🐛 Fix text editor select all functionality and inner paste corner cases

frontend/text-editor/src/editor/TextEditor.js

@@ -106,6 +106,7 @@ export class TextEditor extends EventTarget {
 
       beforeinput: this.#onBeforeInput,
       input: this.#onInput,
+      keydown: this.#onKeyDown,
     };
     this.#styleDefaults = options?.styleDefaults;
     this.#setup(options);
@@ -363,6 +364,36 @@ export class TextEditor extends EventTarget {
     }
   };
 
+  /**
+   * Handles keydown events
+   *
+   * @param {KeyboardEvent} e
+   */
+  #onKeyDown = (e) => {
+    if ((e.ctrlKey || e.metaKey) && e.key === "a") {
+      e.preventDefault();
+      this.selectAll();
+      return;
+    }
+
+    if ((e.ctrlKey || e.metaKey) && e.key === "Backspace") {
+      e.preventDefault();
+
+      if (!this.#selectionController.startMutation()) {
+        return;
+      }
+
+      if (this.#selectionController.isCollapsed) {
+        this.#selectionController.removeWordBackward();
+      } else {
+        this.#selectionController.removeSelected();
+      }
+
+      const mutations = this.#selectionController.endMutation();
+      this.#notifyLayout(LayoutType.FULL, mutations);
+    }
+  };
+
   /**
    * Notifies that the edited texts needs layout.
    *

frontend/text-editor/src/editor/content/Text.js

@@ -24,7 +24,7 @@ function tryOffset(offset) {
  * @throws {TypeError}
  */
 function tryString(str) {
-  if (typeof str !== "string") throw new TypeError("Invalid string");
+  if (typeof str !== "string") throw new TypeError(`Invalid string ${str}`);
 }
 
 /**
@@ -102,3 +102,66 @@ export function removeSlice(str, start, end) {
   tryOffset(end);
   return str.slice(0, start) + str.slice(end);
 }
+
+/**
+ * Finds the start of the previous word from the given offset.
+ * Word boundaries are defined by whitespace and punctuation.
+ *
+ * @param {string} str
+ * @param {number} offset
+ * @returns {number}
+ */
+export function findPreviousWordBoundary(str, offset) {
+  if (str == null) {
+    return 0;
+  }
+
+  tryString(str);
+  tryOffset(offset);
+
+  if (offset === 0) {
+    return 0;
+  }
+
+  // Start from the character before the cursor
+  let pos = offset - 1;
+
+  // Skip any whitespace characters
+  while (pos >= 0 && /\s/.test(str[pos])) {
+    pos--;
+  }
+
+  // If we're now at a non-word character, skip all non-word characters
+  if (pos >= 0 && /\W/.test(str[pos]) && !/\s/.test(str[pos])) {
+    while (pos >= 0 && /\W/.test(str[pos]) && !/\s/.test(str[pos])) {
+      pos--;
+    }
+  }
+  // Otherwise, skip all word characters
+  else if (pos >= 0 && /\w/.test(str[pos])) {
+    while (pos >= 0 && /\w/.test(str[pos])) {
+      pos--;
+    }
+  }
+
+  return pos + 1;
+}
+
+/**
+ * Removes a word backward from specified offset.
+ *
+ * @param {string} str
+ * @param {number} offset
+ * @returns {string}
+ */
+export function removeWordBackward(str, offset) {
+  if (str == null) {
+    return "";
+  }
+
+  tryString(str);
+  tryOffset(offset);
+
+  const wordStart = findPreviousWordBoundary(str, offset);
+  return str.slice(0, wordStart) + str.slice(offset);
+}

frontend/text-editor/src/editor/content/dom/Content.js

@@ -116,6 +116,52 @@ export function mapContentFragmentFromDocument(document, root, styleDefaults) {
   return fragment;
 }
 
