Index: Source/devtools/front_end/SimpleHistoryManager.js |
diff --git a/Source/devtools/front_end/SimpleHistoryManager.js b/Source/devtools/front_end/SimpleHistoryManager.js |
new file mode 100644 |
index 0000000000000000000000000000000000000000..5771e7a0e971a68b8d37ebbd34f13eabd6d821a7 |
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+++ b/Source/devtools/front_end/SimpleHistoryManager.js |
@@ -0,0 +1,167 @@ |
+/* |
+ * Copyright (C) 2014 Google Inc. All rights reserved. |
+ * |
+ * Redistribution and use in source and binary forms, with or without |
+ * modification, are permitted provided that the following conditions are |
+ * met: |
+ * |
+ * * Redistributions of source code must retain the above copyright |
+ * notice, this list of conditions and the following disclaimer. |
+ * * Redistributions in binary form must reproduce the above |
+ * copyright notice, this list of conditions and the following disclaimer |
+ * in the documentation and/or other materials provided with the |
+ * distribution. |
+ * * Neither the name of Google Inc. nor the names of its |
+ * contributors may be used to endorse or promote products derived from |
+ * this software without specific prior written permission. |
+ * |
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
+ */ |
+ |
+/** |
+ * @interface |
+ */ |
+WebInspector.HistoryEntry = function() { } |
+ |
+WebInspector.HistoryEntry.prototype = { |
+ /** |
+ * @return {boolean} |
+ */ |
+ valid: function() { }, |
+ |
+ reveal: function() { } |
+}; |
+ |
+/** |
+ * @constructor |
+ * @param {number} historyDepth |
+ */ |
+WebInspector.SimpleHistoryManager = function(historyDepth) |
+{ |
+ this._entries = []; |
+ this._activeEntryIndex = -1; |
+ this._coalescingReadonly = 0; |
+ this._historyDepth = historyDepth; |
+} |
+ |
+WebInspector.SimpleHistoryManager.prototype = { |
+ readOnlyLock: function() |
+ { |
+ ++this._coalescingReadonly; |
+ }, |
+ |
+ releaseReadOnlyLock: function() |
+ { |
+ --this._coalescingReadonly; |
+ }, |
+ |
+ /** |
+ * @return {boolean} |
+ */ |
+ readOnly: function() |
+ { |
+ return !!this._coalescingReadonly; |
+ }, |
+ |
+ /** |
+ * @param {!function(!WebInspector.HistoryEntry):boolean} filterOutCallback |
+ */ |
+ filterOut: function(filterOutCallback) |
+ { |
+ if (this.readOnly()) |
+ return; |
+ var filteredEntries = []; |
+ var removedBeforeActiveEntry = 0; |
+ for (var i = 0; i < this._entries.length; ++i) { |
+ if (!filterOutCallback(this._entries[i])) { |
+ filteredEntries.push(this._entries[i]); |
+ } else if (i <= this._activeEntryIndex) |
+ ++removedBeforeActiveEntry; |
+ } |
+ this._entries = filteredEntries; |
+ this._activeEntryIndex = Math.max(0, this._activeEntryIndex - removedBeforeActiveEntry); |
+ }, |
+ |
+ /** |
+ * @return {boolean} |
+ */ |
+ empty: function() |
+ { |
+ return !this._entries.length; |
+ }, |
+ |
+ /** |
+ * @return {?WebInspector.HistoryEntry} |
+ */ |
+ active: function() |
+ { |
+ return this.empty() ? null : this._entries[this._activeEntryIndex]; |
+ }, |
+ |
+ /** |
+ * @param {!WebInspector.HistoryEntry} entry |
+ */ |
+ push: function(entry) |
+ { |
+ if (this.readOnly()) |
+ return; |
+ if (!this.empty()) |
+ this._entries.splice(this._activeEntryIndex + 1); |
+ this._entries.push(entry); |
+ if (this._entries.length > this._historyDepth) |
+ this._entries.shift(); |
+ this._activeEntryIndex = this._entries.length - 1; |
+ }, |
+ |
+ /** |
+ * @return {boolean} |
+ */ |
+ rollback: function() |
+ { |
+ if (this.empty()) |
+ return false; |
+ |
+ var revealIndex = this._activeEntryIndex - 1; |
+ while (revealIndex >= 0 && !this._entries[revealIndex].valid()) |
+ --revealIndex; |
+ if (revealIndex < 0) |
+ return false; |
+ |
+ this.readOnlyLock(); |
+ this._entries[revealIndex].reveal(); |
+ this.releaseReadOnlyLock(); |
+ |
+ this._activeEntryIndex = revealIndex; |
+ return true; |
+ }, |
+ |
+ /** |
+ * @return {boolean} |
+ */ |
+ rollover: function() |
+ { |
+ var revealIndex = this._activeEntryIndex + 1; |
+ |
+ while (revealIndex < this._entries.length && !this._entries[revealIndex].valid()) |
+ ++revealIndex; |
+ if (revealIndex >= this._entries.length) |
+ return false; |
+ |
+ this.readOnlyLock(); |
+ this._entries[revealIndex].reveal(); |
+ this.releaseReadOnlyLock(); |
+ |
+ this._activeEntryIndex = revealIndex; |
+ return true; |
+ }, |
+}; |