@advanced-rest-client/code-mirror/src/lib/show-hint.js

CodeMirror as a web component

/* eslint-disable object-shorthand */
/* eslint-disable func-names */
// This is to prevent errors
/* eslint-disable no-inner-declarations, no-prototype-builtins */

// @ts-ignore
const CodeMirror = window.CodeMirror || undefined;
if (CodeMirror) {
  const HINT_ELEMENT_CLASS = 'CodeMirror-hint';
  const ACTIVE_HINT_ELEMENT_CLASS = 'selected';

  const defaultOptions = {
    // hint: CodeMirror.hint.auto,
    completeSingle: true,
    alignWithWord: true,
    closeCharacters: /[\s()\\[\\]{};:>,]/,
    closeOnUnfocus: true,
    completeOnSingleClick: false,
    container: null,
    customKeys: null,
    extraKeys: null
  };

  function Completion(cm, options) {
    this.cm = cm;
    this.options = this.buildOptions(options);
    this.widget = null;
    this.debounce = 0;
    this.tick = 0;
    this.startPos = this.cm.getCursor();
    this.startLen = this.cm.getLine(this.startPos.line).length;

    const self = this;
    cm.on('cursorActivity', this.activityFunc = function() {
      self.cursorActivity();
    });
  }
  function getText(completion) {
    if (typeof completion === 'string') {
      return completion;
    } else {
      return completion.text;
    }
  }
  function buildKeyMap(completion, handle) {
    const baseMap = {
      Up: function() {
        handle.moveFocus(-1);
      },
      Down: function() {
        handle.moveFocus(1);
      },
      PageUp: function() {
        handle.moveFocus(-handle.menuSize() + 1, true);
      },
      PageDown: function() {
        handle.moveFocus(handle.menuSize() - 1, true);
      },
      Home: function() {
        handle.setFocus(0);
      },
      End: function() {
        handle.setFocus(handle.length - 1);
      },
      Enter: handle.pick,
      Tab: handle.pick,
      Esc: handle.close
    };
    const custom = completion.options.customKeys;
    const ourMap = custom ? {} : baseMap;

    function addBinding(key, val) {
      let bound;
      if (typeof val !== 'string') {
        bound = function(cm) {
          return val(cm, handle);
        };
        // This mechanism is deprecated
      } else if (baseMap.hasOwnProperty(val)) {
        bound = baseMap[val];
      } else {
        bound = val;
      }
      ourMap[key] = bound;
    }
    if (custom) {
      Object.keys(custom).forEach((key) => {
        addBinding(key, custom[key]);
      });
    }
    const extra = completion.options.extraKeys;
    if (extra) {
      Object.keys(extra).forEach((key) => {
        addBinding(key, extra[key]);
      });
    }
    return ourMap;
  }

  function getHintElement(hintsElement, el) {
    while (el && el !== hintsElement) {
      if (el.nodeName.toUpperCase() === 'ANYPOINT-ITEM' && el.parentNode === hintsElement) {
        return el;
      }
      el = el.parentNode;
    }
  }
  function Widget(completion, data) {
    this.completion = completion;
    this.data = data;
    this.picked = false;
    const widget = this;
    const cm = completion.cm;

    const hints = this.hints = document.createElement('code-mirror-hint-container');
    hints.slot = 'hints';
    hints.className = 'CodeMirror-hints';
    this.selectedHint = data.selectedHint || 0;
    const container = document.createElement('anypoint-listbox');
    container.selected = 0;
    hints.appendChild(container);

