Added scroll delta mode constants.

core/utils.js

@@ -304,6 +304,32 @@ Blockly.utils.mouseToSvg = function(e, svg, matrix) {
   return svgPoint.matrixTransform(matrix);
 };
 
+/**
+ * Get the scroll delta of a mouse event in pixel units.
+ * @param {!Event} e Mouse event.
+ * @return {{x: number, y: number}} Scroll delta object with .x and .y
+ *    properties.
+ */
+Blockly.utils.getScrollDeltaPixels = function(e) {
+  switch (e.deltaMode) {
+    case 0x00:  // Pixel mode.
+      return {
+        x: e.deltaX,
+        y: e.deltaY
+      };
+    case 0x01:  // Line mode.
+      return {
+        x: e.deltaX * Blockly.LINE_MODE_MULTIPLIER,
+        y: e.deltaY * Blockly.LINE_MODE_MULTIPLIER
+      };
+    case 0x02:  // Page mode.
+      return {
+        x: e.deltaX * Blockly.PAGE_MODE_MULTIPLIER,
+        y: e.deltaY * Blockly.PAGE_MODE_MULTIPLIER
+      };
+  }
+};
+
 /**
  * Given an array of strings, return the length of the shortest one.
  * @param {!Array.<string>} array Array of strings.