Dependency Injection Pattern

Topic: Don’t Look For Things!
Speaker: Miško Hevery
Subject: Dependency Injection

Video: 


Slides:

for more details: http://martinfowler.com/articles/injection.html

Subpixel Layout And Rendering

Gecko does subpixel layout and rounds coordinates to device pixels for rendering.

He's right that in some sense, when you have to render a CSS layout to a screen with discrete pixels, all the options are imperfect and browsers are choosing different imperfect options. However I think we need to explain the big picture a little better.

Gecko intentionally supports subpixel layout because for high resolution output devices, especially printers but also high-DPI screens that will become more common, one CSS "px" should be mapped to many device pixels, so you can in fact do sub-CSS-pixel rendering. For those devices, rounding layout units to CSS pixels is actually throwing away information and giving you a strictly worse layout than Gecko will give. For example, try printing in FF3 beta. You should see that in the printout (or generated PDF), no rounding has occurred and each child DIV looks identical.

Because this is important and we don't want layout to vary unnecessarily across devices, we do subpixel layout on all devices. When we have to draw to a regular-DPI screen, we then have to round the edges of drawn objects to the nearest screen pixel. This explains the results. Note that our approach of rounding at drawing time is optimal for avoiding gross layout changes due to rounding; it limits the impact of rounding to moving object edges by one pixel in some direction. It avoids gross layout changes like IE moving a DIV to the next line, or Safari leaving a 2px strip vacant at the end of the line. Thus I believe our approach is better than the alternatives in important ways.

The preceding paragraph is actually a slight oversimplification. We do have to do some rounding during layout simply due to the fact that computer arithmetic has limited precision. So during layout we round measurements to the nearest 1/60th of a CSS pixel. This number was chosen so that common fractions of a CSS pixel can be represented exactly. Note that rounding to 1/60th of a CSS pixel is far more benign than rounding to CSS pixels; 1/60th of a CSS pixel is approximately 1/5760th of an inch, not something most people are going to worry about!

In practice, we have seen very few Web compatibility issues caused by this scheme. Web authors should just not worry about the rounding, and should not attempt to round coordinates themselves. The new getBoundingClientRect and getClientRects APIs in FF3 can return fractional coordinates, just go with the flow. Feel free to position elements at those fractional boundaries, it will be lined up visually. If you insist on consistent rendering down to the pixel, then the only way to go is to specify px values for everything, including line-heights, and avoid percentage units. Or better still, use SVG. Or a PNG.

Add Copy To / Move To to the Windows Explorer Right Click Menu

A hidden functionality in Windows allows you to right click on a file, select Copy To Folder or Move To Folder, and the move to box will pop up and let you choose a location to either copy or move the file or folder to.

Here's the quick registry hack to get this working. As usual, back up your registry just in case. You will want to browse down to this key:

HKEY_CLASSES_ROOT\AllFilesystemObjects\shellex\ContextMenuHandlers

Once you are at that key, right click and choose the New Key option:

Now you will double-click on the (Default) value and enter the following:

{C2FBB630-2971-11D1-A18C-00C04FD75D13}

Click OK and continue.

If you want to enable Move To, you will repeat the same steps, except creating a new key named Move To, and using this value:

{C2FBB631-2971-11D1-A18C-00C04FD75D13}

Now when you right click on a file or folder, you should see the following options:

Let's click Copy To Folder just to see what happens….

And that's it. Useful!

.SO extension

• Extension: .so
• Type: Unix Shared Library
• Category: Development
• Mime type: application/octet-stream
• Description: SO file is an Unix Shared Library (Shared Object). A shared library is a library of functions or classes (for C/C++ programmers) that are compiled, linked, and stored separately from the clients (applications) that use them. The UNIX equivalent of a DLL file in Windows is a Shared Library (SO) file.