    const completions = data.list;
    for (let i = 0; i < completions.length; ++i) {
      const elt = container.appendChild(document.createElement('anypoint-item'));
      const cur = completions[i];
      let className = HINT_ELEMENT_CLASS + (i !== this.selectedHint ? '' : ' ' +
        ACTIVE_HINT_ELEMENT_CLASS);
      if (cur.className !== null) {
        className = cur.className ? cur.className + ' ' + className : className;
      }
      elt.className = className;
      if (cur.render) {
        cur.render(elt, data, cur);
      } else {
        elt.appendChild(document.createTextNode(cur.displayText || getText(cur)));
      }
      elt.hintId = i;
    }
    if (hints.children[0].children[0].nodeName === 'DIV') {
      this._indexOffset = 1;
    } else {
      this._indexOffset = 0;
    }
    let pos = cm.cursorCoords(completion.options.alignWithWord ? data.from : null, 'local');
    let left = pos.left;
    let top = pos.bottom;
    let below = true;
    hints.style.left = left + 'px';
    hints.style.top = top + 'px';
    // If we're at the edge of the screen, then we want the menu to appear on the left of the
    // cursor.
    const winW = window.innerWidth || Math.max(document.body.offsetWidth,
        document.documentElement.offsetWidth);
    const winH = window.innerHeight || Math.max(document.body.offsetHeight,
        document.documentElement.offsetHeight);
    (completion.options.container || document.body).appendChild(hints);
    let box = hints.getBoundingClientRect();
    const overlapY = box.bottom - winH;
    if (overlapY > 0) {
      const height = box.bottom - box.top;
      const curTop = pos.top - (pos.bottom - box.top);
      if (curTop - height > 0) { // Fits above cursor
        hints.style.top = (top = pos.top - height) + 'px';
        below = false;
      } else if (height > winH) {
        hints.style.height = (winH - 5) + 'px';
        hints.style.top = (top = pos.bottom - box.top) + 'px';
        const cursor = cm.getCursor();
        if (data.from.ch !== cursor.ch) {
          pos = cm.cursorCoords(cursor);
          hints.style.left = (left = pos.left) + 'px';
          box = hints.getBoundingClientRect();
        }
      }
    }
    let overlapX = box.right - winW;
    if (overlapX > 0) {
      if (box.right - box.left > winW) {
        hints.style.width = (winW - 5) + 'px';
        overlapX -= (box.right - box.left) - winW;
      }
      hints.style.left = (left = pos.left - overlapX) + 'px';
    }

    cm.addKeyMap(this.keyMap = buildKeyMap(completion, {
      moveFocus: function(n, avoidWrap) {
        widget.changeActive(widget.selectedHint + n, avoidWrap);
      },
      setFocus: function(n) {
        widget.changeActive(n);
      },
      menuSize: function() {
        return widget.screenAmount();
      },
      length: completions.length,
      close: function() {
        completion.close();
      },
      pick: function() {
        widget.pick();
      },
      data: data
    }));

    if (completion.options.closeOnUnfocus) {
      let closingOnBlur;
      cm.on('blur', this.onBlur = function() {
        closingOnBlur = setTimeout(function() {
          completion.close();
        }, 100);
      });
      cm.on('focus', this.onFocus = function() {
        clearTimeout(closingOnBlur);
      });
    }

    const startScroll = cm.getScrollInfo();
    cm.on('scroll', this.onScroll = function() {
      const curScroll = cm.getScrollInfo();
      const editor = cm.getWrapperElement().getBoundingClientRect();
      const newTop = top + startScroll.top - curScroll.top;
      let point = newTop -
        (window.pageYOffset || (document.documentElement || document.body).scrollTop);
      if (!below) {
        point += hints.offsetHeight;
      }
      if (point <= editor.top || point >= editor.bottom) {
        return completion.close();
      }
      hints.style.top = newTop + 'px';
      hints.style.left = (left + startScroll.left - curScroll.left) + 'px';
    });

    CodeMirror.on(container, 'click', function(e) {
      const t = getHintElement(hints.children[0], e.target || e.srcElement);
      if (t && t.hintId !== undefined) {
        widget.changeActive(t.hintId);
        widget.pick();
      }
    });

    CodeMirror.on(hints, 'mousedown', function() {
      setTimeout(function() {
        cm.focus();
      }, 20);
    });

