File yui3/src/scrollview/js/scrollview-base.js
/**
* The scrollview-base module provides a basic ScrollView Widget, without scrollbar indicators
*
* @module scrollview
* @submodule scrollview-base
*/
// Local vars
var getClassName = Y.ClassNameManager.getClassName,
DOCUMENT = Y.config.doc,
IE = Y.UA.ie,
NATIVE_TRANSITIONS = Y.Transition.useNative,
vendorPrefix = Y.Transition._VENDOR_PREFIX, // Todo: This is a private property, and alternative approaches should be investigated
SCROLLVIEW = 'scrollview',
CLASS_NAMES = {
vertical: getClassName(SCROLLVIEW, 'vert'),
horizontal: getClassName(SCROLLVIEW, 'horiz')
},
EV_SCROLL_END = 'scrollEnd',
FLICK = 'flick',
DRAG = 'drag',
MOUSEWHEEL = 'mousewheel',
UI = 'ui',
TOP = 'top',
LEFT = 'left',
PX = 'px',
AXIS = 'axis',
SCROLL_Y = 'scrollY',
SCROLL_X = 'scrollX',
BOUNCE = 'bounce',
DISABLED = 'disabled',
DECELERATION = 'deceleration',
DIM_X = 'x',
DIM_Y = 'y',
BOUNDING_BOX = 'boundingBox',
CONTENT_BOX = 'contentBox',
GESTURE_MOVE = 'gesturemove',
START = 'start',
END = 'end',
EMPTY = '',
ZERO = '0s',
SNAP_DURATION = 'snapDuration',
SNAP_EASING = 'snapEasing',
EASING = 'easing',
FRAME_DURATION = 'frameDuration',
BOUNCE_RANGE = 'bounceRange',
_constrain = function (val, min, max) {
return Math.min(Math.max(val, min), max);
};
/**
* ScrollView provides a scrollable widget, supporting flick gestures,
* across both touch and mouse based devices.
*
* @class ScrollView
* @param config {Object} Object literal with initial attribute values
* @extends Widget
* @constructor
*/
function ScrollView() {
ScrollView.superclass.constructor.apply(this, arguments);
}
Y.ScrollView = Y.extend(ScrollView, Y.Widget, {
// *** Y.ScrollView prototype
/**
* Flag driving whether or not we should try and force H/W acceleration when transforming. Currently enabled by default for Webkit.
* Used by the _transform method.
*
* @property _forceHWTransforms
* @type boolean
* @protected
*/
_forceHWTransforms: Y.UA.webkit ? true : false,
/**
* <p>Used to control whether or not ScrollView's internal
* gesturemovestart, gesturemove and gesturemoveend
* event listeners should preventDefault. The value is an
* object, with "start", "move" and "end" properties used to
* specify which events should preventDefault and which shouldn't:</p>
*
* <pre>
* {
* start: false,
* move: true,
* end: false
* }
* </pre>
*
* <p>The default values are set up in order to prevent panning,
* on touch devices, while allowing click listeners on elements inside
* the ScrollView to be notified as expected.</p>
*
* @property _prevent
* @type Object
* @protected
*/
_prevent: {
start: false,
move: true,
end: false
},
/**
* Contains the distance (postive or negative) in pixels by which
* the scrollview was last scrolled. This is useful when setting up
* click listeners on the scrollview content, which on mouse based
* devices are always fired, even after a drag/flick.
*
* <p>Touch based devices don't currently fire a click event,
* if the finger has been moved (beyond a threshold) so this
* check isn't required, if working in a purely touch based environment</p>
*
* @property lastScrolledAmt
* @type Number
* @public
* @default 0
*/
lastScrolledAmt: 0,
/**
* Internal state, defines the minimum amount that the scrollview can be scrolled along the X axis
*
* @property _minScrollX
* @type number
* @protected
*/
_minScrollX: null,
/**
* Internal state, defines the maximum amount that the scrollview can be scrolled along the X axis
*
* @property _maxScrollX
* @type number
* @protected
*/
_maxScrollX: null,
/**
* Internal state, defines the minimum amount that the scrollview can be scrolled along the Y axis
*
* @property _minScrollY
* @type number
* @protected
*/
_minScrollY: null,
/**
* Internal state, defines the maximum amount that the scrollview can be scrolled along the Y axis
*
* @property _maxScrollY
* @type number
* @protected
*/
_maxScrollY: null,
/**
* Designated initializer
*
* @method initializer
* @param {Object} Configuration object for the plugin
*/
initializer: function () {
var sv = this;
// Cache these values, since they aren't going to change.
