Scrollbars in EdgeHtml WebView and Edge browser

2019 Aug 22, 5:35

The scrollbars in UWP WebView and in Edge have different default behavior leading to many emails to my team. (Everything I talk about here is for the EdgeHtml based WebView and Edge browser and does not apply to the Chromium based Edge browser and WebView2).

There is a Edge only -ms-overflow-style CSS property that controls scroll behavior. We have a different default for this in the WebView as compared to the Edge browser. If you want the appearance of the scrollbar in the WebView to match the browser then you must explicitly set that CSS property. The Edge browser default is scrollbar which gives us a Windows desktop styled non-auto-hiding scrollbar. The WebView default is -ms-autohiding-scrollbar which gives a sort of compromise between desktop and UWP app scrollbar behavior. In this configuration it is auto-hiding. When used with the mouse you'll get Windows desktop styled scrollbars and when used with touch you'll get the UWP styled scrollbars.

Since WebViews are intended to be used in apps this style is the default in order to better match the app's scrollbars. However this difference between the browser and WebView has led to confusion.

Here’s an -ms-overflow-style JSFiddle showing the difference between the two styles. Try it in the Edge browser and in WebView. An easy way to try it in the Edge WebView is using the JavaScript Browser.

Tweet from Jen Gentleman 🌺

2016 Oct 8, 2:19

In case you were wondering: Yes, the new address bar that was added to RegEdit supports Alt+D to set keyboard focus

#WindowsInsiders

Retweet of rcallimachi

2016 Jan 7, 2:51

Wow: When is the last time a sitting American president penned an OpEd in the New York Times? Barack Obama just did http://mobile.nytimes.com/2016/01/08/opinion/president-barack-obama-guns-are-our-shared-responsibility.html?emc=edit_na_20160107&nlid=69115476&ref=cta&_r=0&referer= …

Retweet of tombkeeper

2015 Nov 11, 11:07

Another demo of our talk "BadBarcode" in PacSec 2015: start a shell by one single boarding pass.

Tweet from David_Risney

2015 Aug 4, 10:59

The song Don't You Want Me redone using the only non-titular line you can recall: "Workin' In A Cocktail Bar" https://www.youtube.com/watch?v=X58g1HKxXPo …

Retweet of lakey

2015 Aug 3, 2:26

@danbarker Lots more lovely 3D tube maps here: http://bit.ly/1P33Tws

Retweet of paulcbetts

2015 Mar 15, 9:55

@DrPizza Holy shit, they finally caved and added the search bar to the ribbon

Retweet of stevefaulkner

2015 Mar 3, 2:49

browser support? "no clue" "I do not understand the point of this type. Neither do browsers." http://quirksmode.org/html5/inputs/mobile.html …

Retweet of ericlaw

2015 Feb 1, 6:02

http://www.theonion.com/articles/fingerprints-on-lombardi-trophy-to-be-used-in-doze,37899/ …

Debugging anecdote - the color transparent black breaks accessibility

2014 May 22, 10:36

Some time back while I was working on getting the Javascript Windows Store app platform running on Windows Phone (now available on the last Windows Phone release!) I had an interesting bug that in retrospect is amusing.

I had just finished a work item to get accessibility working for JS WinPhone apps when I got a new bug: With some set of JS apps, accessibility appeared to be totally broken. At that time in development the only mechanism we had to test accessibility was a test tool that runs on the PC, connects to the phone, and dumps out the accessibility tree of whatever app is running on the phone. In this bug, the tool would spin for a while and then timeout with an error and no accessibility information.

My first thought was this was an issue in my new accessibility code. However, debugging with breakpoints on my code I could see none of my code was run nor the code that should call it. The code that called that code was a more generic messaging system that hit my breakpoints constantly.

Rather than trying to work backward from the failure point, I decided to try and narrow down the repro and work forwards from there. One thing all the apps with the bug had in common was their usage of WinJS, but not all WinJS apps demonstrated the issue. Using a binary search approach on one such app I removed unrelated app code until all that was left was the app's usage of the WinJS AppBar and the bug still occurred. I replaced the WinJS AppBar usage with direct usage of the underlying AppBar WinRT APIs and continued.

Only some calls to the AppBar WinRT object produced the issue:

        var appBar = Windows.UI.WebUI.Core.WebUICommandBar.getForCurrentView(); 
        // appBar.opacity = 1;
        // appBar.closeDisplayMode = Windows.UI.WebUI.Core.WebUICommandBarClosedDisplayMode.default;
        appBar.backgroundColor = Windows.UI.Colors.white; // Bug!

