YJL

Last week, We Wish You a Merry Christmas was playing somewhere, an idea came to me, what if your computer sings one note on every key you press? That would be fun, wouldnt it?

And here is the merryxmas.sh and a video to demonstrate.

It always is a wonderful experience when you witness an evolution. Since the invention of typewriter, only low-skilled users would require 10 fingers to operate on a keyboard. Until today, it remains perfectly true.

As technology progresses, computer entered our daily life and has been dominating every corner in the entire world since then. At the beginning of commercial computing, only the people like secretaries, data entry, or code monkeys would require having no skill of the 10-finger typing whilst bosses only use 1 finger or 2 fingers to type in.

Using 1 finger or 2 fingers are the hardest way to type, because, firstly, you need to clear the field. You need a clear view of keyboard, so you can locate the key you are about to press. Imagining that there are around 100 keys on the board, you need to spot them as fast as you can. And for aged keyboard, the printing would have worn out, you may have to guess which one is correct key, this only demonstrate how skillful of 1-or-2-finger typer is.

After a desired key is spotted, the typer's motor skill kicks in, he or she presses the key with quick and precise press, then immediately retreats from the keyboard.

At this moment, the task hasn't been completed, far from it. The typer must change the focus from keyboard to monitor, the typer's eyes have to adapt such dramatic change in a short time. Seeking for the new typed letter on the screen where the cursor at which typer has to remember before typing.

Once confirmed, then repeat the process. As you can see, 1-or-2-finger is more skillful than 10-finger typer, who only stares at the screen all the time and type like nothing, there is no skill in them.

After the mouse device invented, till today, it's basically a three-button pointer device. Some 1-or-2-finger typers evolve into more skillful, then now may only use only one hand to control the whole computer, which is the same hand control the mouse.

Using a mouse is even harder then typing. The main goal is to find the Next button on the screen, which isn't always on the screen or it could be hard to be seen. Often times, the mouse users have to combine different types of controlling skills, suck as double-click, right-click, drag-and-drop, etc. On keyboard, it's only one, press.

Later, the mobile devices has become more important for one's life. Screen gets smaller as well as the keyboard, physical or virtual, the typer's skill is forced to evolve once more.

Then, the groundbreaking device was invented, the mighty iPhone and later iPad. Typer is no longer a typer, but a toucher. With only one finger to operate, as you can guess, it requires smarter people to use such devices. They have to learn new gestures in order to operate, such as slide. Fortunately, multi-touch is added later for people less skilled, who used to 10-finger typing.

Not only the devices evolve, but also the web. Less than a year ago, Google began a process to unify its products' designs starting with its navigation bar, Gmail, Google Groups, Google Reader, and more has already adopted. Things got bigger, such as buttons, that's good for toucher to touch. The looks is more like designs on *pad, like a millions of websites have already imitated *pad design. A more recent example is the Google+: Toward a simpler, more beautiful Google.

Google was wrong about it, it never was simpler. Such design requires users' long-trained skills. For users who have trained themselves from 10-finger typing to 1-finger touching, then it is simpler. But for newcomers, it requires a long period of training. Unfortunately, for less skilled 10-finger typer, the old aged and stubborned users who just won't die, but there is no resolution for them.

In foreseeable future, human may no longer need any fingers to operate a computer. However, it requires more skillful person to operate without a finger as it already is proved with decades of computing history as described above.

I recently found out you can use xinput to enable or disable an input device. I used to use synclient to disable my touchpad, or using this tricky way to disable my laptop keyboard.

The first step to get device name or id of the device:

% xinput list
 Virtual core pointer                          id=2    [master pointer  (3)]
    Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
    USB Optical Mouse                         id=8    [slave  pointer  (2)]
    SynPS/2 Synaptics TouchPad                id=7    [slave  pointer  (2)]
 Virtual core keyboard                         id=3    [master keyboard (2)]
     Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
     Sleep Button                              id=9    [slave  keyboard (3)]
     Power Button                              id=10   [slave  keyboard (3)]
     Video Bus                                 id=11   [slave  keyboard (3)]
     AT Translated Set 2 keyboard              id=6    [slave  keyboard (3)]

For touchpad, the device name is 'SynPS/2 Synaptics TouchPad' and id is 7; for keyboard, they are 'AT Translated Set 2 keyboard' and 6. Next step is to know the properties of a device:

% xinput list-props 'AT Translated Set 2 keyboard'
Device 'AT Translated Set 2 keyboard':
        Device Enabled (127):   1

This keyboard only has a property 'Device Enabled' whose value is 1, that means this keyboard is enabled. To test disabling:

sleep 0.1 ; xinput set-prop 'AT Translated Set 2 keyboard' 'Device Enabled' 0 ; sleep 5 ; xinput set-prop 'AT Translated Set 2 keyboard' 'Device Enabled' 1

The first sleep 0.1 is to prevent enter keypress being repeatedly sent somehow when you directly disable the keyboard, I am guessing when you hit the enter and the command is executed, meaning the keyboard is disabled, but the keyup event is not yet sent, so X still thinks the enter key is pressed down.

Another simple way is to use id, so you dont need long device name:

sleep 0.1 ; xinput set-prop 8 127 0 ; sleep 5 ; xinput set-prop 8 127 1

8 is id of this keyboard and 127 is the property id of 'Device Enabled'. When you list properties of device using list-props, the numbers after property names are the property ids. It seems that 'Device Enabled' always has id 127, but device id is not always the same. It depends on device attached time, who shows up first who gets next available id.

One more thing to note: I dont need root privilege to set property value.

I first knew Reverse Len from Flickr Blog, then I googled to learn how to do it. The following photos are my first try.