Folding and scope tree support for sections

src/gwt/acesupport/acemode/r_code_model.js

@@ -278,7 +278,18 @@ var RCodeModel = function(doc, tokenizer, statePattern) {
          //console.log("                                 Token: " + tokenCursor.currentValue() + " [" + tokenCursor.currentPosition().row + "x" + tokenCursor.currentPosition().column + "]");
 
          var tokenType = tokenCursor.currentToken().type;
-         if (/\bcodebegin\b/.test(tokenType))
+         if (/\bsectionhead\b/.test(tokenType))
+         {
+            var sectionHeadMatch = /^#+'?[-=#\s]*(.*?)\s*[-=#]+\s*$/.exec(
+                  tokenCursor.currentValue());
+
+            var label = "Section: " + sectionHeadMatch[1];
+            if (label.length > 50)
+               label = label.substring(0, 50) + "...";
+
+            this.$scopes.onSectionHead(label, tokenCursor.currentPosition());
+         }
+         else if (/\bcodebegin\b/.test(tokenType))
          {
             var chunkStartPos = tokenCursor.currentPosition();
             var chunkPos = {row: chunkStartPos.row + 1, column: 0};
@@ -348,6 +359,9 @@ var RCodeModel = function(doc, tokenizer, statePattern) {
 
       var rowTokens = this.$tokens[row];
 
+      if (rowTokens.length == 1 && /\bsectionhead\b/.test(rowTokens[0].type))
+         return rowTokens[0];
+
       var depth = 0;
       var unmatchedOpen = null;
       var unmatchedClose = null;
@@ -404,6 +418,8 @@ var RCodeModel = function(doc, tokenizer, statePattern) {
          return "start";
       else if (/\bcodeend\b/.test(foldToken.type))
          return "end";
+      else if (/\bsectionhead\b/.test(foldToken.type))
+         return "start";
 
       return "";
    };
@@ -457,6 +473,25 @@ var RCodeModel = function(doc, tokenizer, statePattern) {
          }
          return;
       }
+      else if (/\bsectionhead\b/.test(foldToken.type)) {
+         var match = /([-=#])\1+\s*$/.exec(foldToken.value);
+         if (!match)
+            return;  // this would be surprising
+
+         pos.column += match.index - 1; // Not actually sure why -1 is needed
+         var tokenIterator3 = new TokenIterator(session, row, 0);
+         var lastRow = row;
+         for (var tok3; tok3 = tokenIterator3.stepForward(); ) {
+            if (/\bsectionhead\b/.test(tok3.type)) {
+               break;
+            }
+            lastRow = tokenIterator3.getCurrentTokenRow();
+         }
+
+         return Range.fromPoints(
+               pos,
+               {row: lastRow, column: session.getLine(lastRow).length});
+      }
 
       return;
    };
@@ -470,7 +505,7 @@ var RCodeModel = function(doc, tokenizer, statePattern) {
          return "";
       this.$buildScopeTreeUpToRow(position.row);
 
-      var scopePath = this.$scopes.findScope(position);
+      var scopePath = this.$scopes.getActiveScopes(position);
       if (scopePath)
       {
          for (var i = scopePath.length-1; i >= 0; i--) {
@@ -1009,6 +1044,9 @@ var RCodeModel = function(doc, tokenizer, statePattern) {
       if (/\bcode(?:begin|end)\b/.test(token.type))
          return false;
 
+      if (/\bsectionhead\b/.test(token.type))
+         return false;
+
       return /^\s*$/.test(token.value) ||
              token.type.match(/\b(?:ace_virtual-)?comment\b/);
    }

src/gwt/acesupport/acemode/r_highlight_rules.js

@@ -42,6 +42,11 @@ define("mode/r_highlight_rules", function(require, exports, module)
 
       this.$rules = {
          "start" : [
+            {
+               // Roxygen
+               token : "comment.sectionhead",
+               regex : "#+(?!').*(?:----|====|####)\\s*$"
+            },
             {
                // Roxygen
                token : "comment",

src/gwt/acesupport/acemode/r_scope_tree.js

@@ -41,6 +41,18 @@ define('mode/r_scope_tree', function(require, exports, module) {
 
