mediawiki-extensions-Visual.../modules/ve/ve.Range.js
Christian Williams 23ac4b79bb Clickable inline images
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Change-Id: I505665f2dac2e52140cc049e63e3355190dcbfec
2013-04-08 17:58:46 -07:00

164 lines
3.8 KiB
JavaScript

/*!
* VisualEditor Range class.
*
* @copyright 2011-2013 VisualEditor Team and others; see AUTHORS.txt
* @license The MIT License (MIT); see LICENSE.txt
*/
/**
* Range.
*
* @class
* @constructor
* @param {number} from Starting offset
* @param {number} [to=from] Ending offset
* @property {number} from Starting offset
* @property {number} to Ending offset
* @property {number} start Starting offset (the lesser of #to and #from)
* @property {number} end Ending offset (the greater of #to and #from)
*/
ve.Range = function VeRange( from, to ) {
this.from = from || 0;
this.to = to === undefined ? this.from : to;
this.start = this.from < this.to ? this.from : this.to;
this.end = this.from < this.to ? this.to : this.from;
};
/* Static Methods */
/**
* Create a new range that's a translated version of another.
*
* @method
* @param {ve.Range} range Range to base new range on
* @param {number} distance Distance to move range by
* @returns {ve.Range} New translated range
*/
ve.Range.newFromTranslatedRange = function ( range, distance ) {
return new ve.Range( range.from + distance, range.to + distance );
};
/**
* Create a range object that covers all of the given ranges.
*
* @method
* @param {Array} ranges Array of ve.Range objects (at least one)
* @param {boolean} backwards Return a backwards range
* @returns {ve.Range} Range that spans all of the given ranges
*/
ve.Range.newCoveringRange = function ( ranges, backwards ) {
var minStart, maxEnd, i, range;
if ( !ranges || ranges.length === 0 ) {
throw new Error( 'newCoveringRange() requires at least one range' );
}
minStart = ranges[0].start;
maxEnd = ranges[0].end;
for ( i = 1; i < ranges.length; i++ ) {
if ( ranges[i].start < minStart ) {
minStart = ranges[i].start;
}
if ( ranges[i].end > maxEnd ) {
maxEnd = ranges[i].end;
}
}
if ( backwards ) {
range = new ve.Range( maxEnd, minStart );
} else {
range = new ve.Range( minStart, maxEnd );
}
return range;
};
/* Methods */
/**
* Get a clone.
*
* @method
* @returns {ve.Range} Clone of range
*/
ve.Range.prototype.clone = function () {
return new ve.Range( this.from, this.to );
};
/**
* Check if an offset is within the range.
*
* @method
* @param {number} offset Offset to check
* @returns {boolean} If offset is within the range
*/
ve.Range.prototype.containsOffset = function ( offset ) {
return offset >= this.start && offset < this.end;
};
/**
* Get the length of the range.
*
* @method
* @returns {number} Length of range
*/
ve.Range.prototype.getLength = function () {
return Math.abs( this.from - this.to );
};
/**
* Gets a range with reversed direction.
*
* @method
*/
ve.Range.prototype.flip = function () {
return new ve.Range( this.to, this.from );
};
/**
* Check if two ranges are equal, taking direction into account.
*
* @method
* @param {ve.Range}
* @returns {boolean}
*/
ve.Range.prototype.equals = function ( other ) {
return this.from === other.from && this.to === other.to;
};
/**
* Create a new range with a limited length.
*
* @method
* @param {number} Length of the new range (negative for left-side truncation)
* @returns {ve.Range} A new range
*/
ve.Range.prototype.truncate = function ( length ) {
if ( length >= 0 ) {
return new ve.Range(
this.start, Math.min( this.start + length, this.end )
);
} else {
return new ve.Range(
Math.max( this.end + length, this.start ), this.end
);
}
};
/**
* Check if the range is collapsed.
*
* A collapsed range has equal start and end values making its length zero.
*
* @method
* @returns {boolean} Range is collapsed
*/
ve.Range.prototype.isCollapsed = function () {
return this.from === this.to;
};
/**
* Check if the range is backwards, i.e. from > to
*
* @method
* @returns {boolean} Range is backwards
*/
ve.Range.prototype.isBackwards = function () {
return this.from > this.to;
};