konva/src/shapes/Text.ts

import { Util, Collection } from '../Util';
import { Factory, Validators } from '../Factory';
import { Shape } from '../Shape';
import { UA } from '../Global';

import { GetSet } from '../types';

// constants
var AUTO = 'auto',
  //CANVAS = 'canvas',
  CENTER = 'center',
  JUSTIFY = 'justify',
  CHANGE_KONVA = 'Change.konva',
  CONTEXT_2D = '2d',
  DASH = '-',
  LEFT = 'left',
  TEXT = 'text',
  TEXT_UPPER = 'Text',
  TOP = 'top',
  BOTTOM = 'bottom',
  MIDDLE = 'middle',
  NORMAL = 'normal',
  PX_SPACE = 'px ',
  SPACE = ' ',
  RIGHT = 'right',
  WORD = 'word',
  CHAR = 'char',
  NONE = 'none',
  ELLIPSIS = '…',
  ATTR_CHANGE_LIST = [
    'fontFamily',
    'fontSize',
    'fontStyle',
    'fontVariant',
    'padding',
    'align',
    'verticalAlign',
    'lineHeight',
    'text',
    'width',
    'height',
    'wrap',
    'ellipsis',
    'letterSpacing'
  ],
  // cached variables
  attrChangeListLen = ATTR_CHANGE_LIST.length;
var dummyContext;
function getDummyContext() {
  if (dummyContext) {
    return dummyContext;
  }
  dummyContext = Util.createCanvasElement().getContext(CONTEXT_2D);
  return dummyContext;
}

function _fillFunc(context) {
  context.fillText(this.partialText, 0, 0);
}
function _strokeFunc(context) {
  context.strokeText(this.partialText, 0, 0);
}

/**
 * Text constructor
 * @constructor
 * @memberof Konva
 * @augments Konva.Shape
 * @param {Object} config
 * @param {String} [config.fontFamily] default is Arial
 * @param {Number} [config.fontSize] in pixels.  Default is 12
 * @param {String} [config.fontStyle] can be normal, bold, or italic.  Default is normal
 * @param {String} [config.fontVariant] can be normal or small-caps.  Default is normal
 * @param {String} [config.textDecoration] can be line-through, underline or empty string. Default is empty string.
 * @param {String} config.text
 * @param {String} [config.align] can be left, center, or right
 * @param {String} [config.verticalAlign] can be top, middle or bottom
 * @param {Number} [config.padding]
 * @param {Number} [config.lineHeight] default is 1
 * @param {String} [config.wrap] can be word, char, or none. Default is word
 * @param {Boolean} [config.ellipsis] can be true or false. Default is false. if Konva.Text config is set to wrap="none" and ellipsis=true, then it will add "..." to the end
 * @@shapeParams
 * @@nodeParams
 * @example
 * var text = new Konva.Text({
 *   x: 10,
 *   y: 15,
 *   text: 'Simple Text',
 *   fontSize: 30,
 *   fontFamily: 'Calibri',
 *   fill: 'green'
 * });
 */
export class Text extends Shape {
  textArr: Array<{ text: string; width: number }>;
  partialText: string;

  textWidth: number;
  textHeight: number;
  constructor(config) {
    config = config || {};

    // set default color to black
    if (
      !config.fillLinearGradientColorStops &&
      !config.fillRadialGradientColorStops
    ) {
      config.fill = config.fill || 'black';
    }

    super(config);

    // update text data for certain attr changes
    for (var n = 0; n < attrChangeListLen; n++) {
      this.on(ATTR_CHANGE_LIST[n] + CHANGE_KONVA, this._setTextData);
    }

    this._setTextData();
    this.sceneFunc(this._sceneFunc);
    this.hitFunc(this._hitFunc);
  }

  _sceneFunc(context) {
    var padding = this.padding(),
      textHeight = this.getTextHeight(),
      lineHeightPx = this.lineHeight() * textHeight,
      textArr = this.textArr,
      textArrLen = textArr.length,
      verticalAlign = this.verticalAlign(),
      alignY = 0,
      align = this.align(),
      totalWidth = this.getWidth(),
      letterSpacing = this.letterSpacing(),
      textDecoration = this.textDecoration(),
      fill = this.fill(),
      fontSize = this.fontSize(),
      n;

    context.setAttr('font', this._getContextFont());

    context.setAttr('textBaseline', MIDDLE);
    context.setAttr('textAlign', LEFT);

