explorer page 2 - Dave's Blog

PowerShell Scanning Script

I've hooked up the printer/scanner to the Media Center PC since I leave that on all the time anyway so we can have a networked printer. I wanted to hook up the scanner in a somewhat similar fashion but I didn't want to install HP's software (other than the drivers of course). So I've written my own script for scanning in PowerShell that does the following:

1. Scans using the Windows Image Acquisition APIs via COM
2. Runs OCR on the image using Microsoft Office Document Imaging via COM (which may already be on your PC if you have Office installed)
3. Converts the image to JPEG using .NET Image APIs
4. Stores the OCR text into the EXIF comment field using .NET Image APIs (which means Windows Search can index the image by the text in the image)
5. Moves the image to the public share

Here's the actual code from my scan.ps1 file:

param([Switch] $ShowProgress, [switch] $OpenCompletedResult)

$filePathTemplate = "C:\users\public\pictures\scanned\scan {0} {1}.{2}";
$time = get-date -uformat "%Y-%m-%d";

[void]([reflection.assembly]::loadfile( "C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Drawing.dll"))

$deviceManager = new-object -ComObject WIA.DeviceManager
$device = $deviceManager.DeviceInfos.Item(1).Connect();

foreach ($item in $device.Items) {
        $fileIdx = 0;
        while (test-path ($filePathTemplate -f $time,$fileIdx,"*")) {
                [void](++$fileIdx);
        }

        if ($ShowProgress) { "Scanning..." }

        $image = $item.Transfer();
        $fileName = ($filePathTemplate -f $time,$fileIdx,$image.FileExtension);
        $image.SaveFile($fileName);
        clear-variable image

        if ($ShowProgress) { "Running OCR..." }

        $modiDocument = new-object -comobject modi.document;
        $modiDocument.Create($fileName);
        $modiDocument.OCR();
        if ($modiDocument.Images.Count -gt 0) {
                $ocrText = $modiDocument.Images.Item(0).Layout.Text.ToString().Trim();
                $modiDocument.Close();
                clear-variable modiDocument

                if (!($ocrText.Equals(""))) {
                        $fileAsImage = New-Object -TypeName system.drawing.bitmap -ArgumentList $fileName
                        if (!($fileName.EndsWith(".jpg") -or $fileName.EndsWith(".jpeg"))) {
                                if ($ShowProgress) { "Converting to JPEG..." }

                                $newFileName = ($filePathTemplate -f $time,$fileIdx,"jpg");
                                $fileAsImage.Save($newFileName, [System.Drawing.Imaging.ImageFormat]::Jpeg);
                                $fileAsImage.Dispose();
                                del $fileName;

                                $fileAsImage = New-Object -TypeName system.drawing.bitmap -ArgumentList $newFileName 
                                $fileName = $newFileName
                        }

                        if ($ShowProgress) { "Saving OCR Text..." }

                        $property = $fileAsImage.PropertyItems[0];
                        $property.Id = 40092;
                        $property.Type = 1;
                        $property.Value = [system.text.encoding]::Unicode.GetBytes($ocrText);
                        $property.Len = $property.Value.Count;
                        $fileAsImage.SetPropertyItem($property);
                        $fileAsImage.Save(($fileName + ".new"));
                        $fileAsImage.Dispose();
                        del $fileName;
                        ren ($fileName + ".new") $fileName
                }
        }
        else {
                $modiDocument.Close();
                clear-variable modiDocument
        }

        if ($ShowProgress) { "Done." }

        if ($OpenCompletedResult) {
                . $fileName;
        }
        else {
                $result = dir $fileName;
                $result | add-member -membertype noteproperty -name OCRText -value $ocrText
                $result
        }
}

I ran into a few issues:

• MODI doesn't seem to be in the Office 2010 Technical Preview I installed first. Installing Office 2007 fixed that.
• The MODI.Document class, at least via PowerShell, can't be instantiated in a 64bit environment. To run the script on my 64bit OS I had to start powershell from the 32bit cmd.exe (C:\windows\syswow64\cmd.exe).
• I was planning to hook up my script to the scanner's 'Scan' button, but HP didn't get the button working for their Vista driver. Their workaround is "don't do that!".
• You must call Image.Dispose() to get .NET to release its reference to the corresponding image file.
• In trying to figure out how to store the text in the files comment, I ran into a dead-end trying to find the corresponding setter for GetDetailsOf which folks like James O'Neil use in PowerShell for interesting ends.

