text.js

var _util = require("../../core/util");

var retrieve2 = _util.retrieve2;
var retrieve3 = _util.retrieve3;
var each = _util.each;
var normalizeCssArray = _util.normalizeCssArray;
var isString = _util.isString;
var isObject = _util.isObject;

var textContain = require("../../contain/text");

var roundRectHelper = require("./roundRect");

var imageHelper = require("./image");

var fixShadow = require("./fixShadow");

var _constant = require("../constant");

var ContextCachedBy = _constant.ContextCachedBy;
var WILL_BE_RESTORED = _constant.WILL_BE_RESTORED;
var DEFAULT_FONT = textContain.DEFAULT_FONT; // TODO: Have not support 'start', 'end' yet.

var VALID_TEXT_ALIGN = {
  left: 1,
  right: 1,
  center: 1
};
var VALID_TEXT_VERTICAL_ALIGN = {
  top: 1,
  bottom: 1,
  middle: 1
}; // Different from `STYLE_COMMON_PROPS` of `graphic/Style`,
// the default value of shadowColor is `'transparent'`.

var SHADOW_STYLE_COMMON_PROPS = [['textShadowBlur', 'shadowBlur', 0], ['textShadowOffsetX', 'shadowOffsetX', 0], ['textShadowOffsetY', 'shadowOffsetY', 0], ['textShadowColor', 'shadowColor', 'transparent']];
/**
 * @param {module:zrender/graphic/Style} style
 * @return {module:zrender/graphic/Style} The input style.
 */

function normalizeTextStyle(style) {
  normalizeStyle(style);
  each(style.rich, normalizeStyle);
  return style;
}

function normalizeStyle(style) {
  if (style) {
    style.font = textContain.makeFont(style);
    var textAlign = style.textAlign;
    textAlign === 'middle' && (textAlign = 'center');
    style.textAlign = textAlign == null || VALID_TEXT_ALIGN[textAlign] ? textAlign : 'left'; // Compatible with textBaseline.

    var textVerticalAlign = style.textVerticalAlign || style.textBaseline;
    textVerticalAlign === 'center' && (textVerticalAlign = 'middle');
    style.textVerticalAlign = textVerticalAlign == null || VALID_TEXT_VERTICAL_ALIGN[textVerticalAlign] ? textVerticalAlign : 'top';
    var textPadding = style.textPadding;

    if (textPadding) {
      style.textPadding = normalizeCssArray(style.textPadding);
    }
  }
}
/**
 * @param {CanvasRenderingContext2D} ctx
 * @param {string} text
 * @param {module:zrender/graphic/Style} style
 * @param {Object|boolean} [rect] {x, y, width, height}
 *                  If set false, rect text is not used.
 * @param {Element|module:zrender/graphic/helper/constant.WILL_BE_RESTORED} [prevEl] For ctx prop cache.
 */


function renderText(hostEl, ctx, text, style, rect, prevEl) {
  style.rich ? renderRichText(hostEl, ctx, text, style, rect, prevEl) : renderPlainText(hostEl, ctx, text, style, rect, prevEl);
} // Avoid setting to ctx according to prevEl if possible for
// performance in scenarios of large amount text.


function renderPlainText(hostEl, ctx, text, style, rect, prevEl) {
  'use strict';

  var needDrawBg = needDrawBackground(style);
  var prevStyle;
  var checkCache = false;
  var cachedByMe = ctx.__attrCachedBy === ContextCachedBy.PLAIN_TEXT; // Only take and check cache for `Text` el, but not RectText.

  if (prevEl !== WILL_BE_RESTORED) {
    if (prevEl) {
      prevStyle = prevEl.style;
      checkCache = !needDrawBg && cachedByMe && prevStyle;
    } // Prevent from using cache in `Style::bind`, because of the case:
    // ctx property is modified by other properties than `Style::bind`
    // used, and Style::bind is called next.


