polymer_1.0.4/bower_components/paper-scroll-header-panel/paper-scroll-header-panel.html - infra/third_party/npm_modules - Git at Google

 <!--
 @license
 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-resizable-behavior/iron-resizable-behavior.html">

 <!--
 `paper-scroll-header-panel` contains a header section and a content section.  The
 header is initially on the top part of the view but it scrolls away with the
 rest of the scrollable content.  Upon scrolling slightly up at any point, the
 header scrolls back into view.  This saves screen space and allows users to
 access important controls by easily moving them back to the view.

 __Important:__ The `paper-scroll-header-panel` will not display if its parent does not have a height.

 Using [layout classes](https://www.polymer-project.org/1.0/docs/migration.html#layout-attributes) or custom properties, you can easily make the `paper-scroll-header-panel` fill the screen

     <body class="fullbleed layout vertical">
       <paper-scroll-header-panel class="flex">
         <paper-toolbar>
           <div>Hello World!</div>
         </paper-toolbar>
       </paper-scroll-header-panel>
     </body>

 or, if you would prefer to do it in CSS, just give `html`, `body`, and `paper-scroll-header-panel` a height of 100%:

     html, body {
       height: 100%;
       margin: 0;
     }
     paper-scroll-header-panel {
       height: 100%;
     }

 `paper-scroll-header-panel` works well with `paper-toolbar` but can use any element
 that represents a header by adding a `paper-header` class to it.

     <paper-scroll-header-panel>
       <paper-toolbar>Header</paper-toolbar>
       <div>Content goes here...</div>
     </paper-scroll-header-panel>

 Styling scroll-header-panel:

 To change background for toolbar when it is at its full size:

     paper-scroll-header-panel {
       --paper-scroll-header-panel-full-header: {
         background-color: red;
       };
     }

 To change the background for toolbar when it is condensed:

     paper-scroll-header-panel {
       --paper-scroll-header-panel-condensed-header: {
         background-color: #f4b400;
       };
     }

 @group Paper Element
 @element paper-scroll-header-panel
 @demo demo/index.html
 @hero hero.svg
 -->

 <dom-module id="paper-scroll-header-panel">

   <style>
     :host {
       display: block;
       position: relative;
       overflow: hidden;
     }

     #mainContainer {
       position: absolute;
       top: 0;
       right: 0;
       bottom: 0;
       left: 0;
       -moz-box-sizing: border-box;
       box-sizing: border-box;
       -webkit-overflow-scrolling: touch;
       overflow-x: hidden;
       overflow-y: auto;
       -webkit-transform: translateZ(0);
       transform: translateZ(0);
     }

     #headerContainer {
       position: absolute;
       top: 0;
       right: 0;
       left: 0;
     }

     .bg-container {
       position: absolute;
       top: 0;
       left: 0;
       width: 100%;
       height: 100%;
       overflow: hidden;
     }

     #headerBg {
       @apply(--paper-scroll-header-panel-full-header);
     }

     #condensedHeaderBg {
       @apply(--paper-scroll-header-panel-condensed-header);
     }

     #headerBg, #condensedHeaderBg {
       position: absolute;
       top: 0;
       left: 0;
       width: 100%;
       height: 100%;
       background-repeat: no-repeat;
       background-size: cover;
       background-position: center center;
     }

     #condensedHeaderBg {
       opacity: 0;
     }
   </style>
   <template>
     <div id="mainContainer">
       <content id="mainContent" select=":not(paper-toolbar):not(.paper-header)"></content>
     </div>
     <div id="headerContainer">
       <div class="bg-container">
         <div id="condensedHeaderBg"></div>
         <div id="headerBg"></div>
       </div>
       <content id="headerContent" select="paper-toolbar, .paper-header"></content>
     </div>
   </template>
 </dom-module>

 <script>
 (function() {

   'use strict';

   Polymer({

     /**
      * Fired when the content has been scrolled.
      *
      * @event content-scroll
      */

     /**
      * Fired when the header is transformed.
      *
      * @event paper-header-transform
      */

     is: 'paper-scroll-header-panel',

     behaviors: [
       Polymer.IronResizableBehavior
     ],

     properties: {

       /**
        * If true, the header's height will condense to `condensedHeaderHeight`
        * as the user scrolls down from the top of the content area.
        */
       condenses: {
         type: Boolean,
         value: false,
         observer: '_condensesChanged'
       },

