Add ability to use git branch -d.

index.html

@@ -42,6 +42,7 @@ <h4>&nbsp;</h4>
     <div class="twocol">
       <h4>Undo/Delete</h4>
       <a id="open-reset" class="openswitch" href="#">git reset</a>
+      <a id="open-branch-d" class="openswitch" href="#">git branch -d</a>
     </div>
     <div class="twocol">
       <h4>Combine Branches</h4>
@@ -123,6 +124,14 @@ <h4>Interacting with Remote Server</h4>
         the command <span class="cmd">git clean -df</span>.
       </p>
     </div>
+    <div id="ExplainGitBranch-d-Container" class="twelvecol concept-container">
+      <p>
+        <span class="cmd">git branch -d</span> is used to delete branches.
+        I have pre-created a bunch of branches for you to delete in the playground below.
+        Have at it.
+      </p>
+    </div>
+    </div>
     <div id="ExplainGitMerge-Container" class="twelvecol concept-container">
       <p>
         <span class="cmd">git merge</span> will create a new commit with two parents. The resulting
@@ -253,6 +262,37 @@ <h4>Interacting with Remote Server</h4>
 });
 </script>
 
+<script type="text/javascript">
+require(['explaingit'], function (explainGit) {
+    var openSwitch = document.getElementById('open-branch-d'),
+		open;
+
+    open = function () {
+		explainGit.reset();
+
+		explainGit.open({
+			name: 'Branch-d',
+			height: 500,
+			commitData: [
+				{id: '98ca9b5', tags: ['origin/master']},
+				{id: '77oa0ph', parent: '98ca9b5'},
+                {id: 'cj5mlg3', parent: '77oa0ph', tags: ['master']},
+                {id: '4gc3uuf', parent: '98ca9b5', tags: ['protoss']},
+                {id: 'def6ayi', parent: '77oa0ph'},
+				{id: 'amcqj4r', parent: 'def6ayi', tags: ['zerg']},
+                {id: 'a21i3m6', parent: '77oa0ph'},
+                {id: 'y73kv3k', parent: 'a21i3m6', tags: ['terran']}
+			],
+            currentBranch: 'terran',
+			initialMessage:
+				'Delete some branches.'
+		});
+    };
+
+    openSwitch.addEventListener('click', open, false);
+});
+</script>
+
 <script type="text/javascript">
 require(['explaingit'], function (explainGit) {
     var openSwitch = document.getElementById('open-merge'),

js/controlbox.js

@@ -168,6 +168,10 @@ define(['d3'], function () {
 					);
 					args.length = 0;
 					break;
+                case '-d':
+                    var name = args.pop();
+                    this.historyView.deleteBranch(name);
+                    break;
 				default:
 					var remainingArgs = [arg].concat(args);
 					args.length = 0;

js/historyview.js

@@ -580,6 +580,8 @@ define(['d3'], function () {
             existingTags = this.svg.selectAll('g.branch-tag')
                 .data(tagData, function (d) { return d.name; });
 
+            existingTags.exit().remove();
+
             existingTags.select('rect')
                 .transition()
                 .duration(500)
@@ -737,6 +739,35 @@ define(['d3'], function () {
             return this;
         },
 
+        deleteBranch: function (name) {
+            var branchIndex,
+                commit;
+
+            if (!name || name.trim() === '') {
+                throw new Error('You need to give a branch name.');
+            }
+
+            if (name === this.currentBranch) {
+                throw new Error('Cannot delete the currently checked-out branch.');
+            }
+
+            branchIndex = this.branches.indexOf(name);
+
+            if (branchIndex === -1) {
+                throw new Error('That branch doesn\'t exist.');
+            }
+
+            this.branches.splice(branchIndex, 1);
+            commit = this.getCommit(name);
+            branchIndex = commit.tags.indexOf(name);
+
+            if (branchIndex > -1) {
+                commit.tags.splice(branchIndex, 1);
+            }
+
+            this._renderTags();
+        },
+
         checkout: function (ref) {
             var commit = this.getCommit(ref);