/documentation/videos/02-strokes

 1# -*- mode: org -*-
 2
 3* [[http://www.youtube.com/watch%3Fv%3DMu5FCQmtdJU][Video: Stroke Dialer For Eyes-Free Keypad Input]]
 4
 5
 6The /stroke dialer/ enables one-handed keypad input using the
 7touch-screen --- and that without having to even look at the
 8screen. Here is how it works --- we start with a brief
 9description of the problem  that asks the /right/
10question. The answer becomes self-evident as you follow this
11video.
12
13** The Problem
14
15On-screen keyboards typically show some buttons on the screen
16that you activate by touching the screen. To activate such
17buttons, one needs to look at the screen, because the buttons are
18placed at specific points on the screen, i.e., they are
19/absolutely/ positioned. So what if you want to activate such
20buttons /without/ looking at the screen?
21From the foregoing description, it's clear that the only reason
22one is forced to  look at  an on-screen keyboard  is because the
23buttons are /absolutely/ positioned. So let's relax that
24constraint, let's use /relative/ positioning to place the
25buttons.
26
27We'll start with a keyboard we're all familiar with, the
28telephone keypad. Since we're using relative positioning,
29let's place  the center of the keypad  /wherever/ you  first
30touch the screen.
31So, to dial a _5_, you just touch the screen.
32
33Now, you know where _5_ is --- it's where you first touch
34down. But look, since you know the layout of a phone keypad, you
35can now find all the other digits /relative/ to the _5_. So for
36example, _2_ is directly above _5_ --- so to    press _2_, you
37touch down on the screen, and stroke up before lifting your
38finger.
39similarly, you stroke down for an _8_, or diagonally up for a
40_1_.
41
42In real life, we both /hear/ and /feel/ as we press physical
43buttons. This form of synchronized auditory and tactile feedback
44is essential for creating user interfaces that /feel/
45realistic. The stroke dialer produces a slight vibration as  the
46finger moves over the various buttons that is synchronized with
47an auditory /tick/ to achieve this effect. It also produces
48spoken feedback to indicate the button that was pressed.
49
50To conclude this video, let's dial a few numbers.
51
52#+TITLE: Video: Stroke Dialer For Android
53#+AUTHOR: T.V Raman
54#+EMAIL: raman@google.com
55#+DATE: 2009-03-30 Mon
56#+LANGUAGE: en
57#+OPTIONS: H:3 num:t toc:nil \n:nil @:t ::t |:t ^:t -:t f:t *:t
58#TeX:t LaTeX:nil skip:nil d:nil tags:not-in-toc +LINK_UP:
59#http://eyes-free.googlecode.com/svn/trunk/documentation/videos/index.html
60#+LINK_HOME: http://eyes-free.googlecode.com/