spiegel-keyman/web/source/dom/editableElement.ts

// Defines a basic HTMLInputElement wrapper.
///<reference path="input.ts" />
// Defines a basic HTMLTextAreaElement wrapper.
///<reference path="textarea.ts" />
// Makes TS aware of Window-based type prototypes
///<reference path="../kmwexthtml.ts" />

namespace com.keyman.dom {
  export function wrapElement(elem: Element|Document): EditableElement {
    // Complex type scoping is implemented here so that kmwutils.ts is not a dependency for test compilations.

    if (elem['defaultView']) { // A property held by Document.
      let v: Window = elem['defaultView'];

      if(elem instanceof v.Document) {
        let Ldoc = <Document> elem;

        return null; // TODO:  Wrap the document if editable.
      } else if(!elem['ownerDocument'] || elem['ownerDocument'] == null) { // Property held by HTMLElements, useful to scope the class.
        return null;
      }
    } 
    
    let e = <HTMLElement> elem;

    if(e instanceof e.ownerDocument.defaultView.HTMLInputElement) {
      return new Input(e);
    } else if(e instanceof e.ownerDocument.defaultView.HTMLTextAreaElement) {
      return new TextArea(e);
    }
    
    return null;
  }

  export interface EditableElement {
    /**
     * Returns the underlying element / document modeled by the wrapper.
     */
    getElement(): Element | Document;

    /**
     * Clears any selected text within the wrapper's element(s).
     * Silently does nothing if no such text exists.
     */
    clearSelection(): void;

    /**
     * Clears any cached selection-related state values.
     */
    invalidateSelection(): void;
    
    /**
     * Indicates whether or not the underlying element has its own selection (input, textarea)
     * or is part of (or possesses) the DOM's active selection.
     */
    hasSelection(): boolean;
    
    /**
     * Relative to the caret, gets the current context within the wrapper's element.
     */
    getTextBeforeCaret(): string;

    /**
     * Relative to the caret, overwrites the context within the wrapper's element, leaving
     * any text not part of the context unchanged.
     * @param text Text to replace the existing context.
     */
    setTextBeforeCaret(text: string);

    /**
     * Relative to the caret (and/or active selection), gets the element's text after the caret,
     * excluding any actively selected text that would be immediately replaced upon text entry.
     */
    getTextAfterCaret(): string;

    /**
     * Gets the element's full text, including any text that is actively selected.
     */
    getText(): string;

    /**
     * Performs context deletions as needed by the KeymanWeb engine.
     * @param dn The number of characters to delete.  If negative, context will be left unchanged.
     */
    deleteCharsFromContext(dn: number): void
  }
}