Considerations To Know About view
Considerations To Know About view
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int: Optional. Otherwise null, on return this will consist of the offset in nearby view coordinates of the view from in advance of this Procedure to following it completes. View implementations might use this to regulate expected input coordinate monitoring.
requested listing of useful resource ID which might be regarded as when resolving attribute values for this View. This value can't be null.
int: Optional. If not null, on return this will have the offset in area view coordinates of this view from in advance of this Procedure to following it completes. View implementations could use this to regulate predicted input coordinate monitoring.
A handler affiliated with the thread functioning the View. This handler can be used to pump gatherings inside the UI situations queue.
The OnBackInvokedDispatcher from this or the nearest ancestor, or null if this view is equally not attached and have no ancestor giving an OnBackInvokedDispatcher.
Defines the following view to give emphasis to when another target is View.FOCUS_FORWARD When the reference refers into a view that does not exist or is an element of a hierarchy that may be invisible, a RuntimeException will end result if the reference is accessed.
Structure is really a two pass procedure: a evaluate pass and also a layout go. The measuring move is implemented in evaluate(int, int) and is a top-down traversal of the view tree. Each individual view pushes dimension technical specs down the tree in the recursion. At the end of the measure go, every view has saved its measurements. The second pass happens in format(int, int, int, int) and is also major-down. In the course of this go Each individual mother or father is liable for positioning all of its little ones utilizing the sizes computed inside the measure pass. Whenever a view's evaluate() system returns, its getMeasuredWidth() and getMeasuredHeight() values has to be established, as well as Those people for all of that view's descendants. A view's calculated width and calculated height values must respect the constraints imposed via the view's mothers and fathers. This assures that at the end of the evaluate move, all moms and dads settle for all of their kid's measurements. A mum or dad view could connect with measure() a lot more than the moment on its young children. As an example, the mum or dad may well measure Just about every little one once with unspecified dimensions to find out how major they want to be, then get in touch with evaluate() on them yet again with precise figures In case the sum of all the kids's unconstrained dimensions is too huge or too tiny. The evaluate move makes use of two lessons to communicate Proportions. The MeasureSpec course is employed by views to tell their moms and dads how they want to be measured and positioned.
Dispatch a vital occasion in advance of it really is processed by any enter process connected to the view hierarchy. This can be utilized to intercept critical gatherings in Exclusive circumstances prior to the IME consumes them; a typical illustration will be handling the Back again key to update the applying's UI instead of making it possible for the IME to discover it and shut itself.
The view drawing cache was mostly manufactured obsolete with the introduction of hardware-accelerated rendering in API eleven. With components-acceleration, intermediate cache layers are mostly unwanted and can certainly cause a Web loss in general performance as a result of the expense of producing and get more info updating the layer. Within the rare situations exactly where caching levels are valuable, for example for alpha animations, setLayerType(int, android.graphics.Paint) handles this with components rendering.
Defines the drawable to draw more than the content. This may be applied as an overlay. The foreground drawable participates while in the padding on the content material Should the gravity is about to fill.
Utility to return a default sizing. Employs the supplied measurement If your MeasureSpec imposed no constraints. Will get much larger if authorized with the MeasureSpec.}