       /**
        * If true, no cross-fade transition from one background to another.
        */
       noDissolve: {
         type: Boolean,
         value: false
       },

       /**
        * If true, the header doesn't slide back in when scrolling back up.
        */
       noReveal: {
         type: Boolean,
         value: false
       },

       /**
        * If true, the header is fixed to the top and never moves away.
        */
       fixed: {
         type: Boolean,
         value: false
       },

       /**
        * If true, the condensed header is always shown and does not move away.
        */
       keepCondensedHeader: {
         type: Boolean,
         value: false
       },

       /**
        * The height of the header when it is at its full size.
        *
        * By default, the height will be measured when it is ready.  If the height
        * changes later the user needs to either set this value to reflect the
        * new height or invoke `measureHeaderHeight()`.
        */
       headerHeight: {
         type: Number,
         value: 0
       },

       /**
        * The height of the header when it is condensed.
        *
        * By default, `condensedHeaderHeight` is 1/3 of `headerHeight` unless
        * this is specified.
        */
       condensedHeaderHeight: {
         type: Number,
         value: 0
       },

       /**
        * By default, the top part of the header stays when the header is being
        * condensed.  Set this to true if you want the top part of the header
        * to be scrolled away.
        */
       scrollAwayTopbar: {
         type: Boolean,
         value: false
       },

       _headerMargin: {
         type: Number
       },

       _prevScrollTop: {
         type: Number
       },

       _y: {
         type: Number
       }

     },

     observers: [
       '_setup(_headerMargin, headerHeight, fixed)',
       '_headerHeightChanged(headerHeight, condensedHeaderHeight)',
       '_condensedHeaderHeightChanged(headerHeight, condensedHeaderHeight)'
     ],

     listeners: {
       'iron-resize': 'measureHeaderHeight'
     },

     ready: function() {
       this.async(this.measureHeaderHeight, 5);
       this._scrollHandler = this._scroll.bind(this);
       this.scroller.addEventListener('scroll', this._scrollHandler);
     },

     detached: function() {
       this.scroller.removeEventListener('scroll', this._scrollHandler);
     },

     /**
      * Returns the header element.
      *
      * @property header
      * @type Object
      */
     get header() {
       return Polymer.dom(this.$.headerContent).getDistributedNodes()[0];
     },

     /**
      * Returns the content element.
      *
      * @property content
      * @type Object
      */
     get content() {
       return Polymer.dom(this.$.mainContent).getDistributedNodes()[0];
     },

     /**
      * Returns the scrollable element.
      *
      * @property scroller
      * @type Object
      */
     get scroller() {
       return this.$.mainContainer;
     },

     /**
      * Invoke this to tell `paper-scroll-header-panel` to re-measure the header's
      * height.
      *
      * @method measureHeaderHeight
      */
     measureHeaderHeight: function() {
       var header = this.header;
       if (header && header.offsetHeight) {
         this.headerHeight = header.offsetHeight;
       }
     },

     _headerHeightChanged: function() {
       if (!this.condensedHeaderHeight) {
         // assume condensedHeaderHeight is 1/3 of the headerHeight
         this.condensedHeaderHeight = this.headerHeight * 1 / 3;
       }
     },

     _condensedHeaderHeightChanged: function() {
       if (this.headerHeight) {
         this._headerMargin = this.headerHeight - this.condensedHeaderHeight;
       }
     },

     _condensesChanged: function() {
       if (this.condenses) {
         this._scroll();
       } else {
         // reset transform/opacity set on the header
         this._condenseHeader(null);
       }
     },

     _setup: function() {
       var s = this.scroller.style;
       s.paddingTop = this.fixed ? '' : this.headerHeight + 'px';

       s.top = this.fixed ? this.headerHeight + 'px' : '';

       if (this.fixed) {
         this._transformHeader(null);
       } else {
         this._scroll();
       }
     },

     _transformHeader: function(y) {
       var s = this.$.headerContainer.style;
       this._translateY(s, -y);

       if (this.condenses) {
         this._condenseHeader(y);
       }

       this.fire('paper-header-transform', {y: y, height: this.headerHeight,
           condensedHeight: this.condensedHeaderHeight});
     },

     _condenseHeader: function(y) {
       var reset = (y === null);