+/**
+ * Converts HTML to plain text, preserving line breaks from <br> tags and block elements.
+ *
+ * @param {string} html - The HTML string to convert
+ * @returns {string} Plain text with preserved line breaks
+ */
+export function htmlToText(html) {
+  const tmp = document.createElement("div");
+  tmp.innerHTML = html;
+
+  const blockTags = [
+    "P", "DIV", "SECTION", "ARTICLE", "HEADER", "FOOTER",
+    "UL", "OL", "LI", "TABLE", "TR", "TD", "TH", "PRE"
+  ];
+
+  function walk(node) {
+    let text = "";
+
+    node.childNodes.forEach(child => {
+      if (child.nodeType === Node.TEXT_NODE) {
+        text += child.textContent;
+      } else if (child.nodeType === Node.ELEMENT_NODE) {
+
+        if (child.tagName === "BR") {
+          text += "\n";
+        }
+
+        if (blockTags.includes(child.tagName)) {
+          text += "\n" + walk(child) + "\n";
+          return;
+        }
+
+        text += walk(child);
+      }
+    });
+
+    return text;
+  }
+
+  let result = walk(tmp);
+  result = result.replace(/\n{3,}/g, "\n\n");
+
+  return result.trim();
+}
+
+
 /**
  * Maps any HTML into a valid content DOM element.
  *
@@ -124,13 +170,8 @@ export function mapContentFragmentFromDocument(document, root, styleDefaults) {
  * @returns {DocumentFragment}
  */
 export function mapContentFragmentFromHTML(html, styleDefaults) {
-  const parser = new DOMParser();
-  const htmlDocument = parser.parseFromString(html, "text/html");
-  return mapContentFragmentFromDocument(
-    htmlDocument,
-    htmlDocument.documentElement,
-    styleDefaults,
-  );
+  const plainText = htmlToText(html);
+  return mapContentFragmentFromString(plainText, styleDefaults);
 }
 
 /**

frontend/text-editor/src/editor/controllers/SelectionController.js

@@ -39,6 +39,8 @@ import {
   replaceWith,
   insertInto,
   removeSlice,
+  findPreviousWordBoundary,
+  removeWordBackward,
 } from "../content/Text.js";
 import {
   getTextNodeLength,
@@ -502,7 +504,51 @@ export class SelectionController extends EventTarget {
     if (this.#textEditor.isEmpty) {
       return this;
     }
-    this.#selection.selectAllChildren(this.#textEditor.root);
+
+    // Find the first and last text nodes to create a proper text selection
+    // instead of selecting container elements
+    const root = this.#textEditor.root;
+    const firstParagraph = root.firstElementChild;
+    const lastParagraph = root.lastElementChild;
+    
+    if (!firstParagraph || !lastParagraph) {
+      return this;
+    }
+
+    const firstTextSpan = firstParagraph.firstElementChild;
+    const lastTextSpan = lastParagraph.lastElementChild;
+    
+    if (!firstTextSpan || !lastTextSpan) {
+      return this;
+    }
+
+    const firstTextNode = firstTextSpan.firstChild;
+    const lastTextNode = lastTextSpan.lastChild;
+    
+    if (!firstTextNode || !lastTextNode) {
+      return this;
+    }
+
+    // Create a range from first text node to last text node
+    const range = document.createRange();
+    range.setStart(firstTextNode, 0);
+    range.setEnd(lastTextNode, lastTextNode.nodeValue?.length || 0);
+    
+    this.#selection.removeAllRanges();
+    this.#selection.addRange(range);
+    
+    // Ensure internal state is synchronized
+    this.#focusNode = this.#selection.focusNode;
+    this.#focusOffset = this.#selection.focusOffset;
+    this.#anchorNode = this.#selection.anchorNode;
+    this.#anchorOffset = this.#selection.anchorOffset;
+    this.#range = range;
+    this.#ranges.clear();
+    this.#ranges.add(range);
+    
+    // Notify style changes
+    this.#notifyStyleChange();
+    
     return this;
   }
 
