394 lines
11 KiB
JavaScript

// drag
( function( window, factory ) {
// universal module definition
/* jshint strict: false */
if ( typeof define == 'function' && define.amd ) {
// AMD
define( [
'./flickity',
'unidragger/unidragger',
'fizzy-ui-utils/utils'
], function( Flickity, Unidragger, utils ) {
return factory( window, Flickity, Unidragger, utils );
});
} else if ( typeof module == 'object' && module.exports ) {
// CommonJS
module.exports = factory(
window,
require('./flickity'),
require('unidragger'),
require('fizzy-ui-utils')
);
} else {
// browser global
window.Flickity = factory(
window,
window.Flickity,
window.Unidragger,
window.fizzyUIUtils
);
}
}( window, function factory( window, Flickity, Unidragger, utils ) {
'use strict';
// ----- defaults ----- //
utils.extend( Flickity.defaults, {
draggable: '>1',
dragThreshold: 3,
});
// ----- create ----- //
Flickity.createMethods.push('_createDrag');
// -------------------------- drag prototype -------------------------- //
var proto = Flickity.prototype;
utils.extend( proto, Unidragger.prototype );
proto._touchActionValue = 'pan-y';
// -------------------------- -------------------------- //
var isTouch = 'createTouch' in document;
var isTouchmoveScrollCanceled = false;
proto._createDrag = function() {
this.on( 'activate', this.onActivateDrag );
this.on( 'uiChange', this._uiChangeDrag );
this.on( 'deactivate', this.onDeactivateDrag );
this.on( 'cellChange', this.updateDraggable );
// TODO updateDraggable on resize? if groupCells & slides change
// HACK - add seemingly innocuous handler to fix iOS 10 scroll behavior
// #457, RubaXa/Sortable#973
if ( isTouch && !isTouchmoveScrollCanceled ) {
window.addEventListener( 'touchmove', function() {});
isTouchmoveScrollCanceled = true;
}
};
proto.onActivateDrag = function() {
this.handles = [ this.viewport ];
this.bindHandles();
this.updateDraggable();
};
proto.onDeactivateDrag = function() {
this.unbindHandles();
this.element.classList.remove('is-draggable');
};
proto.updateDraggable = function() {
// disable dragging if less than 2 slides. #278
if ( this.options.draggable == '>1' ) {
this.isDraggable = this.slides.length > 1;
} else {
this.isDraggable = this.options.draggable;
}
if ( this.isDraggable ) {
this.element.classList.add('is-draggable');
} else {
this.element.classList.remove('is-draggable');
}
};
// backwards compatibility
proto.bindDrag = function() {
this.options.draggable = true;
this.updateDraggable();
};
proto.unbindDrag = function() {
this.options.draggable = false;
this.updateDraggable();
};
proto._uiChangeDrag = function() {
delete this.isFreeScrolling;
};
// -------------------------- pointer events -------------------------- //
proto.pointerDown = function( event, pointer ) {
if ( !this.isDraggable ) {
this._pointerDownDefault( event, pointer );
return;
}
var isOkay = this.okayPointerDown( event );
if ( !isOkay ) {
return;
}
this._pointerDownPreventDefault( event );
this.pointerDownFocus( event );
// blur
if ( document.activeElement != this.element ) {
// do not blur if already focused
this.pointerDownBlur();
}
// stop if it was moving
this.dragX = this.x;
this.viewport.classList.add('is-pointer-down');
// track scrolling
this.pointerDownScroll = getScrollPosition();
window.addEventListener( 'scroll', this );
this._pointerDownDefault( event, pointer );
};
// default pointerDown logic, used for staticClick
proto._pointerDownDefault = function( event, pointer ) {
// track start event position
// Safari 9 overrides pageX and pageY. These values needs to be copied. #779
this.pointerDownPointer = {
pageX: pointer.pageX,
pageY: pointer.pageY,
};
// bind move and end events
this._bindPostStartEvents( event );
this.dispatchEvent( 'pointerDown', event, [ pointer ] );
};
var focusNodes = {
INPUT: true,
TEXTAREA: true,
SELECT: true,
};
proto.pointerDownFocus = function( event ) {
