View: use saved surface trees for transactions

4 files changed, 86 insertions, 108 deletions

diff --git a/river/Root.zig b/river/Root.zig
index 1a57426..2e7d705 100644
--- a/river/Root.zig
+++ b/river/Root.zig
@@ -393,9 +393,9 @@ pub fn startTransaction(self: *Self) void {
                     view.sendFrameDone();
                 }
 
-                // If there are saved buffers present, then this transaction is interrupting
-                // a previous transaction and we should keep the old buffers.
-                if (view.saved_buffers.items.len == 0) view.saveBuffers();
+                // If the saved surface tree is enabled, then this transaction is interrupting
+                // a previous transaction and we should keep the old surface tree.
+                if (!view.saved_surface_tree.node.enabled) view.saveSurfaceTree();
             } else {
                 if (view.needsConfigure()) view.configure();
             }
@@ -473,7 +473,7 @@ fn commitTransaction(self: *Self) void {
             view_it = view_node.next;
 
             if (!view.tree.node.enabled) {
-                view.dropSavedBuffers();
+                view.dropSavedSurfaceTree();
                 view.output.views.remove(view_node);
                 if (view.destroying) view.destroy();
                 continue;
diff --git a/river/View.zig b/river/View.zig
index 8cd96fe..8fb07cd 100644
--- a/river/View.zig
+++ b/river/View.zig
@@ -63,14 +63,6 @@ const State = struct {
     urgent: bool = false,
 };
 
-const SavedBuffer = struct {
-    client_buffer: *wlr.ClientBuffer,
-    /// x/y relative to the root surface in the surface tree.
-    surface_box: wlr.Box,
-    source_box: wlr.FBox,
-    transform: wl.Output.Transform,
-};
-
 /// The implementation of this view
 impl: Impl,
 
@@ -78,6 +70,8 @@ impl: Impl,
 output: *Output,
 
 tree: *wlr.SceneTree,
+surface_tree: *wlr.SceneTree,
+saved_surface_tree: *wlr.SceneTree,
 borders: struct {
     left: *wlr.SceneRect,
     right: *wlr.SceneRect,
@@ -97,17 +91,6 @@ pending: State,
 /// The serial sent with the currently pending configure event
 pending_serial: ?u32 = null,
 
-/// The currently commited geometry of the surface. The x/y may be negative if
-/// for example the client has decided to draw CSD shadows a la GTK.
-surface_box: wlr.Box = undefined,
-
-/// The geometry the view's surface had when the transaction started and
-/// buffers were saved.
-saved_surface_box: wlr.Box = undefined,
-
-/// These are what we render while a transaction is in progress
-saved_buffers: std.ArrayListUnmanaged(SavedBuffer) = .{},
-
 /// The floating dimensions the view, saved so that they can be restored if the
 /// view returns to floating mode.
 float_box: wlr.Box = undefined,
@@ -121,29 +104,45 @@ draw_borders: bool = true,
 request_activate: wl.Listener(*wlr.XdgActivationV1.event.RequestActivate) =
     wl.Listener(*wlr.XdgActivationV1.event.RequestActivate).init(handleRequestActivate),
 
-pub fn init(self: *Self, output: *Output, tree: *wlr.SceneTree, impl: Impl) error{OutOfMemory}!void {
+pub fn create(output: *Output, impl: Impl) error{OutOfMemory}!*Self {
+    const node = try util.gpa.create(ViewStack(Self).Node);
+    errdefer util.gpa.destroy(node);
+    const self = &node.view;
+
     const initial_tags = blk: {
         const tags = output.current.tags & server.config.spawn_tagmask;
         break :blk if (tags != 0) tags else output.current.tags;
     };
 
+    const tree = try output.layers.views.createSceneTree();
+    errdefer tree.node.destroy();
+
+    const popup_tree = try output.layers.popups.createSceneTree();
+    errdefer popup_tree.node.destroy();
+
     self.* = .{
         .impl = impl,
         .output = output,
         .tree = tree,
+        .surface_tree = try tree.createSceneTree(),
+        .saved_surface_tree = try tree.createSceneTree(),
         .borders = .{
             .left = try tree.createSceneRect(0, 0, &server.config.border_color_unfocused),
             .right = try tree.createSceneRect(0, 0, &server.config.border_color_unfocused),
             .top = try tree.createSceneRect(0, 0, &server.config.border_color_unfocused),
             .bottom = try tree.createSceneRect(0, 0, &server.config.border_color_unfocused),
         },
-        .popup_tree = try output.layers.popups.createSceneTree(),
+        .popup_tree = popup_tree,
         .current = .{ .tags = initial_tags },
         .pending = .{ .tags = initial_tags },
     };
 
+    self.saved_surface_tree.node.setEnabled(false);
+
     try SceneNodeData.attach(&self.tree.node, .{ .view = self });
     try SceneNodeData.attach(&self.popup_tree.node, .{ .view = self });
+
+    return self;
 }
 
