From ae1f10b43eacc6d9be214605d2dc41c9d2b53e93 Mon Sep 17 00:00:00 2001
From: Priya Kanabar <119392691+priyakanabar-crest@users.noreply.github.com>
Date: Sat, 21 Dec 2024 07:33:27 +0530
Subject: [PATCH] fix(text-cell-traversal): Debugged the issue with text cell
 traversal and handled all the edge cases for traversal with different
 decorations and elements (#395)

fix(text-cell-traversal):Debugged the issue with text cell traversal and handled all the edge cases for traversal with different decorations and elements
---
 .../src/components/EditorComponent.vue        | 121 +++++++++++++++---
 1 file changed, 104 insertions(+), 17 deletions(-)

diff --git a/zt_frontend/src/components/EditorComponent.vue b/zt_frontend/src/components/EditorComponent.vue
index 57876ac0..77a48632 100644
--- a/zt_frontend/src/components/EditorComponent.vue
+++ b/zt_frontend/src/components/EditorComponent.vue
@@ -150,33 +150,120 @@ export default {
     createCell(cellType: string) {
       this.$emit("createCell", this.cellData.id, cellType);
     },
-    handleEditorInit(editor: any) {
-      this.editor = editor;
+    getEditorView() {
+        return this.editor;
     },
+
     isCursorAtStart(editor: any): boolean {
     const selection = editor.selection;
     const rng = selection.getRng(true);
-    const isAtStart = rng.startOffset === 0 && rng.startContainer === editor.getBody().firstChild;
-    return isAtStart;
-  },
-  isCursorAtEnd(editor: any): boolean {
+    const body = editor.getBody();
+
+    if (!body || !body.childNodes.length) return true;
+
+    const blocks = Array.from(body.childNodes as NodeListOf<ChildNode>).flatMap((node: Node) => {
+        if (node.nodeName === "UL" || node.nodeName === "OL") {
+            return Array.from(node.childNodes).filter((child: Node) => child.nodeName === "LI");
+        }
+        return ["P", "DIV", "LI", "H1", "H2", "H3", "H4", "H5", "H6"].includes((node as HTMLElement).nodeName)
+            ? [node]
+            : [];
+    });
+
+    if (!blocks.length) return true;
+
+    const firstBlock = blocks[0] as HTMLElement;
+    const currentBlock = editor.dom.getParent(rng.startContainer, "p,div,li,h1,h2,h3,h4,h5,h6,ul,ol");
+
+    if (currentBlock !== firstBlock) return false;
+
+    // Handle links at start
+    if (rng.startContainer.nodeType === Node.ELEMENT_NODE && 
+        (rng.startContainer as HTMLElement).nodeName === "A") {
+        return rng.startOffset === 0;
+    }
+
+    const isFirstBlockEmpty = !firstBlock.textContent?.trim() || firstBlock.innerHTML === "<br>";
+    const isAtTextStart = rng.startContainer.nodeType === Node.TEXT_NODE && rng.startOffset === 0;
+
+    return isFirstBlockEmpty || isAtTextStart;
+},
+// Modify isCursorAtEnd method
+isCursorAtEnd(editor: any): boolean {
     const selection = editor.selection;
     const rng = selection.getRng(true);
-    const lastNode = editor.getBody().lastChild;
-    let isAtEnd = false;
+    const body = editor.getBody();
+
+    if (!body.childNodes.length) return true;
+
+    const blocks = Array.from(body.childNodes as NodeListOf<ChildNode>).flatMap((node: Node) => {
+        if (node.nodeName === "UL" || node.nodeName === "OL") {
+            return Array.from(node.childNodes).filter((child: Node) => child.nodeName === "LI");
+        }
+        return ["P", "DIV", "LI", "H1", "H2", "H3", "H4", "H5", "H6"].includes((node as HTMLElement).nodeName)
+            ? [node]
+            : [];
+    });
 
-    if (rng.endContainer.nodeType === Node.TEXT_NODE) {
-      isAtEnd = rng.startOffset === rng.endContainer.length;
-    } else {
-      isAtEnd = rng.endContainer === lastNode && rng.startOffset === 0;
+    if (!blocks.length) return true;
+
+    const lastBlock = blocks[blocks.length - 1] as HTMLElement;
+    const currentBlock = editor.dom.getParent(rng.endContainer, "p,div,li,h1,h2,h3,h4,h5,h6,ul,ol");
+
+    if (currentBlock !== lastBlock) return false;
+
+    const isLastBlockEmpty = !lastBlock.textContent?.trim() || 
+                           lastBlock.innerHTML === "<br>" || 
+                           lastBlock.childNodes.length === 0;
+
+    if (isLastBlockEmpty) return true;
+
+    // Handle links at end
+    if (rng.endContainer.nodeType === Node.ELEMENT_NODE && 
+        (rng.endContainer as HTMLElement).nodeName === "A") {
+        const link = rng.endContainer as HTMLElement;
+        return rng.endOffset === link.childNodes.length;
+    }
+
+    // Handle lists
+    if (lastBlock.nodeName === "LI") {
+        const listItem = lastBlock as HTMLLIElement;
+        return rng.endOffset === (listItem.textContent || "").length;
     }
 
-    const isCursorAtEnd = isAtEnd && rng.endContainer === lastNode;
-    return isCursorAtEnd;
+    const isAtTextEnd = rng.endContainer.nodeType === Node.TEXT_NODE &&
+                       rng.endOffset === (rng.endContainer.textContent || "").length;
+
+    return isAtTextEnd && !rng.endContainer.nextSibling;
+},
+
+  handleEditorInit(editor: any) {
+    this.editor = editor;
+
+    editor.on("keydown", (e: any) => {
+      try {
+        if (e.keyCode === 38) {
+          const isAtStart = this.isCursorAtStart(editor);
+          console.log("Up arrow pressed. Is at start:", isAtStart);
+          if (isAtStart) {
+            e.preventDefault();
+            this.$emit("navigateToCell", this.cellData.id, "up");
+          }
+        }
+
+        if (e.keyCode === 40) {
+          const isAtEnd = this.isCursorAtEnd(editor);
+          console.log("Down arrow pressed. Is at end:", isAtEnd);
+          if (isAtEnd) {
+            e.preventDefault();
+            this.$emit("navigateToCell", this.cellData.id, "down");
+          }
+        }
+      } catch (error) {
+        console.error("Error in editor navigation:", error);
+      }
+    });
   },
-      getEditorView() {
-        return this.editor;
-      },
     },
 };
 </script>