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/*
* Collapser: Takes two elements and creates a visual "expando:" clicking on one element expands/collapses the other.
* Required properties:
* clicker: The element that will be clicked on.
* content: The element that will expand or collapse as the clicker is clicked on.
* Optional properties:
* isCollapsed: Is the content collapsed. Set to true on serialization (or initialization) to start content in collapsed state.
* Can be manually set as well.
* collapsibleClass: The CSS class to apply to the content and the clicker when collapsed. Defaults to "collapsible-collapsed".
* isAnimated: Set to true to apply a transition to expand/collapse (defaults to false).
* transitionClass: If isAnimated is set to true, the component will apply transitionClass to the content during the
* collapse process. You can then define transitionClass in your style sheet with the desired CSS transitions.
* Defaults to "collapsible-transition".
* contentHeight: If both isAnimated and isCollapsedAtStart are set to true, set contentHeight to the height of the content
* (in pixels, but without the "px") when not collapsed. If this value is not set, the first time the content is expanded
* the transition will not work. Subsequent collapses (and expansions) will transition as expected.
* isLabelClickable: Boolean that indicates whether or not the clicker should have listener events. Defaults to true; set to
* false for collapsers that will only be operated remotely.
* toggle(): Manually toggle the expand/collapse of the content.
*
*/
var Montage = require("montage/core/core").Montage,
Component = require("montage/ui/component").Component,
Collapser = exports.Collapser = Montage.create(Component, {
// This component has no template.
hasTemplate:{
value: false
},
/* === BEGIN: Models === */
// contentHeight: Stores the height of the content just before collapse.
_contentHeight: {
value: 0
},
contentHeight: {
get: function() {
return this._contentHeight;
},
set: function(newVal) {
this._contentHeight = newVal;
}
},
// isCollapsing: true if the collapser is collapsing (or expanding); used in the draw cycle.
_isCollapsing: {
value: false
},
// isAnimated: boolean to apply transition to expand/collapse
_isAnimated : {
value: false
},
isAnimated: {
get: function() {
return this._isAnimated;
},
set: function(newVal) {
this._isAnimated = newVal;
}
},
_bypassAnimation : {
value: false
},
bypassAnimation: {
get: function() {
return this._bypassAnimation;
},
set: function(newVal) {
this._bypassAnimation= newVal;
}
},
// transitionClass: The CSS class to apply to the content during collapse to provide CSS transition.
// Note that this CSS class must be defined in your style sheet with the desired transitions.
_transitionClass : {
value: "collapsible-transition"
},
transitionClass: {
get: function() {
return this._transitionClass;
},
set: function(newVal) {
this._transitionClass = newVal;
}
},
// isCollapsed: is the content actually collapsed at this moment
_isCollapsed: {
value: ""
},
isCollapsed : {
get: function() {
return this._isCollapsed;
},
set: function(newVal) {
if (newVal !== this._isCollapsed) {
this._isCollapsed = newVal;
this.needsDraw = true;
}
}
},
// collapsedClass: the class to apply to the clicker and content when the content is collapsed.
_collapsedClass : {
value: "collapsible-collapsed"
},
collapsedClass: {
get: function() {
return this._collapsedClass;
},
set: function(newVal) {
this._collapsedClass = newVal;
}
},
// _origOverflowValue: Stores the original overflow value of the collapsible element.
// Why store the value? While the collapsible element is collapsed, obviously we will need overflow: hidden.
// But when the collapsible element is open, we will need overflow to return to its original value.
_origOverflowValue : {
value: false
},
// isLabelClickable: Boolean for whether or not the label is clickable. If set to false,
// the label click listener is never applied. For collapsibles that will only be operated remotely.
// Defaults to true.
_isLabelClickable : {
value: true
},
isLabelClickable : {
get: function() {
return this._isLabelClickable;
},
set: function(newVal) {
this._isLabelClickable = newVal;
}
},
// labelClickEvent: an event to fire when the label is clicked.
