iOS Text Field Suggestions in Appcelerator Titanium

app.js

/**
 * This demonstrates how to show suggestions on a text field using just JavaScript with Appcelerator Titanium.
 *
 * You will need to download four images to get this to work:
 *
 * 1) http://dl.dropbox.com/u/16441391/Suggest/bg.png
 * 2) http://dl.dropbox.com/u/16441391/Suggest/[email protected]
 * 3) http://dl.dropbox.com/u/16441391/Suggest/separator.png
 * 4) http://dl.dropbox.com/u/16441391/Suggest/[email protected]
 *
 * I suggest placing them in "images/suggest/", but you can configure where they go in the "config" method.
 * 
 * By Dawson Toth, Appcelerator Inc.
 */

// STEP 1: Include our JavaScript module.
var suggest = require('suggest');
suggest.config({
    imageDirectory: 'images/suggest/'
});

var win = Ti.UI.createWindow({
    layout: 'vertical', backgroundColor: '#fff'
});

// STEP 2: We'll define four text field in a loop, down below.
var fields = [
    'To', 'From', 'CC', 'BCC'
];

var customerEngineers = [ 'Dawson Toth', 'Pedro Enrique', 'Jon Alter', 'Alan Leard', 'Rick Blalock', 'Matthew Congrove' ];
function findCustomerEngineers(evt) {
    var results = [];
    // No text in the text field? That's fine, we won't show any suggestions.
    if (evt.value.length == 0)
        return results;
    var searchFor = evt.value.toLowerCase();
    for (var p in customerEngineers) {
        if (customerEngineers[p].toLowerCase().split(searchFor).length > 1) {
            results.push(customerEngineers[p]);
            if (results.length > 3) {
                break;
            }
        }
    }
    return results;
}

for (var f in fields) {
    // STEP 3: We need to wrap the text field in a view; the suggestions will be added to the bottom of this.
    var wrapper = Ti.UI.createView({
        top: 0, left: 20, right: 20, height: 50
    });
    // STEP 4: Create the text field itself, and add it to the wrapper.
    var text = Ti.UI.createTextField({
        top: 20, left: 0, right: 0, height: 30,
        hintText: fields[f], autocapitalization: 0,
        borderStyle: Ti.UI.INPUT_BORDERSTYLE_ROUNDED
    });
    wrapper.add(text);
    // STEP 5: Call the "bind" method of our module. 
    suggest.bind({
        wrapper: wrapper,
        control: text,
        dataSource: findCustomerEngineers
    });

    // STEP 6: Add the wrapper to the window, open the window, and we're done!
    win.add(wrapper);
}

win.open();

suggest.js

/**
 * This module lets you set up suggestions on text fields.
 * 
 * You will need to download four images to get this to work:
 *
 * 1) http://dl.dropbox.com/u/16441391/Suggest/bg.png
 * 2) http://dl.dropbox.com/u/16441391/Suggest/[email protected]
 * 3) http://dl.dropbox.com/u/16441391/Suggest/separator.png
 * 4) http://dl.dropbox.com/u/16441391/Suggest/[email protected]
 *
 * I suggest placing them in "images/suggest/", but you can configure where they go in the "config" method.
 */

// Instance Variables
var baseImageDirectory;

/**
 * Allows you to customize the behavior of the module.
 * @param args A dictionary with the following keys: imageDirectory, controls where the images are loaded from.
 */
exports.config = function(args) {
    baseImageDirectory = args.imageDirectory || '';
};

/**
 * Sets up a text field for showing suggestions.
 * @param args A dictionary with the following keys: control, wrapper, and dataSource.
 */
exports.bind = function(args) {
    if (!args.control || !args.wrapper || !args.dataSource) {
        throw 'Not all required parameters provided: "control", "wrapper", and "dataSource" must be specified!';
    }

    var visible = false, changed = false, latestValue = '';

    var suggestions = Ti.UI.createView({
        backgroundImage: baseImageDirectory + 'bg.png',
        backgroundLeftCap: 9,
        height: 43,
        top: args.wrapper.size.height - 5,
        left: 20, right: 20
    });

    var container = Ti.UI.createScrollView({
        left: 5, right: 5, height: 43, width: 'auto',
        layout: 'horizontal', contentWidth: 'auto'
    });
    suggestions.add(container);

    function clickListener(evt) {
        if (evt.source.isSuggestion) {
            args.control.value = latestValue = evt.source.text;
            visible = changed = false;
            hide();
        }
    }

    var children = [];

    var originalHeight = args.wrapper.size.height || 0;

    function show() {
        args.wrapper.height = originalHeight + suggestions.height - 5;
        args.wrapper.add(suggestions);
    }

    function hide() {
        args.wrapper.remove(suggestions);
        args.wrapper.height = originalHeight;
    }

    function sync() {
        if (changed) {
            changed = false;
            var data = args.dataSource({ source: args.control, value: latestValue });
            if (!data || data.length == 0) {
                if (visible) {
                    visible = false;
                    hide();
                }
            }
            else {
                if (!visible) {
                    visible = true;
                    show();
                }
                for (var c = 0; c < children.length; c++) {
                    if (children[c].isSuggestion) {
                        children[c].removeEventListener('click', clickListener);
                    }
                    container.remove(children[c]);
                }
                children = [];
                for (var i = 0; i < data.length; i++) {
                    var child = Ti.UI.createLabel({
                        isSuggestion: true,
                        text: data[i], font: { fontSize: 14 },
                        color: '#fff', shadowColor: '#000', shadowOffset: { x: 0, y: -1 },
                        width: 'auto', height: 14, top: 13, bottom: 16, left: 15, right: 15
                    });
                    child.addEventListener('click', clickListener);
                    children.push(child);
                    container.add(child);
                    if (i != data.length - 1) {
                        var separator = Ti.UI.createView({
                            backgroundImage: baseImageDirectory + 'separator.png',
                            width: 2, height: 36, top: 2
                        });
                        children.push(separator);
                        container.add(separator);
                    }
                }
            }
        }
    }

    args.control.onChange = function(evt) {
        if (evt.source.value != latestValue) {
            latestValue = evt.source.value;
            changed = true;
        }
    };

    args.control.onFocus = function() {
        args.control.onChangeIntervalID = setInterval(sync, 1000);
        args.control.addEventListener('change', args.control.onChange);
        // force a refresh
        changed = true;
        if (visible) {
            show();
        }
    };
    args.control.addEventListener('focus', args.control.onFocus);

    args.control.onBlur = function() {
        clearInterval(args.control.onChangeIntervalID);
        args.control.removeEventListener('change', args.control.onChange);
        if (visible) {
            hide();
        }
    };
    args.control.addEventListener('blur', args.control.onBlur);
};

/**
 * Stops a text field from showing suggestions.
 * @param args A dictionary with the following keys: control.
 */
exports.unbind = function(args) {
    if (!args.control) {
        throw 'Not all required parameters provided: "control" must be specified!';
    }
    clearInterval(args.control.onChangeIntervalID);
    args.control.fireEvent('blur');
    args.control.removeEventListener('focus', args.control.onFocus);
    args.control.removeEventListener('blur', args.control.onBlur);
    args.control.removeEventListener('change', args.control.onChange);
    args.control.onChange
        = args.control.onFocus
        = args.control.onBlur
        = args.control.onChangeIntervalID
        = null;
};

I didn't see that you coud scroll horizontally the suggestions. This allows the user to see all the suggestions, so it's fine. Your code is great : bravo