mediawiki-extensions-Visual.../modules/rangy/rangy-selectionsaverestore.js
Alexandre Emsenhuber bfa0a28968 svn:eol-style native
2012-02-10 16:57:02 +00:00

196 lines
7.4 KiB
JavaScript

/**
* @license Selection save and restore module for Rangy.
* Saves and restores user selections using marker invisible elements in the DOM.
*
* Part of Rangy, a cross-browser JavaScript range and selection library
* http://code.google.com/p/rangy/
*
* Depends on Rangy core.
*
* Copyright 2011, Tim Down
* Licensed under the MIT license.
* Version: 1.2.2
* Build date: 13 November 2011
*/
rangy.createModule("SaveRestore", function(api, module) {
api.requireModules( ["DomUtil", "DomRange", "WrappedRange"] );
var dom = api.dom;
var markerTextChar = "\ufeff";
function gEBI(id, doc) {
return (doc || document).getElementById(id);
}
function insertRangeBoundaryMarker(range, atStart) {
var markerId = "selectionBoundary_" + (+new Date()) + "_" + ("" + Math.random()).slice(2);
var markerEl;
var doc = dom.getDocument(range.startContainer);
// Clone the Range and collapse to the appropriate boundary point
var boundaryRange = range.cloneRange();
boundaryRange.collapse(atStart);
// Create the marker element containing a single invisible character using DOM methods and insert it
markerEl = doc.createElement("span");
markerEl.id = markerId;
markerEl.style.lineHeight = "0";
markerEl.style.display = "none";
markerEl.className = "rangySelectionBoundary";
markerEl.appendChild(doc.createTextNode(markerTextChar));
boundaryRange.insertNode(markerEl);
boundaryRange.detach();
return markerEl;
}
function setRangeBoundary(doc, range, markerId, atStart) {
var markerEl = gEBI(markerId, doc);
if (markerEl) {
range[atStart ? "setStartBefore" : "setEndBefore"](markerEl);
markerEl.parentNode.removeChild(markerEl);
} else {
module.warn("Marker element has been removed. Cannot restore selection.");
}
}
function compareRanges(r1, r2) {
return r2.compareBoundaryPoints(r1.START_TO_START, r1);
}
function saveSelection(win) {
win = win || window;
var doc = win.document;
if (!api.isSelectionValid(win)) {
module.warn("Cannot save selection. This usually happens when the selection is collapsed and the selection document has lost focus.");
return;
}
var sel = api.getSelection(win);
var ranges = sel.getAllRanges();
var rangeInfos = [], startEl, endEl, range;
// Order the ranges by position within the DOM, latest first
ranges.sort(compareRanges);
for (var i = 0, len = ranges.length; i < len; ++i) {
range = ranges[i];
if (range.collapsed) {
endEl = insertRangeBoundaryMarker(range, false);
rangeInfos.push({
markerId: endEl.id,
collapsed: true
});
} else {
endEl = insertRangeBoundaryMarker(range, false);
startEl = insertRangeBoundaryMarker(range, true);
rangeInfos[i] = {
startMarkerId: startEl.id,
endMarkerId: endEl.id,
collapsed: false,
backwards: ranges.length == 1 && sel.isBackwards()
};
}
}
// Now that all the markers are in place and DOM manipulation over, adjust each range's boundaries to lie
// between its markers
for (i = len - 1; i >= 0; --i) {
range = ranges[i];
if (range.collapsed) {
range.collapseBefore(gEBI(rangeInfos[i].markerId, doc));
} else {
range.setEndBefore(gEBI(rangeInfos[i].endMarkerId, doc));
range.setStartAfter(gEBI(rangeInfos[i].startMarkerId, doc));
}
}
// Ensure current selection is unaffected
sel.setRanges(ranges);
return {
win: win,
doc: doc,
rangeInfos: rangeInfos,
restored: false
};
}
function restoreSelection(savedSelection, preserveDirection) {
if (!savedSelection.restored) {
var rangeInfos = savedSelection.rangeInfos;
var sel = api.getSelection(savedSelection.win);
var ranges = [];
// Ranges are in reverse order of appearance in the DOM. We want to restore earliest first to avoid
// normalization affecting previously restored ranges.
for (var len = rangeInfos.length, i = len - 1, rangeInfo, range; i >= 0; --i) {
rangeInfo = rangeInfos[i];
range = api.createRange(savedSelection.doc);
if (rangeInfo.collapsed) {
var markerEl = gEBI(rangeInfo.markerId, savedSelection.doc);
if (markerEl) {
markerEl.style.display = "inline";
var previousNode = markerEl.previousSibling;
// Workaround for issue 17
if (previousNode && previousNode.nodeType == 3) {
markerEl.parentNode.removeChild(markerEl);
range.collapseToPoint(previousNode, previousNode.length);
} else {
range.collapseBefore(markerEl);
markerEl.parentNode.removeChild(markerEl);
}
} else {
module.warn("Marker element has been removed. Cannot restore selection.");
}
} else {
setRangeBoundary(savedSelection.doc, range, rangeInfo.startMarkerId, true);
setRangeBoundary(savedSelection.doc, range, rangeInfo.endMarkerId, false);
}
// Normalizing range boundaries is only viable if the selection contains only one range. For example,
// if the selection contained two ranges that were both contained within the same single text node,
// both would alter the same text node when restoring and break the other range.
if (len == 1) {
range.normalizeBoundaries();
}
ranges[i] = range;
}
if (len == 1 && preserveDirection && api.features.selectionHasExtend && rangeInfos[0].backwards) {
sel.removeAllRanges();
sel.addRange(ranges[0], true);
} else {
sel.setRanges(ranges);
}
savedSelection.restored = true;
}
}
function removeMarkerElement(doc, markerId) {
var markerEl = gEBI(markerId, doc);
if (markerEl) {
markerEl.parentNode.removeChild(markerEl);
}
}
function removeMarkers(savedSelection) {
var rangeInfos = savedSelection.rangeInfos;
for (var i = 0, len = rangeInfos.length, rangeInfo; i < len; ++i) {
rangeInfo = rangeInfos[i];
if (rangeInfo.collapsed) {
removeMarkerElement(savedSelection.doc, rangeInfo.markerId);
} else {
removeMarkerElement(savedSelection.doc, rangeInfo.startMarkerId);
removeMarkerElement(savedSelection.doc, rangeInfo.endMarkerId);
}
}
}
api.saveSelection = saveSelection;
api.restoreSelection = restoreSelection;
api.removeMarkerElement = removeMarkerElement;
api.removeMarkers = removeMarkers;
});