Implement Page Selection in PDF Toolbar

chrome/browser/resources/pdf/elements/page-selector/page-selector.js

Index: chrome/browser/resources/pdf/elements/page-selector/page-selector.js
diff --git a/chrome/browser/resources/pdf/elements/page-selector/page-selector.js b/chrome/browser/resources/pdf/elements/page-selector/page-selector.js
new file mode 100644
index 0000000000000000000000000000000000000000..9b22421a847172a4465059c3c3450602755f147e
--- /dev/null
+++ b/chrome/browser/resources/pdf/elements/page-selector/page-selector.js
@@ -0,0 +1,44 @@
+// Copyright 2015 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.
+
+Polymer('page-selector', {
+  // The current entry in the input field.
+  pageNo: '1',
+  // The index of the current page being viewed.
+  index: 0,
+  docLength: 1,
+  // The submitted input from the user.
+  chosenPageNo: '1',
+  pageLabels: null,

[benwells, 2015/01/27 02:01:41]

Could you add more comment for all of these fields?

In particular:
- pageNo and chosenPageNo being 1 based should be pointed out
- index is 0 based should be pointed out
- what are the pageLabels? E.g. what types are they and what are they used for
- what does digitLength do? (actually should this just be a constant, or can it
be set?)

Also I *think* only some of these are exposed. Should they be highlighted in
some way? Should the non-exposed ones have a trailing underscore?

[Alexandre Carlton, 2015/01/27 04:04:54]

digitLength is used in setting the length of the field; I haven't yet found a
way to make the input field grow otherwise. Is there a better way?

+  digitLength: 0.6,
+
+  chosenPageNoChanged: function() {
+    var page = parseInt(this.chosenPageNo);
+    if (!isNaN(page)) {
+      // TODO(alexandrec): This is not correct if pageLabels is set.

[benwells, 2015/01/27 02:01:41]

This TODO confuses me. Is the TODO to handle pageLabels being non-null and
having a label entered in the else statement?

[Alexandre Carlton, 2015/01/27 04:04:54]

This is more to do with Print Preview; I've modified the TODO statement.

+      this.fire('changePage', {page: page - 1});
+    } else {
+      // Repopulate the input.
+      this.indexChanged();
+      // Change the chosenPageNo so if it is '' again we can repopulate it.
+      this.chosenPageNo = this.pageNo;
+    }
+  },
+
+  pageLabelsChanged: function() {
+    this.indexChanged();
+  },
+
+  indexChanged: function() {
+    if (this.pageLabels)
+      this.pageNo = this.pageLabels[this.index];
+    else
+      this.pageNo = String(this.index + 1);
+  },
+
+  docLengthChanged: function() {
+    var numDigits = this.docLength.toString().length;
+    this.$.pageselector.style.width = (numDigits * this.digitLength) + 'em';
+  }
+});