_labelClickEvent: {
value: false
},
labelClickEvent: {
get: function() {
return this._labelClickEvent;
},
set: function(newVal) {
this._labelClickEvent = newVal;
}
},
// toggle: manually toggle the collapser.
toggle: {
value: function() {
if (this.bypassAnimation) {
this.isAnimated = false;
}
this.myContent.classList.remove(this.transitionClass);
this.handleCollapserLabelClick();
}
},
/* === END: Models === */
/* === BEGIN: Draw cycle === */
prepareForDraw: {
value: function() {
// Add a click listener to the label for expand/collapse
if (this.isLabelClickable) {
this.clicker.identifier = "collapserLabel";
this.clicker.addEventListener("click", this, false);
}
// Get the original value of the overflow property:
this._origOverflowValue = window.getComputedStyle(this.myContent, null).getPropertyValue("overflow");
// If the content area is supposed to start out collapsed:
if (this.isCollapsed) {
this.myContent.style.height = "0px";
// Set the overflow to hidden if it's not already
if (this._origOverflowValue !== "hidden") {
this.myContent.style.overflow = "hidden";
}
this.myContent.classList.add(this.collapsedClass);
this.clicker.classList.add(this.collapsedClass);
} else {
this.myContent.style.height = "auto";
this.myContent.classList.remove(this.collapsedClass);
this.clicker.classList.remove(this.collapsedClass);
}
}
},
draw: {
value: function() {
// Is the content area expanding/collapsing?
this.myContent.classList.remove(this.transitionClass);
if (this._isCollapsing) {
if (this.isAnimated) {
// Apply the transition class to the content.
this.myContent.classList.add(this.transitionClass);
// Add a handler for the end of the transition, so we can tidy things up after
// the transition completes
this.myContent.addEventListener("webkitTransitionEnd", this, false);
this.myContent.style.overflow = "hidden";
}
// Next, are we expanding or collapsing?
if (this.myContent.classList.contains(this.collapsedClass)) {
// It's already collapsed so we are expanding
this.myContent.style.height = this.contentHeight + "px";
this.isCollapsed = false;
} else {
// It's expanded so we are collapsing
this.myContent.style.height = "0px";
this.isCollapsed = true;
// Set the overflow to hidden if it isn't already
if (this._origOverflowValue !== "hidden") {
this.myContent.style.overflow = "hidden";
}
}
// Toggle the CSS class and deactivate the collapsing flag because we are now done.
this.myContent.classList.toggle(this.collapsedClass);
this.clicker.classList.toggle(this.collapsedClass);
this._isCollapsing = false;
// Special cases: If transition does not happen (in the case of a contentHeight of 0
// or isAnimated = false) we need to manually fire it here to do the cleanup.
if ((this.contentHeight < 3) || (!this.isAnimated)) {
this.handleWebkitTransitionEnd();
}
}
}
},
/* === END: Draw cycle === */
/* === BEGIN: Event handlers === */
// Handle a click on the label
handleCollapserLabelClick: {
value: function() {
// The user has clicked on one of the expandos. What should we do?
// First, are we expanding or collapsing?
if (!this.myContent.classList.contains(this.collapsedClass)) {
// We are collapsing!
// Save the current height of the content.
this.contentHeight = this.myContent.offsetHeight;
// Set the current height of the content to a pixel height instead of "auto"
// so that the transition can happen.
// (This doesn't actually change the appearance of the element,
// so it's okay to do here, outside the draw cycle.)
this.myContent.style.height = this.contentHeight + "px";
this.isCollapsed = true;
} else {
this.isCollapsed = false;
}
// Set the collapsing flag so when the draw cycle begins
// it will know to expand/collapse.
this._isCollapsing = true;
// Set the component to run its draw cycle.
this.needsDraw = true;
// Dispatch my labelClick event
if (this.labelClickEvent) {
this.labelClickEvent(this.bypassAnimation);
}
}
},
// This handler is bound to the transitionEnd event. If transitions
// are disabled, it is called manually.
handleWebkitTransitionEnd: {
value: function(event) {
// Are we animating the transitions?
if (this.isAnimated) {
// Yes, transitions are animated.
// Remove the event listener so it won't fire again.
this.myContent.removeEventListener("webkitTransitionEnd", this, false);
// remove the CSS class that supplies the transition
this.myContent.classList.remove(this.transitionClass);
}
// Set the height of the content area to auto; this way it can expand/collapse as interactions
// happen within.
if (!this.myContent.classList.contains(this.collapsedClass)) {
this.myContent.style.height = "auto";
// Return the overflow to its original value if it wasn't hidden
if (this._origOverflowValue !== "hidden") {
this.myContent.style.overflow = this._origOverflowValue;
}
}
if (this.bypassAnimation) {
this.bypassAnimation = false;
this.isAnimated = true;
}
}
}
/* === END: Event handlers === */
});
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