    ctx.__attrCachedBy = needDrawBg ? ContextCachedBy.NONE : ContextCachedBy.PLAIN_TEXT;
  } // Since this will be restored, prevent from using these props to check cache in the next
  // entering of this method. But do not need to clear other cache like `Style::bind`.
  else if (cachedByMe) {
      ctx.__attrCachedBy = ContextCachedBy.NONE;
    }

  var styleFont = style.font || DEFAULT_FONT; // PENDING
  // Only `Text` el set `font` and keep it (`RectText` will restore). So theoretically
  // we can make font cache on ctx, which can cache for text el that are discontinuous.
  // But layer save/restore needed to be considered.
  // if (styleFont !== ctx.__fontCache) {
  //     ctx.font = styleFont;
  //     if (prevEl !== WILL_BE_RESTORED) {
  //         ctx.__fontCache = styleFont;
  //     }
  // }

  if (!checkCache || styleFont !== (prevStyle.font || DEFAULT_FONT)) {
    ctx.font = styleFont;
  } // Use the final font from context-2d, because the final
  // font might not be the style.font when it is illegal.
  // But get `ctx.font` might be time consuming.


  var computedFont = hostEl.__computedFont;

  if (hostEl.__styleFont !== styleFont) {
    hostEl.__styleFont = styleFont;
    computedFont = hostEl.__computedFont = ctx.font;
  }

  var textPadding = style.textPadding;
  var textLineHeight = style.textLineHeight;
  var contentBlock = hostEl.__textCotentBlock;

  if (!contentBlock || hostEl.__dirtyText) {
    contentBlock = hostEl.__textCotentBlock = textContain.parsePlainText(text, computedFont, textPadding, textLineHeight, style.truncate);
  }

  var outerHeight = contentBlock.outerHeight;
  var textLines = contentBlock.lines;
  var lineHeight = contentBlock.lineHeight;
  var boxPos = getBoxPosition(outerHeight, style, rect);
  var baseX = boxPos.baseX;
  var baseY = boxPos.baseY;
  var textAlign = boxPos.textAlign || 'left';
  var textVerticalAlign = boxPos.textVerticalAlign; // Origin of textRotation should be the base point of text drawing.

  applyTextRotation(ctx, style, rect, baseX, baseY);
  var boxY = textContain.adjustTextY(baseY, outerHeight, textVerticalAlign);
  var textX = baseX;
  var textY = boxY;

  if (needDrawBg || textPadding) {
    // Consider performance, do not call getTextWidth util necessary.
    var textWidth = textContain.getWidth(text, computedFont);
    var outerWidth = textWidth;
    textPadding && (outerWidth += textPadding[1] + textPadding[3]);
    var boxX = textContain.adjustTextX(baseX, outerWidth, textAlign);
    needDrawBg && drawBackground(hostEl, ctx, style, boxX, boxY, outerWidth, outerHeight);

    if (textPadding) {
      textX = getTextXForPadding(baseX, textAlign, textPadding);
      textY += textPadding[0];
    }
  } // Always set textAlign and textBase line, because it is difficute to calculate
  // textAlign from prevEl, and we dont sure whether textAlign will be reset if
  // font set happened.


  ctx.textAlign = textAlign; // Force baseline to be "middle". Otherwise, if using "top", the
  // text will offset downward a little bit in font "Microsoft YaHei".

  ctx.textBaseline = 'middle'; // Set text opacity

  ctx.globalAlpha = style.opacity || 1; // Always set shadowBlur and shadowOffset to avoid leak from displayable.

  for (var i = 0; i < SHADOW_STYLE_COMMON_PROPS.length; i++) {
    var propItem = SHADOW_STYLE_COMMON_PROPS[i];
    var styleProp = propItem[0];
    var ctxProp = propItem[1];
    var val = style[styleProp];

    if (!checkCache || val !== prevStyle[styleProp]) {
      ctx[ctxProp] = fixShadow(ctx, ctxProp, val || propItem[2]);
    }
  } // `textBaseline` is set as 'middle'.


  textY += lineHeight / 2;
  var textStrokeWidth = style.textStrokeWidth;
  var textStrokeWidthPrev = checkCache ? prevStyle.textStrokeWidth : null;
  var strokeWidthChanged = !checkCache || textStrokeWidth !== textStrokeWidthPrev;
  var strokeChanged = !checkCache || strokeWidthChanged || style.textStroke !== prevStyle.textStroke;
  var textStroke = getStroke(style.textStroke, textStrokeWidth);
  var textFill = getFill(style.textFill);

  if (textStroke) {
    if (strokeWidthChanged) {
      ctx.lineWidth = textStrokeWidth;
    }

    if (strokeChanged) {
      ctx.strokeStyle = textStroke;
    }
  }

  if (textFill) {
    if (!checkCache || style.textFill !== prevStyle.textFill) {
      ctx.fillStyle = textFill;
    }
  } // Optimize simply, in most cases only one line exists.


