added AttributeManager, ChangesetUtils

1 files changed, 109 insertions, 0 deletions

diff --git a/src/static/js/AttributeManager.js b/src/static/js/AttributeManager.js
new file mode 100644
index 00000000..5373a41d
--- /dev/null
+++ b/src/static/js/AttributeManager.js
@@ -0,0 +1,109 @@
+var Changeset = require('./Changeset');
+var ChangesetUtils = require('./ChangesetUtils');
+var _ = require('./underscore');
+
+var AttributeManager = function(rep, applyChangesetCallback)
+{
+  this.rep = rep;
+  this.applyChangesetCallback = applyChangesetCallback;
+  this.author = '';
+};
+
+AttributeManager.prototype = _(AttributeManager.prototype).extend({
+  
+  applyChangeset: function(changeset){
+    var cs = changeset.toString();
+    if (!Changeset.isIdentity(cs))
+    {
+      this.applyChangesetCallback(cs);
+    }
+  },
+  
+  lineHasMarker: function(lineNum){
+    // get "list" attribute of first char of line
+    return this.getAttributeOnLine(lineNum, 'list');
+  },
+  
+  getAttributeOnLine: function(lineNum, attributeName){
+    // get  `attributeName` attribute of first char of line
+    var aline = this.rep.alines[lineNum];
+    if (aline)
+    {
+      var opIter = Changeset.opIterator(aline);
+      if (opIter.hasNext())
+      {
+        return Changeset.opAttributeValue(opIter.next(), attributeName, this.rep.apool) || '';
+      }
+    }
+    return '';
+  },
+  
+  /*
+    Sets a specified attribute on a line
+    @param lineNum: the number of the line to set the attribute for
+    @param attributeKey: the name of the attribute to set, e.g. list
+    @param attributeValue: an optional parameter to pass to the attribute (e.g. indention level)
+  
+  */
+  setAttributeOnLine: function(lineNum, attributeName, attributeValue){
+    var loc = [0,0];
+    var builder = Changeset.builder(this.rep.lines.totalWidth());
+    var hasMarker = this.lineHasMarker(lineNum);
+    
+    ChangesetUtils.buildKeepRange(this.rep, builder, loc, (loc = [lineNum, 0]));
+
+    if(hasMarker){
+      ChangesetUtils.buildKeepRange(this.rep, builder, loc, (loc = [lineNum, 1]), [
+        [attributeName, attributeValue]
+      ], this.rep.apool);
+    }else{      
+        // add a line marker
+        builder.insert('*', [
+          ['author', this.author],
+          ['insertorder', 'first'],
+          [attributeName, attributeValue]
+        ], this.rep.apool);
+    }
+    
+    return this.applyChangeset(builder);
+  },
+  
+  /*
+     Removes a specified attribute on a line
+     @param lineNum: the number of the affected line
+     @param attributeKey: the name of the attribute to remove, e.g. list
+
+   */
+   removeAttributeOnLine: function(lineNum, attributeName, attributeValue){
+     
+     var loc = [0,0];
+     var builder = Changeset.builder(this.rep.lines.totalWidth());
+     var hasMarker = this.lineHasMarker(lineNum);
+     
+     // TODO
+     
+     if(hasMarker){
+       ChangesetUtils.buildKeepRange(this.rep, builder, loc, (loc = [lineNum, 0]), [
+         [attributeName, attributeValue]
+       ], this.rep.apool);
+       ChangesetUtils.buildRemoveRange(this.rep, builder, loc, (loc = [lineNum, 1]));
+     }
+     
+     return this.applyChangeset(builder);
+   },
+  
+   /*
+     Sets a specified attribute on a line
+     @param lineNum: the number of the line to set the attribute for
+     @param attributeKey: the name of the attribute to set, e.g. list
+     @param attributeValue: an optional parameter to pass to the attribute (e.g. indention level)
+  */
+  toggleAttributeOnLine: function(lineNum, attributeName, attributeValue) {
+    return this.getAttributeOnLine(attributeName) ?
+      this.removeAttributeOnLine(lineNum, attributeName) :
+      this.setAttributeOnLine(lineNum, attributeName, attributeValue);
+    
+  }
+});
+
+module.exports = AttributeManager;
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