Showing archive results for 2013

Last time, we learned about how connection points work. One special case of this is where the connection interface is a dispatch interface. Dispatch interfaces are, as the name suggests, COM interfaces based on IDispatch. The IDispatch interface is the base interface for OLE automation objects, and if you want your connection point interface to...

Last time, we saw how to enumerate all the Internet Explorer and Explorer Windows and see what they are viewing. But that program printed static information. It didn't track the changes to the windows if the user clicked to another Web page or navigated to a different folder. In order to hook that up, we need to understand the connection point ...

I dreamed that Swedish had separate third-person-plural pronouns based on gender. They were formed from han and hon by adding a common suffix, but the pattern broke down for det, and I got stuck trying to finish a sentence without knowing the correct word. I was able to escape from this embarrassing situation by using a technique available only i...

Normally, Monday is the day for Little Programs, but this time I'm going to spend a few days on a single Little Program. Now, this might very well disqualify it from the name Little Program, but the concepts are still little; all I'm doing is snapping blocks together. (Plus, it's my Web site, so you can just suck it.) The goal of our Little Pro...

As I noted earlier in the series, attaching input queues puts you back into the world of coöperative multitasking, where the two attached threads need to work together to get anything done. Back in the old 16-bit days, when input was synchronous, there was only one active window, only one focus window, only one window with capture, only one...

Today, we'll illustrate the consequences of the way the window manager synchronizes input when two or more threads decide to share an input queue. Since I need to keep separate state for the two windows, I'm going to start with the new scratch program and make the following changes: #include <strsafe.h> class RootWindow : public Window...

Now that we've had a quick introduction to asynchronous input, let's look at some of the details. Remember, this is a peek under the hood at how the sausage is made. The algorithm described here is not part of the API contract and it can change at any time, as long as it services the overall goal of serializing input. Let's start by looking at ...

One of the topics I covered at my PDC talk was the asynchronous input model. I don't think I ever discussed it on this Web site, so I guess I'll do it now, so that I can point people at it in the future. In the old days of 16-bit Windows, input was synchronous. All input went into a system-wide input queue, and the intuitive rule for input proce...

One night, the CD player got stuck due to a scratched disc and ended up repeating the same track over and over again. I dreamed that the song was O(n²) in length,¹ with each new verse one bar longer than the previous one, but unlike a cumulative song,² the location of the inserted bar varied randomly from verse to verse. Moral of ...

Ultimately, you can't stop somebody from ignoring the words Confidential at the top of a document and whipping out a digital camera and taking a picture of the screen. But at least starting in Windows 7 you can make it a little more difficult. Take our scratch program and add this one line: ... SetWindowDisplayAffinity(hwnd, WDA...