internal NPatch Diff()
{
var update = _force || ShouldComponentUpdate(_props, _state, _propsCommitted, _stateCommitted);
Commit();
if (!update)
{
return(null);
}
var oldUI = _ui;
var newUI = RenderUI();
var patch = NPropDiffer.Diff(oldUI, ref newUI);
//if (oldUI is NClass) // oldUI represented by nested class which is assigned after NPropDiffer anyway
// return patch;
_ui = newUI;
if (patch == NPatch.AssignNewValue) // Assign New UI
{
patch = new NActionPatch(i =>
{
var result = Xaml = newUI.Create();
oldUI?.Free();
return(result);
});
}
return(patch);
}
void Update(int idx, NElement newE, NElement oldE)
{
if (oldE is NClass)
{
_target[idx] = oldE; // transfer updated classes
}
var p = NPropDiffer.Diff(oldE, ref newE);
if (p != null)
{
Add(new NListPatchEntry {
Op = NListPatchOp.Patch, Value = oldE, iFinal = idx, Patch = p
});
}
}
void OptimizeRemove(NListPatchEntry e)
{
var delta = 0;
var oldE = e.Finalizer;
var last = e;
for (var i = e.Next; i != null; i = i.Next)
{
switch (i.Op)
{
case NListPatchOp.Insert:
{
var newE = i.Value;
if (NPatch.ElementEquals(newE, oldE))
{
e.Op = NListPatchOp.Move; // transform to move
e.Finalizer = null; // remove finalizer
e.iInsert = i.iInsert + delta; // correct insert index at the time of move
e.iFinal = i.iFinal; // preserve final index
e.Patch = NPropDiffer.Diff(oldE, ref newE); // make patch
e.Value = oldE; // preserve moved value
last.Next = i.Next; // delete insertion
return;
}
delta--;
}
break;
case NListPatchOp.Remove:
delta++;
break;
}
last = i;
}
}
