Add util.makeXPath for constructing XPath expressions.

--HG--
extra : transplant_source : G%A7_%1B%9B%7BN%9C%FF%14%A9g%BA%04%99%B3%8B%23%ED%F2

common/content/buffer.js

@@ -336,24 +336,16 @@ function Buffer() //{{{
                 buffer.focusElement(buffer.lastInputField);
             else
             {
-                let elements = [];
+                let xpath = util.makeXPath(["input[not(@type) or @type='text' or @type='password' or @type='file']",
-                let matches = buffer.evaluateXPath(
+                                            "textarea[not(@disabled) and not(@readonly)]"]);
-                    "//input[not(@type) or @type='text' or @type='password' or @type='file'] | //textarea[not(@disabled) and not(@readonly)] |" +
-                    "//xhtml:input[not(@type) or @type='text' or @type='password' or @type='file'] | //xhtml:textarea[not(@disabled) and not(@readonly)]"
-                );
 
-                for (let match in matches)
+                let elements = [m for (m in buffer.evaluateXPath(xpath))].filter(function (match) {
-                {
                     let computedStyle = util.computedStyle(match);
-                    if (computedStyle.visibility != "hidden" && computedStyle.display != "none")
+                    return computedStyle.visibility != "hidden" && computedStyle.display != "none";
-                        elements.push(match);
+                });
-                }
 
                 if (elements.length > 0)
-                {
+                    buffer.focusElement(elements[util.Math.constrain(count, 1, elements.length) - 1]);
-                    count = util.Math.constrain(count, 1, elements.length);
-                    buffer.focusElement(elements[count - 1]);
-                }
                 else
                     liberator.beep();
             }

common/content/hints.js

@@ -63,14 +63,14 @@ function Hints() //{{{
     const Mode = new Struct("prompt", "action", "tags");
     Mode.defaultValue("tags", function () function () options.hinttags);
     function extended() options.extendedhinttags;
-    function images() "//img | //xhtml:img";
+    function images() util.makeXPath(["img"]);
 
     const hintModes = {
         ";": Mode("Focus hint",                         function (elem) buffer.focusElement(elem),                             extended),
         "?": Mode("Show information for hint",          function (elem) buffer.showElementInfo(elem),                          extended),
         s: Mode("Save hint",                            function (elem) buffer.saveLink(elem, true)),
         a: Mode("Save hint with prompt",                function (elem) buffer.saveLink(elem, false)),
-        f: Mode("Focus frame",                          function (elem) elem.ownerDocument.defaultView.focus(), function () "//body | //xhtml:body"),
+        f: Mode("Focus frame",                          function (elem) elem.ownerDocument.defaultView.focus(), function () util.makeXPath(["body"])),
         o: Mode("Follow hint",                          function (elem) buffer.followLink(elem, liberator.CURRENT_TAB)),
         t: Mode("Follow hint in a new tab",             function (elem) buffer.followLink(elem, liberator.NEW_TAB)),
         b: Mode("Follow hint in a background tab",      function (elem) buffer.followLink(elem, liberator.NEW_BACKGROUND_TAB)),
@@ -786,10 +786,8 @@ function Hints() //{{{
     /////////////////////////////////////////////////////////////////////////////{{{
 
     const DEFAULT_HINTTAGS =
-        util.Array(["input[not(@type='hidden')]", "a", "area", "iframe", "textarea", "button", "select"])
+        util.makeXPath(["input[not(@type='hidden')]", "a", "area", "iframe", "textarea", "button", "select"])
-            .map(function (spec) [spec, "xhtml:" + spec]).flatten()
+            + " | //*[@onclick or @onmouseover or @onmousedown or @onmouseup or @oncommand or @role='link']";
-            .concat("*[@onclick or @onmouseover or @onmousedown or @onmouseup or @oncommand or @role='link']")
-            .map(function (node) "//" + node).join(" | ");
 
     function checkXPath(val)
     {

common/content/util.js

@@ -178,6 +178,20 @@ const util = { //{{{
         return dest;
     },
 
+    /**
+     * Returns an XPath union expression constructed from the specified node
+     * tests. An expression is built with node tests for both the null and
+     * XHTML namespaces. See {@link Buffer#evaluateXPath}.
+     *
+     * @param nodes {Array(string)}
+     * @returns {string}
+     */
+    makeXPath: function makeXPath(nodes)
+    {
+        return util.Array(nodes).map(function (node) [node, "xhtml:" + node]).flatten()
+                                .map(function (node) "//" + node).join(" | ");
+    },
+
     /**
      * Memoize the lookup of a property in an object.
      *