var isFocusNode = focusNodes[ event.target.nodeName ];
if ( !isFocusNode ) {
this.focus();
}
};
proto._pointerDownPreventDefault = function( event ) {
var isTouchStart = event.type == 'touchstart';
var isTouchPointer = event.pointerType == 'touch';
var isFocusNode = focusNodes[ event.target.nodeName ];
if ( !isTouchStart && !isTouchPointer && !isFocusNode ) {
event.preventDefault();
}
};
// ----- move ----- //
proto.hasDragStarted = function( moveVector ) {
return Math.abs( moveVector.x ) > this.options.dragThreshold;
};
// ----- up ----- //
proto.pointerUp = function( event, pointer ) {
delete this.isTouchScrolling;
this.viewport.classList.remove('is-pointer-down');
this.dispatchEvent( 'pointerUp', event, [ pointer ] );
this._dragPointerUp( event, pointer );
};
proto.pointerDone = function() {
window.removeEventListener( 'scroll', this );
delete this.pointerDownScroll;
};
// -------------------------- dragging -------------------------- //
proto.dragStart = function( event, pointer ) {
if ( !this.isDraggable ) {
return;
}
this.dragStartPosition = this.x;
this.startAnimation();
window.removeEventListener( 'scroll', this );
this.dispatchEvent( 'dragStart', event, [ pointer ] );
};
proto.pointerMove = function( event, pointer ) {
var moveVector = this._dragPointerMove( event, pointer );
this.dispatchEvent( 'pointerMove', event, [ pointer, moveVector ] );
this._dragMove( event, pointer, moveVector );
};
proto.dragMove = function( event, pointer, moveVector ) {
if ( !this.isDraggable ) {
return;
}
event.preventDefault();
this.previousDragX = this.dragX;
// reverse if right-to-left
var direction = this.options.rightToLeft ? -1 : 1;
if ( this.options.wrapAround ) {
// wrap around move. #589
moveVector.x = moveVector.x % this.slideableWidth;
}
var dragX = this.dragStartPosition + moveVector.x * direction;
if ( !this.options.wrapAround && this.slides.length ) {
// slow drag
var originBound = Math.max( -this.slides[0].target, this.dragStartPosition );
dragX = dragX > originBound ? ( dragX + originBound ) * 0.5 : dragX;
var endBound = Math.min( -this.getLastSlide().target, this.dragStartPosition );
dragX = dragX < endBound ? ( dragX + endBound ) * 0.5 : dragX;
}
this.dragX = dragX;
this.dragMoveTime = new Date();
this.dispatchEvent( 'dragMove', event, [ pointer, moveVector ] );
};
proto.dragEnd = function( event, pointer ) {
if ( !this.isDraggable ) {
return;
}
if ( this.options.freeScroll ) {
this.isFreeScrolling = true;
}
// set selectedIndex based on where flick will end up
var index = this.dragEndRestingSelect();
if ( this.options.freeScroll && !this.options.wrapAround ) {
// if free-scroll & not wrap around
// do not free-scroll if going outside of bounding slides
// so bounding slides can attract slider, and keep it in bounds
var restingX = this.getRestingPosition();
this.isFreeScrolling = -restingX > this.slides[0].target &&
-restingX < this.getLastSlide().target;
} else if ( !this.options.freeScroll && index == this.selectedIndex ) {
// boost selection if selected index has not changed
index += this.dragEndBoostSelect();
}
delete this.previousDragX;
// apply selection
// TODO refactor this, selecting here feels weird
// HACK, set flag so dragging stays in correct direction
this.isDragSelect = this.options.wrapAround;
this.select( index );
delete this.isDragSelect;
this.dispatchEvent( 'dragEnd', event, [ pointer ] );
};
proto.dragEndRestingSelect = function() {
var restingX = this.getRestingPosition();
// how far away from selected slide
var distance = Math.abs( this.getSlideDistance( -restingX, this.selectedIndex ) );
// get closet resting going up and going down
var positiveResting = this._getClosestResting( restingX, distance, 1 );
var negativeResting = this._getClosestResting( restingX, distance, -1 );
// use closer resting for wrap-around
var index = positiveResting.distance < negativeResting.distance ?
