private InputControl InstantiateLayout(InputControlLayout layout, InternedString variant, InternedString name, InputControl parent, InputControl existingControl)
{
InputControl control;
// If we have an existing control, see whether it's usable.
if (existingControl != null && existingControl.layout == layout.name && existingControl.GetType() == layout.type)
{
control = existingControl;
////FIXME: the re-use path probably has some data that could stick around when it shouldn't
control.m_UsagesReadOnly = new ReadOnlyArray <InternedString>();
control.ClearProcessors();
}
else
{
Debug.Assert(layout.type != null);
// No, so create a new control.
var controlObject = Activator.CreateInstance(layout.type);
control = controlObject as InputControl;
if (control == null)
{
throw new Exception(string.Format("Type '{0}' referenced by layout '{1}' is not an InputControl",
layout.type.Name, layout.name));
}
}
// If it's a device, perform some extra work specific to the control
// hierarchy root.
var controlAsDevice = control as InputDevice;
if (controlAsDevice != null)
{
if (parent != null)
{
throw new Exception(string.Format(
"Cannot instantiate device layout '{0}' as child of '{1}'; devices must be added at root",
layout.name, parent.path));
}
m_Device = controlAsDevice;
m_Device.m_StateBlock.byteOffset = 0;
m_Device.m_StateBlock.format = layout.stateFormat;
// If we have an existing device, we'll start the various control arrays
// from scratch. Note that all the controls still refer to the existing
// arrays and so we can iterate children, for example, just fine while
// we are rebuilding the control hierarchy.
m_Device.m_AliasesForEachControl = null;
m_Device.m_ChildrenForEachControl = null;
m_Device.m_UsagesForEachControl = null;
m_Device.m_UsageToControl = null;
// But we preserve IDs and descriptions of existing devices.
if (existingControl != null)
{
var existingDevice = (InputDevice)existingControl;
m_Device.m_Id = existingDevice.m_Id;
m_Device.m_Description = existingDevice.m_Description;
}
if (layout.m_UpdateBeforeRender == true)
{
m_Device.m_Flags |= InputDevice.Flags.UpdateBeforeRender;
}
}
else if (parent == null)
{
// Someone did "new InputDeviceBuilder(...)" with a control layout.
// We don't support creating control hierarchies without a device at the root.
throw new InvalidOperationException(
string.Format(
"Toplevel layout used with InputDeviceBuilder must be a device layout; '{0}' is a control layout",
layout.name));
}
// Name defaults to name of layout.
if (name.IsEmpty())
{
name = layout.name;
// If there's a namespace in the layout name, snip it out.
var indexOfLastColon = name.ToString().LastIndexOf(':');
if (indexOfLastColon != -1)
{
name = new InternedString(name.ToString().Substring(indexOfLastColon + 1));
}
}
// Variant defaults to variant of layout.
if (variant.IsEmpty())
{
variant = layout.variant;
if (variant.IsEmpty())
{
variant = InputControlLayout.DefaultVariant;
}
}
control.m_Name = name;
control.m_DisplayNameFromLayout = layout.m_DisplayName;
control.m_Layout = layout.name;
control.m_Variant = variant;
control.m_Parent = parent;
control.m_Device = m_Device;
// Create children and configure their settings from our
// layout values.
var haveChildrenUsingStateFromOtherControl = false;
try
{
// Pass list of existing control on to function as we may have decided to not
// actually reuse the existing control (and thus control.m_ChildrenReadOnly will
// now be blank) but still want crawling down the hierarchy to preserve existing
// controls where possible.
AddChildControls(layout, variant, control,
existingControl != null ? existingControl.m_ChildrenReadOnly : (ReadOnlyArray <InputControl>?)null,
ref haveChildrenUsingStateFromOtherControl);
}
catch
{
////TODO: remove control from collection and rethrow
throw;
}
// Come up with a layout for our state.
ComputeStateLayout(control);
// Finally, if we have child controls that take their state blocks from other
// controls, assign them their blocks now.
if (haveChildrenUsingStateFromOtherControl)
{
foreach (var controlLayout in layout.controls)
{
if (string.IsNullOrEmpty(controlLayout.useStateFrom))
{
continue;
}
var child = TryGetControl(control, controlLayout.name);
Debug.Assert(child != null);
// Find the referenced control.
var referencedControl = TryGetControl(control, controlLayout.useStateFrom);
if (referencedControl == null)
{
throw new Exception(
string.Format(
"Cannot find control '{0}' referenced in 'useStateFrom' of control '{1}' in layout '{2}'",
controlLayout.useStateFrom, controlLayout.name, layout.name));
}
// Copy its state settings.
child.m_StateBlock = referencedControl.m_StateBlock;
// At this point, all byteOffsets are relative to parents so we need to
// walk up the referenced control's parent chain and add offsets until
// we are at the same level that we are at.
for (var parentInChain = referencedControl.parent; parentInChain != control; parentInChain = parentInChain.parent)
{
child.m_StateBlock.byteOffset += parentInChain.m_StateBlock.byteOffset;
}
}
}
return(control);
}