    // handle vertical alignment
    if (verticalAlign === MIDDLE) {
      alignY = (this.getHeight() - textArrLen * lineHeightPx - padding * 2) / 2;
    } else if (verticalAlign === BOTTOM) {
      alignY = this.getHeight() - textArrLen * lineHeightPx - padding * 2;
    }

    if (padding) {
      context.translate(padding, 0);
      context.translate(0, alignY + padding + lineHeightPx / 2);
    } else {
      context.translate(0, alignY + lineHeightPx / 2);
    }

    // draw text lines
    for (n = 0; n < textArrLen; n++) {
      var obj = textArr[n],
        text = obj.text,
        width = obj.width,
        lastLine = n !== textArrLen - 1,
        spacesNumber,
        oneWord,
        lineWidth;

      // horizontal alignment
      context.save();
      if (align === RIGHT) {
        context.translate(totalWidth - width - padding * 2, 0);
      } else if (align === CENTER) {
        context.translate((totalWidth - width - padding * 2) / 2, 0);
      }

      if (textDecoration.indexOf('underline') !== -1) {
        context.save();
        context.beginPath();

        context.moveTo(0, Math.round(lineHeightPx / 2));
        spacesNumber = text.split(' ').length - 1;
        oneWord = spacesNumber === 0;
        lineWidth =
          align === JUSTIFY && lastLine && !oneWord
            ? totalWidth - padding * 2
            : width;
        context.lineTo(Math.round(lineWidth), Math.round(lineHeightPx / 2));
        // TODO: I have no idea what is real ratio
        // just /15 looks good enough
        context.lineWidth = fontSize / 15;
        context.strokeStyle = fill;
        context.stroke();
        context.restore();
      }
      if (textDecoration.indexOf('line-through') !== -1) {
        context.save();
        context.beginPath();
        context.moveTo(0, 0);
        spacesNumber = text.split(' ').length - 1;
        oneWord = spacesNumber === 0;
        lineWidth =
          align === JUSTIFY && lastLine && !oneWord
            ? totalWidth - padding * 2
            : width;
        context.lineTo(Math.round(lineWidth), 0);
        context.lineWidth = fontSize / 15;
        context.strokeStyle = fill;
        context.stroke();
        context.restore();
      }
      if (letterSpacing !== 0 || align === JUSTIFY) {
        //   var words = text.split(' ');
        spacesNumber = text.split(' ').length - 1;
        for (var li = 0; li < text.length; li++) {
          var letter = text[li];
          // skip justify for the last line
          if (letter === ' ' && n !== textArrLen - 1 && align === JUSTIFY) {
            context.translate(
              Math.floor((totalWidth - padding * 2 - width) / spacesNumber),
              0
            );
          }
          this.partialText = letter;
          context.fillStrokeShape(this);
          context.translate(
            Math.round(this._getTextSize(letter).width) + letterSpacing,
            0
          );
        }
      } else {
        this.partialText = text;

        context.fillStrokeShape(this);
      }
      context.restore();
      if (textArrLen > 1) {
        context.translate(0, lineHeightPx);
      }
    }
  }
  _hitFunc(context) {
    var width = this.getWidth(),
      height = this.getHeight();

    context.beginPath();
    context.rect(0, 0, width, height);
    context.closePath();
    context.fillStrokeShape(this);
  }
  setText(text) {
    var str = Util._isString(text) ? text : (text || '').toString();
    this._setAttr(TEXT, str);
    return this;
  }
  getWidth() {
    var isAuto = this.attrs.width === AUTO || this.attrs.width === undefined;
    return isAuto ? this.getTextWidth() + this.padding() * 2 : this.attrs.width;
  }
  getHeight() {
    var isAuto = this.attrs.height === AUTO || this.attrs.height === undefined;
    return isAuto
      ? this.getTextHeight() * this.textArr.length * this.lineHeight() +
          this.padding() * 2
      : this.attrs.height;
  }
  /**
   * get pure text width without padding
   * @method
   * @name Konva.Text#getTextWidth
   * @returns {Number}
   */
  getTextWidth() {
    return this.textWidth;
  }
  /**
   * get height of one line of text
   * @method
   * @name Konva.Text#getTextHeight
   * @returns {Number}
   */
  getTextHeight() {
    return this.textHeight;
  }
  _getTextSize(text) {
    var _context = getDummyContext(),
      fontSize = this.fontSize(),
      metrics;