sv._bb = sv.get(BOUNDING_BOX);
sv._cb = sv.get(CONTENT_BOX);
// Cache some attributes
sv._cAxis = sv.get(AXIS);
sv._cBounce = sv.get(BOUNCE);
sv._cBounceRange = sv.get(BOUNCE_RANGE);
sv._cDeceleration = sv.get(DECELERATION);
sv._cFrameDuration = sv.get(FRAME_DURATION);
},
/**
* bindUI implementation
*
* Hooks up events for the widget
* @method bindUI
*/
bindUI: function () {
var sv = this;
// Bind interaction listers
sv._bindFlick(sv.get(FLICK));
sv._bindDrag(sv.get(DRAG));
sv._bindMousewheel(true);
// Bind change events
sv._bindAttrs();
// IE SELECT HACK. See if we can do this non-natively and in the gesture for a future release.
if (IE) {
sv._fixIESelect(sv._bb, sv._cb);
}
// Set any deprecated static properties
if (ScrollView.SNAP_DURATION) {
sv.set(SNAP_DURATION, ScrollView.SNAP_DURATION);
}
if (ScrollView.SNAP_EASING) {
sv.set(SNAP_EASING, ScrollView.SNAP_EASING);
}
if (ScrollView.EASING) {
sv.set(EASING, ScrollView.EASING);
}
if (ScrollView.FRAME_STEP) {
sv.set(FRAME_DURATION, ScrollView.FRAME_STEP);
}
if (ScrollView.BOUNCE_RANGE) {
sv.set(BOUNCE_RANGE, ScrollView.BOUNCE_RANGE);
}
// Recalculate dimension properties
// TODO: This should be throttled.
// Y.one(WINDOW).after('resize', sv._afterDimChange, sv);
},
/**
* Bind event listeners
*
* @method _bindAttrs
* @private
*/
_bindAttrs: function () {
var sv = this,
scrollChangeHandler = sv._afterScrollChange,
dimChangeHandler = sv._afterDimChange;
// Bind any change event listeners
sv.after({
'scrollEnd': sv._afterScrollEnd,
'disabledChange': sv._afterDisabledChange,
'flickChange': sv._afterFlickChange,
'dragChange': sv._afterDragChange,
'axisChange': sv._afterAxisChange,
'scrollYChange': scrollChangeHandler,
'scrollXChange': scrollChangeHandler,
'heightChange': dimChangeHandler,
'widthChange': dimChangeHandler
});
},
/**
* Bind (or unbind) gesture move listeners required for drag support
*
* @method _bindDrag
* @param drag {boolean} If true, the method binds listener to enable
* drag (gesturemovestart). If false, the method unbinds gesturemove
* listeners for drag support.
* @private
*/
_bindDrag: function (drag) {
var sv = this,
bb = sv._bb;
// Unbind any previous 'drag' listeners
bb.detach(DRAG + '|*');
if (drag) {
bb.on(DRAG + '|' + GESTURE_MOVE + START, Y.bind(sv._onGestureMoveStart, sv));
}
},
/**
* Bind (or unbind) flick listeners.
*
* @method _bindFlick
* @param flick {Object|boolean} If truthy, the method binds listeners for
* flick support. If false, the method unbinds flick listeners.
* @private
*/
_bindFlick: function (flick) {
var sv = this,
bb = sv._bb;
// Unbind any previous 'flick' listeners
bb.detach(FLICK + '|*');
if (flick) {
bb.on(FLICK + '|' + FLICK, Y.bind(sv._flick, sv), flick);
// Rebind Drag, becuase _onGestureMoveEnd always has to fire -after- _flick
sv._bindDrag(sv.get(DRAG));
}
},
/**
* Bind (or unbind) mousewheel listeners.
*
* @method _bindMousewheel
* @param mousewheel {Object|boolean} If truthy, the method binds listeners for
* mousewheel support. If false, the method unbinds mousewheel listeners.
* @private
*/
_bindMousewheel: function (mousewheel) {
var sv = this,
bb = sv._bb;
// Unbind any previous 'mousewheel' listeners
// TODO: This doesn't actually appear to work properly. Fix. #2532743
bb.detach(MOUSEWHEEL + '|*');
// Only enable for vertical scrollviews
if (mousewheel) {
// Bound to document, because that's where mousewheel events fire off of.
Y.one(DOCUMENT).on(MOUSEWHEEL, Y.bind(sv._mousewheel, sv));
}
},
/**
* syncUI implementation.
*
* Update the scroll position, based on the current value of scrollX/scrollY.
*
* @method syncUI
*/
syncUI: function () {
var sv = this,
scrollDims = sv._getScrollDims(),
width = scrollDims.offsetWidth,
height = scrollDims.offsetHeight,
scrollWidth = scrollDims.scrollWidth,
scrollHeight = scrollDims.scrollHeight;
// If the axis is undefined, auto-calculate it
if (sv._cAxis === undefined) {
// This should only ever be run once (for now).
