gojs/extensions/TextEditor.js

"use strict";
/*
*  Copyright (C) 1998-2021 by Northwoods Software Corporation. All Rights Reserved.
*/

// This is the definitions of the predefined text editor used by TextEditingTool
// when you set or bind TextBlock.editable to true.
// You do not need to load this file in order to use in-place text editing.

// HTML + JavaScript text editor menu, made with HTMLInfo
// This is a re-implementation of the default text editor
// This file exposes one instance of HTMLInfo, window.TextEditor
// See also TextEditor.html
(function(window) {
  var textarea = document.createElement('textarea');
  textarea.id = "myTextArea";

  textarea.addEventListener('input', function(e) {
    var tool = TextEditor.tool;
    if (tool.textBlock === null) return;
    var tempText = tool.measureTemporaryTextBlock(this.value);
    var scale = this.textScale;
    this.style.width = 20 + tempText.measuredBounds.width * scale + 'px';
    this.rows = tempText.lineCount;
  }, false);

  textarea.addEventListener('keydown', function(e) {
    var tool = TextEditor.tool;
    if (tool.textBlock === null) return;
    var key = e.key;
    if (key === "Enter") {
      if (tool.textBlock.isMultiline === false) e.preventDefault();
      tool.acceptText(go.TextEditingTool.Enter);
      return;
    } else if (key === "Tab") {
      tool.acceptText(go.TextEditingTool.Tab);
      e.preventDefault();
      return;
    } else if (key === "Escape") {
      tool.doCancel();
      if (tool.diagram !== null) tool.diagram.doFocus();
    }
  }, false);

  // handle focus:
  textarea.addEventListener('focus', function(e) {
    var tool = TextEditor.tool;
    if (!tool || tool.currentTextEditor === null) return;

    if (tool.state === go.TextEditingTool.StateActive) {
      tool.state = go.TextEditingTool.StateEditing;
    }

    if (tool.selectsTextOnActivate) {
      textarea.select();
      textarea.setSelectionRange(0, 9999);
    }
  }, false);

  // Disallow blur.
  // If the textEditingTool blurs and the text is not valid,
  // we do not want focus taken off the element just because a user clicked elsewhere.
  textarea.addEventListener('blur', function(e) {
    var tool = TextEditor.tool;
    if (!tool || tool.currentTextEditor === null || tool.state === go.TextEditingTool.StateNone) return;

    textarea.focus();

    if (tool.selectsTextOnActivate) {
      textarea.select();
      textarea.setSelectionRange(0, 9999);
    }
  }, false);


  var TextEditor = new go.HTMLInfo();

  TextEditor.valueFunction = function() { return textarea.value; }

  TextEditor.mainElement = textarea; // to reference it more easily

  TextEditor.tool = null; // Initialize

  // used to be in doActivate
  TextEditor.show = function(textBlock, diagram, tool) {
    if (!(textBlock instanceof go.TextBlock)) return;
    if (TextEditor.tool !== null) return; // Only one at a time.

    TextEditor.tool = tool;  // remember the TextEditingTool for use by listeners

    // This is called during validation, if validation failed:
    if (tool.state === go.TextEditingTool.StateInvalid) {
      textarea.style.border = '3px solid red';
      textarea.focus();
      return;
    }

    // This part is called during initalization:

    var loc = textBlock.getDocumentPoint(go.Spot.Center);
    var pos = diagram.position;
    var sc = diagram.scale;
    var textscale = textBlock.getDocumentScale() * sc;
    if (textscale < tool.minimumEditorScale) textscale = tool.minimumEditorScale;
    // Add slightly more width/height to stop scrollbars and line wrapping on some browsers
    // +6 is firefox minimum, otherwise lines will be wrapped improperly
    var textwidth = (textBlock.naturalBounds.width * textscale) + 6;
    var textheight = (textBlock.naturalBounds.height * textscale) + 2;
    var left = (loc.x - pos.x) * sc;
    var top = (loc.y - pos.y) * sc;

    textarea.value = textBlock.text;
    // the only way you can mix font and fontSize is if the font inherits and the fontSize overrides
    // in the future maybe have textarea contained in its own div
    diagram.div.style['font'] = textBlock.font;

    var paddingsize = 1;
    textarea.style['position'] = 'absolute';
    textarea.style['zIndex'] = '100';
    textarea.style['font'] = 'inherit';
    textarea.style['fontSize'] = (textscale * 100) + '%';
    textarea.style['lineHeight'] = 'normal';
    textarea.style['width'] = (textwidth) + 'px';
    textarea.style['left'] = ((left - (textwidth / 2) | 0) - paddingsize) + 'px';
    textarea.style['top'] = ((top - (textheight / 2) | 0) - paddingsize) + 'px';
    textarea.style['textAlign'] = textBlock.textAlign;
    textarea.style['margin'] = '0';
    textarea.style['padding'] = paddingsize + 'px';
    textarea.style['border'] = '0';
    textarea.style['outline'] = 'none';
    textarea.style['whiteSpace'] = 'pre-wrap';
    textarea.style['overflow'] = 'hidden'; // for proper IE wrap
    textarea.rows = textBlock.lineCount;
    textarea.textScale = textscale; // attach a value to the textarea, for convenience
    textarea.className = 'goTXarea';

    // Show:
    diagram.div.appendChild(textarea);

    // After adding, focus:
    textarea.focus();
    if (tool.selectsTextOnActivate) {
      textarea.select();
      textarea.setSelectionRange(0, 9999);
    }
  };

  TextEditor.hide = function(diagram, tool) {
    diagram.div.removeChild(textarea);
    TextEditor.tool = null;  // forget reference to TextEditingTool
  }

  window.TextEditor = TextEditor;
})(window);