NexusDialog

Simple Form Generator for Android

NexusDialog is a library that allows you to dynamically generate forms in Android with little code. It's great for apps with many form-based UIs, since it reduces the boilerplate code to setup the view layout and tie things together in the Activity. Currently, it supports Android API 10+.

This library follows semantic versioning. Note that since this library is still active in development, new releases might introduce interface-breaking changes, which will be indicated in the changelog. NexusDialog 1.0.0 will be the first stable release.

A Simple Example

To give you an idea of the simplicity of NexusDialog, here's a screenshot of a simple example:

Here's the code for that example (less than 7 lines of real code!):

import java.util.Arrays;
import com.github.dkharrat.nexusdialog.FormActivity;
import com.github.dkharrat.nexusdialog.controllers.*;

public class SimpleExample extends FormActivity {

    @Override protected void initForm() {
        setTitle("Simple Example");

        FormSectionController section = new FormSectionController(this, "Personal Info");
        section.addElement(new EditTextController(this, "firstName", "First name"));
        section.addElement(new EditTextController(this, "lastName", "Last name"));
        section.addElement(new SelectionController(this, "gender", "Gender", true, "Select", Arrays.asList("Male", "Female"), true));

        getFormController().addSection(section);
    }
}

For more examples, browse the sample directory.

Features

NexusDialog supports many built-in fields for your form, like text boxes, date pickers, spinners, etc. The framework is also designed to be extensible so that you can easily add custom form elements if needed. Contributions are also welcome! If you've implemented a custom control that is useful, pull requests are welcome and appreciated! Currently, the following form elements are supported:

• ValueController: Shows a TextView containing a value
• EditTextController: EditText view that allows for free-form text input.
• CheckBoxController: CheckBox view that allows for two-states: either checked or unchecked.
• DatePickerController: Displays a date picker to allow choosing a specific date
• TimePickerController: Displays a time picker to allow choosing a specific time
• SelectionController: Displays a spinner with a list of item to select from
• SearchableSelectionController: Displays a (typically large) list of items to select from, with the ability to search the list and also allow free-form text.

Apps Using NexusDialog

Do you have an app that's utilizing NexusDialog? Let me know and I'll add a link to it here!

How to Add NexusDialog to Your Project

There are multiple ways to include your project, depending on your build environment:

Gradle

Add the following dependency to your build.gradle file for your project:

dependencies {
  compile 'com.github.dkharrat.nexusdialog:nexusdialog:0.4.0'
}

Make sure your application is using the Android SDK v23 or later in your build.gradle file:

android {
    compileSdkVersion 23
    buildToolsVersion "23"
    ...
}

Maven

Add the following dependency to your pom.xml file for your project (requires android-maven-plugin 3.8.0+):

<dependency>
    <groupId>com.github.dkharrat.nexusdialog</groupId>
    <artifactId>nexusdialog</artifactId>
    <version>0.4.0</version>
    <type>aar</type>
</dependency>

Android Studio or IntelliJ 13+

Add the appropriate dependency in your build.gradle file and refresh your project.

Eclipse

1. In Eclipse, import the android-support-v7-appcompat library by following the instructions at this page.
2. Ensure the android-support-v7-appcompat library has been imported and is compiling without errors.
3. Import the nexusdialog library project into Eclipse:
   1. Select Existing Android Code Into Workspace and click Next.
   2. Browse to the library path: nexusdialog/src/main.
   3. Click Finish to import the project. You should now see a project called main.
   4. Right-click on the project in the Package Explorer and select Refactor > Rename.
   5. Name the project 'nexusdialog'
   6. Right-click the nexusdialog project in the Package Explorer and select Properties.
   7. Select the Java Build Path page and click on the Source tab.
   8. Remove the nexusdialog/src source folder from the list.
   9. Click on the Add Folder button.
   10. Select the folder java and click OK.
   11. In the same Properties dialog, select the Android page.
   12. Under the Project Build Target select a target of API 17 or higher.
   13. Enable the Is Library checkbox.
   14. Click on the Add button to add a library dependency.
   15. Select the android-support-v7-appcompat library and click OK.
   16. Press OK in the Properties dialog to close it.
   17. Ensure the library compiles without errors. You may need to clean the project multiple times to be in a clean state.
4. Add the nexusdialog project as a dependency to your project:
   1. Right-click on your project in the Package Explorer list and select Properties.
   2. Select the Android page.
   3. Under the Library section, click the Add button.
   4. Select nexusdialog and press OK.
   5. Press OK in the Properties dialog to close it.
5. You can now start using NexusDialog in your project.