// In the future SV might post-load axis changes
sv._cAxis = {
x: (scrollWidth > width),
y: (scrollHeight > height)
};
sv._set(AXIS, sv._cAxis);
}
// get text direction on or inherited by scrollview node
sv.rtl = (sv._cb.getComputedStyle('direction') === 'rtl');
// Cache the disabled value
sv._cDisabled = sv.get(DISABLED);
// Run this to set initial values
sv._uiDimensionsChange();
// If we're out-of-bounds, snap back.
if (sv._isOutOfBounds()) {
sv._snapBack();
}
},
/**
* Utility method to obtain widget dimensions
*
* @method _getScrollDims
* @return {Object} The offsetWidth, offsetHeight, scrollWidth and
* scrollHeight as an array: [offsetWidth, offsetHeight, scrollWidth,
* scrollHeight]
* @private
*/
_getScrollDims: function () {
var sv = this,
cb = sv._cb,
bb = sv._bb,
TRANS = ScrollView._TRANSITION,
// Ideally using CSSMatrix - don't think we have it normalized yet though.
// origX = (new WebKitCSSMatrix(cb.getComputedStyle("transform"))).e,
// origY = (new WebKitCSSMatrix(cb.getComputedStyle("transform"))).f,
origX = sv.get(SCROLL_X),
origY = sv.get(SCROLL_Y),
origHWTransform,
dims;
// TODO: Is this OK? Just in case it's called 'during' a transition.
if (NATIVE_TRANSITIONS) {
cb.setStyle(TRANS.DURATION, ZERO);
cb.setStyle(TRANS.PROPERTY, EMPTY);
}
origHWTransform = sv._forceHWTransforms;
sv._forceHWTransforms = false; // the z translation was causing issues with picking up accurate scrollWidths in Chrome/Mac.
sv._moveTo(cb, 0, 0);
dims = {
'offsetWidth': bb.get('offsetWidth'),
'offsetHeight': bb.get('offsetHeight'),
'scrollWidth': bb.get('scrollWidth'),
'scrollHeight': bb.get('scrollHeight')
};
sv._moveTo(cb, -(origX), -(origY));
sv._forceHWTransforms = origHWTransform;
return dims;
},
/**
* This method gets invoked whenever the height or width attributes change,
* allowing us to determine which scrolling axes need to be enabled.
*
* @method _uiDimensionsChange
* @protected
*/
_uiDimensionsChange: function () {
var sv = this,
bb = sv._bb,
scrollDims = sv._getScrollDims(),
width = scrollDims.offsetWidth,
height = scrollDims.offsetHeight,
scrollWidth = scrollDims.scrollWidth,
scrollHeight = scrollDims.scrollHeight,
rtl = sv.rtl,
svAxis = sv._cAxis,
minScrollX = (rtl ? Math.min(0, -(scrollWidth - width)) : 0),
maxScrollX = (rtl ? 0 : Math.max(0, scrollWidth - width)),
minScrollY = 0,
maxScrollY = Math.max(0, scrollHeight - height);
if (svAxis && svAxis.x) {
bb.addClass(CLASS_NAMES.horizontal);
}
if (svAxis && svAxis.y) {
bb.addClass(CLASS_NAMES.vertical);
}
sv._setBounds({
minScrollX: minScrollX,
maxScrollX: maxScrollX,
minScrollY: minScrollY,
maxScrollY: maxScrollY
});
},
/**
* Set the bounding dimensions of the ScrollView
*
* @method _setBounds
* @protected
* @param bounds {Object} [duration] ms of the scroll animation. (default is 0)
* @param {Number} [bounds.minScrollX] The minimum scroll X value
* @param {Number} [bounds.maxScrollX] The maximum scroll X value
* @param {Number} [bounds.minScrollY] The minimum scroll Y value
* @param {Number} [bounds.maxScrollY] The maximum scroll Y value
*/
_setBounds: function (bounds) {
var sv = this;
// TODO: Do a check to log if the bounds are invalid
sv._minScrollX = bounds.minScrollX;
sv._maxScrollX = bounds.maxScrollX;
sv._minScrollY = bounds.minScrollY;
sv._maxScrollY = bounds.maxScrollY;
},
/**
* Get the bounding dimensions of the ScrollView
*
* @method _getBounds
* @protected
*/
_getBounds: function () {
var sv = this;
return {
minScrollX: sv._minScrollX,
maxScrollX: sv._maxScrollX,
minScrollY: sv._minScrollY,
maxScrollY: sv._maxScrollY
};
},
/**
* Scroll the element to a given xy coordinate
*
* @method scrollTo
* @param x {Number} The x-position to scroll to. (null for no movement)
* @param y {Number} The y-position to scroll to. (null for no movement)
* @param {Number} [duration] ms of the scroll animation. (default is 0)
* @param {String} [easing] An easing equation if duration is set. (default is `easing` attribute)
* @param {String} [node] The node to transform. Setting this can be useful in
* dual-axis paginated instances. (default is the instance's contentBox)
*/
scrollTo: function (x, y, duration, easing, node) {
// Check to see if widget is disabled
if (this._cDisabled) {
return;
}
var sv = this,
cb = sv._cb,
TRANS = ScrollView._TRANSITION,
callback = Y.bind(sv._onTransEnd, sv), // @Todo : cache this
newX = 0,
newY = 0,
transition = {},
transform;
// default the optional arguments
duration = duration || 0;
easing = easing || sv.get(EASING); // @TODO: Cache this
node = node || cb;
if (x !== null) {
sv.set(SCROLL_X, x, {src:UI});
newX = -(x);
}
if (y !== null) {
sv.set(SCROLL_Y, y, {src:UI});
newY = -(y);
}
transform = sv._transform(newX, newY);
if (NATIVE_TRANSITIONS) {
// ANDROID WORKAROUND - try and stop existing transition, before kicking off new one.
