Dialogs in SystemUI

Creating a dialog

Styling

In order to have uniform styling in dialogs, use SystemUIDialog with its default theme. If not possible, use AlertDialog with the SystemUI theme R.style.Theme_SystemUI_Dialog. If needed, consider extending this theme instead of creating a new one.

Setting the internal elements

The internal elements of the dialog are laid out using the following resources:

Use the default components of the layout by calling the appropriate setters (in the dialog or AlertDialog.Builder). The supported styled setters are:

setIcon: tinted using attr/colorAccentPrimaryVariant.
setTitle: this will use R.style.TextAppearance_Dialog_Title.
setMessage: this will use R.style.TextAppearance_Dialog_Body_Message.
SystemUIDialog.set<Positive|Negative|Neutral>Button or AlertDialog.setButton: this will use the following styles for buttons.
- R.style.Widget_Dialog_Button for the positive button.
- R.style.Widget_Dialog_Button_BorderButton for the negative and neutral buttons.
If needed to use the same style for all three buttons, the style attributes ?android:attr/buttonBar<Positive|NegativeNeutral>Button can be overriden in a theme that extends from R.style.Theme_SystemUI_Dialog.
setView: to set a custom view in the dialog instead of using setMessage.

Using setContentView is discouraged as this replaces the content completely.

All these calls should be made before Dialog#create or Dialog#show (which internally calls create) are called, as that's when the content is installed.

Showing the dialog

When showing a dialog triggered by clicking on a View, you should use DialogTransitionAnimator to nicely animate the dialog from/to that View, instead of calling Dialog.show.

This animator provides the following methods:

showFromView: animates the dialog show from a view , and the dialog dismissal/cancel/hide to the same view.
showFromDialog: animates the dialog show from a currently showing dialog, and the dialog dismissal/cancel/hide back to that dialog. The originating dialog must have been shown using DialogTransitionAnimator.
dismissStack: dismisses a stack of dialogs that were launched using showFromDialog animating the top-most dialog back into the view that was used in the initial showFromView.

Example

Here's a short code snippet with an example on how to use the guidelines.

val dialog = SystemUIDialog(context).apply {
    setIcon(R.drawable.my_icon)
    setTitle(context.getString(R.string.title))
    setMessage(context.getString(R.string.message))
    // Alternatively to setMessage:
    // val content = LayoutManager.from(context).inflate(R.layout.content, null)
    // setView(content)
    setPositiveButton(R.string.positive_button_text, ::onPositiveButton)
    setNegativeButton(R.string.negative_button_text, ::onNegativeButton)
    setNeutralButton(R.string.neutral_button_text, ::onNeutralButton)
}
dialogTransitionAnimator.showFromView(dialog, view)

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