<!--
@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">
<link rel="import" href="../iron-a11y-keys-behavior/iron-a11y-keys-behavior.html">
<link rel="import" href="../iron-behaviors/iron-control-state.html">
<link rel="import" href="../iron-overlay-behavior/iron-overlay-behavior.html">
<link rel="import" href="../neon-animation/neon-animation-runner-behavior.html">
<link rel="import" href="../neon-animation/animations/opaque-animation.html">
<link rel="import" href="iron-dropdown-scroll-manager.html">
<!--
`<iron-dropdown>` is a generalized element that is useful when you have
hidden content (`.dropdown-content`) that is revealed due to some change in
state that should cause it to do so.
Note that this is a low-level element intended to be used as part of other
composite elements that cause dropdowns to be revealed.
Examples of elements that might be implemented using an `iron-dropdown`
include comboboxes, menubuttons, selects. The list goes on.
The `<iron-dropdown>` element exposes attributes that allow the position
of the `.dropdown-content` relative to the `.dropdown-trigger` to be
configured.
<iron-dropdown horizontal-align="right" vertical-align="top">
<div class="dropdown-content">Hello!</div>
</iron-dropdown>
In the above example, the `<div>` with class `.dropdown-content` will be
hidden until the dropdown element has `opened` set to true, or when the `open`
method is called on the element.
@demo demo/index.html
-->
<dom-module id="iron-dropdown">
<style>
:host {
position: fixed;
}
#contentWrapper ::content > * {
overflow: auto;
}
#contentWrapper.animating ::content > * {
overflow: hidden;
}
</style>
<template>
<div id="contentWrapper">
<content id="content" select=".dropdown-content"></content>
</div>
</template>
<script>
(function() {
'use strict';
Polymer({
is: 'iron-dropdown',
behaviors: [
Polymer.IronControlState,
Polymer.IronA11yKeysBehavior,
Polymer.IronOverlayBehavior,
Polymer.NeonAnimationRunnerBehavior
],
properties: {
/**
* The orientation against which to align the dropdown content
* horizontally relative to the dropdown trigger.
* Overridden from `Polymer.IronFitBehavior`.
*/
horizontalAlign: {
type: String,
value: 'left',
reflectToAttribute: true
},
/**
* The orientation against which to align the dropdown content
* vertically relative to the dropdown trigger.
* Overridden from `Polymer.IronFitBehavior`.
*/
verticalAlign: {
type: String,
value: 'top',
reflectToAttribute: true
},
/**
* An animation config. If provided, this will be used to animate the
* opening of the dropdown.
*/
openAnimationConfig: {
type: Object
},
/**
* An animation config. If provided, this will be used to animate the
* closing of the dropdown.
*/
closeAnimationConfig: {
type: Object
},
/**
* If provided, this will be the element that will be focused when
* the dropdown opens.
*/
focusTarget: {
type: Object
},
/**
* Set to true to disable animations when opening and closing the
* dropdown.
*/
noAnimations: {
type: Boolean,
value: false
},
/**
* By default, the dropdown will constrain scrolling on the page
* to itself when opened.
* Set to true in order to prevent scroll from being constrained
* to the dropdown when it opens.
*/
allowOutsideScroll: {
type: Boolean,
value: false
}
},
listeners: {
'neon-animation-finish': '_onNeonAnimationFinish'
},
observers: [
'_updateOverlayPosition(positionTarget, verticalAlign, horizontalAlign, verticalOffset, horizontalOffset)'
],
/**
* The element that is contained by the dropdown, if any.
*/
get containedElement() {
return Polymer.dom(this.$.content).getDistributedNodes()[0];
},
/**
* The element that should be focused when the dropdown opens.
* @deprecated
*/
get _focusTarget() {
return this.focusTarget || this.containedElement;
},
detached: function() {
this.cancelAnimation();
Polymer.IronDropdownScrollManager.removeScrollLock(this);
},
/**
* Called when the value of `opened` changes.
* Overridden from `IronOverlayBehavior`
*/
_openedChanged: function() {
if (this.opened && this.disabled) {
this.cancel();
} else {
this.cancelAnimation();
this.sizingTarget = this.containedElement || this.sizingTarget;
this._updateAnimationConfig();
if (this.opened && !this.allowOutsideScroll) {
Polymer.IronDropdownScrollManager.pushScrollLock(this);
} else {
Polymer.IronDropdownScrollManager.removeScrollLock(this);
}
Polymer.IronOverlayBehaviorImpl._openedChanged.apply(this, arguments);
}
},
/**
* Overridden from `IronOverlayBehavior`.
*/
_renderOpened: function() {
if (!this.noAnimations && this.animationConfig.open) {
this.$.contentWrapper.classList.add('animating');
this.playAnimation('open');
} else {
Polymer.IronOverlayBehaviorImpl._renderOpened.apply(this, arguments);
}
},
/**
* Overridden from `IronOverlayBehavior`.
*/
_renderClosed: function() {
if (!this.noAnimations && this.animationConfig.close) {
this.$.contentWrapper.classList.add('animating');
this.playAnimation('close');
} else {
Polymer.IronOverlayBehaviorImpl._renderClosed.apply(this, arguments);
}
},
/**
* Called when animation finishes on the dropdown (when opening or
* closing). Responsible for "completing" the process of opening or
* closing the dropdown by positioning it or setting its display to
* none.
*/
_onNeonAnimationFinish: function() {
this.$.contentWrapper.classList.remove('animating');
if (this.opened) {
this._finishRenderOpened();
} else {
this._finishRenderClosed();
}
},
/**
* Constructs the final animation config from different properties used
* to configure specific parts of the opening and closing animations.
*/
_updateAnimationConfig: function() {
var animations = (this.openAnimationConfig || []).concat(this.closeAnimationConfig || []);
for (var i = 0; i < animations.length; i++) {
animations[i].node = this.containedElement;
}
this.animationConfig = {
open: this.openAnimationConfig,
close: this.closeAnimationConfig
};
},
/**
* Updates the overlay position based on configured horizontal
* and vertical alignment.
*/
_updateOverlayPosition: function() {
if (this.isAttached) {
// This triggers iron-resize, and iron-overlay-behavior will call refit if needed.
this.notifyResize();
}
},
/**
* Apply focus to focusTarget or containedElement
*/
_applyFocus: function () {
var focusTarget = this.focusTarget || this.containedElement;
if (focusTarget && this.opened && !this.noAutoFocus) {
focusTarget.focus();
} else {
Polymer.IronOverlayBehaviorImpl._applyFocus.apply(this, arguments);
}
}
});
})();
</script>
</dom-module>