node.setStyle(TRANS.DURATION, ZERO).setStyle(TRANS.PROPERTY, EMPTY);
}
// Move
if (duration === 0) {
if (NATIVE_TRANSITIONS) {
node.setStyle('transform', transform);
}
else {
// TODO: If both set, batch them in the same update
// Update: Nope, setStyles() just loops through each property and applies it.
if (x !== null) {
node.setStyle(LEFT, newX + PX);
}
if (y !== null) {
node.setStyle(TOP, newY + PX);
}
}
}
// Animate
else {
transition.easing = easing;
transition.duration = duration / 1000;
if (NATIVE_TRANSITIONS) {
transition.transform = transform;
}
else {
transition.left = newX + PX;
transition.top = newY + PX;
}
node.transition(transition, callback);
}
},
/**
* Utility method, to create the translate transform string with the
* x, y translation amounts provided.
*
* @method _transform
* @param {Number} x Number of pixels to translate along the x axis
* @param {Number} y Number of pixels to translate along the y axis
* @private
*/
_transform: function (x, y) {
// TODO: Would we be better off using a Matrix for this?
var prop = 'translate(' + x + 'px, ' + y + 'px)';
if (this._forceHWTransforms) {
prop += ' translateZ(0)';
}
return prop;
},
/**
* Utility method, to move the given element to the given xy position
*
* @method _moveTo
* @param node {Node} The node to move
* @param x {Number} The x-position to move to
* @param y {Number} The y-position to move to
* @private
*/
_moveTo : function(node, x, y) {
if (NATIVE_TRANSITIONS) {
node.setStyle('transform', this._transform(x, y));
} else {
node.setStyle(LEFT, x + PX);
node.setStyle(TOP, y + PX);
}
},
/**
* Content box transition callback
*
* @method _onTransEnd
* @param {EventFacade} e The event facade
* @private
*/
_onTransEnd: function () {
var sv = this;
// If for some reason we're OOB, snapback
if (sv._isOutOfBounds()) {
sv._snapBack();
}
else {
/**
* Notification event fired at the end of a scroll transition
*
* @event scrollEnd
* @param e {EventFacade} The default event facade.
*/
sv.fire(EV_SCROLL_END);
}
},
/**
* gesturemovestart event handler
*
* @method _onGestureMoveStart
* @param e {EventFacade} The gesturemovestart event facade
* @private
*/
_onGestureMoveStart: function (e) {
if (this._cDisabled) {
return false;
}
var sv = this,
bb = sv._bb,
currentX = sv.get(SCROLL_X),
currentY = sv.get(SCROLL_Y),
clientX = e.clientX,
clientY = e.clientY;
if (sv._prevent.start) {
e.preventDefault();
}
// if a flick animation is in progress, cancel it
if (sv._flickAnim) {
sv._cancelFlick();
sv._onTransEnd();
}
// Reset lastScrolledAmt
sv.lastScrolledAmt = 0;
// Stores data for this gesture cycle. Cleaned up later
sv._gesture = {
// Will hold the axis value
axis: null,
// The current attribute values
startX: currentX,
startY: currentY,
// The X/Y coordinates where the event began
startClientX: clientX,
startClientY: clientY,
// The X/Y coordinates where the event will end
endClientX: null,
endClientY: null,
// The current delta of the event
deltaX: null,
deltaY: null,
// Will be populated for flicks
flick: null,
// Create some listeners for the rest of the gesture cycle
onGestureMove: bb.on(DRAG + '|' + GESTURE_MOVE, Y.bind(sv._onGestureMove, sv)),
// @TODO: Don't bind gestureMoveEnd if it's a Flick?