Just setting the background color appeared to cause the issue and I didn't even have to display the AppBar. Through additional trial and error I was blown away to discover that some colors I would set caused the issue and other colors did not. Black wouldn't cause the issue but transparent black would. So would aqua but not white.

I eventually realized that predefined WinRT color values like Windows.UI.Colors.aqua would cause the issue while JS literal based colors didn't cause the issue (Windows.UI.Color is a WinRT struct which projects in JS as a JS literal object with the struct members as JS object properties so its easy to write something like {r: 0, g: 0, b: 0, a: 0} to make a color) and I had been mixing both in my tests without realizing there would be a difference. I debugged into the backgroundColor property setter that consumed the WinRT color struct to see what was different between Windows.UI.Colors.black and {a: 1, r: 0, g: 0, b: 0} and found the two structs to be byte wise exactly the same.

On a hunch I tried my test app with only a reference to the color and otherwise no interaction with the AppBar and not doing anything with the actual reference to the color: Windows.UI.Colors.black;. This too caused the issue. I knew that the implementation for these WinRT const values live in a DLL and guessed that something in the code to create these predefined colors was causing the issue. I debugged in and no luck. Now I also have experienced crusty code that would do exciting things in its DllMain, the function that's called when a DLL is loaded into the process so I tried modifying my C++ code to simply LoadLibrary the DLL containing the WinRT color definition, windows.ui.xaml.dll and found the bug still occurred! A short lived moment of relief as the world seemed to make sense again.

Debugging into DllMain nothing interesting happened. There were interesting calls in there to be sure, but all of them behind conditions that were false. I was again stumped. On another hunch I tried renaming the DLL and only LoadLibrary'ing it and the bug went away. I took a different DLL renamed it windows.ui.xaml.dll and tried LoadLibrary'ing that and the bug came back. Just the name of the DLL was causing the issue.

I searched for the DLL name in our source code index and found hits in the accessibility tool. Grinning I opened the source to find that the accessibility tool's phone side service was trying to determine if a process belonged to a XAML app or not because XAML apps had a different accessibility contract. It did this by checking to see if windows.ui.xaml.dll was loaded in the target process.

At this point I got to fix my main issue and open several new bugs for the variety of problems I had just run into. This is a how to on writing software that is difficult to debug.

bug debug javascript JS technical windows winrt

YouTube - Dead Man’s Bones (Dance) Nathan Barnatt has...

2014 May 19, 3:21

YouTube - Dead Man’s Bones (Dance)

Nathan Barnatt has some great videos

Nathan-barnatt video dance

URI functions in Windows Store Applications

2013 Jul 25, 1:00

Summary

The Modern SDK contains some URI related functionality as do libraries available in particular projection languages. Unfortunately, collectively these APIs do not cover all scenarios in all languages. Specifically, JavaScript and C++ have no URI building APIs, and C++ additionally has no percent-encoding/decoding APIs.

	WinRT (JS and C++)	JS Only	C++ Only	.NET Only
Parse	Windows.Foundation.Uri		WsDecodeUrl*	System.Uri
Build			WsEncodeUrl*	System.UriBuilder
Normalize	Windows.Foundation.Uri			System.Uri
Equality	Windows.Foundation.Uri. Equals			System.Uri.Compare
Relative resolution	Windows.Foundation.Uri. CombineUri			System.Uri
Encode data for including in URI property	Windows.Foundation.Uri. EscapeComponent	encodeURIComponent	WsEncodeUrl*	System.Uri. EscapeDataString
Decode data extracted from URI property	Windows.Foundation.Uri. UnescapeComponent	decodeURIComponent	WsDecodeUrl*	System.Uri. UnescapeDataString
Build Query
Parse Query	Windows.Foundation. Uri.QueryParsed / Windows.Foundation. WwwFormUrlDecoder*

The Windows.Foudnation.Uri type is not projected into .NET modern applications. Instead those applications use System.Uri and the platform ensures that it is correctly converted back and forth between Windows.Foundation.Uri as appropriate. Accordingly the column marked WinRT above is applicable to JS and C++ modern applications but not .NET modern applications. The only entries above applicable to .NET are the .NET Only column and the WwwFormUrlDecoder in the bottom left which is available to .NET.

Scenarios

Parse

This functionality is provided by the WinRT API Windows.Foundation.Uri in C++ and JS, and by System.Uri in .NET.

