Refactor document delta handling

lib/ace/anchor.js

@@ -101,66 +101,49 @@ var Anchor = exports.Anchor = function(doc, row, column) {
      **/
     this.onChange = function(e) {
         var delta = e.data;
-        var range = delta.range;
-
-        if (range.start.row == range.end.row && range.start.row != this.row)
-            return;
-
-        if (range.start.row > this.row)
-            return;
-
-        if (range.start.row == this.row && range.start.column > this.column)
-            return;
-
-        var row = this.row;
-        var column = this.column;
-        var start = range.start;
-        var end = range.end;
-
-        if (delta.action === "insertText") {
-            if (start.row === row && start.column <= column) {
-                if (start.column === column && this.$insertRight) {
-                    // do nothing
-                } else if (start.row === end.row) {
-                    column += end.column - start.column;
-                } else {
-                    column -= start.column;
-                    row += end.row - start.row;
-                }
-            } else if (start.row !== end.row && start.row < row) {
-                row += end.row - start.row;
-            }
-        } else if (delta.action === "insertLines") {
-            if (start.row <= row) {
-                row += end.row - start.row;
-            }
-        } else if (delta.action === "removeText") {
-            if (start.row === row && start.column < column) {
-                if (end.column >= column)
-                    column = start.column;
-                else
-                    column = Math.max(0, column - (end.column - start.column));
-
-            } else if (start.row !== end.row && start.row < row) {
-                if (end.row === row)
-                    column = Math.max(0, column - end.column) + start.column;
-                row -= (end.row - start.row);
-            } else if (end.row === row) {
-                row -= end.row - start.row;
-                column = Math.max(0, column - end.column) + start.column;
-            }
-        } else if (delta.action == "removeLines") {
-            if (start.row <= row) {
-                if (end.row <= row)
-                    row -= end.row - start.row;
-                else {
-                    row = start.row;
-                    column = 0;
-                }
-            }
+        var point = this.$getTransformedPoint(delta, {row: this.row, column: this.column});
+        this.setPosition(point.row, point.column, true);
+    };
+
+    function $pointsInOrder(point1, point2, equalPointsInOrder) {
+        var bColIsAfter = equalPointsInOrder ? point1.column <= point2.column : point1.column < point2.column;
+        return (point1.row < point2.row) || (point1.row == point2.row && bColIsAfter);
+    }
+
+    this.$getTransformedPoint = function (delta, point) {
+
+        // Get delta info.
+        var moveIfEqual   = this.$insertRight;
+        var deltaIsInsert = (delta.action == 'insert')
+        var deltaRowShift = (deltaIsInsert ? 1 : -1) * (delta.range.end.row    - delta.range.start.row);
+        var deltaColShift = (deltaIsInsert ? 1 : -1) * (delta.range.end.column - delta.range.start.column);
+        var deltaStart    = delta.range.start;
+        var deltaEnd      = (deltaIsInsert ? deltaStart : delta.range.end); // Collapse insert range.
+
+        // DELTA AFTER POINT: No change needed.
+        if ($pointsInOrder(point, deltaStart, moveIfEqual)) {
+            return {
+                row: point.row,
+                column: point.column
+            };
         }
-
-        this.setPosition(row, column, true);
+
+        // DELTA BEFORE POINT: Move point by delta shift.
+        if ($pointsInOrder(deltaEnd, point, !moveIfEqual)) {
+            return {
+                row: point.row + deltaRowShift,
+                column: point.column + (point.row == deltaEnd.row ? deltaColShift : 0)
+            };
+        }
+
+        // DELTA ENVELOPS POINT (delete only): Move point to delta start.
+        if (delta.action != 'remove')
+            throw 'Delete action expected.';
+
+        return {
+            row: deltaStart.row,
+            column: deltaStart.column
+        };
     };
 
     /**

lib/ace/anchor_test.js

@@ -62,23 +62,23 @@ module.exports = {
         var doc = new Document("juhu\nkinners");
         var anchor = new Anchor(doc, 1, 4);
 
-        doc.insertLines(1, ["123", "456"]);
+        doc.insertFullLines(1, ["123", "456"]);
         assert.position(anchor.getPosition(), 3, 4);    
     },
 
     "test insert new line before cursor should move anchor column": function() {
         var doc = new Document("juhu\nkinners");
         var anchor = new Anchor(doc, 1, 4);
 
-        doc.insertNewLine({row: 0, column: 0});
+        doc.insertMergedLines({row: 0, column: 0}, ['', '']);
         assert.position(anchor.getPosition(), 2, 4);    
     },
 
     "test insert new line in anchor line before anchor should move anchor column and row": function() {
         var doc = new Document("juhu\nkinners");
         var anchor = new Anchor(doc, 1, 4);
 
-        doc.insertNewLine({row: 1, column: 2});
+        doc.insertMergedLines({row: 1, column: 2}, ['', '']);
         assert.position(anchor.getPosition(), 2, 2);
     },
 
@@ -110,7 +110,7 @@ module.exports = {
         var doc = new Document("juhu\n1\n2\nkinners");
         var anchor = new Anchor(doc, 3, 4);
 
-        doc.removeLines(1, 2);
+        doc.removeFullLines(1, 2);
         assert.position(anchor.getPosition(), 1, 4);
     },
 
@@ -134,7 +134,7 @@ module.exports = {
         var doc = new Document("juhu\nkinners\n123");
         var anchor = new Anchor(doc, 1, 5);
 