       // adjust top bar in paper-header so the top bar stays at the top
       if (!this.scrollAwayTopbar && this.header.$ && this.header.$.topBar) {
         this._translateY(this.header.$.topBar.style,
             reset ? null : Math.min(y, this._headerMargin));
       }
       // transition header bg
       var hbg = this.$.headerBg.style;
       if (!this.noDissolve) {
         hbg.opacity = reset ? '' : (this._headerMargin - y) / this._headerMargin;
       }
       // adjust header bg so it stays at the center
       this._translateY(hbg, reset ? null : y / 2);
       // transition condensed header bg
       if (!this.noDissolve) {
         var chbg = this.$.condensedHeaderBg.style;
         chbg = this.$.condensedHeaderBg.style;
         chbg.opacity = reset ? '' : y / this._headerMargin;

         // adjust condensed header bg so it stays at the center
         this._translateY(chbg, reset ? null : y / 2);
       }
     },

     _translateY: function(s, y) {
       var t = (y === null) ? '' : 'translate3d(0, ' + y + 'px, 0)';
       setTransform(s, t);
     },

     /** @param {Event=} event */
     _scroll: function(event) {
       if (!this.header) {
         return;
       }

       var sTop = this.scroller.scrollTop;

       this._y = this._y || 0;
       this._prevScrollTop = this._prevScrollTop || 0;

       var y = Math.min(this.keepCondensedHeader ?
           this._headerMargin : this.headerHeight, Math.max(0,
           (this.noReveal ? sTop : this._y + sTop - this._prevScrollTop)));

       if (this.condenses && this._prevScrollTop >= sTop && sTop > this._headerMargin) {
         y = Math.max(y, this._headerMargin);
       }

       if (!event || !this.fixed && y !== this._y) {
         this._transformHeader(y);
       }

       this._prevScrollTop = Math.max(sTop, 0);
       this._y = y;

       if (event) {
         this.fire('content-scroll', {target: this.scroller}, {cancelable: false});
       }
     }

   });

   //determine proper transform mechanizm
   if (document.documentElement.style.transform !== undefined) {
     var setTransform = function(style, string) {
       style.transform = string;
     }
   } else {
     var setTransform = function(style, string) {
       style.webkitTransform = string;
     }
   }

 })();

 </script>
	<!--
	@license
	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-resizable-behavior/iron-resizable-behavior.html">

	<!--
	`paper-scroll-header-panel` contains a header section and a content section. The
	header is initially on the top part of the view but it scrolls away with the
	rest of the scrollable content. Upon scrolling slightly up at any point, the
	header scrolls back into view. This saves screen space and allows users to
	access important controls by easily moving them back to the view.

	__Important:__ The `paper-scroll-header-panel` will not display if its parent does not have a height.

	Using [layout classes](https://www.polymer-project.org/1.0/docs/migration.html#layout-attributes) or custom properties, you can easily make the `paper-scroll-header-panel` fill the screen

	<body class="fullbleed layout vertical">
	<paper-scroll-header-panel class="flex">
	<paper-toolbar>
	<div>Hello World!</div>
	</paper-toolbar>
	</paper-scroll-header-panel>
	</body>

	or, if you would prefer to do it in CSS, just give `html`, `body`, and `paper-scroll-header-panel` a height of 100%:

	html, body {
	height: 100%;
	margin: 0;
	}
	paper-scroll-header-panel {
	height: 100%;
	}

	`paper-scroll-header-panel` works well with `paper-toolbar` but can use any element
	that represents a header by adding a `paper-header` class to it.

	<paper-scroll-header-panel>
	<paper-toolbar>Header</paper-toolbar>
	<div>Content goes here...</div>
	</paper-scroll-header-panel>

	Styling scroll-header-panel:

	To change background for toolbar when it is at its full size:

	paper-scroll-header-panel {
	--paper-scroll-header-panel-full-header: {
	background-color: red;
	};
	}

	To change the background for toolbar when it is condensed:

	paper-scroll-header-panel {
	--paper-scroll-header-panel-condensed-header: {
	background-color: #f4b400;
	};
	}

	@group Paper Element
	@element paper-scroll-header-panel
	@demo demo/index.html
	@hero hero.svg
	-->

