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.
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 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 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 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.
This depends upon the cwac-parcel library for accessing
project-level resources.
This is version v0.4.1 of this module, meaning it is creeping towards respectability.
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.
The code in this project is licensed under the Apache Software License 2.0, per the terms of the included LICENSE file.
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.
v0.4.1: fixed ColorPreference to work better on Honeycomb
v0.4.0: converted to Android library project, added ColorMixerActivity