    CodeMirror.signal(data, 'select', completions[0], hints.children[0].firstChild);
    return true;
  }

  Widget.prototype = {
    close: function() {
      if (this.completion.widget !== this) {
        return;
      }
      this.completion.widget = null;
      this.hints.parentNode.removeChild(this.hints);
      this.completion.cm.removeKeyMap(this.keyMap);

      const cm = this.completion.cm;
      if (this.completion.options.closeOnUnfocus) {
        cm.off('blur', this.onBlur);
        cm.off('focus', this.onFocus);
      }
      cm.off('scroll', this.onScroll);
    },

    disable: function() {
      this.completion.cm.removeKeyMap(this.keyMap);
      const widget = this;
      this.keyMap = {
        Enter: function() {
          widget.picked = true;
        }
      };
      this.completion.cm.addKeyMap(this.keyMap);
    },

    pick: function() {
      this.completion.pick(this.data, this.selectedHint);
    },

    changeActive: function(i, avoidWrap) {
      // i += this._indexOffset;
      if (i >= this.data.list.length) {
        i = avoidWrap ? this.data.list.length - 1 : 0;
      } else if (i < 0) {
        i = avoidWrap ? 0 : this.data.list.length - 1;
      }
      if (this.selectedHint === i) {
        return;
      }
      let selectedHint = this.selectedHint + this._indexOffset;
      let node = this.hints.children[0].children[selectedHint];
      node.classList.remove(ACTIVE_HINT_ELEMENT_CLASS);
      selectedHint = i + this._indexOffset;
      this.selectedHint = i;
      node = this.hints.children[0].children[selectedHint];
      node.classList.add(ACTIVE_HINT_ELEMENT_CLASS);
      if (node.offsetTop < this.hints.scrollTop) {
        this.hints.scrollTop = node.offsetTop - 3;
      } else if (node.offsetTop + node.offsetHeight > this.hints.scrollTop +
        this.hints.clientHeight) {
        this.hints.scrollTop = node.offsetTop + node.offsetHeight - this.hints.clientHeight + 3;
      }
      CodeMirror.signal(this.data, 'select', this.data.list[selectedHint], node);
    },

    screenAmount: function() {
      return Math.floor(this.hints.clientHeight /
        this.hints.children[0].children[0].offsetHeight) || 1;
    }
  };
  
  // This is the old interface, kept around for now to stay
  // backwards-compatible.
  CodeMirror.showHint = function(cm, getHints, options) {
    if (!getHints) {
      return cm.showHint(options);
    }
    if (options && options.async) {
      getHints.async = true;
    }
    const newOpts = {
      hint: getHints
    };
    if (options) {
      Object.keys(options).forEach((prop) => {
        newOpts[prop] = options[prop];
      });
    }
    return cm.showHint(newOpts);
  };


  function ShowHintFn(options) {
    // We want a single cursor position.
    if (this.listSelections().length > 1 || this.somethingSelected()) {
      return;
    }

    if (this.state.completionActive) {
      this.state.completionActive.close();
    }
    const completion = this.state.completionActive = new Completion(this, options);
    if (!completion.options.hint) {
      return;
    }

    CodeMirror.signal(this, 'startCompletion', this);
    completion.update(true);
  }

  CodeMirror.defineExtension('showHint', ShowHintFn);

  const raf = window.requestAnimationFrame || function(fn) {
    return setTimeout(fn, 1000 / 60);
  };
  const caf = window.cancelAnimationFrame || clearTimeout;