	<dom-module id="paper-scroll-header-panel">

	<style>
	:host {
	display: block;
	position: relative;
	overflow: hidden;
	}

	#mainContainer {
	position: absolute;
	top: 0;
	right: 0;
	bottom: 0;
	left: 0;
	-moz-box-sizing: border-box;
	box-sizing: border-box;
	-webkit-overflow-scrolling: touch;
	overflow-x: hidden;
	overflow-y: auto;
	-webkit-transform: translateZ(0);
	transform: translateZ(0);
	}

	#headerContainer {
	position: absolute;
	top: 0;
	right: 0;
	left: 0;
	}

	.bg-container {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	overflow: hidden;
	}

	#headerBg {
	@apply(--paper-scroll-header-panel-full-header);
	}

	#condensedHeaderBg {
	@apply(--paper-scroll-header-panel-condensed-header);
	}

	#headerBg, #condensedHeaderBg {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background-repeat: no-repeat;
	background-size: cover;
	background-position: center center;
	}

	#condensedHeaderBg {
	opacity: 0;
	}
	</style>
	<template>
	<div id="mainContainer">
	<content id="mainContent" select=":not(paper-toolbar):not(.paper-header)"></content>
	</div>
	<div id="headerContainer">
	<div class="bg-container">
	<div id="condensedHeaderBg"></div>
	<div id="headerBg"></div>
	</div>
	<content id="headerContent" select="paper-toolbar, .paper-header"></content>
	</div>
	</template>
	</dom-module>

	<script>
	(function() {

	'use strict';

	Polymer({

	/**
	* Fired when the content has been scrolled.
	*
	* @event content-scroll
	*/

	/**
	* Fired when the header is transformed.
	*
	* @event paper-header-transform
	*/

	is: 'paper-scroll-header-panel',

	behaviors: [
	Polymer.IronResizableBehavior
	],

	properties: {

	/**
	* If true, the header's height will condense to `condensedHeaderHeight`
	* as the user scrolls down from the top of the content area.
	*/
	condenses: {
	type: Boolean,
	value: false,
	observer: '_condensesChanged'
	},

	/**
	* If true, no cross-fade transition from one background to another.
	*/
	noDissolve: {
	type: Boolean,
	value: false
	},

	/**
	* If true, the header doesn't slide back in when scrolling back up.
	*/
	noReveal: {
	type: Boolean,
	value: false
	},

	/**
	* If true, the header is fixed to the top and never moves away.
	*/
	fixed: {
	type: Boolean,
	value: false
	},

	/**
	* If true, the condensed header is always shown and does not move away.
	*/
	keepCondensedHeader: {
	type: Boolean,
	value: false
	},

	/**
	* The height of the header when it is at its full size.
	*
	* By default, the height will be measured when it is ready. If the height
	* changes later the user needs to either set this value to reflect the
	* new height or invoke `measureHeaderHeight()`.
	*/
	headerHeight: {
	type: Number,
	value: 0
	},

	/**
	* The height of the header when it is condensed.
	*
	* By default, `condensedHeaderHeight` is 1/3 of `headerHeight` unless
	* this is specified.
	*/
	condensedHeaderHeight: {
	type: Number,
	value: 0
	},

	/**
	* By default, the top part of the header stays when the header is being
	* condensed. Set this to true if you want the top part of the header
	* to be scrolled away.
	*/
	scrollAwayTopbar: {
	type: Boolean,
	value: false
	},

	_headerMargin: {
	type: Number
	},

	_prevScrollTop: {
	type: Number
	},

	_y: {
	type: Number
	}

	},

	observers: [
	'_setup(_headerMargin, headerHeight, fixed)',
	'_headerHeightChanged(headerHeight, condensedHeaderHeight)',
	'_condensedHeaderHeightChanged(headerHeight, condensedHeaderHeight)'
	],

	listeners: {
	'iron-resize': 'measureHeaderHeight'
	},

	ready: function() {
	this.async(this.measureHeaderHeight, 5);
	this._scrollHandler = this._scroll.bind(this);
	this.scroller.addEventListener('scroll', this._scrollHandler);
	},

	detached: function() {
	this.scroller.removeEventListener('scroll', this._scrollHandler);
	},

	/**
	* Returns the header element.
	*
	* @property header
	* @type Object
	*/
	get header() {
	return Polymer.dom(this.$.headerContent).getDistributedNodes()[0];
	},