    (function() {
 
+      this.onSectionHead = function(sectionLabel, sectionPos) {
+         var existingScopes = this.getActiveScopes(sectionPos);
+         if (existingScopes.length == 2 && existingScopes[1].isSection()) {
+            this.$root.closeScope(sectionPos, ScopeNode.TYPE_SECTION);
+         }
+         else if (existingScopes.length != 1)
+            return;
+
+         this.$root.addNode(new ScopeNode(sectionLabel, sectionPos, sectionPos,
+                                          ScopeNode.TYPE_SECTION));
+      };
+
       this.onChunkStart = function(chunkLabel, label, chunkStartPos, chunkPos) {
          // Starting a chunk means closing the previous chunk, if any
          var prev = this.$root.closeScope(chunkStartPos, ScopeNode.TYPE_CHUNK);
@@ -89,7 +101,7 @@ define('mode/r_scope_tree', function(require, exports, module) {
          return closed;
       };
 
-      this.findScope = function(pos) {
+      this.getActiveScopes = function(pos) {
          return this.$root.findNode(pos);
       };
 
@@ -144,12 +156,14 @@ define('mode/r_scope_tree', function(require, exports, module) {
    ScopeNode.TYPE_ROOT = 1; // document root
    ScopeNode.TYPE_BRACE = 2; // curly brace
    ScopeNode.TYPE_CHUNK = 3; // Sweave chunk
+   ScopeNode.TYPE_SECTION = 4; // Section header
 
    (function() {
 
       this.isRoot = function() { return this.scopeType == ScopeNode.TYPE_ROOT; };
       this.isBrace = function() { return this.scopeType == ScopeNode.TYPE_BRACE; };
       this.isChunk = function() { return this.scopeType == ScopeNode.TYPE_CHUNK; };
+      this.isSection = function() { return this.scopeType == ScopeNode.TYPE_SECTION; };
 
       this.addNode = function(node) {
          assert(!node.end, "New node is already closed");

src/gwt/src/org/rstudio/studio/client/workbench/views/source/editors/text/Scope.java

@@ -37,6 +37,10 @@ public native final boolean isChunk() /*-{
       return this.isChunk();
    }-*/;
 
+   public native final boolean isSection() /*-{
+      return this.isSection();
+   }-*/;
+
    public native final Position getPreamble() /*-{
       return this.preamble;
    }-*/;

src/gwt/src/org/rstudio/studio/client/workbench/views/source/editors/text/TextEditingTarget.java

@@ -660,6 +660,8 @@ public void execute()
                                   (fileType_.isRnw() && function.isTopLevel());
                      if (useChunk)
                         statusBar_.setScopeType(StatusBar.SCOPE_CHUNK);
+                     else if (function.isSection())
+                        statusBar_.setScopeType(StatusBar.SCOPE_SECTION);
                      else
                         statusBar_.setScopeType(StatusBar.SCOPE_FUNCTION);
                   }

src/gwt/src/org/rstudio/studio/client/workbench/views/source/editors/text/status/StatusBar.java

@@ -14,6 +14,7 @@
 
 public interface StatusBar
 {
+   public static final int SCOPE_SECTION = 3;
    public static final int SCOPE_CHUNK = 2;
    public static final int SCOPE_FUNCTION = 1;
 

src/gwt/src/org/rstudio/studio/client/workbench/views/source/editors/text/status/StatusBarWidget.java

@@ -87,6 +87,8 @@ public void setScopeType(int type)
          scopeIcon_.setResource(RES.function());
       else if (type == StatusBar.SCOPE_CHUNK)
          scopeIcon_.setResource(RES.chunk());
+      else if (type == StatusBar.SCOPE_SECTION)
+         scopeIcon_.setResource(RES.section());
    }
 
    @UiField