CWAC ColorMixer: Appealing To Your Users' Sense of Fashion

Sometimes, you want your users to pick a color. A simple approach is to give the user a fixed roster of a handful of colors -- easy, but limited. A fancy approach is to use some form of color wheel, but these can be difficult to use on a touchscreen and perhaps impossible without a touchscreen.

ColorMixer is a widget that provides a simple set of SeekBars to let the user mix red, green, and blue to pick an arbitrary color. It is not very big, so it is easy to fit on a form, and it is still fairly finger-friendly.

It is also packaged as a dialog (ColorMixerDialog), a dialog-themed activity (ColorMixerActivity), and a preference (ColorPreference).

This is distributed as an Android library project, following the conventions of the Android Parcel Project. You can download a ZIP file containing just the library project (sans sample code) from the Downloads section of this GitHub repository.

Usage

ColorMixer

ColorMixer is a simple widget. Given that you have the parcel installed in your project, or have manually merged the source and resources into your project, you can add the widget to a layout like any other:

<com.commonsware.cwac.colormixer.ColorMixer
	android:id="@+id/mixer"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
/>

You can call getColor() and setColor() to manipulate the color at runtime. You can also call setOnColorChangedListener() to register a ColorMixer.OnColorChangedListener object, which will be called with onColorChanged() when the color is altered by the user.

ColorMixerDialog

ColorMixerDialog is an AlertDialog subclass. Hence, to create and show the dialog, all you need to do is create an instance and show() it:

new ColorMixerDialog(this, someColor, onDialogSet).show();

In the above code snippet, this is a Context (e.g., an Activity), someColor is the color you want to start with, and onDialogSet is a ColorMixer.OnColorChangedListener that will be notified if the user clicks the "Set" button on the dialog and has changed the color from the initial value.

ColorMixerActivity

ColorMixerActivity is a dialog-themed Activity. This is useful for situations where you want a dialog but do not want to deal with a dialog.

To use it, add it as an activity to your project. You will need to use the full package in your <activity> element, marking it as using Theme.Dialog. Here is one implementation, from the demo/ project:

<activity android:name="com.commonsware.cwac.colormixer.ColorMixerActivity"
				android:label="@string/app_name"
				android:theme="@android:style/Theme.Dialog">
</activity>

In the Intent you use to start the activity, you can supply the starting color via a ColorMixerActivity.COLOR integer extra, and the dialog title via a ColorMixerActivity.TITLE string extra. For example:

Intent i=new Intent(this, ColorMixerActivity.class);

i.putExtra(ColorMixerActivity.TITLE, "Pick a Color");
i.putExtra(ColorMixerActivity.COLOR, mixer.getColor());

startActivityForResult(i, COLOR_REQUEST);

ColorPreference

ColorPreference is a Preference class, to be referenced in preference XML and loaded into a PreferenceActivity. It has no attributes beyond the standard ones.

<PreferenceScreen
	xmlns:android="http://schemas.android.com/apk/res/android">
	<com.commonsware.cwac.colormixer.ColorPreference
		android:key="favoriteColor"
		android:defaultValue="0xFFA4C639"
		android:title="Your Favorite Color"
		android:summary="Blue.  No yel--  Auuuuuuuugh!" />
</PreferenceScreen>

The preference is stored as an integer under the key you specify in the XML.

Dependencies

This depends upon the cwac-parcel library for accessing project-level resources.

Version

This is version v0.4.1 of this module, meaning it is creeping towards respectability.

Demo

There is a demo/ directory containing a demo project. It uses the library project itself to access the source code and resources of the ColorMixer library.

License

The code in this project is licensed under the Apache Software License 2.0, per the terms of the included LICENSE file.

Questions

If you have questions regarding the use of this code, please post a question on StackOverflow tagged with commonsware and android. Be sure to indicate what CWAC module you are having issues with, and be sure to include source code and stack traces if you are encountering crashes.

If you have encountered what is clearly a bug, please post an issue. Be certain to include complete steps for reproducing the issue.

Do not ask for help via Twitter.

Release Notes

v0.4.1: fixed ColorPreference to work better on Honeycomb v0.4.0: converted to Android library project, added ColorMixerActivity

bearmingo / cwac-colormixer