawedWidth, height + aContentList.height
  • mFontMetrics.descent, paint); realDrawedWidth += width; } else// 做字符串处理 { canvas.drawText(((SpanObject) ob).source.toString(), realDrawedWidth, height + aContentList.height
  • mFontMetrics.descent, paint); realDrawedWidth += width; } } } // 如果要绘制段间距 if (newParagraph) { height += aContentList.height + paragraphSpacing; } else { height += aContentList.height + lineSpacing; } } }

@Override public void setTextColor(int color) { super.setTextColor(color); textColor = color; }

/**

  • 用于带ImageSpan的文本内容所占高度测量
  • @param width
  •        预定的宽度
  • @return 所需的高度 */ private int measureContentHeight(int width) { int cachedHeight = getCachedData(text.toString(), width);

if (cachedHeight > 0) { return cachedHeight; }

// 已绘的宽度 float obWidth = 0; float obHeight = 0;

float textSize = this.getTextSize(); FontMetrics fontMetrics = paint.getFontMetrics(); // 行高 float lineHeight = fontMetrics.bottom - fontMetrics.top; // 计算出的所需高度 float height = lineSpacing;

int leftPadding = getCompoundPaddingLeft(); int rightPadding = getCompoundPaddingRight();

float drawedWidth = 0;

boolean splitFlag = false;// BackgroundColorSpan拆分用

width = width - leftPadding - rightPadding;

oneLineWidth = -1;

contentList.clear();

StringBuilder sb;

LINE line = new LINE();

for (int i = 0; i < obList.size(); i++) { Object ob = obList.get(i);

if (ob instanceof String) { obWidth = paint.measureText((String) ob); obHeight = textSize; if ("\n".equals(ob)) { // 遇到"\n"则换行 obWidth = width - drawedWidth; } } else if (ob instanceof SpanObject) { Object span = ((SpanObject) ob).span; if (span instanceof DynamicDrawableSpan) { int start = ((Spannable) text).getSpanStart(span); int end = ((Spannable) text).getSpanEnd(span); obWidth = ((DynamicDrawableSpan) span).getSize(getPaint(), text, start, end, mSpanFmInt); obHeight = Math.abs(mSpanFmInt.top)

  • Math.abs(mSpanFmInt.bottom); if (obHeight > lineHeight) { lineHeight = obHeight; } } else if (span instanceof BackgroundColorSpan) { String str = ((SpanObject) ob).source.toString(); obWidth = paint.measureText(str); obHeight = textSize;

// 如果太长,拆分 int k = str.length() - 1; while (width - drawedWidth < obWidth) { obWidth = paint.measureText(str.substring(0, k--)); } if (k < str.length() - 1) { splitFlag = true; SpanObject so1 = new SpanObject(); so1.start = ((SpanObject) ob).start; so1.end = so1.start + k; so1.source = str.substring(0, k + 1); so1.span = ((SpanObject) ob).span;

SpanObject so2 = new SpanObject(); so2.start = so1.end; so2.end = ((SpanObject) ob).end; so2.source = str.substring(k + 1, str.length()); so2.span = ((SpanObject) ob).span;

ob = so1; obList.set(i, so2); i--; } }// 做字符串处理 else { String str = ((SpanObject) ob).source.toString(); obWidth = paint.measureText(str); obHeight = textSize; } }

// 这一行满了，存入contentList,新起一行 if (width - drawedWidth < obWidth || splitFlag) { splitFlag = false; contentList.add(line);

if (drawedWidth > lineWidthMax) { lineWidthMax = drawedWidth; } drawedWidth = 0; // 判断是否有分段 int objNum = line.line.size(); if (paragraphSpacing > 0 && objNum > 0 && line.line.get(objNum - 1) instanceof String && "\n".equals(line.line.get(objNum - 1))) { height += line.height + paragraphSpacing; } else { height += line.height + lineSpacing; }

lineHeight = obHeight;

line = new LINE(); }

drawedWidth += obWidth;

if (ob instanceof String && line.line.size() > 0 && (line.line.get(line.line.size() - 1) instanceof String)) { int size = line.line.size(); sb = new StringBuilder(); sb.append(line.line.get(size - 1)); sb.append(ob); ob = sb.toString(); obWidth = obWidth + line.widthList.get(size - 1); line.line.set(size - 1, ob); line.widthList.set(size - 1, (int) obWidth); line.height = (int) lineHeight; } else { line.line.add(ob); line.widthList.add((int) obWidth); line.height = (int) lineHeight; }