  Completion.prototype = {
    close: function() {
      if (!this.active()) {
        return;
      }
      this.cm.state.completionActive = null;
      this.tick = null;
      this.cm.off('cursorActivity', this.activityFunc);

      if (this.widget && this.data) {
        CodeMirror.signal(this.data, 'close');
      }
      if (this.widget) {
        this.widget.close();
      }
      CodeMirror.signal(this.cm, 'endCompletion', this.cm);
    },

    active: function() {
      return this.cm.state.completionActive === this;
    },

    pick: function(data, i) {
      const completion = data.list[i];
      if (completion.hint) {
        completion.hint(this.cm, data, completion);
      } else {
        this.cm.replaceRange(getText(completion), completion.from || data.from,
            completion.to || data.to, 'complete');
      }
      CodeMirror.signal(data, 'pick', completion);
      this.close();
      CodeMirror.signal(this.cm, 'hintSelected', completion);
    },

    cursorActivity: function() {
      if (this.debounce) {
        caf(this.debounce);
        this.debounce = 0;
      }

      const pos = this.cm.getCursor();
      const line = this.cm.getLine(pos.line);
      if (pos.line !== this.startPos.line ||
        line.length - pos.ch !== this.startLen - this.startPos.ch ||
        pos.ch < this.startPos.ch || this.cm.somethingSelected() ||
        (pos.ch && this.options.closeCharacters.test(line.charAt(pos.ch - 1)))) {
        this.close();
      } else {
        const self = this;
        this.debounce = raf(function() {
          self.update();
        });
        if (this.widget) {
          this.widget.disable();
        }
      }
    },

    update: function(first) {
      if (this.tick === null) {
        return;
      }
      if (this.data) {
        CodeMirror.signal(this.data, 'update');
      }
      if (!this.options.hint.async) {
        this.finishUpdate(this.options.hint(this.cm, this.options), first);
      } else {
        const myTick = ++this.tick;
        const self = this;
        this.options.hint(this.cm, function(data) {
          if (self.tick === myTick) {
            self.finishUpdate(data, first);
          }
        }, this.options);
      }
    },

    finishUpdate: function(data, first) {
      this.data = data;

      const picked = (this.widget && this.widget.picked) || (first && this.options.completeSingle);
      if (this.widget) {
        this.widget.close();
      }
      if (data && data.list.length) {
        if (picked && data.list.length === 1) {
          this.pick(data, 0);
        } else {
          this.widget = new Widget(this, data);
          CodeMirror.signal(data, 'shown');
        }
      }
    },

    buildOptions: function(options) {
      const editor = this.cm.options.hintOptions;
      const out = {};
      Object.keys(defaultOptions).forEach((prop) => {
        out[prop] = defaultOptions[prop];
      });
      out.auto = CodeMirror.hint.auto;
      if (editor) {
        for (const prop in editor) {
          if (editor[prop] !== undefined) {
            out[prop] = editor[prop];
          }
        }
      }
      if (options) {
        for (const prop in options) {
          if (options[prop] !== undefined) {
            out[prop] = options[prop];
          }
        }
      }
      return out;
    }
  };

  CodeMirror.registerHelper('hint', 'auto', function(cm, options) {
    const helpers = cm.getHelpers(cm.getCursor(), 'hint');
    let words;
    if (helpers.length) {
      for (let i = 0; i < helpers.length; i++) {
        const cur = helpers[i](cm, options);
        if (cur && cur.list.length) {
          return cur;
        }
      }
    } else if ((words = cm.getHelper(cm.getCursor(), 'hintWords'))) {
      if (words) {
        return CodeMirror.hint.fromList(cm, {
          words: words
        });
      }
    } else if (CodeMirror.hint.anyword) {
      return CodeMirror.hint.anyword(cm, options);
    }
  });

  CodeMirror.registerHelper('hint', 'fromList', function(cm, options) {
    const cur = cm.getCursor();
    const token = cm.getTokenAt(cur);
    const found = [];
    for (let i = 0; i < options.words.length; i++) {
      const word = options.words[i];
      if (word.slice(0, token.string.length) === token.string) {
        found.push(word);
      }
    }

    if (found.length) {
      return {
        list: found,
        from: CodeMirror.Pos(cur.line, token.start),
        to: CodeMirror.Pos(cur.line, token.end)
      };
    }
  });

  CodeMirror.commands.autocomplete = CodeMirror.showHint;

  CodeMirror.defineOption('hintOptions', null);
}