smithay/src/wayland/compositor/tree.rs

453 lines
16 KiB
Rust

use super::{roles::*, SubsurfaceRole, SurfaceAttributes};
use std::sync::Mutex;
use wayland_server::protocol::wl_surface::WlSurface;
/// Node of a subsurface tree, holding some user specified data type U
/// at each node
///
/// This type is internal to Smithay, and should not appear in the
/// public API
///
/// It is a bidirectional tree, meaning we can move along it in both
/// direction (top-bottom or bottom-up). We are taking advantage of the
/// fact that lifetime of objects are decided by Wayland-server to ensure
/// the cleanup will be done properly, and we won't leak anything.
///
/// Each node also appears within its children list, to allow relative placement
/// between them.
pub struct SurfaceData<R> {
parent: Option<WlSurface>,
children: Vec<WlSurface>,
role: R,
attributes: SurfaceAttributes,
}
pub enum Location {
Before,
After,
}
/// Possible actions to do after handling a node diring tree traversal
pub enum TraversalAction<T> {
/// Traverse its children as well, providing them the data T
DoChildren(T),
/// Skip its children
SkipChildren,
/// Stop traversal completely
Break,
}
impl<R: Default> SurfaceData<R> {
pub fn new() -> Mutex<SurfaceData<R>> {
Mutex::new(SurfaceData {
parent: None,
children: vec![],
role: Default::default(),
attributes: Default::default(),
})
}
}
impl<R> SurfaceData<R>
where
R: 'static,
{
/// Initializes the surface, must be called at creation for state coherence
pub fn init(surface: &WlSurface) {
let my_data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut my_data = my_data_mutex.lock().unwrap();
debug_assert!(my_data.children.is_empty());
my_data.children.push(surface.clone());
}
/// Cleans the `as_ref().user_data` of that surface, must be called when it is destroyed
pub fn cleanup(surface: &WlSurface) {
let my_data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut my_data = my_data_mutex.lock().unwrap();
if let Some(old_parent) = my_data.parent.take() {
// We had a parent, lets unregister ourselves from it
let old_parent_mutex = old_parent
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut old_parent_guard = old_parent_mutex.lock().unwrap();
old_parent_guard
.children
.retain(|c| !c.as_ref().equals(surface.as_ref()));
}
// orphan all our children
for child in &my_data.children {
let child_mutex = child.as_ref().user_data().get::<Mutex<SurfaceData<R>>>().unwrap();
if std::ptr::eq(child_mutex, my_data_mutex) {
// This child is ourselves, don't do anything.
continue;
}
let mut child_guard = child_mutex.lock().unwrap();
child_guard.parent = None;
}
}
}
impl<R: RoleType + 'static> SurfaceData<R> {
pub fn has_a_role(surface: &WlSurface) -> bool {
debug_assert!(surface.as_ref().is_alive());
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let data_guard = data_mutex.lock().unwrap();
<R as RoleType>::has_role(&data_guard.role)
}
/// Check whether a surface has a given role
pub fn has_role<RoleData>(surface: &WlSurface) -> bool
where
R: Role<RoleData>,
{
debug_assert!(surface.as_ref().is_alive());
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let data_guard = data_mutex.lock().unwrap();
<R as Role<RoleData>>::has(&data_guard.role)
}
/// Register that this surface has a role, fails if it already has one
pub fn give_role<RoleData>(surface: &WlSurface) -> Result<(), ()>
where
R: Role<RoleData>,
RoleData: Default,
{
debug_assert!(surface.as_ref().is_alive());
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut data_guard = data_mutex.lock().unwrap();
<R as Role<RoleData>>::set(&mut data_guard.role)
}
/// Register that this surface has a role with given data
///
/// Fails if it already has one and returns the data
pub fn give_role_with<RoleData>(surface: &WlSurface, data: RoleData) -> Result<(), RoleData>
where
R: Role<RoleData>,
{
debug_assert!(surface.as_ref().is_alive());
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut data_guard = data_mutex.lock().unwrap();
<R as Role<RoleData>>::set_with(&mut data_guard.role, data)
}
/// Register that this surface has no role and returns the data
///
/// It is a noop if this surface already didn't have one, but fails if
/// the role was "subsurface", it must be removed by the `unset_parent` method.