}

if (drawedWidth > lineWidthMax) { lineWidthMax = drawedWidth; }

if (line != null && line.line.size() > 0) { contentList.add(line); height += lineHeight + lineSpacing; } if (contentList.size() <= 1) { oneLineWidth = (int) drawedWidth + leftPadding + rightPadding; height = lineSpacing + lineHeight + lineSpacing; }

cacheData(width, (int) height); return (int) height; }

/**

  • 获取缓存的测量数据，避免多次重复测量
  • @param text
  • @param width
  • @return height */ @SuppressWarnings("unchecked") private int getCachedData(String text, int width) { SoftReference cache = measuredData.get(text); if (cache == null) { return -1; } MeasuredData md = cache.get(); if (md != null && md.textSize == this.getTextSize() && width == md.width) { lineWidthMax = md.lineWidthMax; contentList = (ArrayList) md.contentList.clone(); oneLineWidth = md.oneLineWidth;

StringBuilder sb = new StringBuilder(); for (int i = 0; i < contentList.size(); i++) { LINE line = contentList.get(i); sb.append(line.toString()); } return md.measuredHeight; } else { return -1; } }

/**

  • 缓存已测量的数据
  • @param width
  • @param height */ @SuppressWarnings("unchecked") private void cacheData(int width, int height) { MeasuredData md = new MeasuredData(); md.contentList = (ArrayList) contentList.clone(); md.textSize = this.getTextSize(); md.lineWidthMax = lineWidthMax; md.oneLineWidth = oneLineWidth; md.measuredHeight = height; md.width = width; md.hashIndex = ++hashIndex;

StringBuilder sb = new StringBuilder(); for (int i = 0; i < contentList.size(); i++) { LINE line = contentList.get(i); sb.append(line.toString()); }

SoftReference cache = new SoftReference(md); measuredData.put(text.toString(), cache); }

/**

  • 用本函数代替{@link #setText(CharSequence)}
  • @param cs */ public void setMText(CharSequence cs) { text = cs;

obList.clear();

ArrayList isList = new ArrayList(); useDefault = false;

if (cs instanceof Spannable) { CharacterStyle[] spans = ((Spannable) cs).getSpans(0, cs.length(), CharacterStyle.class); for (int i = 0; i < spans.length; i++) { int s = ((Spannable) cs).getSpanStart(spans[i]); int e = ((Spannable) cs).getSpanEnd(spans[i]); SpanObject iS = new SpanObject(); iS.span = spans[i]; iS.start = s; iS.end = e; iS.source = cs.subSequence(s, e); isList.add(iS); } }

// 对span进行排序，以免不同种类的span位置错乱 SpanObject[] spanArray = new SpanObject[isList.size()]; isList.toArray(spanArray); Arrays.sort(spanArray, 0, spanArray.length, new SpanObjectComparator()); isList.clear(); for (int i = 0; i < spanArray.length; i++) { isList.add(spanArray[i]); }

String str = cs.toString();

for (int i = 0, j = 0; i < cs.length();) { if (j < isList.size()) { SpanObject is = isList.get(j); if (i < is.start) { Integer cp = str.codePointAt(i); // 支持增补字符 if (Character.isSupplementaryCodePoint(cp)) { i += 2; } else { i++; }

obList.add(new String(Character.toChars(cp)));

} else if (i >= is.start) { obList.add(is); j++; i = is.end; } } else { Integer cp = str.codePointAt(i); if (Character.isSupplementaryCodePoint(cp)) { i += 2; } else { i++; }

obList.add(new String(Character.toChars(cp))); } }

requestLayout(); }

public void setUseDefault(boolean useDefault) { this.useDefault = useDefault; if (useDefault) { this.setText(text); this.setTextColor(textColor); } }

/**

  • 设置行距
  • @param lineSpacingDP
  •        行距，单位dp

*/ public void setLineSpacingDP(int lineSpacingDP) { this.lineSpacingDP = lineSpacingDP; lineSpacing = dip2px(context, lineSpacingDP); }

public void setParagraphSpacingDP(int paragraphSpacingDP) { paragraphSpacing = dip2px(context, paragraphSpacingDP); }

/**

  • 获取行距
  • @return 行距，单位dp */ public int getLineSpacingDP() { return lineSpacingDP; }

/**

  • 存储Span对象及相关信息 */ class SpanObject { public Object span; public int start; public int end; public CharSequence source; }

/**

  • 对SpanObject进行排序 */ class SpanObjectComparator implements Comparator { @Override public int compare(SpanObject lhs, SpanObject rhs) {

return lhs.start - rhs.start; } }

/**

  • 存储测量好的一行数据 */ class LINE { public ArrayList line = new ArrayList(); public ArrayList widthList = new ArrayList(); public float height;

    @Override public String toString() { StringBuilder sb = new StringBuilder("height:" + height + " "); for (int i = 0; i < line.size(); i++) { sb.append(line.get(i) + ":" + widthList.get(i)); } return sb.toString(); } } /**

    • 缓存的数据 */ class MeasuredData { public int measuredHeight; public float textSize; public int width; public float lineWidthMax; public int oneLineWidth; public int hashIndex; ArrayList contentList; } } 设置的时候使用setMText
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