John Skottis giannissc

There are four user levels to using a GUI framework:

View composition

Event and Lifecycle are propagated down the entire tree but if every single events was processed by every widget that would cause performance issues.
The mechanism which decides which events and lifecycles will be propagated to which parts of the tree is the Pod
Some events are global (e.g. WindowSize) and are handled directly by the Pod and some are local and targeted to specific subset of widgets in the tree (e.g.MouseMove).
Targeted events are controlled by the IS_DISABLED, IS_HANDLED, HAS_ACTIVE, IS_HOT, and HAS_FOCUS flags.

The IS_HANDLED flag is set to false at the root of the tree by the Pod
The widget that processes the event must set the IS_HANDLED flag through its context.
The IS_HANDLED flag applies to keyboard and mouse events.

The current state/value of a widget should be obvious/visible.
If the value doesn't fit the last digit should be faded to indicate that the value shown is only partial. A good heuristic would be to choose a size that is large enough to fit 3 digit numbers (e.g. selecting a value between 0-100)
Expand the label when the user is interacting with the widget.
The the widget's state/value should always be visible, move the location of the label if necessary (e.g. when pointer is interacting with the widget)
A widget should optionally provide an indication of the min/max boundaries, where relevant.
The slider should optionally provide an indication of intermediate values (e.g. axis ticks) between the min/max boundaries, where relevant.
UI elements that are used for fine control (e.g. knobs) should be big enough to make them easy to grab.
For widgets with a single functionality the entire widget's area should optionally be wired to trigger the widget's action.

Global Scope State = Application Data or Model
Local Scope State = UI State / Empemeral State (e.g. animation progress)
Inherited Scope State = Shared UI State / Ambient State (e.g. month selection in calendar element)
Distributed State (e.g. tab selection shared by tab bar and a tab grid that live in different parts of the view tree)
Transient State/Impulse Response (e.g. a button is pressed and a side bar is revealed)

	Buffer<uint> Input;
	RWBuffer<uint> Output;

	//returns the index that this value should be moved to to sort the array
	uint CuteSort(uint value, uint laneIndex)
	{
	uint smallerValuesMask = 0;
	uint equalValuesMask = ~0;

	//don't need to test every bit if your value is constrained to a smaller range