Use aria range values for sliders

chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
index 6981549d8859b56bdcdbdb8cd41124d79f371459..8c7cf1b81b46e65fef29b652ee4b93f98bdd2718 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
@@ -527,7 +527,11 @@ Output.RULES = {
       speak: '$descendants $state'
     },
     slider: {

[dmazzoni, 2016/11/17 23:07:41]

You should expose range value attributes for these roles, it's potentially legal
for any of them:

      AX_ROLE_PROGRESS_INDICATOR
      AX_ROLE_METER
      AX_ROLE_SCROLL_BAR
      AX_ROLE_SLIDER
      AX_ROLE_SPIN_BUTTON

Alternatively, could you just trust that Blink won't expose these attributes
unless
they're relevant? I think there are quite a few rare attributes that might be
simpler to handle that way.

[David Tseng, 2017/01/20 22:18:05]

It would be, but it also prevents us from fine-tuning the output for each role
and clearly seeing how the output should look for a given role.

This is especially considering the confusion/disagreement about how these things
should bhave anyway (e.g. for meter:
https://github.com/w3c/aria/issues/451).

 I've added an abstractRange role so each of the above types can inherit from it
so it gives us good behavoir but also with the option to specialize if needed.

-      speak: '$earcon(SLIDER) @describe_slider($value, $name) $description ' +
+      speak:
+          '$if($valueForRange, $valueForRange) ' +

[dmazzoni, 2016/11/17 23:07:41]

I think $value is almost always better because it should contain aria-valuetext
if present, but the value otherwise.

[David Tseng, 2017/01/20 22:18:05]

ok, done.

+          '$if($minValueForRange, @aria_value_min($minValueForRange)) ' +
+          '$if($maxValueForRange, @aria_value_max($maxValueForRange)) ' +
+          '$earcon(SLIDER) @describe_slider($value, $name) $description ' +
           '$state'
     },
     staticText: {
@@ -1069,6 +1073,12 @@ Output.prototype = {
           if (earcon)
             options.annotation.push(earcon);
           this.append_(buff, node.name, options);
+        } else if (token == 'description') {
+          if (node.name == node.description)
+            return;
+
+          options.annotation.push(token);
+          this.append_(buff, node.description, options);
         } else if (token == 'urlFilename') {
           options.annotation.push('name');
           var url = node.url;
@@ -1260,7 +1270,7 @@ Output.prototype = {
           if (token == 'if') {
             var cond = tree.firstChild;
             var attrib = cond.value.slice(1);
-            if (node[attrib] || node.state[attrib])
+            if (node[attrib] !== undefined || node.state[attrib])
               this.format_(node, cond.nextSibling, buff);
             else
               this.format_(node, cond.nextSibling.nextSibling, buff);