Android Themes: A dialog without a title


Most of the times, I have seen developers not leveraging the power of themes and styles. Themes and styles are a great way to easily create UI that are  manageable and compatible for various platforms. Here’s the official documentation that explains styles and themes in details, and I consider this portion of documentation to be equally important to any developer working with Android.

For the example of this post, we will see how to make a dialog, a custom dialog, not to have a title. The easiest way to do this, is through code byt writing this snippet in your custom dialog class.

requestWindowFeature(Window.FEATURE_NO_TITLE);

Dialog with Title on Android 2.2


Dialog with no title on Android 2.2

While this would work anyway, and would also be compatible with all the versions of Android. But, it’s a good idea to use more of your themes and styles in your programming, so that your code base is maintainable and your apps would behave and feel consistently. Using styles and themes makes it very easy to tweak or adapt to various platform versions and/or device sizes and resolutions. So, let’s get in.

The application tag, has a configurable attribute called “android:theme” with which you can set a theme to your application as a whole. You can also specify themes for individual themes for all your activities separately. Sounds nice!!! But, let’s stick to one theme for our application as a whole for simplicity.

For this example, we have a theme (it’s actually called a style), called MyThemeSelector as shown below. This is specified in the styles.xml in your values folder. Notice, your custom theme is a child of the Theme, which is one of the system’s default themes.

<resources>        <style name=”MyThemeSelector” parent=”@android:style/Theme”></style></resources>

Ideally, you should also declare your custom theme to extend one of the basic themes that are available with platforms on or above Honeycomb. For example, here we have created another styles.xml in a folder called values-v11, which looks like this.

<resources>
        <style name=”MyThemeSelector” parent=”@android:style/Theme.DeviceDefault.Light”></style>
</resources>

So, your basic theme is now compatible with both older versions and versions greater than Honeycomb. By this, I mean, that, when you run the app, your app would adapt to the platform that it is running on, and would give a consistent look and feel for your users.

Now, coming back to the main problem. “Creating a dialog without title”. Here also, we would use themes, as against code. Here are the two new themes that you would be declaring.

For values folder: (Platform versions older than Honeycomb)

<style name=”My.Theme.Dialog” parent=”@android:style/Theme.Dialog”>
            <item name=”android:windowNoTitle”>true</item>
</style>
<style name=”MyThemedDialog” parent=”@style/My.Theme.Dialog”></style>

For values-v11 folder: (Platform version for Honeycomb and above)

<style name=”My.Dialog.Theme” parent=”@android:style/Theme.DeviceDefault.Light.Dialog.NoActionBar”></style>
<style name=”MyThemedDialog” parent=”@style/My.Dialog.Theme”></style>

There’s a subtle difference between the two versions. Of course, other than the parent classes. In older platform versions, there wasn’t a version of the Dialog theme without a title bar. So, what we do here, is to extend the basic Dialog them, and overwrite an attribute, so that our custom “My.Theme.Dialog” is a dialog without a title bar.

But, for Honeycomb and above, the platform itself provides a version of the Dialog theme, without the title bar (or the Action Bar).

And finally, the last step for getting everything to work is set the theme to your dialogs.

MyDialog dialog = new MyDialog(this, R.style.MyThemedDialog);
dialog.setTitle(“Here’s my title”);
dialog.show(); 

Why didn’t we use “My.Theme.Dialog” directly? Well, we could still try and tweak the theme for older versions, in the values folder, by adding a few more attributes.

Dialog with title on Android 4.1


Dialog with no title on Android 4.1

As you can see, for both older and newer platforms, the app runs by adapting itself and gives a consistent look and feel. You didn’t have to do much with your code. 
15 lines of XML is the MAGIC here!!!!  (I didn’t count though, just guessing)

Sample project here.

Drag and Drop (Honeycomb/ICS)

Drag and drop is already available with Honeycomb and up. In this example, we will see how to implement a simple Drag and Drop Operation.

We have a ListView with some items. The other half of the screen would have a drop area which has a single TextView. We will see, how to drag items from the ListView, drop them into the drop area, which will update the TextView with the list item’s title, and also, that particular item would be removed from the ListView.

We will trigger the drag operation, when you long tap on an item in the ListView. After the drag operation is started, you will see a floating view of the selected item, which you can move around the screen. When you approach the drop area, the background of the drop area would change, which means that you can now drop your item. Once you leave the item, the TextView inside the drop area will show the text of the selected item.

This should also work on Ice Cream Sandwich. You can find the whole source code here. The code is quite self-explanatory. But, if you have any queries, let me know through the comment form. There are a few comments in the code to help you.