Mon 21 Jul 22:43:21 CEST 2025

js/dos/web/history.js

@@ -0,0 +1,153 @@
+/* ------------------------------------------------------------------------*
+ * Copyright 2013-2014 Arne F. Claassen
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------*/
+
+var Josh = Josh || {};
+(function (root) {
+  Josh.History = function (config) {
+    config = config || {};
+
+    var _console = Josh.Debug && root.console ? root.console : {log: function() {}};
+    var _history = config.history || [''];
+    var _cursor = config.cursor || 0;
+    var _searchCursor = _cursor;
+    var _lastSearchTerm = '';
+    var _storage = config.storage || root.localStorage;
+    var _key = config.key || 'josh.history';
+
+    if (_storage) {
+      try {
+        var data = _storage.getItem(_key);
+      } catch(e) {
+        _console.log("Error accessing storage");
+      }
+      if (data) {
+        _history = JSON.parse(data);
+        _searchCursor = _cursor = _history.length - 1;
+      } else {
+        save();
+      }
+    }
+    function save() {
+      if (_storage) {
+        try {
+          _storage.setItem(_key, JSON.stringify(_history));
+        } catch(e) {
+          _console.log("Error accessing storage");
+        }
+      }
+    }
+
+    function setHistory() {
+      _searchCursor = _cursor;
+      _lastSearchTerm = '';
+      return _history[_cursor];
+    }
+
+    return {
+      update:function (text) {
+        _console.log("updating history to " + text);
+        _history[_cursor] = text;
+        save();
+      },
+      accept:function (text) {
+        _console.log("accepting history " + text);
+        var last = _history.length - 1;
+        if (text) {
+          if (_cursor == last) {
+            _console.log("we're at the end already, update last position");
+            _history[_cursor] = text;
+          } else if (!_history[last]) {
+            _console.log("we're not at the end, but the end was blank, so update last position");
+            _history[last] = text;
+          } else {
+            _console.log("appending to end");
+            _history.push(text);
+          }
+          _history.push('');
+        }
+        _searchCursor = _cursor = _history.length - 1;
+        save();
+      },
+      items:function () {
+        return _history.slice(0, _history.length - 1);
+      },
+      clear:function () {
+        _history = [_history[_history.length - 1]];
+        save();
+      },
+      hasNext:function () {
+        return _cursor < (_history.length - 1);
+      },
+      hasPrev:function () {
+        return _cursor > 0;
+      },
+      prev:function () {
+        --_cursor;
+        return setHistory();
+      },
+      next:function () {
+        ++_cursor;
+        return setHistory();
+      },
+      top:function () {
+        _cursor = 0;
+        return setHistory();
+      },
+      end:function () {
+        _cursor = _history.length - 1;
+        return setHistory();
+      },
+      search:function (term) {
+        if (!term && !_lastSearchTerm) {
+          return null;
+        }
+        var iterations = _history.length;
+        if (term == _lastSearchTerm) {
+          _searchCursor--;
+          iterations--;
+        }
+        if (!term) {
+          term = _lastSearchTerm;
+        }
+        _lastSearchTerm = term;
+        for (var i = 0; i < iterations; i++) {
+          if (_searchCursor < 0) {
+            _searchCursor = _history.length - 1;
+          }
+          var idx = _history[_searchCursor].indexOf(term);
+          if (idx != -1) {
+            return {
+              text:_history[_searchCursor],
+              cursoridx:idx,
+              term:term
+            };
+          }
+          _searchCursor--;
+        }
+        return null;
+      },
+      applySearch:function () {
+        if (_lastSearchTerm) {
+          _console.log("setting history to position" + _searchCursor + "(" + _cursor + "): " + _history[_searchCursor]);
+          _cursor = _searchCursor;
+          return _history[_cursor];
+        }
+        return null;
+      }
+    };
+  };
+})(this);
+