-        doc.removeLines(1, 1);
+        doc.removeFullLines(1, 1);
         assert.position(anchor.getPosition(), 1, 0);
     },
 
@@ -173,9 +173,9 @@ module.exports = {
         var doc = new Document("juhu\nkinners\n123");
         var anchor = new Anchor(doc, 2, 4);
 
-        doc.removeLines(0, 3);
+        doc.removeFullLines(0, 3);
         assert.position(anchor.getPosition(), 0, 0);
-        doc.insertLines(0, ["a", "b", "c"]);        
+        doc.insertFullLines(0, ["a", "b", "c"]);        
         assert.position(anchor.getPosition(), 3, 0);
         assert.equal(doc.getValue(), "a\nb\nc\n");
     }

lib/ace/apply_delta.js

@@ -0,0 +1,137 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Distributed under the BSD license:
+ *
+ * Copyright (c) 2010, Ajax.org B.V.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Ajax.org B.V. nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+define(function(require, exports, module) {
+"use strict";
+
+var Range = require("./range").Range;
+
+function splitLine (docLines, position) {
+    var text = docLines[position.row];
+    docLines[position.row] = text.slice(0, position.column);
+    docLines.splice(position.row + 1, 0, text.slice(position.column));
+}
+
+function joinLineWithNext(docLines, row) {
+    docLines[row] += docLines[row + 1];
+    docLines.splice(row + 1, 1);            
+}
+
+function throwDeltaError(delta, errorText){
+    console.log('Invalid Delta:', delta);    
+    throw 'Invalid Delta: ' + errorText;
+}
+
+function positionInDocument(docLines, position) {
+    return position.row    >= 0 && position.row    <  docLines.length &&
+           position.column >= 0 && position.column <= docLines[position.row].length;
+}
+
+function validateDelta(docLines, delta) {
+
+    // Validate action string.
+    if (delta.action != 'insert' && delta.action != 'remove')
+        throwDeltaError(delta, 'delta.action must be "insert" or "remove"');
+
+    // Validate lines type.
+    if (!(delta.lines instanceof Array))
+        throwDeltaError(delta, 'delta.lines must be an Array');
+
+    // Validate range type.
+    if (!(delta.range instanceof Range))
+       throwDeltaError(delta, 'delta.range must be an instance of the Range class');        
+
+    // Validate that the start point is contained in the document.
+    var start = delta.range.start;
+    if (!positionInDocument(docLines, delta.range.start))
+        throwDeltaError(delta, 'delta.range.start must be contained in document');
+
+    // Validate that the end point is contained in the document (remove deltas only).
+    var end = delta.range.end;
+    if (delta.action == 'remove' && !positionInDocument(docLines, end))
+        throwDeltaError(delta, 'delta.range.end must contained in document for "remove" actions');
+
+    // Validate that the .range size matches the .lines size.
+    var numRangeRows = end.row - start.row;
+    var numRangeLastLineChars = (end.column - (numRangeRows == 0 ? start.column : 0));
+    if (numRangeRows != delta.lines.length - 1 || delta.lines[numRangeRows].length != numRangeLastLineChars)
+        throwDeltaError(delta, 'delta.range must match delta lines');
+}
+
+exports.applyDelta = function(docLines, delta, doNotValidate) {
+
+    // Validate delta.
+    if (!doNotValidate)
+        validateDelta(docLines, delta);
+
+    // Apply delta.
+    if (delta.range.start.row == delta.range.end.row) {
+        // Apply single-line delta.
+        // Note: The multi-line code below correctly handle single-line
+        //       deltas too, but we need to short-circuit for speed.
+        var row         = delta.range.start.row;
+        var startColumn = delta.range.start.column;
+        var endColumn   = delta.range.end.column;
+        var line        = docLines[row];
+        switch (delta.action) {
+
+            case 'insert':
+                docLines[row] = line.substring(0, startColumn) + delta.lines[0] + line.substring(startColumn);
+                break;
+
+            case 'remove':
+                docLines[row] = line.substring(0, startColumn) + line.substring(endColumn);
+                break;
+        }
+    } else {
+
+        // Apply multi-line delta.
+        switch (delta.action) {
+
+            case 'insert':
+                splitLine(docLines, delta.range.start);
+                docLines.splice.apply(docLines, [delta.range.start.row + 1, 0].concat(delta.lines));
+                joinLineWithNext(docLines, delta.range.start.row);
+                joinLineWithNext(docLines, delta.range.end.row);
+                break;
+
+            case 'remove':                
+                splitLine(docLines, delta.range.end);
+                splitLine(docLines, delta.range.start);
+                docLines.splice(
+                    delta.range.start.row + 1,                       // Where to start deleting
+                    delta.range.end.row - delta.range.start.row + 1  // Num lines to delete.
+                );
+                joinLineWithNext(docLines, delta.range.start.row);
+                break;
+        }
+    }
+}
+});

lib/ace/background_tokenizer.js

@@ -183,7 +183,7 @@ var BackgroundTokenizer = function(tokenizer, editor) {
 
         if (len === 0) {
             this.lines[startRow] = null;
-        } else if (delta.action == "removeText" || delta.action == "removeLines") {
+        } else if (delta.action == 'remove') {
             this.lines.splice(startRow, len + 1, null);
             this.states.splice(startRow, len + 1, null);
         } else {