+++ /dev/null
-/**
- * Storage and control for undo information within a CodeMirror
- * editor. 'Why on earth is such a complicated mess required for
- * that?', I hear you ask. The goal, in implementing this, was to make
- * the complexity of storing and reverting undo information depend
- * only on the size of the edited or restored content, not on the size
- * of the whole document. This makes it necessary to use a kind of
- * 'diff' system, which, when applied to a DOM tree, causes some
- * complexity and hackery.
- *
- * In short, the editor 'touches' BR elements as it parses them, and
- * the UndoHistory stores these. When nothing is touched in commitDelay
- * milliseconds, the changes are committed: It goes over all touched
- * nodes, throws out the ones that did not change since last commit or
- * are no longer in the document, and assembles the rest into zero or
- * more 'chains' -- arrays of adjacent lines. Links back to these
- * chains are added to the BR nodes, while the chain that previously
- * spanned these nodes is added to the undo history. Undoing a change
- * means taking such a chain off the undo history, restoring its
- * content (text is saved per line) and linking it back into the
- * document.
- */
-
-// A history object needs to know about the DOM container holding the
-// document, the maximum amount of undo levels it should store, the
-// delay (of no input) after which it commits a set of changes, and,
-// unfortunately, the 'parent' window -- a window that is not in
-// designMode, and on which setTimeout works in every browser.
-function UndoHistory(container, maxDepth, commitDelay, editor) {
- this.container = container;
- this.maxDepth = maxDepth; this.commitDelay = commitDelay;
- this.editor = editor; this.parent = editor.parent;
- // This line object represents the initial, empty editor.
- var initial = {text: "", from: null, to: null};
- // As the borders between lines are represented by BR elements, the
- // start of the first line and the end of the last one are
- // represented by null. Since you can not store any properties
- // (links to line objects) in null, these properties are used in
- // those cases.
- this.first = initial; this.last = initial;
- // Similarly, a 'historyTouched' property is added to the BR in
- // front of lines that have already been touched, and 'firstTouched'
- // is used for the first line.
- this.firstTouched = false;
- // History is the set of committed changes, touched is the set of
- // nodes touched since the last commit.
- this.history = []; this.redoHistory = []; this.touched = [];
-}
-
-UndoHistory.prototype = {
- // Schedule a commit (if no other touches come in for commitDelay
- // milliseconds).
- scheduleCommit: function() {
- var self = this;
- this.parent.clearTimeout(this.commitTimeout);
- this.commitTimeout = this.parent.setTimeout(function(){self.tryCommit();}, this.commitDelay);
- },
-
- // Mark a node as touched. Null is a valid argument.
- touch: function(node) {
- this.setTouched(node);
- this.scheduleCommit();
- },
-
- // Undo the last change.
- undo: function() {
- // Make sure pending changes have been committed.
- this.commit();
-
- if (this.history.length) {
- // Take the top diff from the history, apply it, and store its
- // shadow in the redo history.
- var item = this.history.pop();
- this.redoHistory.push(this.updateTo(item, "applyChain"));
- this.notifyEnvironment();
- return this.chainNode(item);
- }
- },
-
- // Redo the last undone change.
- redo: function() {
- this.commit();
- if (this.redoHistory.length) {
- // The inverse of undo, basically.
- var item = this.redoHistory.pop();
- this.addUndoLevel(this.updateTo(item, "applyChain"));
- this.notifyEnvironment();
- return this.chainNode(item);
- }
- },
-
- clear: function() {
- this.history = [];
- this.redoHistory = [];
- },
-
- // Ask for the size of the un/redo histories.
- historySize: function() {
- return {undo: this.history.length, redo: this.redoHistory.length};
- },
-
- // Push a changeset into the document.
- push: function(from, to, lines) {
- var chain = [];
- for (var i = 0; i < lines.length; i++) {
- var end = (i == lines.length - 1) ? to : this.container.ownerDocument.createElement("BR");
- chain.push({from: from, to: end, text: cleanText(lines[i])});
- from = end;
- }
- this.pushChains([chain], from == null && to == null);
- this.notifyEnvironment();
- },
-
- pushChains: function(chains, doNotHighlight) {
- this.commit(doNotHighlight);
- this.addUndoLevel(this.updateTo(chains, "applyChain"));
- this.redoHistory = [];
- },
-
- // Retrieve a DOM node from a chain (for scrolling to it after undo/redo).
- chainNode: function(chains) {
- for (var i = 0; i < chains.length; i++) {
- var start = chains[i][0], node = start && (start.from || start.to);
- if (node) return node;
- }
- },
-
- // Clear the undo history, make the current document the start
- // position.
