Replace Enter and Tab actions with execCommand + test

Author: WebCoder49

plugins/indent.js

@@ -24,16 +24,8 @@
         event.preventDefault(); // stop normal
 
         if(!event.shiftKey && input_element.selectionStart == input_element.selectionEnd) {
-            // Shift always means dedent - this places a tab here.
-            let before_selection = code.slice(0, input_element.selectionStart); // text before tab
-            let after_selection = code.slice(input_element.selectionEnd, input_element.value.length); // text after tab
-
-            let cursor_pos = input_element.selectionEnd + 1; // where cursor moves after tab - moving forward by 1 char to after tab
-            input_element.value = before_selection + "\t" + after_selection; // add tab char
-
-            // move cursor
-            input_element.selectionStart = cursor_pos;
-            input_element.selectionEnd = cursor_pos;
+            // Just place a tab here.
+            document.execCommand("insertText", false, "\t");
 
         } else {
             let lines = input_element.value.split("\n");
@@ -45,32 +37,46 @@
             let number_indents = 0;
             let first_line_indents = 0;
 
-            for (let i = 0; i < lines.length; i++) {
-                letter_i += lines[i].length+1; // newline counted
-                
-                console.log(lines[i], ": start", input_element.selectionStart, letter_i, "&& end", input_element.selectionEnd , letter_i - lines[i].length)
-                if(input_element.selectionStart <= letter_i && input_element.selectionEnd >= letter_i - lines[i].length) {
+            for (let i = 0; i < lines.length; i++) {                
+                console.log(lines[i], ": start", selection_start, letter_i + lines[i].length + 1, "&& end", selection_end , letter_i + 1)
+                if(selection_start <= letter_i+lines[i].length && selection_end >= letter_i + 1) { // + 1 so newlines counted
                     // Starts before or at last char and ends after or at first char
                     if(event.shiftKey) {
                         if(lines[i][0] == "\t") {
                             // Remove first tab
-                            lines[i] = lines[i].slice(1);
-                            if(number_indents == 0) first_line_indents--;
-                            number_indents--;
+                            input_element.selectionStart = letter_i;
+                            input_element.selectionEnd = letter_i+1;
+                            document.execCommand("delete", false, "");
+
+                            // Change selection
+                            if(selection_start > letter_i) { // Indented outside selection
+                                selection_start--;
+                            }
+                            selection_end--;
+                            letter_i--;
                         }
                     } else {
-                        lines[i] = "\t" + lines[i];
-                        if(number_indents == 0) first_line_indents++;
-                        number_indents++;
-                    }
-                    
+                        // Add tab at start
+                        input_element.selectionStart = letter_i;
+                        input_element.selectionEnd = letter_i;
+                        document.execCommand("insertText", false, "\t");
+
+                        // Change selection
+                        if(selection_start > letter_i) { // Indented outside selection
+                            selection_start++;
+                        }
+                        selection_end++;
+                        letter_i++;
+                    }                    
                 }
+                
+                letter_i += lines[i].length+1; // newline counted
             }
-            input_element.value = lines.join("\n");
+            // input_element.value = lines.join("\n");
 
             // move cursor
-            input_element.selectionStart = selection_start + first_line_indents;
-            input_element.selectionEnd = selection_end + number_indents;
+            input_element.selectionStart = selection_start;
+            input_element.selectionEnd = selection_end;
         }
 
         codeInput.update(input_element.value);
@@ -119,15 +125,12 @@
         for (let i = 0; i < number_indents; i++) {
             new_line += "\t";
         }
-        new_line += text_after_cursor;
 
         // save the current cursor position
         let selection_start = input_element.selectionStart;
         let selection_end = input_element.selectionEnd;
 
-        // splice our new line into the list of existing lines and join them all back up
-        lines.splice(current_line + 1, 0, new_line);
-        input_element.value = lines.join("\n");
+        document.execCommand("insertText", false, "\n" + new_line); // Write new line, including auto-indentation
 
         // move cursor to new position
         input_element.selectionStart = selection_start + number_indents + 1;  // count the indent level and the newline character