update navigation

ts_web/elements/wysiwyg/blocks/text/code.block.ts

@@ -161,7 +161,7 @@ export class CodeBlockHandler extends BaseBlockHandler {
     
     // Keydown handler
     editor.addEventListener('keydown', (e) => {
-      // Handle Tab
+      // Handle Tab key for code blocks
       if (e.key === 'Tab') {
         e.preventDefault();
         const selection = window.getSelection();
@@ -179,6 +179,34 @@ export class CodeBlockHandler extends BaseBlockHandler {
         return;
       }
       
+      // Check cursor position for navigation keys
+      if (['ArrowLeft', 'ArrowRight', 'ArrowUp', 'ArrowDown'].includes(e.key)) {
+        const cursorPos = this.getCursorPosition(element);
+        const textLength = editor.textContent?.length || 0;
+        
+        // For ArrowLeft at position 0 or ArrowRight at end, let parent handle navigation
+        if ((e.key === 'ArrowLeft' && cursorPos === 0) || 
+            (e.key === 'ArrowRight' && cursorPos === textLength)) {
+          // Pass to parent handler for inter-block navigation
+          handlers.onKeyDown(e);
+          return;
+        }
+        
+        // For ArrowUp/Down, check if we're at first/last line
+        if (e.key === 'ArrowUp' || e.key === 'ArrowDown') {
+          const lines = (editor.textContent || '').split('\n');
+          const currentLine = this.getCurrentLineIndex(editor);
+          
+          if ((e.key === 'ArrowUp' && currentLine === 0) ||
+              (e.key === 'ArrowDown' && currentLine === lines.length - 1)) {
+            // Let parent handle navigation to prev/next block
+            handlers.onKeyDown(e);
+            return;
+          }
+        }
+      }
+      
+      // Pass other keys to parent handler
       handlers.onKeyDown(e);
     });
     
@@ -233,6 +261,21 @@ export class CodeBlockHandler extends BaseBlockHandler {
     lineNumbersContainer.innerHTML = lineNumbersHtml;
   }
   
+  private getCurrentLineIndex(editor: HTMLElement): number {
+    const selection = window.getSelection();
+    if (!selection || selection.rangeCount === 0) return 0;
+    
+    const range = selection.getRangeAt(0);
+    const preCaretRange = range.cloneRange();
+    preCaretRange.selectNodeContents(editor);
+    preCaretRange.setEnd(range.startContainer, range.startOffset);
+    
+    const textBeforeCursor = preCaretRange.toString();
+    const linesBeforeCursor = textBeforeCursor.split('\n');
+    
+    return linesBeforeCursor.length - 1; // 0-indexed
+  }
+  
   private applyHighlighting(element: HTMLElement, block: IBlock): void {
     const editor = element.querySelector('.code-editor') as HTMLElement;
     if (!editor) return;