onGestureMoveEnd: bb.on(DRAG + '|' + GESTURE_MOVE + END, Y.bind(sv._onGestureMoveEnd, sv))
};
},
/**
* gesturemove event handler
*
* @method _onGestureMove
* @param e {EventFacade} The gesturemove event facade
* @private
*/
_onGestureMove: function (e) {
var sv = this,
gesture = sv._gesture,
svAxis = sv._cAxis,
svAxisX = svAxis.x,
svAxisY = svAxis.y,
startX = gesture.startX,
startY = gesture.startY,
startClientX = gesture.startClientX,
startClientY = gesture.startClientY,
clientX = e.clientX,
clientY = e.clientY;
if (sv._prevent.move) {
e.preventDefault();
}
gesture.deltaX = startClientX - clientX;
gesture.deltaY = startClientY - clientY;
// Determine if this is a vertical or horizontal movement
// @TODO: This is crude, but it works. Investigate more intelligent ways to detect intent
if (gesture.axis === null) {
gesture.axis = (Math.abs(gesture.deltaX) > Math.abs(gesture.deltaY)) ? DIM_X : DIM_Y;
}
// Move X or Y. @TODO: Move both if dualaxis.
if (gesture.axis === DIM_X && svAxisX) {
sv.set(SCROLL_X, startX + gesture.deltaX);
}
else if (gesture.axis === DIM_Y && svAxisY) {
sv.set(SCROLL_Y, startY + gesture.deltaY);
}
},
/**
* gesturemoveend event handler
*
* @method _onGestureMoveEnd
* @param e {EventFacade} The gesturemoveend event facade
* @private
*/
_onGestureMoveEnd: function (e) {
var sv = this,
gesture = sv._gesture,
flick = gesture.flick,
clientX = e.clientX,
clientY = e.clientY,
isOOB;
if (sv._prevent.end) {
e.preventDefault();
}
// Store the end X/Y coordinates
gesture.endClientX = clientX;
gesture.endClientY = clientY;
// Cleanup the event handlers
gesture.onGestureMove.detach();
gesture.onGestureMoveEnd.detach();
// If this wasn't a flick, wrap up the gesture cycle
if (!flick) {
// @TODO: Be more intelligent about this. Look at the Flick attribute to see
// if it is safe to assume _flick did or didn't fire.
// Then, the order _flick and _onGestureMoveEnd fire doesn't matter?
// If there was movement (_onGestureMove fired)
if (gesture.deltaX !== null && gesture.deltaY !== null) {
isOOB = sv._isOutOfBounds();
// If we're out-out-bounds, then snapback
if (isOOB) {
sv._snapBack();
}
// Inbounds
else {
// Fire scrollEnd unless this is a paginated instance and the gesture axis is the same as paginator's
// Not totally confident this is ideal to access a plugin's properties from a host, @TODO revisit
if (!sv.pages || (sv.pages && !sv.pages.get(AXIS)[gesture.axis])) {
sv._onTransEnd();
}
}
}
}
},
/**
* Execute a flick at the end of a scroll action
*
* @method _flick
* @param e {EventFacade} The Flick event facade
* @private
*/
_flick: function (e) {
if (this._cDisabled) {
return false;
}
var sv = this,
svAxis = sv._cAxis,
flick = e.flick,
flickAxis = flick.axis,
flickVelocity = flick.velocity,
axisAttr = flickAxis === DIM_X ? SCROLL_X : SCROLL_Y,
startPosition = sv.get(axisAttr);
// Sometimes flick is enabled, but drag is disabled
if (sv._gesture) {
sv._gesture.flick = flick;
}
// Prevent unneccesary firing of _flickFrame if we can't scroll on the flick axis
if (svAxis[flickAxis]) {
sv._flickFrame(flickVelocity, flickAxis, startPosition);
}
},
/**
* Execute a single frame in the flick animation
*
* @method _flickFrame
* @param velocity {Number} The velocity of this animated frame
* @param flickAxis {String} The axis on which to animate
* @param startPosition {Number} The starting X/Y point to flick from
* @protected
*/
_flickFrame: function (velocity, flickAxis, startPosition) {
var sv = this,
axisAttr = flickAxis === DIM_X ? SCROLL_X : SCROLL_Y,
bounds = sv._getBounds(),
// Localize cached values
bounce = sv._cBounce,
bounceRange = sv._cBounceRange,
deceleration = sv._cDeceleration,
frameDuration = sv._cFrameDuration,
// Calculate
newVelocity = velocity * deceleration,
newPosition = startPosition - (frameDuration * newVelocity),
// Some convinience conditions
min = flickAxis === DIM_X ? bounds.minScrollX : bounds.minScrollY,
max = flickAxis === DIM_X ? bounds.maxScrollX : bounds.maxScrollY,
belowMin = (newPosition < min),
belowMax = (newPosition < max),
aboveMin = (newPosition > min),
aboveMax = (newPosition > max),
belowMinRange = (newPosition < (min - bounceRange)),
withinMinRange = (belowMin && (newPosition > (min - bounceRange))),
withinMaxRange = (aboveMax && (newPosition < (max + bounceRange))),
aboveMaxRange = (newPosition > (max + bounceRange)),
tooSlow;
// If we're within the range but outside min/max, dampen the velocity
if (withinMinRange || withinMaxRange) {
newVelocity *= bounce;
}
// Is the velocity too slow to bother?