Outline View Internet Explorer Extension

I've made another extension for IE8, Outline View, which gives you a side bar in IE that displays an outline of the current page and lets you make intrapage bookmarks.

The outline is generated based on the heading tags in the document (e.g. h1, h2, etc), kind of like what W3C's Semantic data extractor tool displays for an outline. So if the page doesn't use heading tags the way the HTML spec intended or just sticks img tags in them, then the outline doesn't look so hot. On a page that does use headings as intended though it looks really good. For instance a section from the HTML 4 spec shows up quite nicely and I find its actually useful to be able to jump around to the different sections. Actually, I've been surprised going to various blogs how well the outline view is actually working -- I thought a lot more webdevs would be abusing their heading tags.

I've also added intrapage bookmarks. When you make a text selection and clear it, that selected text is added as a temporary intrapage bookmark which shows up in the correct place in the outline. You can navigate to the bookmark or right click to make it permanent. Right now I'm storing the permanent intrapage bookmarks in IE8's new per-domain DOM storage because I wanted to avoid writing code to synchronize a cross process store of bookmarks, it allowed me to play with the DOM storage a bit, and the bookmarks will get cleared appropriately when the user clears their history via the control panel.

Internet Explorer 8 Released

IE8, the software I've been working on for some time now, has finally been released at MIX09.

• Download IE8.
• Dean's MIX09 Keynote releasing IE8 is viewable here.
• Louis pointed me to this humorous IE8 advertising that doesn't make me cringe. On the contrary it has Ask a Ninja, Janeane Garofalo, and several comedians I recall collectively from either 'I Love the [decade]' or 'Best Week Ever'.
• It seems like only a year ago that IE8 Beta was released.
• IE Blog: IE8 Released.

Notes on Creating Internet Explorer Extensions in C++ and COM

Working on Internet Explorer extensions in C++ & COM, I had to relearn or rediscover how to do several totally basic and important things. To save myself and possibly others trouble in the future, here's some pertinent links and tips.

First you must choose your IE extensibility point. Here's a very short list of the few I've used:

• Explorer Bars and IE Toolbars
• IE Tools, IE Help, and IE Context Menu menu items
• IE Toolbar Buttons

Once you've created your COM object that implements IObjectWithSite and whatever other interfaces your extensibility point requires as described in the above links you'll see your SetSite method get called by IE. You might want to know how to get the top level browser object from the IUnknown site object passed in via that method.

After that you may also want to listen for some events from the browser. To do this you'll need to:

1. Implement the dispinterface that has the event you want. For instance DWebBrowserEvents2, or HTMLDocumentEvents, or HTMLWindowEvents2. You'll have to search around in that area of the documentation to find the event you're looking for.
2. Register for events using AtlAdvise. The object you need to subscribe to depends on the events you want. For example, DWebBrowserEvents2 come from the webbrowser object, HTMLDocumentEvents come from the document object assuming its an HTML document (I obtained via get_Document method on the webbrowser), and HTMLWindowEvents2 come from the window object (which oddly I obtained via calling the get_script method on the document object). Note that depending on when your SetSite method is called the document may not exist yet. For my extension I signed up for browser events immediately and then listened for events like NavigateComplete before signing up for document and window events.
3. Implement IDispatch. The Invoke method will get called with event notifications from the dispinterfaces you sign up for in AtlAdvise. Implementing Invoke manually is a slight pain as all the parameters come in as VARIANTs and are in reverse order. There's some ATL macros that may make this easier but I didn't bother.
4. Call AtlUnadvise at some point -- at the latest when SetSite is called again and your site object changes.

If you want to check if an IHTMLElement is not visible on screen due how the page is scrolled, try comparing the Body or Document Element's client height and width, which appears to be the dimensions of the visible document area, to the element's bounding client rect which appears to be its position relative to the upper left corner of the visible document area. I've found this to be working for me so far, but I'm not positive that frames, iframes, zooming, editable document areas, etc won't mess this up.

Be sure to use pointers you get from the IWebBrowser/IHTMLDocument/etc. only on the thread on which you obtained the pointer or correctly marshal the pointers to other threads to avoid weird crashes and hangs.