    _context.save();
    _context.font = this._getContextFont();

    metrics = _context.measureText(text);
    _context.restore();
    return {
      width: metrics.width,
      height: fontSize
    };
  }
  _getContextFont() {
    // IE don't want to work with usual font style
    // bold was not working
    // removing font variant will solve
    // fix for: https://github.com/konvajs/konva/issues/94
    if (UA.isIE) {
      return (
        this.fontStyle() +
        SPACE +
        this.fontSize() +
        PX_SPACE +
        this.fontFamily()
      );
    }
    return (
      this.fontStyle() +
      SPACE +
      this.fontVariant() +
      SPACE +
      this.fontSize() +
      PX_SPACE +
      this.fontFamily()
    );
  }
  _addTextLine(line) {
    if (this.align() === JUSTIFY) {
      line = line.trim();
    }
    var width = this._getTextWidth(line);
    return this.textArr.push({ text: line, width: width });
  }
  _getTextWidth(text) {
    var latterSpacing = this.letterSpacing();
    var length = text.length;
    return (
      getDummyContext().measureText(text).width +
      (length ? latterSpacing * (length - 1) : 0)
    );
  }
  _setTextData() {
    var lines = this.text().split('\n'),
      fontSize = +this.fontSize(),
      textWidth = 0,
      lineHeightPx = this.lineHeight() * fontSize,
      width = this.attrs.width,
      height = this.attrs.height,
      fixedWidth = width !== AUTO,
      fixedHeight = height !== AUTO,
      padding = this.padding(),
      maxWidth = width - padding * 2,
      maxHeightPx = height - padding * 2,
      currentHeightPx = 0,
      wrap = this.wrap(),
      // align = this.align(),
      shouldWrap = wrap !== NONE,
      wrapAtWord = wrap !== CHAR && shouldWrap,
      shouldAddEllipsis = this.ellipsis() && !shouldWrap;

    this.textArr = [];
    getDummyContext().font = this._getContextFont();
    for (var i = 0, max = lines.length; i < max; ++i) {
      var line = lines[i];
      var additionalWidth = shouldAddEllipsis
        ? this._getTextWidth(ELLIPSIS)
        : 0;

      var lineWidth = this._getTextWidth(line);
      if (fixedWidth && lineWidth > maxWidth) {
        /*
         * if width is fixed and line does not fit entirely
         * break the line into multiple fitting lines
         */
        while (line.length > 0) {
          /*
           * use binary search to find the longest substring that
           * that would fit in the specified width
           */
          var low = 0,
            high = line.length,
            match = '',
            matchWidth = 0;
          while (low < high) {
            var mid = (low + high) >>> 1,
              substr = line.slice(0, mid + 1),
              substrWidth = this._getTextWidth(substr) + additionalWidth;
            if (substrWidth <= maxWidth) {
              low = mid + 1;
              match = substr + (shouldAddEllipsis ? ELLIPSIS : '');
              matchWidth = substrWidth;
            } else {
              high = mid;
            }
          }
          /*
           * 'low' is now the index of the substring end
           * 'match' is the substring
           * 'matchWidth' is the substring width in px
           */
          if (match) {
            // a fitting substring was found
            if (wrapAtWord) {
              // try to find a space or dash where wrapping could be done
              var wrapIndex;
              var nextChar = line[match.length];
              var nextIsSpaceOrDash = nextChar === SPACE || nextChar === DASH;
              if (nextIsSpaceOrDash && matchWidth <= maxWidth) {
                wrapIndex = match.length;
              } else {
                wrapIndex =
                  Math.max(match.lastIndexOf(SPACE), match.lastIndexOf(DASH)) +
                  1;
              }
              if (wrapIndex > 0) {
                // re-cut the substring found at the space/dash position
                low = wrapIndex;
                match = match.slice(0, low);
                matchWidth = this._getTextWidth(match);
              }
            }
            // if (align === 'right') {
            match = match.trimRight();
            // }
            this._addTextLine(match);
            textWidth = Math.max(textWidth, matchWidth);
            currentHeightPx += lineHeightPx;
            if (
              !shouldWrap ||
              (fixedHeight && currentHeightPx + lineHeightPx > maxHeightPx)
            ) {
              /*
               * stop wrapping if wrapping is disabled or if adding
               * one more line would overflow the fixed height
               */
              break;
            }
            line = line.slice(low);
            line = line.trimLeft();
            if (line.length > 0) {
              // Check if the remaining text would fit on one line
              lineWidth = this._getTextWidth(line);
              if (lineWidth <= maxWidth) {
                // if it does, add the line and break out of the loop
                this._addTextLine(line);
                currentHeightPx += lineHeightPx;
                textWidth = Math.max(textWidth, lineWidth);
                break;
              }
            }
          } else {
            // not even one character could fit in the element, abort
            break;
          }
        }
      } else {
        // element width is automatically adjusted to max line width
        this._addTextLine(line);
        currentHeightPx += lineHeightPx;
        textWidth = Math.max(textWidth, lineWidth);
      }
      // if element height is fixed, abort if adding one more line would overflow
      if (fixedHeight && currentHeightPx + lineHeightPx > maxHeightPx) {
        break;
      }
    }
    this.textHeight = fontSize;
    // var maxTextWidth = 0;
    // for(var j = 0; j < this.textArr.length; j++) {
    //     maxTextWidth = Math.max(maxTextWidth, this.textArr[j].width);
    // }
    this.textWidth = textWidth;
  }

