ViewTreeObserver.OnPreDrawListener

Kotlin |Java

public static interface ViewTreeObserver.OnPreDrawListener

android.view.ViewTreeObserver.OnPreDrawListener

Known indirect subclasses

AutoCompleteTextView, Button, CheckBox, CheckedTextView, Chronometer, CompoundButton, DigitalClock, EditText, ExtractEditText, MultiAutoCompleteTextView, RadioButton, Switch, TextClock, TextView, ToggleButton

AutoCompleteTextView	An editable text view that shows completion suggestions automatically while the user is typing.
Button	A user interface element the user can tap or click to perform an action.
CheckBox	A checkbox is a specific type of two-states button that can be either checked or unchecked.
CheckedTextView	An extension to `TextView` that supports the `Checkable` interface and displays.
Chronometer	Class that implements a simple timer.
CompoundButton	A button with two states, checked and unchecked.
DigitalClock	This class was deprecated in API level 17. It is recommended you use `TextClock` instead.
EditText	A user interface element for entering and modifying text.
ExtractEditText	Specialization of `EditText` for showing and interacting with the extracted text in a full-screen input method.
MultiAutoCompleteTextView	An editable text view, extending `AutoCompleteTextView`, that can show completion suggestions for the substring of the text where the user is typing instead of necessarily for the entire thing.
RadioButton	A radio button is a two-states button that can be either checked or unchecked.
Switch	A Switch is a two-state toggle widget.
TextClock	`TextClock` can display the current date and/or time as a formatted string.
TextView	A user interface element that displays text to the user.
ToggleButton	Displays checked/unchecked states as a button with a "light" indicator and by default accompanied with the text "ON" or "OFF".

Interface definition for a callback to be invoked when the view tree is about to be drawn.

Summary

Public methods
`abstract boolean`	`onPreDraw()` Callback method to be invoked when the view tree is about to be drawn.

Public methods

onPreDraw

Added in API level 1

 public abstract boolean onPreDraw ()

Callback method to be invoked when the view tree is about to be drawn. At this point, all views in the tree have been measured and given a frame. Clients can use this to adjust their scroll bounds or even to request a new layout before drawing occurs.

Returns
`boolean`	Return true to proceed with the current drawing pass, or false to cancel.

See also: