From eecc65d256a65cfc0ab2809671fdc915c79eb046 Mon Sep 17 00:00:00 2001
From: Martin Stamm <martin.stamm@camunda.com>
Date: Tue, 30 Nov 2021 16:33:31 +0100
Subject: [PATCH] feat(canvas): allow passing planes descriptors

---
 lib/core/Canvas.js           | 39 ++++++++++++++++++++----------------
 test/spec/core/CanvasSpec.js | 38 ++++++++++++++++++++++++++++++++++-
 2 files changed, 59 insertions(+), 18 deletions(-)

diff --git a/lib/core/Canvas.js b/lib/core/Canvas.js
index 2c27b1fba..b116fbcd7 100644
--- a/lib/core/Canvas.js
+++ b/lib/core/Canvas.js
@@ -369,38 +369,43 @@ Canvas.prototype.getPlane = function(name) {
  * Creates a plane that is used to draw elements on it. If no
  * root element is provided, an implicit root will be used.
  *
- * @param {string} name
+ * @param {string|Object} plane
  * @param {Object|djs.model.Root} [rootElement] optional root element
  *
  * @return {Object} plane descriptor with { layer, rootElement, name }
  */
-Canvas.prototype.createPlane = function(name, rootElement) {
-  if (!name) {
+Canvas.prototype.createPlane = function(plane, rootElement) {
+  if (!plane) {
     throw new Error('must specify a name');
   }
 
-  if (this._planes[name]) {
-    throw new Error('plane <' + name + '> already exists');
+  if (this._planes[plane] || this._planes[plane.name]) {
+    throw new Error('plane <' + plane + '> already exists');
+  }
+
+  if (typeof plane === 'string') {
+    plane = { name: plane };
   }
 
-  if (!rootElement) {
-    rootElement = {
-      id: '__implicitroot' + name,
+  if (!plane.layer) {
+    var svgLayer = this.getLayer(plane.name, PLANE_LAYER_INDEX);
+    svgAttr(svgLayer, 'display', 'none');
+
+    plane.layer = svgLayer;
+  }
+
+  if (!plane.rootElement) {
+    rootElement = rootElement || {
+      id: '__implicitroot' + plane.name,
       children: [],
       isImplicit: true
     };
-  }
 
-  var svgLayer = this.getLayer(name, PLANE_LAYER_INDEX);
-  svgAttr(svgLayer, 'display', 'none');
 
-  var plane = this._planes[name] = {
-    layer: svgLayer,
-    name: name,
-    rootElement: null
-  };
+    this.setRootElementForPlane(rootElement, plane);
+  }
 
-  this.setRootElementForPlane(rootElement, plane);
+  this._planes[plane.name] = plane;
 
   return plane;
 };
diff --git a/test/spec/core/CanvasSpec.js b/test/spec/core/CanvasSpec.js
index 2514d79e2..2f287dedc 100644
--- a/test/spec/core/CanvasSpec.js
+++ b/test/spec/core/CanvasSpec.js
@@ -2413,7 +2413,43 @@ describe('Canvas', function() {
 
           // when
           canvas.renamePlane(plane);
-        }).to.throw('must specify a name');
+        }).to.throw('must specify a plane');
+      }));
+
+
+      it('should accept a plane descriptor', inject(function(canvas) {
+
+        // given
+        var plane = {
+          name: 'a',
+          rootElement: { id: 'root' },
+          layer: canvas.getLayer('a')
+        };
+
+        // when
+        canvas.createPlane(plane);
+
+        // then
+        expect(canvas.getPlane('a')).to.exist;
+        expect(canvas.getPlane('a')).to.equal(plane);
+      }));
+
+
+      it('should fill missing plane attributes', inject(function(canvas) {
+
+        // given
+        var plane = {
+          name: 'a'
+        };
+
+        // when
+        canvas.createPlane(plane);
+
+        // then
+        expect(canvas.getPlane('a')).to.exist;
+        expect(canvas.getPlane('a')).to.equal(plane);
+        expect(plane.rootElement).to.exist;
+        expect(plane.layer).to.exist;
       }));