public override void OnVersionChanged(VisualElement ve, VersionChangeType versionChangeType)
{
if ((versionChangeType & (VersionChangeType.Transform | VersionChangeType.Size | VersionChangeType.Overflow | VersionChangeType.Hierarchy | VersionChangeType.BorderWidth | VersionChangeType.EventCallbackCategories)) == 0)
{
return;
}
// According to the flags, what operations must be done?
bool mustDirtyWorldTransform = (versionChangeType & VersionChangeType.Transform) != 0;
bool mustDirtyWorldClip = (versionChangeType & (VersionChangeType.Transform | VersionChangeType.Size | VersionChangeType.Overflow | VersionChangeType.BorderWidth)) != 0;
bool mustDirtyEventParentCategories = (versionChangeType & (VersionChangeType.Hierarchy | VersionChangeType.EventCallbackCategories)) != 0;
VisualElementFlags mustDirtyFlags =
(mustDirtyWorldTransform ? VisualElementFlags.WorldTransformDirty | VisualElementFlags.WorldBoundingBoxDirty : 0) |
(mustDirtyWorldClip ? VisualElementFlags.WorldClipDirty : 0) |
(mustDirtyEventParentCategories ? VisualElementFlags.EventCallbackParentCategoriesDirty : 0);
var needDirtyFlags = mustDirtyFlags & ~ve.m_Flags;
if (needDirtyFlags != 0)
{
DirtyHierarchy(ve, needDirtyFlags);
}
DirtyBoundingBoxHierarchy(ve);
++m_Version;
}
static void DirtyHierarchy(VisualElement ve, VisualElementFlags mustDirtyFlags)
{
// We use VisualElementFlags to track changes across the hierarchy since all those values come from m_Flags.
ve.m_Flags |= mustDirtyFlags;
int count = ve.hierarchy.childCount;
for (int i = 0; i < count; i++)
{
var child = ve.hierarchy[i];
// Are these operations already done?
var needDirtyFlags = mustDirtyFlags & ~child.m_Flags;
if (needDirtyFlags != 0)
{
DirtyHierarchy(child, needDirtyFlags);
}
}
}