Parsing a URI pulls it apart into its basic components without decoding or otherwise modifying the contents.

var uri = new Windows.Foundation.Uri("http://example.com/path%20segment1/path%20segment2?key1=value1&key2=value2");

console.log(uri.path);// /path%20segment1/path%20segment2

WsDecodeUrl (C++)

WsDecodeUrl is not suitable for general purpose URI parsing. Use Windows.Foundation.Uri instead.

Build (C#)

URI building is only available in C# via System.UriBuilder.

URI building is the inverse of URI parsing: URI building allows the developer to specify the value of basic components of a URI and the API assembles them into a URI.

To work around the lack of a URI building API developers will likely concatenate strings to form their URIs. This can lead to injection bugs if they don’t validate or encode their input properly, but if based on trusted or known input is unlikely to have issues.

Uri originalUri = new Uri("http://example.com/path1/?query");

UriBuilder uriBuilder = new UriBuilder(originalUri);

uriBuilder.Path = "/path2/";

Uri newUri = uriBuilder.Uri; // http://example.com/path2/?query

WsEncodeUrl (C++)

WsEncodeUrl, in addition to building a URI from components also does some encoding. It encodes non-US-ASCII characters as UTF8, the percent, and a subset of gen-delims based on the URI property: all :/?#[]@ are percent-encoded except :/@ in the path and :/?@ in query and fragment.

Accordingly, WsEncodeUrl is not suitable for general purpose URI building. It is acceptable to use in the following cases:

- You’re building a URI out of non-encoded URI properties and don’t care about the difference between encoded and decoded characters. For instance you’re the only one consuming the URI and you uniformly decode URI properties when consuming – for instance using WsDecodeUrl to consume the URI.

- You’re building a URI with URI properties that don’t contain any of the characters that WsEncodeUrl encodes.

Normalize

This functionality is provided by the WinRT API Windows.Foundation.Uri in C++ and JS and by System.Uri in .NET. Normalization is applied during construction of the Uri object.

URI normalization is the application of URI normalization rules (including DNS normalization, IDN normalization, percent-encoding normalization, etc.) to the input URI.

var normalizedUri = new Windows.Foundation.Uri("HTTP://EXAMPLE.COM/p%61th foo/");

console.log(normalizedUri.absoluteUri); // http://example.com/path%20foo/

This is modulo Win8 812823 in which the Windows.Foundation.Uri.AbsoluteUri property returns a normalized IRI not a normalized URI. This bug does not affect System.Uri.AbsoluteUri which returns a normalized URI.

Equality

This functionality is provided by the WinRT API Windows.Foundation.Uri in C++ and JS and by System.Uri in .NET.

URI equality determines if two URIs are equal or not necessarily equal.

var uri1 = new Windows.Foundation.Uri("HTTP://EXAMPLE.COM/p%61th foo/"),

uri2 = new Windows.Foundation.Uri("http://example.com/path%20foo/");

console.log(uri1.equals(uri2)); // true

Relative resolution

This functionality is provided by the WinRT API Windows.Foundation.Uri in C++ and JS and by System.Uri in .NET

Relative resolution is a function that given an absolute URI A and a relative URI B, produces a new absolute URI C. C is the combination of A and B in which the basic components specified in B override or combine with those in A under rules specified in RFC 3986.

var baseUri = new Windows.Foundation.Uri("http://example.com/index.html"),

relativeUri = "/path?query#fragment",

absoluteUri = baseUri.combineUri(relativeUri);

console.log(baseUri.absoluteUri); // http://example.com/index.html

console.log(absoluteUri.absoluteUri); // http://example.com/path?query#fragment

Encode data for including in URI property

This functionality is available in JavaScript via encodeURIComponent and in C# via System.Uri.EscapeDataString. Although the two methods mentioned above will suffice for this purpose, they do not perform exactly the same operation.

Additionally we now have Windows.Foundation.Uri.EscapeComponent in WinRT, which is available in JavaScript and C++ (not C# since it doesn’t have access to Windows.Foundation.Uri). This is also slightly different from the previously mentioned mechanisms but works best for this purpose.

Encoding data for inclusion in a URI property is necessary when constructing a URI from data. In all the above cases the developer is dealing with a URI or substrings of a URI and so the strings are all encoded as appropriate. For instance, in the parsing example the path contains “path%20segment1” and not “path segment1”. To construct a URI one must first construct the basic components of the URI which involves encoding the data. For example, if one wanted to include “path segment / example” in the path of a URI, one must percent-encode the ‘ ‘ since it is not allowed in a URI, as well as the ‘/’ since although it is allowed, it is a delimiter and won’t be interpreted as data unless encoded.

