<!-- Copyright (c) 2015 The Polymer Project Authors. All rights reserved. This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt Code distributed by Google as part of the polymer project is also subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt --> <link rel="import" href="../polymer/polymer.html"> <link rel="import" href="../iron-flex-layout/iron-flex-layout.html"> <!-- `paper-header-panel` contains a header section and a content panel section. __Important:__ The `paper-header-panel` will not display if its parent does not have a height. Using layout classes, you can make the `paper-header-panel` fill the screen <body class="fullbleed layout vertical"> <paper-header-panel class="flex"> <paper-toolbar> <div>Hello World!</div> </paper-toolbar> </paper-header-panel> </body> Special support is provided for scrolling modes when one uses a paper-toolbar or equivalent for the header section. Example: <paper-header-panel> <paper-toolbar>Header</paper-toolbar> <div>Content goes here...</div> </paper-header-panel> If you want to use other than `paper-toolbar` for the header, add `paper-header` class to that element. Example: <paper-header-panel> <div class="paper-header">Header</div> <div>Content goes here...</div> </paper-header-panel> To have the content fit to the main area, use the `fit` class. <paper-header-panel> <div class="paper-header">standard</div> <div class="fit">content fits 100% below the header</div> </paper-header-panel> Modes Controls header and scrolling behavior. Options are `standard`, `seamed`, `waterfall`, `waterfall-tall`, `scroll` and `cover`. Default is `standard`. Mode | Description ----------------|------------- `standard` | The header is a step above the panel. The header will consume the panel at the point of entry, preventing it from passing through to the opposite side. `seamed` | The header is presented as seamed with the panel. `waterfall` | Similar to standard mode, but header is initially presented as seamed with panel, but then separates to form the step. `waterfall-tall` | The header is initially taller (`tall` class is added to the header). As the user scrolls, the header separates (forming an edge) while condensing (`tall` class is removed from the header). `scroll` | The header keeps its seam with the panel, and is pushed off screen. `cover` | The panel covers the whole `paper-header-panel` including the header. This allows user to style the panel in such a way that the panel is partially covering the header. Example: <paper-header-panel mode="waterfall"> <div class="paper-header">standard</div> <div class="content fit">content fits 100% below the header</div> </paper-header-panel> Styling header panel: To change the shadow that shows up underneath the header: paper-header-panel { --paper-header-panel-shadow: { height: 6px; bottom: -6px; box-shadow: inset 0px 5px 6px -3px rgba(0, 0, 0, 0.4); }; } To change the panel container in different modes: paper-slider { --paper-header-panel-standard-container: { border: 1px solid gray; }; --paper-header-panel-seamed-container: { border: 1px solid gray; }; --paper-header-panel-waterfall-container: { border: 1px solid gray; }; --paper-header-panel-waterfall-tall-container: { border: 1px solid gray; }; --paper-header-panel-scroll-container: { border: 1px solid gray; }; --paper-header-panel-cover-container: { border: 1px solid gray; }; } @group Paper Elements @element paper-header-panel @demo demo/index.html @hero hero.svg --> <dom-module id="paper-header-panel"> <link rel="import" type="css" href="paper-header-panel.css"> <template> <content id="headerContent" select="paper-toolbar, .paper-header"></content> <div id="mainPanel"> <div id="mainContainer" class$="[[_computeMainContainerClass(mode)]]"> <content id="mainContent" select="*"></content> </div> <div id="dropShadow"></div> </div> </template> </dom-module> <script> (function() { 'use strict'; var SHADOW_WHEN_SCROLLING = 1; var SHADOW_ALWAYS = 2; var MODE_CONFIGS = { outerScroll: { 'scroll': true }, shadowMode: { 'standard': SHADOW_ALWAYS, 'waterfall': SHADOW_WHEN_SCROLLING, 'waterfall-tall': SHADOW_WHEN_SCROLLING }, tallMode: { 'waterfall-tall': true } }; Polymer({ is: 'paper-header-panel', /** * Fired when the content has been scrolled. `event.detail.target` returns * the scrollable element which you can use to access scroll info such as * `scrollTop`. * * <paper-header-panel on-content-scroll="scrollHandler"> * ... * </paper-header-panel> * * * scrollHandler: function(event) { * var scroller = event.detail.target; * console.log(scroller.scrollTop); * } * * @event content-scroll */ properties: { /** * Controls header and scrolling behavior. Options are * `standard`, `seamed`, `waterfall`, `waterfall-tall`, `scroll` and * `cover`. Default is `standard`. * * `standard`: The header is a step above the panel. The header will consume the * panel at the point of entry, preventing it from passing through to the * opposite side. * * `seamed`: The header is presented as seamed with the panel. * * `waterfall`: Similar to standard mode, but header is initially presented as * seamed with panel, but then separates to form the step. * * `waterfall-tall`: The header is initially taller (`tall` class is added to * the header). As the user scrolls, the header separates (forming an edge) * while condensing (`tall` class is removed from the header). * * `scroll`: The header keeps its seam with the panel, and is pushed off screen. * * `cover`: The panel covers the whole `paper-header-panel` including the * header. This allows user to style the panel in such a way that the panel is * partially covering the header. * * <paper-header-panel mode="cover"> * <paper-toolbar class="tall"> * <core-icon-button icon="menu"></core-icon-button> * </paper-toolbar> * <div class="content"></div> * </paper-header-panel> */ mode: { type: String, value: 'standard', observer: '_modeChanged', reflectToAttribute: true }, /** * If true, the drop-shadow is always shown no matter what mode is set to. */ shadow: { type: Boolean, value: false }, /** * The class used in waterfall-tall mode. Change this if the header * accepts a different class for toggling height, e.g. "medium-tall" */ tallClass: { type: String, value: 'tall' }, /** * If true, the scroller is at the top */ atTop: { type: Boolean, value: true, readOnly: true } }, observers: [ '_computeDropShadowHidden(atTop, mode, shadow)' ], ready: function() { this.scrollHandler = this._scroll.bind(this); this._addListener(); // Run `scroll` logic once to initialze class names, etc. this._keepScrollingState(); }, detached: function() { this._removeListener(); }, /** * Returns the header element * * @property header * @type Object */ get header() { return Polymer.dom(this.$.headerContent).getDistributedNodes()[0]; }, /** * Returns the scrollable element. * * @property scroller * @type Object */ get scroller() { return this._getScrollerForMode(this.mode); }, /** * Returns true if the scroller has a visible shadow. * * @property visibleShadow * @type Boolean */ get visibleShadow() { return this.$.dropShadow.classList.contains('has-shadow'); }, _computeDropShadowHidden: function(atTop, mode, shadow) { var shadowMode = MODE_CONFIGS.shadowMode[mode]; if (this.shadow) { this.toggleClass('has-shadow', true, this.$.dropShadow); } else if (shadowMode === SHADOW_ALWAYS) { this.toggleClass('has-shadow', true, this.$.dropShadow); } else if (shadowMode === SHADOW_WHEN_SCROLLING && !atTop) { this.toggleClass('has-shadow', true, this.$.dropShadow); } else { this.toggleClass('has-shadow', false, this.$.dropShadow); } }, _computeMainContainerClass: function(mode) { // TODO: It will be useful to have a utility for classes // e.g. Polymer.Utils.classes({ foo: true }); var classes = {}; classes['flex'] = mode !== 'cover'; return Object.keys(classes).filter( function(className) { return classes[className]; }).join(' '); }, _addListener: function() { this.scroller.addEventListener('scroll', this.scrollHandler, false); }, _removeListener: function() { this.scroller.removeEventListener('scroll', this.scrollHandler); }, _modeChanged: function(newMode, oldMode) { var configs = MODE_CONFIGS; var header = this.header; var animateDuration = 200; if (header) { // in tallMode it may add tallClass to the header; so do the cleanup // when mode is changed from tallMode to not tallMode if (configs.tallMode[oldMode] && !configs.tallMode[newMode]) { header.classList.remove(this.tallClass); this.async(function() { header.classList.remove('animate'); }, animateDuration); } else { header.classList.toggle('animate', configs.tallMode[newMode]); } } this._keepScrollingState(); }, _keepScrollingState: function() { var main = this.scroller; var header = this.header; this._setAtTop(main.scrollTop === 0); if (header && this.tallClass && MODE_CONFIGS.tallMode[this.mode]) { this.toggleClass(this.tallClass, this.atTop || header.classList.contains(this.tallClass) && main.scrollHeight < this.offsetHeight, header); } }, _scroll: function() { this._keepScrollingState(); this.fire('content-scroll', {target: this.scroller}, {bubbles: false}); }, _getScrollerForMode: function(mode) { return MODE_CONFIGS.outerScroll[mode] ? this : this.$.mainContainer; } }); })(); </script>