feat: add alignment buttons for multi-element context pad

Closes #1680

assets/bpmn-js.css

@@ -8,7 +8,7 @@
   --color-grey-225-10-80: hsl(225, 10%, 80%);
   --color-grey-225-10-85: hsl(225, 10%, 85%);
   --color-grey-225-10-90: hsl(225, 10%, 90%);
-  --color-grey-225-10-95: hsl(225, 10%, 95%); 
+  --color-grey-225-10-95: hsl(225, 10%, 95%);
   --color-grey-225-10-97: hsl(225, 10%, 97%);
 
   --color-blue-205-100-45: hsl(205, 100%, 45%);
@@ -24,8 +24,8 @@
   --color-red-360-100-97: hsl(360, 100%, 97%);
 
   --color-white: hsl(0, 0%, 100%);
-  --color-black: hsl(0, 0%, 0%); 
-  --color-black-opacity-05: hsla(0, 0%, 0%, 5%); 
+  --color-black: hsl(0, 0%, 0%);
+  --color-black-opacity-05: hsla(0, 0%, 0%, 5%);
   --color-black-opacity-10: hsla(0, 0%, 0%, 10%);
 
   --breadcrumbs-font-family: var(--bjs-font-family);
@@ -113,4 +113,29 @@
 
 .selected .bjs-drilldown-empty {
   display: inherit;
-}
+}
+
+[data-popup="align-elements"] .djs-popup-body {
+  display: flex;
+}
+
+[data-popup="align-elements"] .djs-popup-body [data-group] + [data-group] {
+  border-left: 1px solid var(--popup-border-color);
+}
+
+[data-popup="align-elements"] [data-group="align"] {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+}
+
+[data-popup="align-elements"] .djs-popup-body .entry {
+  height: 22px;
+  width: 22px;
+
+  padding: 8px 10px;
+}
+
+[data-popup="align-elements"] .djs-popup-body .entry img {
+  height: 100%;
+  width: 100%;
+}

lib/Modeler.js

@@ -10,7 +10,7 @@ import MoveCanvasModule from 'diagram-js/lib/navigation/movecanvas';
 import TouchModule from 'diagram-js/lib/navigation/touch';
 import ZoomScrollModule from 'diagram-js/lib/navigation/zoomscroll';
 
-import AlignElementsModule from 'diagram-js/lib/features/align-elements';
+import AlignElementsModule from './features/align-elements';
 import AutoPlaceModule from './features/auto-place';
 import AutoResizeModule from './features/auto-resize';
 import AutoScrollModule from 'diagram-js/lib/features/auto-scroll';

lib/features/align-elements/AlignElementsContextPadProvider.js

@@ -0,0 +1,87 @@
+import {
+  assign
+} from 'min-dash';
+
+import ICONS from './AlignElementsIcons';
+
+var LOW_PRIORITY = 900;
+
+/**
+ * A provider for align elements context pad button
+ */
+export default function AlignElementsContextPadProvider(contextPad, popupMenu, translate, canvas) {
+
+  contextPad.registerProvider(LOW_PRIORITY, this);
+
+  this._contextPad = contextPad;
+  this._popupMenu = popupMenu;
+  this._translate = translate;
+  this._canvas = canvas;
+}
+
+AlignElementsContextPadProvider.$inject = [
+  'contextPad',
+  'popupMenu',
+  'translate',
+  'canvas'
+];
+
+AlignElementsContextPadProvider.prototype.getMultiElementContextPadEntries = function(elements) {
+  var actions = {};
+
+  if (this._isAllowed(elements)) {
+    assign(actions, this._getEntries(elements));
+  }
+
+  return actions;
+};
+
+AlignElementsContextPadProvider.prototype._isAllowed = function(elements) {
+  return !this._popupMenu.isEmpty(elements, 'align-elements');
+};
+
+AlignElementsContextPadProvider.prototype._getEntries = function(elements) {
+  var self = this;
+
+  return {
+    'align-elements': {
+      group: 'align-elements',
+      title: self._translate('Align elements'),
+      imageUrl: ICONS['align'],
+      action: {
+        click: function(event, elements) {
+          var position = self._getMenuPosition(elements);
+
+          assign(position, {
+            cursor: {
+              x: event.x,
+              y: event.y
+            }
+          });
+
+          self._popupMenu.open(elements, 'align-elements', position);
+        }
+      }
+    }
+  };
+};
+
+AlignElementsContextPadProvider.prototype._getMenuPosition = function(elements) {
+  var Y_OFFSET = 5;
+
+  var diagramContainer = this._canvas.getContainer(),
+      pad = this._contextPad.getPad(elements).html;
+
+  var diagramRect = diagramContainer.getBoundingClientRect(),
+      padRect = pad.getBoundingClientRect();
+
+  var top = padRect.top - diagramRect.top;
+  var left = padRect.left - diagramRect.left;
+
+  var pos = {
+    x: left,
+    y: top + padRect.height + Y_OFFSET
+  };
+
+  return pos;
+};

