simple and pretty Prompt Dialog Builder [Android] [Java] [Dialogs] [UI]

PromptDialogBuilder.java

package com.oos.kryten.dialogs;

import static com.google.common.base.Preconditions.checkNotNull;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.widget.EditText;

public class PromptDialogBuilder extends AlertDialog.Builder {

	private InternalListener listener;
	private CharSequence positiveText;
	private Integer positiveResourceId = android.R.string.ok;
	private CharSequence negativeText;
	private Integer negativeResourceId = android.R.string.cancel;
	private static Integer padding;
	private static final float PADDING = 10f; 

	public interface PromptListener {
		public void onInputProvided(String input);

		public void onCancel();

		public class Impl implements PromptListener {
			
			@Override
			public void onInputProvided(String input) {
			}

			@Override
			public void onCancel() {
			}
		}

	}

	@Override
	public AlertDialog create() {
		if (positiveText != null) {
			setPositiveButton(positiveText, listener);
		} else {
			setPositiveButton(positiveResourceId, listener);
		}
		if (negativeText != null) {
			setNegativeButton(negativeText, listener);
		} else {
			setNegativeButton(negativeResourceId, listener);
		}
		AlertDialog dialog = super.create();
		listener.input = new EditText(getContext());
		int pad = padding;
		listener.input.setOnKeyListener(listener);
		dialog.setView(listener.input, pad, 0, pad, pad);
		return dialog;
	}

	public PromptDialogBuilder(Activity activity) {
		super(activity);
		Display display = activity.getWindowManager().getDefaultDisplay();
		DisplayMetrics metrics = new DisplayMetrics();
		display.getMetrics(metrics);
		padding = (int) (PADDING * metrics.density);
		listener = new InternalListener(new PromptListener.Impl());
	}

	public PromptDialogBuilder setPromptListener(PromptListener listener) {
		this.listener = new InternalListener(listener);
		return this;
	}

	public PromptDialogBuilder setPositiveButton(CharSequence text) {
		positiveText = text;
		return this;
	}

	public PromptDialogBuilder setPositiveButton(int textId) {
		positiveResourceId = textId;
		return this;
	}

	public PromptDialogBuilder setNegativeButton(CharSequence text) {
		negativeText = text;
		return this;
	}

	public PromptDialogBuilder setNegativeButton(int textId) {
		negativeResourceId = textId;
		return this;
	}

	private class InternalListener implements OnClickListener, OnKeyListener {

		private final PromptListener listener;
		private EditText input;

		private InternalListener(PromptListener listener) {
			super();
			if(listener == null) {
				throw new NullPointerException("Listener can't be null");
			}
			this.listener = listener;
		}

		@Override
		public void onClick(DialogInterface dialog, int which) {
			switch (which) {
			case AlertDialog.BUTTON_POSITIVE:
				final CharSequence email = input.getText();
				listener.onEmailProvided(email.toString());
			case AlertDialog.BUTTON_NEGATIVE:
			default:
				dialog.dismiss();
				break;
			}
		}

		@Override
		public boolean onKey(View v, int keyCode, KeyEvent event) {
			if (keyCode == KeyEvent.KEYCODE_ENTER) {
				onClick(dialog, AlertDialog.BUTTON_POSITIVE);
				return true;
			}
			return false;
		}
	}

}

Usage

new PromptDialogBuilder(this)
	.setPositiveButton(R.string.offer_signup) // sets the positive (ok) button text
	// .setNegativeButton(R.string.cancel) // we can use it but the default should be sufficient
	.setPromptListener(new PromptListener.Impl() {
		@Override
		public void onInputProvided(String input) {
			// do whatever with the email
		}
	}) //
	.setTitle(R.string.offer_signing) // This one now returns the AlertDialog.Builder and now we handle it as a normal Builder
	.setMessage(R.string.offer_need_email) //
	.show();

How to implement with a custom layout ?