Add 'View Selection/MathML Source' to the context menu & the support for that to work, namely: enlist MathML entity names, break viewSource.xul into a sharable XUL overlay, and implement the necessary logic to automatically re-select a selection into the inflated view-source display. b=49721,1222524, r=bzbarsky, sr=alecf

suite/common/contentAreaContextOverlay.xul

@@ -187,6 +187,14 @@
         </menupopup>
       </menu>
       <menuseparator id="context-sep-properties"/>
+      <menuitem id="context-viewpartialsource-selection"
+                label="&viewPartialSourceForSelectionCmd.label;"
+                accesskey="&viewPartialSourceCmd.accesskey;"
+                oncommand="gContextMenu.viewPartialSource('selection');"/>
+      <menuitem id="context-viewpartialsource-mathml"
+                label="&viewPartialSourceForMathMLCmd.label;"
+                accesskey="&viewPartialSourceCmd.accesskey;"
+                oncommand="gContextMenu.viewPartialSource('mathml');"/>
       <menuitem id="context-viewsource"
                 label="&viewPageSourceCmd.label;"
                 accesskey="&viewPageSourceCmd.accesskey;"

suite/common/nsContextMenu.js

@@ -41,6 +41,7 @@ function nsContextMenu( xulMenu ) {
     this.onLink         = false;
     this.onMailtoLink   = false;
     this.onSaveableLink = false;
+    this.onMathML       = false;
     this.link           = false;
     this.inFrame        = false;
     this.hasBGImage     = false;
@@ -116,6 +117,8 @@ nsContextMenu.prototype = {
     },
     initViewItems : function () {
         // View source is always OK, unless in directory listing.
+        this.showItem( "context-viewpartialsource-selection", this.isTextSelected );
+        this.showItem( "context-viewpartialsource-mathml", this.onMathML && !this.isTextSelected );
         this.showItem( "context-viewsource", !( this.inDirList || this.onImage || this.isTextSelected || this.onLink || this.onTextInput ) );
         this.showItem( "context-viewinfo", !( this.inDirList || this.onImage || this.isTextSelected || this.onLink || this.onTextInput ) );
 
@@ -209,12 +212,14 @@ nsContextMenu.prototype = {
         this.onTextInput = false;
         this.imageURL   = "";
         this.onLink     = false;
+        this.onMathML   = false;
         this.inFrame    = false;
         this.hasBGImage = false;
         this.bgImageURL = "";
 
         // Remember the node that was clicked.
         this.target = node;
+
         // See if the user clicked on an image.
         if ( this.target.nodeType == Node.ELEMENT_NODE ) {
              if ( this.target.localName.toUpperCase() == "IMG" ) {
@@ -331,6 +336,13 @@ nsContextMenu.prototype = {
         // We have meta data on images.
         this.onMetaDataItem = this.onImage;
         
+        // See if the user clicked on MathML
+        const NS_MathML = "http://www.w3.org/1998/Math/MathML";
+        if ((this.target.nodeType == Node.TEXT_NODE &&
+               this.target.parentNode.namespaceURI == NS_MathML) 
+             || (this.target.namespaceURI == NS_MathML))   
+          this.onMathML = true;
+
         // See if the user clicked in a frame.
         if ( this.target.ownerDocument != window._content.document ) {
             this.inFrame = true;
@@ -468,6 +480,31 @@ nsContextMenu.prototype = {
     showOnlyThisFrame : function () {
         window._content.location.href = this.target.ownerDocument.location.href;
     },
+    // View Partial Source
+    viewPartialSource : function ( context ) {
+        var focusedWindow = document.commandDispatcher.focusedWindow;
+        if (focusedWindow == window)
+          focusedWindow = _content;
+        var docCharset = null;
+        if (focusedWindow)
+          docCharset = "charset=" + focusedWindow.document.characterSet;
+
+        // "View Selection Source" and others such as "View MathML Source"
+        // are mutually exclusive, with the precedence given to the selection
+        // when there is one
+        var reference = null;
+        if (context == "selection")
+          reference = focusedWindow.getSelection();
+        else if (context == "mathml")
+          reference = this.target;
+        else
+          throw "not reached";
+
+        var docUrl = null; // unused (and play nice for fragments generated via XSLT too)
+        window.openDialog("chrome://navigator/content/viewPartialSource.xul",
+                          "_blank", "scrollbars,resizable,chrome,dialog=no",
+                          docUrl, docCharset, reference, context);
+    },
     // Open new "view source" window with the frame's URL.
     viewFrameSource : function () {
         BrowserViewSourceOfDocument(this.target.ownerDocument);

suite/locales/en-US/chrome/common/contentAreaCommands.dtd

@@ -24,6 +24,9 @@
 <!ENTITY stopCmd.accesskey            "S">
 <!ENTITY reloadFrameCmd.label         "Reload Frame">
 <!ENTITY reloadFrameCmd.accesskey     "r">
+<!ENTITY viewPartialSourceForSelectionCmd.label "View Selection Source">
+<!ENTITY viewPartialSourceForMathMLCmd.label    "View MathML Source">
+<!ENTITY viewPartialSourceCmd.accesskey "e">
 <!ENTITY viewPageSourceCmd.label      "View Page Source">
 <!ENTITY viewPageSourceCmd.accesskey  "v">
 <!ENTITY viewFrameSourceCmd.label     "View Frame Source">