positiveResting.index : negativeResting.index;
return index;
};
/**
* given resting X and distance to selected cell
* get the distance and index of the closest cell
* @param {Number} restingX - estimated post-flick resting position
* @param {Number} distance - distance to selected cell
* @param {Integer} increment - +1 or -1, going up or down
* @returns {Object} - { distance: {Number}, index: {Integer} }
*/
proto._getClosestResting = function( restingX, distance, increment ) {
var index = this.selectedIndex;
var minDistance = Infinity;
var condition = this.options.contain && !this.options.wrapAround ?
// if contain, keep going if distance is equal to minDistance
function( d, md ) { return d <= md; } : function( d, md ) { return d < md; };
while ( condition( distance, minDistance ) ) {
// measure distance to next cell
index += increment;
minDistance = distance;
distance = this.getSlideDistance( -restingX, index );
if ( distance === null ) {
break;
}
distance = Math.abs( distance );
}
return {
distance: minDistance,
// selected was previous index
index: index - increment
};
};
/**
* measure distance between x and a slide target
* @param {Number} x
* @param {Integer} index - slide index
*/
proto.getSlideDistance = function( x, index ) {
var len = this.slides.length;
// wrap around if at least 2 slides
var isWrapAround = this.options.wrapAround && len > 1;
var slideIndex = isWrapAround ? utils.modulo( index, len ) : index;
var slide = this.slides[ slideIndex ];
if ( !slide ) {
return null;
}
// add distance for wrap-around slides
var wrap = isWrapAround ? this.slideableWidth * Math.floor( index / len ) : 0;
return x - ( slide.target + wrap );
};
proto.dragEndBoostSelect = function() {
// do not boost if no previousDragX or dragMoveTime
if ( this.previousDragX === undefined || !this.dragMoveTime ||
// or if drag was held for 100 ms
new Date() - this.dragMoveTime > 100 ) {
return 0;
}
var distance = this.getSlideDistance( -this.dragX, this.selectedIndex );
var delta = this.previousDragX - this.dragX;
if ( distance > 0 && delta > 0 ) {
// boost to next if moving towards the right, and positive velocity
return 1;
} else if ( distance < 0 && delta < 0 ) {
// boost to previous if moving towards the left, and negative velocity
return -1;
}
return 0;
};
// ----- staticClick ----- //
proto.staticClick = function( event, pointer ) {
// get clickedCell, if cell was clicked
var clickedCell = this.getParentCell( event.target );
var cellElem = clickedCell && clickedCell.element;
var cellIndex = clickedCell && this.cells.indexOf( clickedCell );
this.dispatchEvent( 'staticClick', event, [ pointer, cellElem, cellIndex ] );
};
// ----- scroll ----- //
proto.onscroll = function() {
var scroll = getScrollPosition();
var scrollMoveX = this.pointerDownScroll.x - scroll.x;
var scrollMoveY = this.pointerDownScroll.y - scroll.y;
// cancel click/tap if scroll is too much
if ( Math.abs( scrollMoveX ) > 3 || Math.abs( scrollMoveY ) > 3 ) {
this._pointerDone();
}
};
// ----- utils ----- //
function getScrollPosition() {
return {
x: window.pageXOffset,
y: window.pageYOffset
};
}
// ----- ----- //
return Flickity;
}));