| <!DOCTYPE html> |
| <!-- |
| Copyright 2015 The Chromium Authors. All rights reserved. |
| Use of this source code is governed by a BSD-style license that can be |
| found in the LICENSE file. |
| --> |
| |
| <link rel="import" href="/tracing/ui/brushing_state_controller.html"> |
| |
| <!-- |
| This element handles storing and retrieving the brushing state of arbitrary |
| views (e.g. analysis sub-views). An element can use it by instantiating it and |
| appending it to itself: |
| |
| <div id="some-view-with-specific-brushing-state"> |
| <tr-ui-b-view-specific-brushing-state view-id="unique-view-identifier"> |
| </tr-ui-b-view-specific-brushing-state> |
| ... other child elements ... |
| </div> |
| |
| The state can then be retrieved from and pushed to the state element as |
| follows: |
| |
| newStateElement.set(state); |
| state = newStateElement.get(); |
| |
| Under the hood, the state element searches the DOM tree for an ancestor element |
| with a brushingStateController field to persist the state (see the |
| tr.c.BrushingStateController and tr.ui.b.BrushingState classes for more |
| details). |
| --> |
| <polymer-element name="tr-ui-b-view-specific-brushing-state"> |
| <script> |
| 'use strict'; |
| |
| Polymer({ |
| /** Compulsory unique identifier of the associated view. */ |
| get viewId() { |
| return this.getAttribute('view-id'); |
| }, |
| |
| set viewId(viewId) { |
| this.setAttribute('view-id', viewId); |
| }, |
| |
| /** |
| * Retrieve the persisted state of the associated view. The returned object |
| * (or any of its fields) must not be modified by the caller (unless the |
| * object/field is treated as a reference). |
| * |
| * If no state has been persisted yet or there is no ancestor element with |
| * a brushingStateController field, this method returns undefined. |
| */ |
| get: function() { |
| var viewId = this.viewId; |
| if (!viewId) |
| throw new Error('Element must have a view-id attribute!'); |
| |
| var brushingStateController = |
| tr.c.BrushingStateController.getControllerForElement(this); |
| if (!brushingStateController) |
| return undefined; |
| |
| return brushingStateController.getViewSpecificBrushingState(viewId); |
| }, |
| |
| /** |
| * Persist the provided state of the associated view. The provided object |
| * (or any of its fields) must not be modified afterwards (unless the |
| * object/field is treated as a reference). |
| * |
| * If there is no ancestor element with a brushingStateController field, |
| * this method does nothing. |
| */ |
| set: function(state) { |
| var viewId = this.viewId; |
| if (!viewId) |
| throw new Error('Element must have a view-id attribute!'); |
| |
| var brushingStateController = |
| tr.c.BrushingStateController.getControllerForElement(this); |
| if (!brushingStateController) |
| return; |
| |
| brushingStateController.changeViewSpecificBrushingState(viewId, state); |
| } |
| }); |
| </script> |
| </polymer-element> |