  if (textLines.length === 1) {
    // Fill after stroke so the outline will not cover the main part.
    textStroke && ctx.strokeText(textLines[0], textX, textY);
    textFill && ctx.fillText(textLines[0], textX, textY);
  } else {
    for (var i = 0; i < textLines.length; i++) {
      // Fill after stroke so the outline will not cover the main part.
      textStroke && ctx.strokeText(textLines[i], textX, textY);
      textFill && ctx.fillText(textLines[i], textX, textY);
      textY += lineHeight;
    }
  }
}

function renderRichText(hostEl, ctx, text, style, rect, prevEl) {
  // Do not do cache for rich text because of the complexity.
  // But `RectText` this will be restored, do not need to clear other cache like `Style::bind`.
  if (prevEl !== WILL_BE_RESTORED) {
    ctx.__attrCachedBy = ContextCachedBy.NONE;
  }

  var contentBlock = hostEl.__textCotentBlock;

  if (!contentBlock || hostEl.__dirtyText) {
    contentBlock = hostEl.__textCotentBlock = textContain.parseRichText(text, style);
  }

  drawRichText(hostEl, ctx, contentBlock, style, rect);
}

function drawRichText(hostEl, ctx, contentBlock, style, rect) {
  var contentWidth = contentBlock.width;
  var outerWidth = contentBlock.outerWidth;
  var outerHeight = contentBlock.outerHeight;
  var textPadding = style.textPadding;
  var boxPos = getBoxPosition(outerHeight, style, rect);
  var baseX = boxPos.baseX;
  var baseY = boxPos.baseY;
  var textAlign = boxPos.textAlign;
  var textVerticalAlign = boxPos.textVerticalAlign; // Origin of textRotation should be the base point of text drawing.

  applyTextRotation(ctx, style, rect, baseX, baseY);
  var boxX = textContain.adjustTextX(baseX, outerWidth, textAlign);
  var boxY = textContain.adjustTextY(baseY, outerHeight, textVerticalAlign);
  var xLeft = boxX;
  var lineTop = boxY;

  if (textPadding) {
    xLeft += textPadding[3];
    lineTop += textPadding[0];
  }

  var xRight = xLeft + contentWidth;
  needDrawBackground(style) && drawBackground(hostEl, ctx, style, boxX, boxY, outerWidth, outerHeight);

  for (var i = 0; i < contentBlock.lines.length; i++) {
    var line = contentBlock.lines[i];
    var tokens = line.tokens;
    var tokenCount = tokens.length;
    var lineHeight = line.lineHeight;
    var usedWidth = line.width;
    var leftIndex = 0;
    var lineXLeft = xLeft;
    var lineXRight = xRight;
    var rightIndex = tokenCount - 1;
    var token;

    while (leftIndex < tokenCount && (token = tokens[leftIndex], !token.textAlign || token.textAlign === 'left')) {
      placeToken(hostEl, ctx, token, style, lineHeight, lineTop, lineXLeft, 'left');
      usedWidth -= token.width;
      lineXLeft += token.width;
      leftIndex++;
    }

    while (rightIndex >= 0 && (token = tokens[rightIndex], token.textAlign === 'right')) {
      placeToken(hostEl, ctx, token, style, lineHeight, lineTop, lineXRight, 'right');
      usedWidth -= token.width;
      lineXRight -= token.width;
      rightIndex--;
    } // The other tokens are placed as textAlign 'center' if there is enough space.


    lineXLeft += (contentWidth - (lineXLeft - xLeft) - (xRight - lineXRight) - usedWidth) / 2;

    while (leftIndex <= rightIndex) {
      token = tokens[leftIndex]; // Consider width specified by user, use 'center' rather than 'left'.