@@ -1095,12 +1141,14 @@ export class SelectionController extends EventTarget {
       this.focusParagraph.after(fragment);
       mergeParagraphs(a, b);
     } else {
-      const newParagraph = splitParagraph(
-        this.focusParagraph,
-        this.focusTextSpan,
-        this.focusOffset,
-      );
-      this.focusParagraph.after(fragment, newParagraph);
+      if (this.isTextSpanStart) { 
+        this.focusTextSpan.before(...fragment.firstElementChild.children);
+      } else if (this.isTextSpanEnd) {
+        this.focusTextSpan.after(...fragment.firstElementChild.children);
+      } else {
+        const newTextSpan = splitTextSpan(this.focusTextSpan, this.focusOffset);
+        this.focusTextSpan.after(...fragment.firstElementChild.children, newTextSpan);
+      }
     }
     if (isLineBreak(collapseNode)) {
       return this.collapse(collapseNode, 0);
@@ -1218,6 +1266,79 @@ export class SelectionController extends EventTarget {
     return this.collapse(this.focusNode, this.focusOffset - 1);
   }
 
+  /**
+   * Removes word backward from the current caret position.
+   */
+  removeWordBackward() {
+    if (!this.isCollapsed) {
+      return this.removeSelected();
+    }
+
+    this.#textNodeIterator.currentNode = this.focusNode;
+
+    const originalNodeValue = this.focusNode.nodeValue || "";
+    const wordStart = findPreviousWordBoundary(originalNodeValue, this.focusOffset);
+
+    // Start node
+    if (wordStart === this.focusOffset && this.focusOffset === 0) {
+      if (this.focusTextSpan.previousElementSibling) {
+        const prevTextSpan = this.focusTextSpan.previousElementSibling;
+        const prevTextNode = prevTextSpan.lastChild;
+        if (prevTextNode && prevTextNode.nodeType === Node.TEXT_NODE) {
+          this.collapse(prevTextNode, prevTextNode.nodeValue.length);
+          return this.removeWordBackward();
+        }
+      } else if (this.focusParagraph.previousElementSibling) {
+        // Move to previous paragraph
+        const prevParagraph = this.focusParagraph.previousElementSibling;
+        const prevTextSpan = prevParagraph.lastElementChild;
+        const prevTextNode = prevTextSpan?.lastChild;
+        if (prevTextNode && prevTextNode.nodeType === Node.TEXT_NODE) {
+          this.collapse(prevTextNode, prevTextNode.nodeValue.length);
+          return this.removeWordBackward();
+        } else {
+          return this.mergeBackwardParagraph();
+        }
+      }
+      return this;
+    }
+
+    const removedData = removeWordBackward(originalNodeValue, this.focusOffset);
+
+    if (this.focusNode.nodeValue !== removedData) {
+      this.focusNode.nodeValue = removedData;
+      this.#mutations.update(this.focusTextSpan);
+    }
+
+    const paragraph = this.focusParagraph;
+    if (!paragraph) throw new Error("Cannot find paragraph");
+    const textSpan = this.focusTextSpan;
+    if (!textSpan) throw new Error("Cannot find text span");
+
+    // If the text node is empty, handle cleanup
+    if (this.focusNode.nodeValue === "") {
+      const previousTextNode = this.#textNodeIterator.previousNode();
+      this.focusNode.remove();
+
+      if (paragraph.children.length === 1 && textSpan.childNodes.length === 0) {
+        const lineBreak = createLineBreak();
+        textSpan.appendChild(lineBreak);
+        return this.collapse(lineBreak, 0);
+      } else if (
+        paragraph.children.length > 1 &&
+        textSpan.childNodes.length === 0
+      ) {
+        textSpan.remove();
+        return this.collapse(
+          previousTextNode,
+          getTextNodeLength(previousTextNode),
+        );
+      }
+    }
+
+    return this.collapse(this.focusNode, wordStart);
+  }
+
   /**
    * Inserts some text in the caret position.
    *