tooSlow = (Math.abs(newVelocity).toFixed(4) < 0.015);
// If the velocity is too slow or we're outside the range
if (tooSlow || belowMinRange || aboveMaxRange) {
// Cancel and delete sv._flickAnim
if (sv._flickAnim) {
sv._cancelFlick();
}
// If we're inside the scroll area, just end
if (aboveMin && belowMax) {
sv._onTransEnd();
}
// We're outside the scroll area, so we need to snap back
else {
sv._snapBack();
}
}
// Otherwise, animate to the next frame
else {
// @TODO: maybe use requestAnimationFrame instead
sv._flickAnim = Y.later(frameDuration, sv, '_flickFrame', [newVelocity, flickAxis, newPosition]);
sv.set(axisAttr, newPosition);
}
},
_cancelFlick: function () {
var sv = this;
if (sv._flickAnim) {
// Cancel the flick (if it exists)
sv._flickAnim.cancel();
// Also delete it, otherwise _onGestureMoveStart will think we're still flicking
delete sv._flickAnim;
}
},
/**
* Handle mousewheel events on the widget
*
* @method _mousewheel
* @param e {EventFacade} The mousewheel event facade
* @private
*/
_mousewheel: function (e) {
var sv = this,
scrollY = sv.get(SCROLL_Y),
bounds = sv._getBounds(),
bb = sv._bb,
scrollOffset = 10, // 10px
isForward = (e.wheelDelta > 0),
scrollToY = scrollY - ((isForward ? 1 : -1) * scrollOffset);
scrollToY = _constrain(scrollToY, bounds.minScrollY, bounds.maxScrollY);
// Because Mousewheel events fire off 'document', every ScrollView widget will react
// to any mousewheel anywhere on the page. This check will ensure that the mouse is currently
// over this specific ScrollView. Also, only allow mousewheel scrolling on Y-axis,
// becuase otherwise the 'prevent' will block page scrolling.
if (bb.contains(e.target) && sv._cAxis[DIM_Y]) {
// Reset lastScrolledAmt
sv.lastScrolledAmt = 0;
// Jump to the new offset
sv.set(SCROLL_Y, scrollToY);
// if we have scrollbars plugin, update & set the flash timer on the scrollbar
// @TODO: This probably shouldn't be in this module
if (sv.scrollbars) {
// @TODO: The scrollbars should handle this themselves
sv.scrollbars._update();
sv.scrollbars.flash();
// or just this
// sv.scrollbars._hostDimensionsChange();
}
// Fire the 'scrollEnd' event
sv._onTransEnd();
// prevent browser default behavior on mouse scroll
e.preventDefault();
}
},
/**
* Checks to see the current scrollX/scrollY position beyond the min/max boundary
*
* @method _isOutOfBounds
* @param x {Number} [optional] The X position to check
* @param y {Number} [optional] The Y position to check
* @return {Boolean} Whether the current X/Y position is out of bounds (true) or not (false)
* @private
*/
_isOutOfBounds: function (x, y) {
var sv = this,
svAxis = sv._cAxis,
svAxisX = svAxis.x,
svAxisY = svAxis.y,
currentX = x || sv.get(SCROLL_X),
currentY = y || sv.get(SCROLL_Y),
bounds = sv._getBounds(),
minX = bounds.minScrollX,
minY = bounds.minScrollY,
maxX = bounds.maxScrollX,
maxY = bounds.maxScrollY;
return (svAxisX && (currentX < minX || currentX > maxX)) || (svAxisY && (currentY < minY || currentY > maxY));
},
/**
* Bounces back
* @TODO: Should be more generalized and support both X and Y detection
*
* @method _snapBack
* @private
*/
_snapBack: function () {
var sv = this,
currentX = sv.get(SCROLL_X),
currentY = sv.get(SCROLL_Y),
bounds = sv._getBounds(),
minX = bounds.minScrollX,
minY = bounds.minScrollY,
maxX = bounds.maxScrollX,
maxY = bounds.maxScrollY,
newY = _constrain(currentY, minY, maxY),
newX = _constrain(currentX, minX, maxX),
duration = sv.get(SNAP_DURATION),
easing = sv.get(SNAP_EASING);
if (newX !== currentX) {
sv.set(SCROLL_X, newX, {duration:duration, easing:easing});
}
else if (newY !== currentY) {
sv.set(SCROLL_Y, newY, {duration:duration, easing:easing});
