OOP PDF - Add support for "zoom" open pdf parameter

chrome/browser/resources/pdf/pdf.js

Index: chrome/browser/resources/pdf/pdf.js
diff --git a/chrome/browser/resources/pdf/pdf.js b/chrome/browser/resources/pdf/pdf.js
index 70f53b7afc0068642049aacaeae66f4aae1c5929..59005e590bc2a1af607d66ea292684a0580f56e7 100644
--- a/chrome/browser/resources/pdf/pdf.js
+++ b/chrome/browser/resources/pdf/pdf.js
@@ -264,6 +264,33 @@ PDFViewer.prototype = {
   },
 
   /**
+   * Handle zoom parameter of open PDF parameters. If this
+   * parameter is passed while opening PDF then PDF should be opened
+   * at the specified zoom level.
+   * @param {number} zoom value.
+   */
+  handleZoomParam_: function(paramValue) {
+    var paramValueSplit = paramValue.split(',');
+    if ((paramValueSplit.length != 1) && (paramValueSplit.length != 3))
+      return;
+
+    // User scale of 100 means zoom value of 100% i.e. zoom factor of 1.0.
+    var zoomFactor = parseFloat(paramValueSplit[0]) / 100;
+
+    // Handle #zoom=scale.
+    if (paramValueSplit.length == 1) {
+      this.viewport_.setZoom(zoomFactor);

[Nikhil, 2014/08/19 15:09:42]

setZoom() isn't working as intended. Is this not the correct way to use this?

[raymes, 2014/08/20 00:14:21]

This looks correct. What is it that isn't working? You might need to do some
debugging. Something may be changing the zoom after this call.

[Nikhil, 2014/08/20 04:46:55]

It didn't work as intended since zoom didn't change to what was passed in the
parameter. But if I just attach debugger, pause, and continue execution then it
works fine. Maybe some sort of timing issue?

I wasn't sure if I was calling setZoom() correctly. I'll try to debug this more.

[Nikhil, 2014/08/21 11:36:50]

It wasn't working because chrome.tabs.onZoomChange() listener was changing the
zoom back to 1. I've made a change for this. PTAL.

+      return;
+    }
+
+    // Handle #zoom=scale,left,top.
+    var position = {x: parseFloat(paramValueSplit[1]),

[Lei Zhang, 2014/08/20 00:37:07]

The Adobe open parameters document is rather vague on what units left/top are.
Do we need to do any unit conversion here?

[Nikhil, 2014/08/20 04:46:54]

Yep, it's a bit vague on units. Unlike page which can only take integer values,
the Adobe document says scale, left, and top can be passed as integer or float
values. So I used parseFloat().

Also, do we need NaN check here to make it robust?

+                    y: parseFloat(paramValueSplit[2])};
+    this.viewport_.position = position;
+    this.viewport_.setZoom(zoomFactor);
+  },
+
+  /**
    * @private
    * Handle open PDF parameters. These parameters are mentioned in the URL
    * and specify actions to be performed when opening PDF files.
@@ -290,6 +317,8 @@ PDFViewer.prototype = {
       // value is 1-based.
       this.viewport_.goToPage(paramsDictionary['page'] - 1);
     }
+    if ('zoom' in paramsDictionary)

[Lei Zhang, 2014/08/20 00:37:07]

I think order might also matter between page and zoom? Best to test with Acrobat
and see how it behaves.

One possible interpretation is:

(A) ?zoom=150,100,200&page=2 -> zoom to 150%, go to (100, 200), then go to page
2 -> ends up at top of page 2

vs

(B) ?page=2&zoom=150,100,200 -> go to page 2, zoom to 150%, go to (100, 200) ->
ends up in the middle of page 2

Other possible interpretations are we always do (A) or we always do (B).

[Nikhil, 2014/08/20 04:46:55]

As I understand, page should always be handled before zoom. Both
#zoom=150,100,200&page=2 and #page=2&zoom=150,100,200 should first go to page 2
and then zoom.

Please see "Specifying parameters in a URL" section of Adobe document.

+      this.handleZoomParam_(paramsDictionary['zoom']);
   },
 
   /**