pub fn remove_role<RoleData>(surface: &WlSurface) -> Result<RoleData, WrongRole>
where
R: Role<RoleData>,
{
debug_assert!(surface.as_ref().is_alive());
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut data_guard = data_mutex.lock().unwrap();
<R as Role<RoleData>>::unset(&mut data_guard.role)
}
/// Access to the role data
pub fn with_role_data<RoleData, F, T>(surface: &WlSurface, f: F) -> Result<T, WrongRole>
where
R: Role<RoleData>,
F: FnOnce(&mut RoleData) -> T,
{
debug_assert!(surface.as_ref().is_alive());
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut data_guard = data_mutex.lock().unwrap();
let data = <R as Role<RoleData>>::data_mut(&mut data_guard.role)?;
Ok(f(data))
}
}
impl<R: RoleType + Role<SubsurfaceRole> + 'static> SurfaceData<R> {
/// Checks if the first surface is an ancestor of the second
pub fn is_ancestor(a: &WlSurface, b: &WlSurface) -> bool {
let b_mutex = b.as_ref().user_data().get::<Mutex<SurfaceData<R>>>().unwrap();
let b_guard = b_mutex.lock().unwrap();
if let Some(ref parent) = b_guard.parent {
if parent.as_ref().equals(a.as_ref()) {
true
} else {
Self::is_ancestor(a, parent)
}
} else {
false
}
}
/// Sets the parent of a surface
///
/// if this surface already has a role, does nothing and fails, otherwise
/// its role is now to be a subsurface
pub fn set_parent(child: &WlSurface, parent: &WlSurface) -> Result<(), ()> {
debug_assert!(child.as_ref().is_alive());
debug_assert!(parent.as_ref().is_alive());
// ensure the child is not already a parent of the parent
if Self::is_ancestor(child, parent) {
return Err(());
}
// change child's parent
{
let child_mutex = child.as_ref().user_data().get::<Mutex<SurfaceData<R>>>().unwrap();
let mut child_guard = child_mutex.lock().unwrap();
// if surface already has a role, it cannot become a subsurface
<R as Role<SubsurfaceRole>>::set(&mut child_guard.role)?;
debug_assert!(child_guard.parent.is_none());
child_guard.parent = Some(parent.clone());
}
// register child to new parent
{
let parent_mutex = parent
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut parent_guard = parent_mutex.lock().unwrap();
parent_guard.children.push(child.clone())
}
Ok(())
}
/// Remove a pre-existing parent of this child
///
/// Does nothing if it has no parent
pub fn unset_parent(child: &WlSurface) {
debug_assert!(child.as_ref().is_alive());
let old_parent = {
let child_mutex = child.as_ref().user_data().get::<Mutex<SurfaceData<R>>>().unwrap();
let mut child_guard = child_mutex.lock().unwrap();
let old_parent = child_guard.parent.take();
if old_parent.is_some() {
// We had a parent, so this does not have a role any more
<R as Role<SubsurfaceRole>>::unset(&mut child_guard.role)
.expect("Surface had a parent but not the subsurface role?!");
}
old_parent
};
// unregister from our parent
if let Some(old_parent) = old_parent {
let parent_mutex = old_parent
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut parent_guard = parent_mutex.lock().unwrap();
parent_guard
.children
.retain(|c| !c.as_ref().equals(child.as_ref()));
}
}
/// Retrieve the parent surface (if any) of this surface
pub fn get_parent(child: &WlSurface) -> Option<WlSurface> {
let child_mutex = child.as_ref().user_data().get::<Mutex<SurfaceData<R>>>().unwrap();
let child_guard = child_mutex.lock().unwrap();
child_guard.parent.as_ref().cloned()
}
/// Retrieve the children surface (if any) of this surface
pub fn get_children(parent: &WlSurface) -> Vec<WlSurface> {
let parent_mutex = parent
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let parent_guard = parent_mutex.lock().unwrap();
parent_guard
.children
.iter()
.filter(|s| !s.as_ref().equals(parent.as_ref()))
.cloned()
.collect()
}
/// Reorders a surface relative to one of its sibling
///
/// Fails if `relative_to` is not a sibling or parent of `surface`.