- reset: function() {
- this.history = []; this.redoHistory = [];
- },
-
- textAfter: function(br) {
- return this.after(br).text;
- },
-
- nodeAfter: function(br) {
- return this.after(br).to;
- },
-
- nodeBefore: function(br) {
- return this.before(br).from;
- },
-
- // Commit unless there are pending dirty nodes.
- tryCommit: function() {
- if (!window.UndoHistory) return; // Stop when frame has been unloaded
- if (this.editor.highlightDirty()) this.commit(true);
- else this.scheduleCommit();
- },
-
- // Check whether the touched nodes hold any changes, if so, commit
- // them.
- commit: function(doNotHighlight) {
- this.parent.clearTimeout(this.commitTimeout);
- // Make sure there are no pending dirty nodes.
- if (!doNotHighlight) this.editor.highlightDirty(true);
- // Build set of chains.
- var chains = this.touchedChains(), self = this;
-
- if (chains.length) {
- this.addUndoLevel(this.updateTo(chains, "linkChain"));
- this.redoHistory = [];
- this.notifyEnvironment();
- }
- },
-
- // [ end of public interface ]
-
- // Update the document with a given set of chains, return its
- // shadow. updateFunc should be "applyChain" or "linkChain". In the
- // second case, the chains are taken to correspond the the current
- // document, and only the state of the line data is updated. In the
- // first case, the content of the chains is also pushed iinto the
- // document.
- updateTo: function(chains, updateFunc) {
- var shadows = [], dirty = [];
- for (var i = 0; i < chains.length; i++) {
- shadows.push(this.shadowChain(chains[i]));
- dirty.push(this[updateFunc](chains[i]));
- }
- if (updateFunc == "applyChain")
- this.notifyDirty(dirty);
- return shadows;
- },
-
- // Notify the editor that some nodes have changed.
- notifyDirty: function(nodes) {
- forEach(nodes, method(this.editor, "addDirtyNode"))
- this.editor.scheduleHighlight();
- },
-
- notifyEnvironment: function() {
- if (this.onChange) this.onChange();
- // Used by the line-wrapping line-numbering code.
- if (window.frameElement && window.frameElement.CodeMirror.updateNumbers)
- window.frameElement.CodeMirror.updateNumbers();
- },
-
- // Link a chain into the DOM nodes (or the first/last links for null
- // nodes).
- linkChain: function(chain) {
- for (var i = 0; i < chain.length; i++) {
- var line = chain[i];
- if (line.from) line.from.historyAfter = line;
- else this.first = line;
- if (line.to) line.to.historyBefore = line;
- else this.last = line;
- }
- },
-
- // Get the line object after/before a given node.
- after: function(node) {
- return node ? node.historyAfter : this.first;
- },
- before: function(node) {
- return node ? node.historyBefore : this.last;
- },
-
- // Mark a node as touched if it has not already been marked.
- setTouched: function(node) {
- if (node) {
- if (!node.historyTouched) {
- this.touched.push(node);
- node.historyTouched = true;
- }
- }
- else {
- this.firstTouched = true;
- }
- },
-
- // Store a new set of undo info, throw away info if there is more of
- // it than allowed.
- addUndoLevel: function(diffs) {
- this.history.push(diffs);
- if (this.history.length > this.maxDepth)
- this.history.shift();
- },
-
- // Build chains from a set of touched nodes.
- touchedChains: function() {
- var self = this;
-
- // The temp system is a crummy hack to speed up determining
- // whether a (currently touched) node has a line object associated
- // with it. nullTemp is used to store the object for the first
- // line, other nodes get it stored in their historyTemp property.
- var nullTemp = null;
- function temp(node) {return node ? node.historyTemp : nullTemp;}
- function setTemp(node, line) {
- if (node) node.historyTemp = line;
- else nullTemp = line;
- }
-
- function buildLine(node) {
- var text = [];
- for (var cur = node ? node.nextSibling : self.container.firstChild;
- cur && !isBR(cur); cur = cur.nextSibling)
- if (cur.currentText) text.push(cur.currentText);
- return {from: node, to: cur, text: cleanText(text.join(""))};
- }
-
- // Filter out unchanged lines and nodes that are no longer in the
- // document. Build up line objects for remaining nodes.