}
else {
sv._onTransEnd();
}
},
/**
* After listener for changes to the scrollX or scrollY attribute
*
* @method _afterScrollChange
* @param e {EventFacade} The event facade
* @protected
*/
_afterScrollChange: function (e) {
if (e.src === ScrollView.UI_SRC) {
return false;
}
var sv = this,
duration = e.duration,
easing = e.easing,
val = e.newVal,
scrollToArgs = [];
// Set the scrolled value
sv.lastScrolledAmt = sv.lastScrolledAmt + (e.newVal - e.prevVal);
// Generate the array of args to pass to scrollTo()
if (e.attrName === SCROLL_X) {
scrollToArgs.push(val);
scrollToArgs.push(sv.get(SCROLL_Y));
}
else {
scrollToArgs.push(sv.get(SCROLL_X));
scrollToArgs.push(val);
}
scrollToArgs.push(duration);
scrollToArgs.push(easing);
sv.scrollTo.apply(sv, scrollToArgs);
},
/**
* After listener for changes to the flick attribute
*
* @method _afterFlickChange
* @param e {EventFacade} The event facade
* @protected
*/
_afterFlickChange: function (e) {
this._bindFlick(e.newVal);
},
/**
* After listener for changes to the disabled attribute
*
* @method _afterDisabledChange
* @param e {EventFacade} The event facade
* @protected
*/
_afterDisabledChange: function (e) {
// Cache for performance - we check during move
this._cDisabled = e.newVal;
},
/**
* After listener for the axis attribute
*
* @method _afterAxisChange
* @param e {EventFacade} The event facade
* @protected
*/
_afterAxisChange: function (e) {
this._cAxis = e.newVal;
},
/**
* After listener for changes to the drag attribute
*
* @method _afterDragChange
* @param e {EventFacade} The event facade
* @protected
*/
_afterDragChange: function (e) {
this._bindDrag(e.newVal);
},
/**
* After listener for the height or width attribute
*
* @method _afterDimChange
* @param e {EventFacade} The event facade
* @protected
*/
_afterDimChange: function () {
this._uiDimensionsChange();
},
/**
* After listener for scrollEnd, for cleanup
*
* @method _afterScrollEnd
* @param e {EventFacade} The event facade
* @protected
*/
_afterScrollEnd: function () {
var sv = this;
if (sv._flickAnim) {
sv._cancelFlick();
}
// Ideally this should be removed, but doing so causing some JS errors with fast swiping
// because _gesture is being deleted after the previous one has been overwritten
// delete sv._gesture; // TODO: Move to sv.prevGesture?
},
/**
* Setter for 'axis' attribute
*
* @method _axisSetter
* @param val {Mixed} A string ('x', 'y', 'xy') to specify which axis/axes to allow scrolling on
* @param name {String} The attribute name
* @return {Object} An object to specify scrollability on the x & y axes
*
* @protected
*/
_axisSetter: function (val) {
// Turn a string into an axis object
if (Y.Lang.isString(val)) {
return {
x: val.match(/x/i) ? true : false,
y: val.match(/y/i) ? true : false
};
}
},
/**
* The scrollX, scrollY setter implementation
*
* @method _setScroll
* @private
* @param {Number} val
* @param {String} dim
*
* @return {Number} The value
*/
_setScroll : function(val) {
// Just ensure the widget is not disabled
if (this._cDisabled) {
val = Y.Attribute.INVALID_VALUE;
}
return val;
},
/**
* Setter for the scrollX attribute
*
* @method _setScrollX
* @param val {Number} The new scrollX value
* @return {Number} The normalized value
* @protected
*/
_setScrollX: function(val) {
return this._setScroll(val, DIM_X);
},
/**
* Setter for the scrollY ATTR
*
* @method _setScrollY
* @param val {Number} The new scrollY value
* @return {Number} The normalized value
* @protected
*/
_setScrollY: function(val) {
return this._setScroll(val, DIM_Y);
}
// End prototype properties
}, {
// Static properties
/**
* The identity of the widget.