If a developer does not have this API provided they can write it themselves. Percent-encoding methods appear simple to write, but the difficult part is getting the set of characters to encode correct, as well as handling non-US-ASCII characters.

var uri = new Windows.Foundation.Uri("http://example.com" +

"/" + Windows.Foundation.Uri.escapeComponent("path segment / example") +

"?key=" + Windows.Foundation.Uri.escapeComponent("=&?#"));

console.log(uri.absoluteUri); // http://example.com/path%20segment%20%2F%20example?key=%3D%26%3F%23

WsEncodeUrl (C++)

In addition to building a URI from components, WsEncodeUrl also percent-encodes some characters. However the API is not recommend for this scenario given the particular set of characters that are encoded and the convoluted nature in which a developer would have to use this API in order to use it for this purpose.

There are no general purpose scenarios for which the characters WsEncodeUrl encodes make sense: encode the %, encode a subset of gen-delims but not also encode the sub-delims. For instance this could not replace encodeURIComponent in a C++ version of the following code snippet since if ‘value’ contained ‘&’ or ‘=’ (both sub-delims) they wouldn’t be encoded and would be confused for delimiters in the name value pairs in the query:

"http://example.com/?key=" + Windows.Foundation.Uri.escapeComponent(value)

Since WsEncodeUrl produces a string URI, to obtain the property they want to encode they’d need to parse the resulting URI. WsDecodeUrl won’t work because it decodes the property but Windows.Foundation.Uri doesn’t decode. Accordingly the developer could run their string through WsEncodeUrl then Windows.Foundation.Uri to extract the property.

Decode data extracted from URI property

This functionality is available in JavaScript via decodeURIComponent and in C# via System.Uri.UnescapeDataString. Although the two methods mentioned above will suffice for this purpose, they do not perform exactly the same operation.

Additionally we now also have Windows.Foundation.Uri.UnescapeComponent in WinRT, which is available in JavaScript and C++ (not C# since it doesn’t have access to Windows.Foundation.Uri). This is also slightly different from the previously mentioned mechanisms but works best for this purpose.

Decoding is necessary when extracting data from a parsed URI property. For example, if a URI query contains a series of name and value pairs delimited by ‘=’ between names and values, and by ‘&’ between pairs, one must first parse the query into name and value entries and then decode the values. It is necessary to make this an extra step separate from parsing the URI property so that sub-delimiters (in this case ‘&’ and ‘=’) that are encoded will be interpreted as data, and those that are decoded will be interpreted as delimiters.

If a developer does not have this API provided they can write it themselves. Percent-decoding methods appear simple to write, but have some tricky parts including correctly handling non-US-ASCII, and remembering not to decode .

In the following example, note that if unescapeComponent were called first, the encoded ‘&’ and ‘=’ would be decoded and interfere with the parsing of the name value pairs in the query.

var uri = new Windows.Foundation.Uri("http://example.com/?foo=bar&array=%5B%27%E3%84%93%27%2C%27%26%27%2C%27%3D%27%2C%27%23%27%5D");

uri.query.substr(1).split("&").forEach(

function (keyValueString) {

var keyValue = keyValueString.split("=");

console.log(Windows.Foundation.Uri.unescapeComponent(keyValue[0]) + ": " + Windows.Foundation.Uri.unescapeComponent(keyValue[1]));

// foo: bar

// array: ['ㄓ','&','=','#']

});

WsDecodeUrl (C++)

Since WsDecodeUrl decodes all percent-encoded octets it could be used for general purpose percent-decoding but it takes a URI so would require the dev to construct a stub URI around the string they want to decode. For example they could prefix “http:///#” to their string, run it through WsDecodeUrl and then extract the fragment property. It is convoluted but will work correctly.

Parse Query

The query of a URI is often encoded as application/x-www-form-urlencoded which is percent-encoded name value pairs delimited by ‘&’ between pairs and ‘=’ between corresponding names and values.