How to Use NexusDialog

Once NexusDialog is setup as a dependency in your project (by following the instructions above), you can start creating forms right away! The main classes you will be working with the most are:

• FormActivity or FormActivityWithActionBar: If you wish to use the default Activity implementation for NexusDialog, this is the base class for each activity you wish to display a form in. Your activity must inherit from it. Form setup is done in the initForm() method.

• FormController: This is the main class that manages the form elements of NexusDialog. It provides simple APIs to quickly create and manage form fields. FormActivity creates this class for you, or you can be create one manually for custom Activities.

• FormElementController: Although you will not be using this class directly, you will be using its subclasses. All form elements (text boxes, labels, sections, etc.) inherit from this base class, which provides them common functionality and properties they need. Also, you could use FormSectionController to group a set of form fields together.

• FormModel: This class abstracts the data model your form will use. It's the interface that NexusDialog uses to access and update the underlying data model the form is based on. A FormActivity uses it to initialize the field values to the desired values when its first displayed, as well as update the underlying model when values change in the UI. FromActivity uses a default generic FormModel based on a key-value store that is usually sufficient for most use cases. However, if you need more control over how the form data is retrieved and stored, you can provide your custom implementation (via FormActivity#setModel).

Add some fields grouped by section

public class RegistrationForm extends FormActivity {
    @Override protected void initForm() {
        setTitle("Register Account");

        FormSectionController section1 = new FormSectionController(this, "Personal Info");
        section1.addElement(new EditTextController(this, "firstName", "First name"));
        section1.addElement(new EditTextController(this, "lastName", "Last name"));
        getFormController().addSection(section1);

        FormSectionController section2 = new FormSectionController(this, "Account");
        section2.addElement(new EditTextController(this, "username", "Username"));
        section2.addElement(new EditTextController(this, "password", "Password") {{
            setSecureEntry(true);
        }});
        getFormController().addSection(section2);
    }
}

Initialize fields to certain values when the form is first displayed

@Override protected void initForm() {
    // form setup
    // ...

    getModel().setValue("firstName", "John");
    getModel().setValue("lastName", "Smith");
}

To retrieve the current field value at any time:

getModel().getValue("firstName");

Listen to changes in fields:

getModel().addPropertyChangeListener("firstName", new PropertyChangeListener() {
    @Override public void propertyChange(PropertyChangeEvent event) {
        LOG.i("tag", "Value was: " + event.getOldValue() + ", now: " + event.getNewValue());
    }
});

Please browse through the samples included with the project for examples on how NexusDialog can be used.

Documentation

See the current Javadoc.

Styling

TODO

Adding Custom Elements

If the built-in form controls provided by NexusDialog don't meet your needs, you can easily extend NexusDialog to provide custom form elements. The common parent class for all form elements is FormElementController. Among other things, FormElementController tells NexusDialog how to construct the view to display in the form.

Typically your custom element falls under one of these cases:

1. Your custom element needs to show a label before a custom field: in this case, consider inheriting from LabeledFieldController which can provide the label functionality for you.

2. Your custom element needs full customization for how it's displayed: in this case, inherit from FormElementController and implement the createView method to tell NexusDialog how to create the custom view.

Browse through the catalog sample for an example of implementing a custom element, or go over the code for the built-in form elements to get an idea how they work.

Planned Features

The framework is constantly being improved and new features are being implemented. The following improvements are planned:

• Support buttons
• Support sliders

Contributing

Contributions via pull requests are welcome! For suggestions, feedback, or feature requests, please submit an issue.

Author

Dia Kharrat - dkharrat@gmail.com
Twitter: http://twitter.com/dkharrat

License

Copyright 2013 Dia Kharrat

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.