gojs/extensionsJSM/HyperlinkText.ts

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

/*
* This is an extension and not part of the main GoJS library.
* Note that the API for this class may change with any version, even point releases.
* If you intend to use an extension in production, you should copy the code to your own source directory.
* Extensions can be found in the GoJS kit under the extensions or extensionsTS folders.
* See the Extensions intro page (https://gojs.net/latest/intro/extensions.html) for more information.
*/

import * as go from '../release/go-module.js';

// A "HyperlinkText" is either a TextBlock or a Panel containing a TextBlock that when clicked
// opens a new browser window with a given or computed URL.
// When the user's mouse passes over a "HyperlinkText", the text is underlined.
// When the mouse hovers over a "HyperlinkText", it shows a tooltip that displays the URL.

// This "HyperlinkText" builder is not pre-defined in the GoJS library, so you will need to load this definition.

// Typical usages:
//    $("HyperlinkText", "https://gojs.net", "Visit GoJS")
//
//    $("HyperlinkText",
//        function(node) { return "https://gojs.net/" + node.data.version; },
//        function(node) { return "Visit GoJS version " + node.data.version; })
//
//    $("HyperlinkText",
//        function(node) { return "https://gojs.net/" + node.data.version; },
//        $(go.Panel, "Auto",
//            $(go.Shape, ...),
//            $(go.TextBlock, ...)
//        )
//    )

// The first argument to the "HyperlinkText" builder should be either the URL string or a function
// that takes the data-bound Panel and returns the URL string.
// If the URL string is empty or if the function returns an empty string,
// the text will not be underlined on a mouse-over and a click has no effect.

// The second argument to the "HyperlinkText" builder may be either a string to display in a TextBlock,
// or a function that takes the data-bound Panel and returns the string to display in a TextBlock.
// If no text string or function is provided, it assumes all of the arguments are used to
// define the visual tree for the "HyperlinkText", in the normal fashion for a Panel.

// The result is either a TextBlock or a Panel.

go.GraphObject.defineBuilder('HyperlinkText', (args) => {
  // the URL is required as the first argument, either a string or a side-effect-free function returning a string
  const url = go.GraphObject.takeBuilderArgument(args, undefined, (x) => typeof x === 'string' || typeof x === 'function');
  // the text for the HyperlinkText is the optional second argument, either a string or a side-effect-free function returning a string
  let text = go.GraphObject.takeBuilderArgument(args, null, (x) => typeof x === 'string' || typeof x === 'function');

  // see if the visual tree is supplied in the arguments to the "HyperlinkText"
  let anyGraphObjects = false;
  for (let i = 0; i < args.length; i++) {
    const a = args[i];
    if (a && a instanceof go.GraphObject) anyGraphObjects = true;
  }

  // define the click behavior
  const click =
    (e: go.InputEvent, obj: go.GraphObject) => {
      let u = (obj as any)._url;
      if (typeof u === 'function') u = u(obj.findTemplateBinder());
      if (u) window.open(u, '_blank');
    };

  // define the tooltip
  const tooltip =
    go.GraphObject.make<go.Adornment>('ToolTip',
      go.GraphObject.make(go.TextBlock,
        { name: 'TB', margin: 4 },
        new go.Binding('text', '', function(obj) {
          // here OBJ will be in the Adornment, need to get the HyperlinkText/TextBlock
          obj = obj.part.adornedObject;
          let u = obj._url;
          if (typeof u === 'function') u = u(obj.findTemplateBinder());
          return u;
        }).ofObject()
      ),
      new go.Binding('visible', 'text', function(t) { return !!t; }).ofObject('TB')
    );

  // if the text is provided, use a new TextBlock; otherwise assume the TextBlock is provided
  if (typeof (text) === 'string' || typeof (text) === 'function' || !anyGraphObjects) {
    if (text === null && typeof (url) === 'string') text = url;
    const tb = go.GraphObject.make(go.TextBlock,
      {
        '_url': url,
        cursor: 'pointer',
        mouseEnter: function(e: go.InputEvent, obj: go.GraphObject) {
          let u = (obj as any)._url;
          if (typeof u === 'function') u = u(obj.findTemplateBinder());
          if (u && obj instanceof go.TextBlock) obj.isUnderline = true;
        },
        mouseLeave: (e: go.InputEvent, obj: go.GraphObject) => { if (obj instanceof go.TextBlock) obj.isUnderline = false; },
        click: click,  // defined above
        toolTip: tooltip // shared by all HyperlinkText textblocks
      }
    );
    if (typeof (text) === 'string') {
      tb.text = text;
    } else if (typeof (text) === 'function') {
      tb.bind(new go.Binding('text', '', text).ofObject());
    } else if (typeof (url) === 'function') {
      tb.bind(new go.Binding('text', '', url).ofObject());
    }
    return tb;
  } else {
    const findTextBlock = function(obj: go.GraphObject): go.TextBlock | null {
      if (obj instanceof go.TextBlock) return obj;
      if (obj instanceof go.Panel) {
        const it = obj.elements;
        while (it.next()) {
          const result = findTextBlock(it.value);
          if (result !== null) return result;
        }
      }
      return null;
    };
    return go.GraphObject.make(go.Panel,
      {
        '_url': url,
        cursor: 'pointer',
        mouseEnter: (e: go.InputEvent, panel: go.GraphObject) => {
          const tb = findTextBlock(panel);
          let u = (panel as any)._url;
          if (typeof u === 'function') u = u(panel.findTemplateBinder());
          if (tb !== null && u) tb.isUnderline = true;
        },
        mouseLeave: (e: go.InputEvent, panel: go.GraphObject) => {
          const tb = findTextBlock(panel);
          if (tb !== null) tb.isUnderline = false;
        },
        click: click,  // defined above
        toolTip: tooltip  // shared by all HyperlinkText panels
      }
    );
  }
});