OnPreDrawListener

Kotlin |Java

interface OnPreDrawListener

android.view.ViewTreeObserver.OnPreDrawListener

Known Direct Subclasses

TextView

A user interface element that displays text to the user.

Known Indirect Subclasses

AutoCompleteTextView, Button, CheckBox, CheckedTextView, Chronometer, CompoundButton, DigitalClock, EditText, ExtractEditText, MultiAutoCompleteTextView, RadioButton, Switch, and 2 others.

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	Like AnalogClock, but digital.
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.
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

abstract fun onPreDraw(): Boolean

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.

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

See Also