In WinRT we have a class to parse this form of encoding using Windows.Foundation.WwwFormUrlDecoder. The queryParsed property on the Windows.Foundation.Uri class is of this type and created with the query of its Uri:

var uri = Windows.Foundation.Uri("http://example.com/?foo=bar&array=%5B%27%E3%84%93%27%2C%27%26%27%2C%27%3D%27%2C%27%23%27%5D");

uri.queryParsed.forEach(

function (pair) {

console.log("name: " + pair.name + ", value: " + pair.value);

// name: foo, value: bar

// name: array, value: ['ㄓ','&','=','#']

});

console.log(uri.queryParsed.getFirstValueByName("array")); // ['ㄓ','&','=','#']

The QueryParsed property is only on Windows.Foundation.Uri and not System.Uri and accordingly is not available in .NET. However the Windows.Foundation.WwwFormUrlDecoder class is available in C# and can be used manually:

Uri uri = new Uri("http://example.com/?foo=bar&array=%5B%27%E3%84%93%27%2C%27%26%27%2C%27%3D%27%2C%27%23%27%5D");

WwwFormUrlDecoder decoder = new WwwFormUrlDecoder(uri.Query);

foreach (IWwwFormUrlDecoderEntry entry in decoder)

{

System.Diagnostics.Debug.WriteLine("name: " + entry.Name + ", value: " + entry.Value);

// name: foo, value: bar

// name: array, value: ['ㄓ','&','=','#']

}

Build Query

To build a query of name value pairs encoded as application/x-www-form-urlencoded there is no WinRT API to do this directly. Instead a developer must do this manually making use of the code described in “Encode data for including in URI property”.

In terms of public releases, this property is only in the RC and later builds.

For example in JavaScript a developer may write:

var uri = new Windows.Foundation.Uri("http://example.com/"),

query = "?" + Windows.Foundation.Uri.escapeComponent("array") + "=" + Windows.Foundation.Uri.escapeComponent("['ㄓ','&','=','#']");

console.log(uri.combine(new Windows.Foundation.Uri(query)).absoluteUri); // http://example.com/?array=%5B'%E3%84%93'%2C'%26'%2C'%3D'%2C'%23'%5D

c# c++ javascript technical uri windows windows-runtime windows-store

wilwheaton: cameron-stewart: My contribution in full to the...

2013 Apr 4, 5:34

wilwheaton:

cameron-stewart:

My contribution in full to the #bartkira project. This was tons of fun to do.

Holy shit.

Everything’s coming up Milhouse

humor comic art mashup simpsons akira

Attention:!!!, Behold, you are reading a letter from your President Barack Obama.

2012 Sep 26, 2:43

Eric gets the most entertaining mail.

You have failed to comply with them after all the warning and instructions given to you, but since you are also among the terrorist we are facing in the country, I will personal make sure that I wipe away the crime in the state and I promise you that you will definitely pay with your life because I am here to protect the interest of my people and not to put them in shame, you suppose to support this government and not to spoil it.

humor spam scam email eric-law

Nathan Barnatt makes awesome videos. This is a playlist of my...

2012 Sep 26, 2:21

Nathan Barnatt makes awesome videos. This is a playlist of my favorites of his. (via http://www.youtube.com/playlist?list=PLIjrVnNvXzb8N5tjV3fowJqYwuDM__WVf)

Nathan-barnatt video music dance humor

Stuxnet Explained - Obama Order Sped Up Wave of Cyberattacks Against Iran

2012 Jun 1, 4:57

“From his first months in office, President Obamasecretly ordered increasingly sophisticated attacks on the computer systems that run Iran’s main nuclear enrichment facilities, significantly expanding America’s first sustained use of cyberweapons, according to participants in the program.”

security politics iran nuclear virus

Raising the bar on web uploads

2012 Apr 25, 5:00

Flickr’s new HTML5-ish photo upload feature technical overview.

technical html html5 javascript css3 css flickr file-upload

Slow Jam The News with Barack Obama: Late Night with Jimmy...

2012 Apr 25, 3:45

Slow Jam The News with Barack Obama: Late Night with Jimmy Fallon (by latenight)

humor president jimmy-fallon barack-obama loan

The Dancebulance - Gov Ball 2012 Lineup (by...

2012 Apr 18, 6:10

The Dancebulance - Gov Ball 2012 Lineup (by nathanjbarnatt)

Another Nathan Barnatt video with awesome music and dance moves. Also enjoying the music video for third song in this video “Barbara Streisand” by Duck Sauce: http://www.youtube.com/watch?v=uu_zwdmz0hE

humor music dance nathan-barnatt video

Madeon - Pop Culture (Dance Video) (by nathanjbarnatt)

2012 Apr 17, 12:21

Madeon - Pop Culture (Dance Video) (by nathanjbarnatt)

humor dance video nathan-barnatt madeon