pub fn reorder(surface: &WlSurface, to: Location, relative_to: &WlSurface) -> Result<(), ()> {
let parent = {
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let data_guard = data_mutex.lock().unwrap();
data_guard.parent.as_ref().cloned().unwrap()
};
fn index_of(surface: &WlSurface, slice: &[WlSurface]) -> Option<usize> {
for (i, s) in slice.iter().enumerate() {
if s.as_ref().equals(surface.as_ref()) {
return Some(i);
}
}
None
}
let parent_mutex = parent
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut parent_guard = parent_mutex.lock().unwrap();
let my_index = index_of(surface, &parent_guard.children).unwrap();
let mut other_index = match index_of(relative_to, &parent_guard.children) {
Some(idx) => idx,
None => return Err(()),
};
let me = parent_guard.children.remove(my_index);
if my_index < other_index {
other_index -= 1;
}
let new_index = match to {
Location::Before => other_index,
Location::After => other_index + 1,
};
parent_guard.children.insert(new_index, me);
Ok(())
}
}
impl<R: 'static> SurfaceData<R> {
/// Access the attributes associated with a surface
///
/// Note that an internal lock is taken during access of this data,
/// so the tree cannot be manipulated at the same time
pub fn with_data<T, F>(surface: &WlSurface, f: F) -> T
where
F: FnOnce(&mut SurfaceAttributes) -> T,
{
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.expect("Accessing the data of foreign surfaces is not supported.");
let mut data_guard = data_mutex.lock().unwrap();
f(&mut data_guard.attributes)
}
/// Access sequentially the attributes associated with a surface tree,
/// in a depth-first order.
///
/// Note that an internal lock is taken during access of this data,
/// so the tree cannot be manipulated at the same time.
///
/// The first callback determines if this node children should be processed or not.
///
/// The second actually does the processing, being called on children in display depth
/// order.
///
/// The third is called once all the children of a node has been processed (including itself), only if the first
/// returned `DoChildren`, and gives an opportunity to early stop
pub fn map_tree<F1, F2, F3, T>(
surface: &WlSurface,
initial: &T,
mut filter: F1,
mut processor: F2,
mut post_filter: F3,
reverse: bool,
) where
F1: FnMut(&WlSurface, &mut SurfaceAttributes, &mut R, &T) -> TraversalAction<T>,
F2: FnMut(&WlSurface, &mut SurfaceAttributes, &mut R, &T),
F3: FnMut(&WlSurface, &mut SurfaceAttributes, &mut R, &T) -> bool,
{
Self::map(
surface,
initial,
&mut filter,
&mut processor,
&mut post_filter,
reverse,
);
}
// helper function for map_tree
fn map<F1, F2, F3, T>(
surface: &WlSurface,
initial: &T,
filter: &mut F1,
processor: &mut F2,
post_filter: &mut F3,
reverse: bool,
) -> bool
where
F1: FnMut(&WlSurface, &mut SurfaceAttributes, &mut R, &T) -> TraversalAction<T>,
F2: FnMut(&WlSurface, &mut SurfaceAttributes, &mut R, &T),
F3: FnMut(&WlSurface, &mut SurfaceAttributes, &mut R, &T) -> bool,
{
let data_mutex = surface
.as_ref()
.user_data()
.get::<Mutex<SurfaceData<R>>>()
.unwrap();
let mut data_guard = data_mutex.lock().unwrap();
let data_guard = &mut *data_guard;
// call the filter on ourselves
match filter(surface, &mut data_guard.attributes, &mut data_guard.role, initial) {
TraversalAction::DoChildren(t) => {
// loop over children
if reverse {
for c in data_guard.children.iter().rev() {
if c.as_ref().equals(surface.as_ref()) {
processor(surface, &mut data_guard.attributes, &mut data_guard.role, initial);
} else if !Self::map(c, &t, filter, processor, post_filter, true) {
return false;
}
}
} else {
for c in &data_guard.children {
if c.as_ref().equals(surface.as_ref()) {
processor(surface, &mut data_guard.attributes, &mut data_guard.role, initial);
} else if !Self::map(c, &t, filter, processor, post_filter, false) {
return false;
}
}
}
post_filter(surface, &mut data_guard.attributes, &mut data_guard.role, initial)
}
TraversalAction::SkipChildren => {
// still process ourselves
processor(surface, &mut data_guard.attributes, &mut data_guard.role, initial);
true
}
TraversalAction::Break => false,
}
}
}