*
* @property NAME
* @type String
* @default 'scrollview'
* @readOnly
* @protected
* @static
*/
NAME: 'scrollview',
/**
* Static property used to define the default attribute configuration of
* the Widget.
*
* @property ATTRS
* @type {Object}
* @protected
* @static
*/
ATTRS: {
/**
* Specifies ability to scroll on x, y, or x and y axis/axes.
*
* @attribute axis
* @type String
*/
axis: {
setter: '_axisSetter',
writeOnce: 'initOnly'
},
/**
* The current scroll position in the x-axis
*
* @attribute scrollX
* @type Number
* @default 0
*/
scrollX: {
value: 0,
setter: '_setScrollX'
},
/**
* The current scroll position in the y-axis
*
* @attribute scrollY
* @type Number
* @default 0
*/
scrollY: {
value: 0,
setter: '_setScrollY'
},
/**
* Drag coefficent for inertial scrolling. The closer to 1 this
* value is, the less friction during scrolling.
*
* @attribute deceleration
* @default 0.93
*/
deceleration: {
value: 0.93
},
/**
* Drag coefficient for intertial scrolling at the upper
* and lower boundaries of the scrollview. Set to 0 to
* disable "rubber-banding".
*
* @attribute bounce
* @type Number
* @default 0.1
*/
bounce: {
value: 0.1
},
/**
* The minimum distance and/or velocity which define a flick. Can be set to false,
* to disable flick support (note: drag support is enabled/disabled separately)
*
* @attribute flick
* @type Object
* @default Object with properties minDistance = 10, minVelocity = 0.3.
*/
flick: {
value: {
minDistance: 10,
minVelocity: 0.3
}
},
/**
* Enable/Disable dragging the ScrollView content (note: flick support is enabled/disabled separately)
* @attribute drag
* @type boolean
* @default true
*/
drag: {
value: true
},
/**
* The default duration to use when animating the bounce snap back.
*
* @attribute snapDuration
* @type Number
* @default 400
*/
snapDuration: {
value: 400
},
/**
* The default easing to use when animating the bounce snap back.
*
* @attribute snapEasing
* @type String
* @default 'ease-out'
*/
snapEasing: {
value: 'ease-out'
},
/**
* The default easing used when animating the flick
*
* @attribute easing
* @type String
* @default 'cubic-bezier(0, 0.1, 0, 1.0)'
*/
easing: {
value: 'cubic-bezier(0, 0.1, 0, 1.0)'
},
/**
* The interval (ms) used when animating the flick for JS-timer animations
*
* @attribute frameDuration
* @type Number
* @default 15
*/
frameDuration: {
value: 15
},
/**
* The default bounce distance in pixels
*
* @attribute bounceRange
* @type Number
* @default 150
*/
bounceRange: {
value: 150
}
},
/**
* List of class names used in the scrollview's DOM
*
* @property CLASS_NAMES
* @type Object
* @static
*/
CLASS_NAMES: CLASS_NAMES,
/**
* Flag used to source property changes initiated from the DOM
*
* @property UI_SRC
* @type String
* @static
* @default 'ui'
*/
UI_SRC: UI,
/**
* Object map of style property names used to set transition properties.
* Defaults to the vendor prefix established by the Transition module.
* The configured property names are `_TRANSITION.DURATION` (e.g. "WebkitTransitionDuration") and
* `_TRANSITION.PROPERTY (e.g. "WebkitTransitionProperty").
*
* @property _TRANSITION
* @private
*/
_TRANSITION: {
DURATION: (vendorPrefix ? vendorPrefix + 'TransitionDuration' : 'transitionDuration'),
PROPERTY: (vendorPrefix ? vendorPrefix + 'TransitionProperty' : 'transitionProperty')
},
/**
* The default bounce distance in pixels
*
* @property BOUNCE_RANGE
* @type Number
* @static
* @default false
* @deprecated (in 3.7.0)
*/
BOUNCE_RANGE: false,
/**
* The interval (ms) used when animating the flick
*
* @property FRAME_STEP
* @type Number
* @static
* @default false
* @deprecated (in 3.7.0)
*/
FRAME_STEP: false,
/**
* The default easing used when animating the flick
*
* @property EASING
* @type String
* @static
* @default false
* @deprecated (in 3.7.0)
*/
EASING: false,
/**
* The default easing to use when animating the bounce snap back.
*
* @property SNAP_EASING
* @type String
* @static
* @default false
* @deprecated (in 3.7.0)
*/
SNAP_EASING: false,
/**
* The default duration to use when animating the bounce snap back.
*
* @property SNAP_DURATION
* @type Number
* @static
* @default false
* @deprecated (in 3.7.0)
*/
SNAP_DURATION: false
// End static properties
});