  // for text we can't disable stroke scaling
  // if we do, the result will be unexpected
  getStrokeScaleEnabled() {
    return true;
  }

  fontFamily: GetSet<string, this>;
  fontSize: GetSet<number, this>;
  fontStyle: GetSet<string, this>;
  fontVariant: GetSet<string, this>;
  align: GetSet<string, this>;
  letterSpacing: GetSet<number, this>;
  verticalAlign: GetSet<string, this>;
  padding: GetSet<number, this>;
  lineHeight: GetSet<number, this>;
  textDecoration: GetSet<string, this>;
  text: GetSet<string, this>;
  wrap: GetSet<string, this>;
  ellipsis: GetSet<boolean, this>;
}

Text.prototype._fillFunc = _fillFunc;
Text.prototype._strokeFunc = _strokeFunc;
Text.prototype.className = TEXT_UPPER;

/**
 * get/set width of text area, which includes padding.
 * @name Konva.Text#width
 * @method
 * @param {Number} width
 * @returns {Number}
 * @example
 * // get width
 * var width = text.width();
 *
 * // set width
 * text.width(20);
 *
 * // set to auto
 * text.width('auto');
 * text.width() // will return calculated width, and not "auto"
 */
Factory.addGetterSetter(
  Text,
  'width',
  undefined,
  Validators.getNumberOrAutoValidator()
);

/**
 * get/set the height of the text area, which takes into account multi-line text, line heights, and padding.
 * @name Konva.Text#height
 * @method
 * @param {Number} height
 * @returns {Number}
 * @example
 * // get height
 * var height = text.height();
 *
 * // set height
 * text.height(20);
 *
 * // set to auto
 * text.height('auto');
 * text.height() // will return calculated height, and not "auto"
 */

Factory.addGetterSetter(
  Text,
  'height',
  undefined,
  Validators.getNumberOrAutoValidator()
);

/**
 * get/set font family
 * @name Konva.Text#fontFamily
 * @method
 * @param {String} fontFamily
 * @returns {String}
 * @example
 * // get font family
 * var fontFamily = text.fontFamily();
 *
 * // set font family
 * text.fontFamily('Arial');
 */
Factory.addGetterSetter(Text, 'fontFamily', 'Arial');

/**
 * get/set font size in pixels
 * @name Konva.Text#fontSize
 * @method
 * @param {Number} fontSize
 * @returns {Number}
 * @example
 * // get font size
 * var fontSize = text.fontSize();
 *
 * // set font size to 22px
 * text.fontSize(22);
 */
Factory.addGetterSetter(Text, 'fontSize', 12, Validators.getNumberValidator());

/**
 * get/set font style.  Can be 'normal', 'italic', or 'bold'.  'normal' is the default.
 * @name Konva.Text#fontStyle
 * @method
 * @param {String} fontStyle
 * @returns {String}
 * @example
 * // get font style
 * var fontStyle = text.fontStyle();
 *
 * // set font style
 * text.fontStyle('bold');
 */