      placeToken(hostEl, ctx, token, style, lineHeight, lineTop, lineXLeft + token.width / 2, 'center');
      lineXLeft += token.width;
      leftIndex++;
    }

    lineTop += lineHeight;
  }
}

function applyTextRotation(ctx, style, rect, x, y) {
  // textRotation only apply in RectText.
  if (rect && style.textRotation) {
    var origin = style.textOrigin;

    if (origin === 'center') {
      x = rect.width / 2 + rect.x;
      y = rect.height / 2 + rect.y;
    } else if (origin) {
      x = origin[0] + rect.x;
      y = origin[1] + rect.y;
    }

    ctx.translate(x, y); // Positive: anticlockwise

    ctx.rotate(-style.textRotation);
    ctx.translate(-x, -y);
  }
}

function placeToken(hostEl, ctx, token, style, lineHeight, lineTop, x, textAlign) {
  var tokenStyle = style.rich[token.styleName] || {};
  tokenStyle.text = token.text; // 'ctx.textBaseline' is always set as 'middle', for sake of
  // the bias of "Microsoft YaHei".

  var textVerticalAlign = token.textVerticalAlign;
  var y = lineTop + lineHeight / 2;

  if (textVerticalAlign === 'top') {
    y = lineTop + token.height / 2;
  } else if (textVerticalAlign === 'bottom') {
    y = lineTop + lineHeight - token.height / 2;
  }

  !token.isLineHolder && needDrawBackground(tokenStyle) && drawBackground(hostEl, ctx, tokenStyle, textAlign === 'right' ? x - token.width : textAlign === 'center' ? x - token.width / 2 : x, y - token.height / 2, token.width, token.height);
  var textPadding = token.textPadding;

  if (textPadding) {
    x = getTextXForPadding(x, textAlign, textPadding);
    y -= token.height / 2 - textPadding[2] - token.textHeight / 2;
  }

  setCtx(ctx, 'shadowBlur', retrieve3(tokenStyle.textShadowBlur, style.textShadowBlur, 0));
  setCtx(ctx, 'shadowColor', tokenStyle.textShadowColor || style.textShadowColor || 'transparent');
  setCtx(ctx, 'shadowOffsetX', retrieve3(tokenStyle.textShadowOffsetX, style.textShadowOffsetX, 0));
  setCtx(ctx, 'shadowOffsetY', retrieve3(tokenStyle.textShadowOffsetY, style.textShadowOffsetY, 0));
  setCtx(ctx, 'textAlign', textAlign); // Force baseline to be "middle". Otherwise, if using "top", the
  // text will offset downward a little bit in font "Microsoft YaHei".

  setCtx(ctx, 'textBaseline', 'middle');
  setCtx(ctx, 'font', token.font || DEFAULT_FONT);
  var textStroke = getStroke(tokenStyle.textStroke || style.textStroke, textStrokeWidth);
  var textFill = getFill(tokenStyle.textFill || style.textFill);
  var textStrokeWidth = retrieve2(tokenStyle.textStrokeWidth, style.textStrokeWidth); // Fill after stroke so the outline will not cover the main part.

  if (textStroke) {
    setCtx(ctx, 'lineWidth', textStrokeWidth);
    setCtx(ctx, 'strokeStyle', textStroke);
    ctx.strokeText(token.text, x, y);
  }

  if (textFill) {
    setCtx(ctx, 'fillStyle', textFill);
    ctx.fillText(token.text, x, y);
  }
}

function needDrawBackground(style) {
  return !!(style.textBackgroundColor || style.textBorderWidth && style.textBorderColor);
} // style: {textBackgroundColor, textBorderWidth, textBorderColor, textBorderRadius, text}
// shape: {x, y, width, height}


function drawBackground(hostEl, ctx, style, x, y, width, height) {
  var textBackgroundColor = style.textBackgroundColor;
  var textBorderWidth = style.textBorderWidth;
  var textBorderColor = style.textBorderColor;
  var isPlainBg = isString(textBackgroundColor);
  setCtx(ctx, 'shadowBlur', style.textBoxShadowBlur || 0);
  setCtx(ctx, 'shadowColor', style.textBoxShadowColor || 'transparent');
  setCtx(ctx, 'shadowOffsetX', style.textBoxShadowOffsetX || 0);
  setCtx(ctx, 'shadowOffsetY', style.textBoxShadowOffsetY || 0);

  if (isPlainBg || textBorderWidth && textBorderColor) {
    ctx.beginPath();
    var textBorderRadius = style.textBorderRadius;

    if (!textBorderRadius) {
      ctx.rect(x, y, width, height);
    } else {
      roundRectHelper.buildPath(ctx, {
        x: x,
        y: y,
        width: width,
        height: height,
        r: textBorderRadius
      });
    }

