feat(bpmn-renderer): allow overriding colors, width, and height

* fill, stroke, width and height can be overridden
* no other attributes can be overridden
* public API only exposes renderers for actual BPMN elements
* opacity removed, everything is full opacity

lib/draw/BpmnRenderUtil.js

@@ -1,4 +1,5 @@
 import {
+  has,
   some
 } from 'min-dash';
 
@@ -16,6 +17,9 @@ import {
  * @typedef {import('../model').Element} Element
  *
  * @typedef {import('../model').ShapeLike} ShapeLike
+ *
+ * @typedef {import('diagram-js/lib/util/Types').Dimensions} Dimensions
+ * @typedef {import('diagram-js/lib/util/Types').Rect} Rect
  */
 
 // re-export for compatibility
@@ -26,6 +30,7 @@ export {
 
 
 export var black = 'hsl(225, 10%, 15%)';
+export var white = 'white';
 
 // element utils //////////////////////
 
@@ -73,39 +78,42 @@ export function isCollection(element) {
 /**
  * @param {Element} element
  * @param {string} [defaultColor]
+ * @param {string} [overrideColor]
  *
  * @return {string}
  */
-export function getFillColor(element, defaultColor) {
+export function getFillColor(element, defaultColor, overrideColor) {
   var di = getDi(element);
 
-  return di.get('color:background-color') || di.get('bioc:fill') || defaultColor || 'white';
+  return overrideColor || di.get('color:background-color') || di.get('bioc:fill') || defaultColor || white;
 }
 
 /**
  * @param {Element} element
  * @param {string} [defaultColor]
+ * @param {string} [overrideColor]
  *
  * @return {string}
  */
-export function getStrokeColor(element, defaultColor) {
+export function getStrokeColor(element, defaultColor, overrideColor) {
   var di = getDi(element);
 
-  return di.get('color:border-color') || di.get('bioc:stroke') || defaultColor || black;
+  return overrideColor || di.get('color:border-color') || di.get('bioc:stroke') || defaultColor || black;
 }
 
 /**
  * @param {Element} element
  * @param {string} [defaultColor]
  * @param {string} [defaultStrokeColor]
+ * @param {string} [overrideColor]
  *
  * @return {string}
  */
-export function getLabelColor(element, defaultColor, defaultStrokeColor) {
+export function getLabelColor(element, defaultColor, defaultStrokeColor, overrideColor) {
   var di = getDi(element),
       label = di.get('label');
 
-  return label && label.get('color:color') || defaultColor ||
+  return overrideColor || (label && label.get('color:color')) || defaultColor ||
     getStrokeColor(element, defaultStrokeColor);
 }
 
@@ -208,3 +216,42 @@ export function getRectPath(shape) {
 
   return componentsToPath(rectPath);
 }
+
+/**
+ * Get width and height from element or overrides.
+ *
+ * @param {Dimensions|Rect|Shape} bounds
+ * @param {Object} overrides
+ *
+ * @returns {Dimensions}
+ */
+export function getBounds(bounds, overrides = {}) {
+  return {
+    width: getWidth(bounds, overrides),
+    height: getHeight(bounds, overrides)
+  };
+}
+
+/**
+ * Get width from element or overrides.
+ *
+ * @param {Dimensions|Rect|Shape} bounds
+ * @param {Object} overrides
+ *
+ * @returns {number}
+ */
+export function getWidth(bounds, overrides = {}) {
+  return has(overrides, 'width') ? overrides.width : bounds.width;
+}
+
+/**
+ * Get height from element or overrides.
+ *
+ * @param {Dimensions|Rect|Shape} bounds
+ * @param {Object} overrides
+ *
+ * @returns {number}
+ */
+export function getHeight(bounds, overrides = {}) {
+  return has(overrides, 'height') ? overrides.height : bounds.height;
+}