DevTools: [Documentation] Add property token autodetection

Source/devtools/front_end/documentation/DocumentationView.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  * @extends {WebInspector.VBox}
  */
 WebInspector.DocumentationView = function()
 {
@@ skipping 27 matching lines @@
     /**
      * @param {!Event} event
      * @param {!WebInspector.ContextMenu} contextMenu
      * @param {!Object} target
      */
     appendApplicableItems: function(event, contextMenu, target)
     {
         if (!(target instanceof WebInspector.CodeMirrorTextEditor))
             return;
         var textEditor = /** @type {!WebInspector.CodeMirrorTextEditor} */ (target);
-        var selection = textEditor.selection();
-        if (!selection || selection.isEmpty() || selection.startLine !== selection.endLine)
-            return;
-        var selectedText = textEditor.copyRange(selection);
         var urlProvider = new WebInspector.DocumentationURLProvider();
-        var descriptors = urlProvider.itemDescriptors(selectedText);
+        var propertyName;

[apavlov, 2014/08/14 13:44:56]

The new code should now become a new method due to the increased complexity...

[semeny, 2014/08/14 14:23:11]

Done.

+        var descriptors;
+        var textSelection = textEditor.selection().normalize();
+
+        if (!textSelection.isEmpty() && textSelection.startLine === textSelection.endLine) {

[apavlov, 2014/08/14 13:44:55]

Add
if (textSelection.startLine !== textSelection.endLine)
    return;
before this "if" and remove that check here (we don't want to handle multi-line
selections, right?)

[semeny, 2014/08/14 14:23:11]

Done.

+            propertyName = textEditor.copyRange(textSelection);
+        } else {
+            var token = textEditor.tokenAtTextPosition(textSelection.startLine, textSelection.startColumn);
+            var line = textEditor.line(textSelection.startLine);
+            if (token) {
+                var tokenText = line.substring(token.startColumn, token.endColumn);
+                descriptors = urlProvider.itemDescriptors(tokenText);
+            }
+            if (!token || !descriptors.length) {
+                token = textEditor.tokenAtTextPosition(textSelection.startLine, textSelection.startColumn - 1);
+                if (!token)
+                    return;
+            }
+            propertyName = line.substring(token.startColumn, token.endColumn);
+        }
+        if (!descriptors || !descriptors.length)
+            descriptors = urlProvider.itemDescriptors(propertyName);

[apavlov, 2014/08/14 13:44:55]

Assuming the new code is inside a new method, let's extract an inner function to
determine the descriptors given a token range?

if (!textSelection.isEmpty() && ..)
    return urlProvider.itemDescriptors(textEditor.copyRange(textSelection));

var descriptors = computeDescriptors(textSelection.startColumn);
if (!descriptors.length && textSelection.startColumn > 0)
    descriptors = computeDescriptors(textSelection.startColumn - 1);

if (!descriptors.length)
    return;

... and so on ...


function computeDescriptors(column)
{
    var token = textEditor.tokenAtTextPosition(textSelection.startLine, column);
    if (!token)
        return [];
    var tokenText =
textEditor.line(textSelection.startLine).substring(token.startColumn,
token.endColumn);
    return urlProvider.itemDescriptors(tokenText);
}

[semeny, 2014/08/14 14:23:11]

Done.

         if (!descriptors.length)
             return;
         if (descriptors.length === 1) {
             var formatString = WebInspector.useLowerCaseMenuTitles() ? "Show documentation for %s.%s" : "Show Documentation for %s.%s";
-            contextMenu.appendItem(WebInspector.UIString(formatString, descriptors[0].name, selectedText), WebInspector.DocumentationView.showDocumentationURL.bind(null, descriptors[0].url));
+            contextMenu.appendItem(WebInspector.UIString(formatString, descriptors[0].name, propertyName), WebInspector.DocumentationView.showDocumentationURL.bind(null, descriptors[0].url));
             return;
         }
         var subMenuItem = contextMenu.appendSubMenuItem(WebInspector.UIString(WebInspector.useLowerCaseMenuTitles() ? "Show documentation for..." : "Show Documentation for..."));
         for (var i = 0; i < descriptors.length; ++i)
-            subMenuItem.appendItem(String.sprintf("%s.%s", descriptors[i].name, selectedText), WebInspector.DocumentationView.showDocumentationURL.bind(null, descriptors[i].url));
+            subMenuItem.appendItem(String.sprintf("%s.%s", descriptors[i].name, propertyName), WebInspector.DocumentationView.showDocumentationURL.bind(null, descriptors[i].url));
     }
 }