lib/features/align-elements/AlignElementsMenuProvider.js

@@ -0,0 +1,72 @@
+import ICONS from './AlignElementsIcons';
+
+import {
+  assign,
+  forEach,
+} from 'min-dash';
+
+var ALIGNMENT_OPTIONS = [
+  'left',
+  'center',
+  'right',
+  'top',
+  'middle',
+  'bottom'
+];
+
+/**
+ * A provider for align elements popup menu.
+ */
+export default function AlignElementsMenuProvider(popupMenu, alignElements, translate) {
+
+  this._alignElements = alignElements;
+  this._translate = translate;
+  this._popupMenu = popupMenu;
+
+  popupMenu.registerProvider('align-elements', this);
+}
+
+AlignElementsMenuProvider.$inject = [
+  'popupMenu',
+  'alignElements',
+  'translate'
+];
+
+AlignElementsMenuProvider.prototype.getPopupMenuEntries = function(elements) {
+  var entries = {};
+
+  if (this._isAllowed(elements)) {
+    assign(entries, this._getEntries(elements));
+  }
+
+  return entries;
+};
+
+AlignElementsMenuProvider.prototype._isAllowed = function(elements) {
+
+  // TODO(barmac): implement
+  return true;
+};
+
+AlignElementsMenuProvider.prototype._getEntries = function(elements) {
+  var alignElements = this._alignElements,
+      translate = this._translate,
+      popupMenu = this._popupMenu;
+
+  var entries = {};
+
+  forEach(ALIGNMENT_OPTIONS, function(alignment) {
+    entries[ 'align-elements-' + alignment ] = {
+      group: 'align',
+      title: translate('Align elements ' + alignment),
+      className: 'bjs-align-elements-menu-entry',
+      imageUrl: ICONS[alignment],
+      action: function(event, entry) {
+        alignElements.trigger(elements, alignment);
+        popupMenu.close();
+      }
+    };
+  });
+
+  return entries;
+};

lib/features/align-elements/index.js

@@ -0,0 +1,20 @@
+import AlignElementsModule from 'diagram-js/lib/features/align-elements';
+import ContextPadModule from 'diagram-js/lib/features/context-pad';
+import PopupMenuModule from 'diagram-js/lib/features/popup-menu';
+
+import AlignElementsContextPadProvider from './AlignElementsContextPadProvider';
+import AlignElementsMenuProvider from './AlignElementsMenuProvider';
+
+export default {
+  __depends__: [
+    AlignElementsModule,
+    ContextPadModule,
+    PopupMenuModule
+  ],
+  __init__: [
+    'alignElementsContextPadProvider',
+    'alignElementsMenuProvider'
+  ],
+  alignElementsContextPadProvider: [ 'type', AlignElementsContextPadProvider ],
+  alignElementsMenuProvider: [ 'type', AlignElementsMenuProvider ]
+};