- var lines = [];
- if (self.firstTouched) self.touched.push(null);
- forEach(self.touched, function(node) {
- if (node && node.parentNode != self.container) return;
-
- if (node) node.historyTouched = false;
- else self.firstTouched = false;
-
- var line = buildLine(node), shadow = self.after(node);
- if (!shadow || shadow.text != line.text || shadow.to != line.to) {
- lines.push(line);
- setTemp(node, line);
- }
- });
-
- // Get the BR element after/before the given node.
- function nextBR(node, dir) {
- var link = dir + "Sibling", search = node[link];
- while (search && !isBR(search))
- search = search[link];
- return search;
- }
-
- // Assemble line objects into chains by scanning the DOM tree
- // around them.
- var chains = []; self.touched = [];
- forEach(lines, function(line) {
- // Note that this makes the loop skip line objects that have
- // been pulled into chains by lines before them.
- if (!temp(line.from)) return;
-
- var chain = [], curNode = line.from, safe = true;
- // Put any line objects (referred to by temp info) before this
- // one on the front of the array.
- while (true) {
- var curLine = temp(curNode);
- if (!curLine) {
- if (safe) break;
- else curLine = buildLine(curNode);
- }
- chain.unshift(curLine);
- setTemp(curNode, null);
- if (!curNode) break;
- safe = self.after(curNode);
- curNode = nextBR(curNode, "previous");
- }
- curNode = line.to; safe = self.before(line.from);
- // Add lines after this one at end of array.
- while (true) {
- if (!curNode) break;
- var curLine = temp(curNode);
- if (!curLine) {
- if (safe) break;
- else curLine = buildLine(curNode);
- }
- chain.push(curLine);
- setTemp(curNode, null);
- safe = self.before(curNode);
- curNode = nextBR(curNode, "next");
- }
- chains.push(chain);
- });
-
- return chains;
- },
-
- // Find the 'shadow' of a given chain by following the links in the
- // DOM nodes at its start and end.
- shadowChain: function(chain) {
- var shadows = [], next = this.after(chain[0].from), end = chain[chain.length - 1].to;
- while (true) {
- shadows.push(next);
- var nextNode = next.to;
- if (!nextNode || nextNode == end)
- break;
- else
- next = nextNode.historyAfter || this.before(end);
- // (The this.before(end) is a hack -- FF sometimes removes
- // properties from BR nodes, in which case the best we can hope
- // for is to not break.)
- }
- return shadows;
- },
-
- // Update the DOM tree to contain the lines specified in a given
- // chain, link this chain into the DOM nodes.
- applyChain: function(chain) {
- // Some attempt is made to prevent the cursor from jumping
- // randomly when an undo or redo happens. It still behaves a bit
- // strange sometimes.
- var cursor = select.cursorPos(this.container, false), self = this;
-
- // Remove all nodes in the DOM tree between from and to (null for
- // start/end of container).
- function removeRange(from, to) {
- var pos = from ? from.nextSibling : self.container.firstChild;
- while (pos != to) {
- var temp = pos.nextSibling;
- removeElement(pos);
- pos = temp;
- }
- }
-
- var start = chain[0].from, end = chain[chain.length - 1].to;
- // Clear the space where this change has to be made.
- removeRange(start, end);
-
- // Insert the content specified by the chain into the DOM tree.
- for (var i = 0; i < chain.length; i++) {
- var line = chain[i];
- // The start and end of the space are already correct, but BR
- // tags inside it have to be put back.
- if (i > 0)
- self.container.insertBefore(line.from, end);
-
- // Add the text.
- var node = makePartSpan(fixSpaces(line.text), this.container.ownerDocument);
- self.container.insertBefore(node, end);
- // See if the cursor was on this line. Put it back, adjusting
- // for changed line length, if it was.
- if (cursor && cursor.node == line.from) {
- var cursordiff = 0;
- var prev = this.after(line.from);
- if (prev && i == chain.length - 1) {
- // Only adjust if the cursor is after the unchanged part of
- // the line.
- for (var match = 0; match < cursor.offset &&
- line.text.charAt(match) == prev.text.charAt(match); match++);
- if (cursor.offset > match)
- cursordiff = line.text.length - prev.text.length;
- }
- select.setCursorPos(this.container, {node: line.from, offset: Math.max(0, cursor.offset + cursordiff)});
- }
- // Cursor was in removed line, this is last new line.
- else if (cursor && (i == chain.length - 1) && cursor.node && cursor.node.parentNode != this.container) {
- select.setCursorPos(this.container, {node: line.from, offset: line.text.length});
- }
- }
-
- // Anchor the chain in the DOM tree.
- this.linkChain(chain);
- return start;
- }
-};
fnp / redakcja.git / blobdiff