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YUI Library Examples: Color Picker Control: Inline Color Picker Control from Script

Color Picker Control: Inline Color Picker Control from Script

The simplest way to implement the Color Picker Control is to do so entirely via script. In this example, a Color Picker Control is placed on the page via script and allowed to create its own DOM structure. In cases where you've provided other form controls on the page for color specification (ie, controls not dependent on JavaScript), this approach allows you to provide a richer visual experience for sighted users with JavaScript enabled.

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Building a Color Picker Instance via JavaScript

In this example, the Color Picker Control instance is allowed to create its own DOM structure. We begin with a simple style set for the containing element into which that DOM structure will be rendered and we place the containing element on the page:

1<style type="text/css"
2  #container { position: relative; padding: 6px; background-color: #eeeeee; width: 420px; height:220px; } 
3</style> 
4 
5<div id="container"
6<!--Color Picker will appear here--> 
7</div> 
8 
9<!--We'll use these to trigger interactions with the Color Picker 
10API --> 
11<button id="reset">Reset Color to White</button> 
12<button id="gethex">Write current hex value to the Logger</button>  
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With a target element in place, we can instantiate Color Picker and provide our desired configuration options. In this example, we are specifying that HSV and hex controls should be displayed and we're specifying custom locations for the color-picker slider thumb and the hue slider thumb. For the purposes of the example, we're also hooking into the Color Picker's rgbChange event and logging the newValue to the logger console; you'll see those log messages each time you adjust the color. This example also demonstrates how to use the picker's get method to tap into the current hex value via script.

1(function() { 
2    var Event = YAHOO.util.Event, 
3        picker; 
4 
5    Event.onDOMReady(function() { 
6            YAHOO.log("Creating Color Picker.""info""example"); 
7            picker = new YAHOO.widget.ColorPicker("container", { 
8                    showhsvcontrols: true
9                    showhexcontrols: true
10                    images: { 
11                        PICKER_THUMB: "assets/picker_thumb.png"
12                        HUE_THUMB: "assets/hue_thumb.png" 
13                    } 
14                }); 
15            YAHOO.log("Finished creating Color Picker.""info""example"); 
16             
17            //a listener for logging RGB color changes; 
18            //this will only be visible if logger is enabled: 
19            var onRgbChange = function(o) { 
20                /*o is an object
21                    { newValue: (array of R, G, B values),
22                      prevValue: (array of R, G, B values),
23                      type: "rgbChange"
24                     }
25                */ 
26                YAHOO.log("The new color value is " + o.newValue, "info""example"); 
27            } 
28             
29            //subscribe to the rgbChange event; 
30            picker.on("rgbChange", onRgbChange); 
31 
32            //use setValue to reset the value to white: 
33            Event.on("reset""click"function(e) { 
34                picker.setValue([255, 255, 255], false); //false here means that rgbChange 
35                                                         //will fire; true would silence it 
36            }); 
37             
38            //use the "get" method to get the current value 
39            //of one of the Color Picker's properties; in  
40            //this case, we'll get the hex value and write it 
41            //to the log: 
42            Event.on("gethex""click"function(e) { 
43                YAHOO.log("Current hex value: " + picker.get("hex"), "info""example");  
44            }); 
45 
46        }); 
47})(); 
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It's advisable to provide all necessary configurations at the instantiation of the Color Picker; it renders immediately and automatically upon creation.

Configuration for This Example

You can load the necessary JavaScript and CSS for this example from Yahoo's servers. Click here to load the YUI Dependency Configurator with all of this example's dependencies preconfigured.

YUI Logger Output:

Logger Console

INFO 1053ms (+3) 5:34:48 AM:

ColorPicker

picker update [0, 0]

WARN 1050ms (+13) 5:34:48 AM:

ColorPicker

hue update: 0

INFO 1037ms (+0) 5:34:47 AM:

example

Finished creating Color Picker.

INFO 1037ms (+0) 5:34:47 AM:

ColorPicker

Setting picker slider to 0,0

INFO 1037ms (+0) 5:34:47 AM:

ColorPicker

Hue slider is being set to 0

INFO 1037ms (+1) 5:34:47 AM:

ColorPicker

RGB value set to [255, 255, 255] (hsv: [0, 0, 1])

INFO 1036ms (+1) 5:34:47 AM:

ColorPicker

RGB value set to 255,255,255

INFO 1035ms (+1) 5:34:47 AM:

ColorPicker

picker size180

INFO 1034ms (+2) 5:34:47 AM:

ColorPicker

Building markup

INFO 1032ms (+6) 5:34:47 AM:

example

Creating Color Picker.

INFO 1026ms (+1026) 5:34:47 AM:

LogReader instance0

LogReader initialized

INFO 0ms (+0) 5:34:46 AM:

global

Logger initialized

More Color Picker Control Resources:

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