Flexible Layout (#2201)

* first cut of flexible layout

* better drag handling

* add drop targets to every row

* enable drag and drop between columns and rows

* enable persistance

* add editing capability

* chage rows to frames and columns to containers, switch draggable to whole frame object

* Merge latest, resolve conflicts.

Need to just apply these changes to Deep's branch and push

* enhancements to drag targets

* WIP in flexibleLayout, container.vue files

- Refined classes and markup;
- min-width changed to flex-basis;
- Added toggle direction button;

* Significant progress but still WIP

- Refined classes and markup;
- Layout toggling working;
- Add Container working properly;
- TODOs: fix sizing in empty container, fix bordering, more refinements;

* add resizing of frames - still wip

* Significant enhancements

- Moved all CSS into flexibleLayout.vue;
- Layout now improved for empty container and drop hints;
- Proportional sizing now better for frames and containers;

* Resize handle WIP

* abstract splitter and logic into self contained component that will emit an event when mouse is moving

* Resize handle WIP

- Minor tweak to handle padding and hover;

* add container resize todo persist

* persist container resize

* add frame header, fix column resize on last column

* Refinements to resize-handle

- Fixed sizing;
- Transition on hover;
- TODOs: needs is-dragging to maintain hover style while dragging;

* fix drop hints showing after drop

* move header

* improve mouse move gesture

* Added frame size indicator

* add snapto functionality

* Refined container and frame size indicators

- Also added overflow handling to l-grid-view

* improve resizing logic

* add selection on frames

* Various resizing-frames related

- Fixed overflow - now frame widths can be collapsed to 5% minimum;
- Sizing indicators refined, better positioning and layout;
- Added grippy drag indicators to column heads;
- TODOs: add column head cursors and hover effects, hide indicators
when not in edit mode, handle nested layout and flex layouts while
editing

* Selecting and emtpy layout messaging

- Better empty layout message;
- Moved s-selected to proper element in c-fl-frame;

* Drop-hint and sizing related various

- Drop-hints for first placeholder container now display;
- Drop-hints moved into drag-wrapper;

* add delete frame

* Editing various

- Adjust Snow theme constants related to editing;
- Changed delete message wording;

* Updated icon and added description

* add toggle and remove container to toolbar

* miscellaneous cleanup

* add container button to toolbar

* improve toolbar

* code cleanup in plugin.js

* Various icons, toolbar separator

- Copied in c-toolbar__separator and associated changes in _controls
from Pegah's layout_alpha branch - may have conflicts later.
- Added separator to FL toolbar;
- Updated icons for grippy-ew, toolbar icons;

* add check for empty containers"

* logic to resize frames on drop

* fix delete frame and persisting toolbar

* Significant changes to edit / selection styling

- Both Flexible and fixed Display Layouts addressed;
- Both themes addressed;
- Changed drop-hint icon to icon-plus;

* add correct icons to frame header and fix toolbars showing up in wrong views

* Moving and resizing various

- Cursors;
- Grippy added to frame resize-handle, WIP!;

* add container reordering

* add frame/no frame support to toolbar'

* fix regression of resize handles showing after last frame in container

* force selection of flexible-layout when editing is first clicked, to apply correct toolbar

* make changes to simplify toolbar

* Modified sizing algorithm slightly

* make changes reviewer requested

* fix regression that causes top drop hint to not show

* remove unused variables and bind events to vue

* unsub selection before destroy

src/plugins/flexibleLayout/flexibleLayoutViewProvider.js

@@ -0,0 +1,67 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2018, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+
+define([
+    './components/flexibleLayout.vue',
+    'vue'
+], function (
+    FlexibleLayoutComponent,
+    Vue
+) {
+    function FlexibleLayoutViewProvider(openmct) {
+        return {
+            key: 'flexible-layout',
+            name: 'FlexibleLayout',
+            cssClass: 'icon-layout-view',
+            canView: function (domainObject) {
+                return domainObject.type === 'flexible-layout';
+            },
+            view: function (domainObject) {
+                let component;
+
+                return {
+                    show: function (element) {
+                        component =  new Vue({
+                            components: {
+                                FlexibleLayoutComponent: FlexibleLayoutComponent.default
+                            },
+                            provide: {
+                                openmct,
+                                domainObject
+                            },
+                            el: element,
+                            template: '<flexible-layout-component></flexible-layout-component>'
+                        });
+                    },
+                    destroy: function (element) {
+                        component.$destroy();
+                        component = undefined;
+                    }
+                };
+            },
+            priority: function () {
+                return 1;
+            }
+        };
+    }
+    return FlexibleLayoutViewProvider;
+});