Obtaining the HTML document of a subframe is slightly more complicated then you might hope. On the other hand this might be resolved by the new to IE8 method IHTMLFrameElement3::get_contentDocument

Check out Eric's IE blog post on IE extensibility which has some great links on this topic as well.

FormToAccelerator Internet Explorer Extension

I've made an extension for Internet Explorer 8, FormToAccelerator which turns HTML forms on a web page into either an accelerator or a search provider. In the design of the accelerators format we intentionally had HTML forms in mind so that it would be easy to create accelerators for existing web services. Consequently, creating an accelerator from an HTML form is a natural concept and an extension I've been meaning to finish for many months now.

This is similar in concept to the Opera feature that lets you add a form as a search provider. The user experience is very rough and requires some knowledge of accelerator variables. If I can come up with a better interaction model I may update this in the future, but at the moment all the designs I can come up with require way too much effort. Install IE8 RC1 and then try out FormToAccelerator.

Subst Allows Non-Letter Drive Letters

I knew that the command line tool subst would create virtual drives that map to existing directories but I didn't know that subst lets you name the virtual drives with characters that aren't US-ASCII letters. For instance you can run 'subst 4: C:\windows' and then 'more 4:\win.ini' to dump C:\windows\win.ini. This also works for non-US-ASCII characters like, "Ｃ" (aka U+FF23, Fullwidth Latin Capital Letter C), which when displayed by cmd.exe via some best fit style character conversions looks just like the regular US-ASCII 'C'. None of Explorer, IE, or the common file dialogs allow the use of these odd virtual drives -- just cmd.exe, so I'm not sure how this would ever be useful but I thought it was odd and I wanted to share.

Word Wrapping IE's Plain Text

If you view a plain text document in Internet Explorer 8, for instance the plain text version of Cory Doctorow's book Little Brother and press F12 to bring up the developer toolbar, you can see that IE simply takes the plain text, sticks it inside a

 tag, and renders it.  This means that word wrapping isn't supplied and the only line breaks that appear are those in the document.  However, since the text document is converted to HTML it means I can implement word wrap myself using a bookmarklet:
javascript:function ww() { var preTag = document.getElementsByTagName('pre')[0]; preTag.style.fontFamily="arial"; preTag.style.wordWrap='break-word'; }; ww();
After adding a favorite and setting the favorite's URL to the previous, I can view plain text documents, and select my Word Wrap favorite to apply word wrap and non-fixed width font.

Investigation of a Few Application Protocols (Updated)

Windows allows for application protocols in which, through the registry, you specify a URL scheme and a command line to have that URL passed to your application. Its an easy way to hook a webbrowser up to your application. Anyone can read the doc above and then walk through the registry and pick out the application protocols but just from that info you can't tell what the application expects these URLs to look like. I did a bit of research on some of the application protocols I've seen which is listed below. Good places to look for information on URI schemes: Wikipedia URI scheme, and ESW Wiki UriSchemes.

IE8 Beta2 Shipped

Internet Explorer 8 Beta 2 is now available! Some of the new features from this release that I really enjoy are Tab Grouping, the new address-bar, and InPrivate Subscriptions.

Tab Grouping groups tabs that are opened from the same page. For example, on a Google search results page if you open the first two links the two new tabs will be grouped with the Google search results page. If you close one of the tabs in that group focus goes to another tab in that group. Its small, but I really enjoy this feature and without knowing exactly what I wanted while using IE7 and FF2 I knew I wanted something like this. Plus the colors for the tab groups are pretty!

The new address bar and search box makes life much easier by searching through my browsing history for whatever I'm typing in. Other things are searched besides history but since I ignore favorites and use Delicious I mostly care about history. At any rate its one of the things that makes it impossible for me to go machines running IE7.

InPrivate Subscriptions allows you to subscribe to a feed of URLs from which IE should not download content. This is intended for avoiding sites that track you across websites and could sell or share your personal information, but this feature could be used for anything where the goal is to avoid a set of URLs. For example, phishing, malware sites, ad blocking, etc. etc. I think there's some interesting uses for this feature that we have yet to see.

Anyway, we're another release closer to the final IE8 and I can relax a little more.