    ctx.closePath();
  }

  if (isPlainBg) {
    setCtx(ctx, 'fillStyle', textBackgroundColor);

    if (style.fillOpacity != null) {
      var originalGlobalAlpha = ctx.globalAlpha;
      ctx.globalAlpha = style.fillOpacity * style.opacity;
      ctx.fill();
      ctx.globalAlpha = originalGlobalAlpha;
    } else {
      ctx.fill();
    }
  } else if (isObject(textBackgroundColor)) {
    var image = textBackgroundColor.image;
    image = imageHelper.createOrUpdateImage(image, null, hostEl, onBgImageLoaded, textBackgroundColor);

    if (image && imageHelper.isImageReady(image)) {
      ctx.drawImage(image, x, y, width, height);
    }
  }

  if (textBorderWidth && textBorderColor) {
    setCtx(ctx, 'lineWidth', textBorderWidth);
    setCtx(ctx, 'strokeStyle', textBorderColor);

    if (style.strokeOpacity != null) {
      var originalGlobalAlpha = ctx.globalAlpha;
      ctx.globalAlpha = style.strokeOpacity * style.opacity;
      ctx.stroke();
      ctx.globalAlpha = originalGlobalAlpha;
    } else {
      ctx.stroke();
    }
  }
}

function onBgImageLoaded(image, textBackgroundColor) {
  // Replace image, so that `contain/text.js#parseRichText`
  // will get correct result in next tick.
  textBackgroundColor.image = image;
}

function getBoxPosition(blockHeiht, style, rect) {
  var baseX = style.x || 0;
  var baseY = style.y || 0;
  var textAlign = style.textAlign;
  var textVerticalAlign = style.textVerticalAlign; // Text position represented by coord

  if (rect) {
    var textPosition = style.textPosition;

    if (textPosition instanceof Array) {
      // Percent
      baseX = rect.x + parsePercent(textPosition[0], rect.width);
      baseY = rect.y + parsePercent(textPosition[1], rect.height);
    } else {
      var res = textContain.adjustTextPositionOnRect(textPosition, rect, style.textDistance);
      baseX = res.x;
      baseY = res.y; // Default align and baseline when has textPosition

      textAlign = textAlign || res.textAlign;
      textVerticalAlign = textVerticalAlign || res.textVerticalAlign;
    } // textOffset is only support in RectText, otherwise
    // we have to adjust boundingRect for textOffset.


    var textOffset = style.textOffset;

    if (textOffset) {
      baseX += textOffset[0];
      baseY += textOffset[1];
    }
  }

  return {
    baseX: baseX,
    baseY: baseY,
    textAlign: textAlign,
    textVerticalAlign: textVerticalAlign
  };
}

function setCtx(ctx, prop, value) {
  ctx[prop] = fixShadow(ctx, prop, value);
  return ctx[prop];
}
/**
 * @param {string} [stroke] If specified, do not check style.textStroke.
 * @param {string} [lineWidth] If specified, do not check style.textStroke.
 * @param {number} style
 */


function getStroke(stroke, lineWidth) {
  return stroke == null || lineWidth <= 0 || stroke === 'transparent' || stroke === 'none' ? null // TODO pattern and gradient?
  : stroke.image || stroke.colorStops ? '#000' : stroke;
}

function getFill(fill) {
  return fill == null || fill === 'none' ? null // TODO pattern and gradient?
  : fill.image || fill.colorStops ? '#000' : fill;
}

function parsePercent(value, maxValue) {
  if (typeof value === 'string') {
    if (value.lastIndexOf('%') >= 0) {
      return parseFloat(value) / 100 * maxValue;
    }

    return parseFloat(value);
  }

  return value;
}

function getTextXForPadding(x, textAlign, textPadding) {
  return textAlign === 'right' ? x - textPadding[1] : textAlign === 'center' ? x + textPadding[3] / 2 - textPadding[1] / 2 : x + textPadding[3];
}
/**
 * @param {string} text
 * @param {module:zrender/Style} style
 * @return {boolean}
 */


function needDrawText(text, style) {
  return text != null && (text || style.textBackgroundColor || style.textBorderWidth && style.textBorderColor || style.textPadding);
}

exports.normalizeTextStyle = normalizeTextStyle;
exports.renderText = renderText;
exports.getStroke = getStroke;
exports.getFill = getFill;
exports.needDrawText = needDrawText;