Factory.addGetterSetter(Text, 'fontStyle', NORMAL);

/**
 * get/set font variant.  Can be 'normal' or 'small-caps'.  'normal' is the default.
 * @name Konva.Text#fontVariant
 * @method
 * @param {String} fontVariant
 * @returns {String}
 * @example
 * // get font variant
 * var fontVariant = text.fontVariant();
 *
 * // set font variant
 * text.fontVariant('small-caps');
 */

Factory.addGetterSetter(Text, 'fontVariant', NORMAL);

/**
 * get/set padding
 * @name Konva.Text#padding
 * @method
 * @param {Number} padding
 * @returns {Number}
 * @example
 * // get padding
 * var padding = text.padding();
 *
 * // set padding to 10 pixels
 * text.padding(10);
 */

Factory.addGetterSetter(Text, 'padding', 0, Validators.getNumberValidator());

/**
 * get/set horizontal align of text.  Can be 'left', 'center', 'right' or 'justify'
 * @name Konva.Text#align
 * @method
 * @param {String} align
 * @returns {String}
 * @example
 * // get text align
 * var align = text.align();
 *
 * // center text
 * text.align('center');
 *
 * // align text to right
 * text.align('right');
 */

Factory.addGetterSetter(Text, 'align', LEFT);

/**
 * get/set vertical align of text.  Can be 'top', 'middle', 'bottom'.
 * @name Konva.Text#verticalAlign
 * @method
 * @param {String} verticalAlign
 * @returns {String}
 * @example
 * // get text vertical align
 * var verticalAlign = text.verticalAlign();
 *
 * // center text
 * text.verticalAlign('middle');
 */

Factory.addGetterSetter(Text, 'verticalAlign', TOP);

/**
 * get/set line height.  The default is 1.
 * @name Konva.Text#lineHeight
 * @method
 * @param {Number} lineHeight
 * @returns {Number}
 * @example
 * // get line height
 * var lineHeight = text.lineHeight();
 *
 * // set the line height
 * text.lineHeight(2);
 */

Factory.addGetterSetter(Text, 'lineHeight', 1, Validators.getNumberValidator());

/**
 * get/set wrap.  Can be word, char, or none. Default is word.
 * @name Konva.Text#wrap
 * @method
 * @param {String} wrap
 * @returns {String}
 * @example
 * // get wrap
 * var wrap = text.wrap();
 *
 * // set wrap
 * text.wrap('word');
 */

Factory.addGetterSetter(Text, 'wrap', WORD);

/**
 * get/set ellipsis.  Can be true or false. Default is false.
 * if Konva.Text config is set to wrap="none" and ellipsis=true, then it will add "..." to the end
 * @name Konva.Text#ellipsis
 * @method
 * @param {Boolean} ellipsis
 * @returns {Boolean}
 * @example
 * // get ellipsis
 * var ellipsis = text.ellipsis();
 *
 * // set ellipsis
 * text.ellipsis(true);
 */

Factory.addGetterSetter(Text, 'ellipsis', false);

/**
 * set letter spacing property. Default value is 0.
 * @name Konva.Text#letterSpacing
 * @method
 * @param {Number} letterSpacing
 */

Factory.addGetterSetter(
  Text,
  'letterSpacing',
  0,
  Validators.getNumberValidator()
);

/**
 * get/set text
 * @name Konva.Text#text
 * @method
 * @param {String} text
 * @returns {String}
 * @example
 * // get text
 * var text = text.text();
 *
 * // set text
 * text.text('Hello world!');
 */

Factory.addGetterSetter(Text, 'text', '', Validators.getStringValidator());

/**
 * get/set text decoration of a text.  Possible values are 'underline', 'line-through' or combination of these values separated by space
 * @name Konva.Text#textDecoration
 * @method
 * @param {String} textDecoration
 * @returns {String}
 * @example
 * // get text decoration
 * var textDecoration = text.textDecoration();
 *
 * // underline text
 * text.textDecoration('underline');
 *
 * // strike text
 * text.textDecoration('line-through');
 *
 * // underline and strike text
 * text.textDecoration('underline line-through');
 */

Factory.addGetterSetter(Text, 'textDecoration', '');

Collection.mapMethods(Text);