	/**
	* Returns the content element.
	*
	* @property content
	* @type Object
	*/
	get content() {
	return Polymer.dom(this.$.mainContent).getDistributedNodes()[0];
	},

	/**
	* Returns the scrollable element.
	*
	* @property scroller
	* @type Object
	*/
	get scroller() {
	return this.$.mainContainer;
	},

	/**
	* Invoke this to tell `paper-scroll-header-panel` to re-measure the header's
	* height.
	*
	* @method measureHeaderHeight
	*/
	measureHeaderHeight: function() {
	var header = this.header;
	if (header && header.offsetHeight) {
	this.headerHeight = header.offsetHeight;
	}
	},

	_headerHeightChanged: function() {
	if (!this.condensedHeaderHeight) {
	// assume condensedHeaderHeight is 1/3 of the headerHeight
	this.condensedHeaderHeight = this.headerHeight * 1 / 3;
	}
	},

	_condensedHeaderHeightChanged: function() {
	if (this.headerHeight) {
	this._headerMargin = this.headerHeight - this.condensedHeaderHeight;
	}
	},

	_condensesChanged: function() {
	if (this.condenses) {
	this._scroll();
	} else {
	// reset transform/opacity set on the header
	this._condenseHeader(null);
	}
	},

	_setup: function() {
	var s = this.scroller.style;
	s.paddingTop = this.fixed ? '' : this.headerHeight + 'px';

	s.top = this.fixed ? this.headerHeight + 'px' : '';

	if (this.fixed) {
	this._transformHeader(null);
	} else {
	this._scroll();
	}
	},

	_transformHeader: function(y) {
	var s = this.$.headerContainer.style;
	this._translateY(s, -y);

	if (this.condenses) {
	this._condenseHeader(y);
	}

	this.fire('paper-header-transform', {y: y, height: this.headerHeight,
	condensedHeight: this.condensedHeaderHeight});
	},

	_condenseHeader: function(y) {
	var reset = (y === null);

	// adjust top bar in paper-header so the top bar stays at the top
	if (!this.scrollAwayTopbar && this.header.$ && this.header.$.topBar) {
	this._translateY(this.header.$.topBar.style,
	reset ? null : Math.min(y, this._headerMargin));
	}
	// transition header bg
	var hbg = this.$.headerBg.style;
	if (!this.noDissolve) {
	hbg.opacity = reset ? '' : (this._headerMargin - y) / this._headerMargin;
	}
	// adjust header bg so it stays at the center
	this._translateY(hbg, reset ? null : y / 2);
	// transition condensed header bg
	if (!this.noDissolve) {
	var chbg = this.$.condensedHeaderBg.style;
	chbg = this.$.condensedHeaderBg.style;
	chbg.opacity = reset ? '' : y / this._headerMargin;

	// adjust condensed header bg so it stays at the center
	this._translateY(chbg, reset ? null : y / 2);
	}
	},

	_translateY: function(s, y) {
	var t = (y === null) ? '' : 'translate3d(0, ' + y + 'px, 0)';
	setTransform(s, t);
	},

	/** @param {Event=} event */
	_scroll: function(event) {
	if (!this.header) {
	return;
	}

	var sTop = this.scroller.scrollTop;

	this._y = this._y \|\| 0;
	this._prevScrollTop = this._prevScrollTop \|\| 0;

	var y = Math.min(this.keepCondensedHeader ?
	this._headerMargin : this.headerHeight, Math.max(0,
	(this.noReveal ? sTop : this._y + sTop - this._prevScrollTop)));

	if (this.condenses && this._prevScrollTop >= sTop && sTop > this._headerMargin) {
	y = Math.max(y, this._headerMargin);
	}

	if (!event \|\| !this.fixed && y !== this._y) {
	this._transformHeader(y);
	}

	this._prevScrollTop = Math.max(sTop, 0);
	this._y = y;

	if (event) {
	this.fire('content-scroll', {target: this.scroller}, {cancelable: false});
	}
	}

	});

	//determine proper transform mechanizm
	if (document.documentElement.style.transform !== undefined) {
	var setTransform = function(style, string) {
	style.transform = string;
	}
	} else {
	var setTransform = function(style, string) {
	style.webkitTransform = string;
	}
	}

	})();

	</script>