material-components_material-components-android/docs/components/Dialog.md

Alert Dialogs

An AlertDialog is a window that interrupts the current user flow. It is used to flag important choices like discarding drafts or changing permission settings. Material maintains usage of the framework AlertDialog, but provides a new builder, MaterialAlertDialogBuilder, which configures the instantiated AlertDialog with Material specs and theming. By default, a Material AlertDialog darkens the background with a scrim and appears in the center of the viewport. It is a fixed size based upon screen orientation and size.

Design & API Documentation

• Material Design guidelines: Dialogs
• Class definition
• Class overview

Usage

The MaterialAlertDialogBuilder allows creation of a Material AlertDialog. MaterialAlertDialogBuilder extends AlertDialog.Builder and passes through all builder methods changing the return type to a 'MaterialAlertDialogBuilder'.

        new MaterialAlertDialogBuilder(context)
            .setTitle("Title")
            .setMessage("Message")
            .setPositiveButton("Ok", null)
            .show();

Material Theming

MaterialAlertDialogBuilder requires that your application use a Material Components theme (e.g., Theme.MaterialComponents.Light). Using a Material Components theme with MaterialAlertDialogBuilder will result in an AlertDialog that matches your appplication's color, typography, and shape theming.

Styles

To change the appearance of every AlertDialog built with a MaterialAlertDialogBuilder, use the materialAlertDialogTheme attribute.

  <item name="materialAlertDialogTheme">@style/ThemeOverlay.MaterialComponents.MaterialAlertDialog</item>

To change an individual AlertDialog, pass-in a themeResId to the constructor of a MaterialAlertDialogBuilder instanced.

new MaterialAlertDialogBuilder(context, R.style.ThemeOverlay_MaterialComponents_MaterialAlertDialog)

The materialAlertDialogTheme attribute supports additional choices:

<item name="materialAlertDialogTitlePanelStyle">@style/MaterialAlertDialog.MaterialComponents.Title.Panel</item>
<item name="materialAlertDialogTitleIconStyle">@style/MaterialAlertDialog.MaterialComponents.Title.Icon</item>
<item name="materialAlertDialogTitleTextStyle">@style/MaterialAlertDialog.MaterialComponents.Title.Text</item>

AlertDialog objects created by a MaterialAlertDialogBuilder will also respond to these additional attributes set in alertDialogStyle that help position the window.

<attr name="backgroundInsetStart" format="dimension"/>
<attr name="backgroundInsetTop" format="dimension"/>
<attr name="backgroundInsetEnd" format="dimension"/>
<attr name="backgroundInsetBottom" format="dimension"/>

Template Styles

For the common case of a centered title, use ThemeOverlay.MaterialComponents.MaterialAlertDialog.Centered.

new MaterialAlertDialogBuilder(context, R.style.ThemeOverlay_MaterialComponents_MaterialAlertDialog_Centered)
  .setTitle("Title")
  .setMessage("Message")
  .setPositiveButton("Accept", /* listener = */ null));