 /// If saved buffers of the view are currently in use by a transaction,
@@ -155,8 +154,9 @@ pub fn destroy(self: *Self) void {
     // If there are still saved buffers, then this view needs to be kept
     // around until the current transaction completes. This function will be
     // called again in Root.commitTransaction()
-    if (self.saved_buffers.items.len == 0) {
-        self.saved_buffers.deinit(util.gpa);
+    if (!self.saved_surface_tree.node.enabled) {
+        self.tree.node.destroy();
+        self.popup_tree.node.destroy();
 
         const node = @fieldParentPtr(ViewStack(Self).Node, "view", self);
         util.gpa.destroy(node);
@@ -204,7 +204,7 @@ pub fn updateCurrent(self: *Self) void {
     const config = &server.config;
 
     self.current = self.pending;
-    self.dropSavedBuffers();
+    if (self.saved_surface_tree.node.enabled) self.dropSavedSurfaceTree();
 
     const color = blk: {
         if (self.current.urgent) break :blk &config.border_color_urgent;
@@ -274,39 +274,40 @@ pub fn sendFrameDone(self: Self) void {
     self.rootSurface().sendFrameDone(&now);
 }
 
-pub fn dropSavedBuffers(self: *Self) void {
-    for (self.saved_buffers.items) |buffer| buffer.client_buffer.base.unlock();
-    self.saved_buffers.items.len = 0;
+pub fn dropSavedSurfaceTree(self: *Self) void {
+    assert(self.saved_surface_tree.node.enabled);
+
+    var it = self.saved_surface_tree.children.safeIterator(.forward);
+    while (it.next()) |node| node.destroy();
+
+    self.saved_surface_tree.node.setEnabled(false);
+    self.surface_tree.node.setEnabled(true);
 }
 
-pub fn saveBuffers(self: *Self) void {
-    assert(self.saved_buffers.items.len == 0);
-    self.saved_surface_box = self.surface_box;
-    self.forEachSurface(*std.ArrayListUnmanaged(SavedBuffer), saveBuffersIterator, &self.saved_buffers);
+pub fn saveSurfaceTree(self: *Self) void {
+    assert(!self.saved_surface_tree.node.enabled);
+    assert(self.saved_surface_tree.children.empty());
+
+    self.surface_tree.node.forEachBuffer(*wlr.SceneTree, saveSurfaceTreeIter, self.saved_surface_tree);
+
+    self.surface_tree.node.setEnabled(false);
+    self.saved_surface_tree.node.setEnabled(true);
 }
 
-fn saveBuffersIterator(
-    surface: *wlr.Surface,
-    surface_x: c_int,
-    surface_y: c_int,
-    saved_buffers: *std.ArrayListUnmanaged(SavedBuffer),
+fn saveSurfaceTreeIter(
+    buffer: *wlr.SceneBuffer,
+    sx: c_int,
+    sy: c_int,
+    saved_surface_tree: *wlr.SceneTree,
 ) void {
-    if (surface.buffer) |buffer| {
-        var source_box: wlr.FBox = undefined;
-        surface.getBufferSourceBox(&source_box);
-        saved_buffers.append(util.gpa, .{
-            .client_buffer = buffer,
-            .surface_box = .{
-                .x = surface_x,
-                .y = surface_y,
-                .width = surface.current.width,
-                .height = surface.current.height,
-            },
-            .source_box = source_box,
-            .transform = surface.current.transform,
-        }) catch return;
-        _ = buffer.base.lock();
-    }
+    const saved = saved_surface_tree.createSceneBuffer(buffer.buffer) catch {
+        log.err("out of memory", .{});
+        return;
+    };
+    saved.node.setPosition(sx, sy);
+    saved.setDestSize(buffer.dst_width, buffer.dst_height);
+    saved.setSourceBox(&buffer.src_box);
+    saved.setTransform(buffer.transform);
 }
 
 /// Move a view from one output to another, sending the required enter/leave
@@ -524,7 +525,7 @@ pub fn unmap(self: *Self) void {
     self.tree.node.setEnabled(false);
     self.popup_tree.node.setEnabled(false);
 
-    if (self.saved_buffers.items.len == 0) self.saveBuffers();
+    if (!self.saved_surface_tree.node.enabled) self.saveSurfaceTree();
 
     // Inform all seats that the view has been unmapped so they can handle focus
     var it = server.input_manager.seats.first;
diff --git a/river/XdgToplevel.zig b/river/XdgToplevel.zig
index 73c1efa..a15a3d1 100644
--- a/river/XdgToplevel.zig
+++ b/river/XdgToplevel.zig
@@ -32,12 +32,13 @@ const ViewStack = @import("view_stack.zig").ViewStack;
 
 const log = std.log.scoped(.xdg_shell);
 
-/// The view this xdg toplevel implements
+/// TODO(zig): get rid of this and use @fieldParentPtr(), https://github.com/ziglang/zig/issues/6611
 view: *View,
 
-/// The corresponding wlroots object
 xdg_toplevel: *wlr.XdgToplevel,
 
+geometry: wlr.Box,
+
 /// Set to true when the client acks the configure with serial View.pending_serial.
 acked_pending_serial: bool = false,
 
@@ -59,19 +60,18 @@ request_resize: wl.Listener(*wlr.XdgToplevel.event.Resize) =
 set_title: wl.Listener(void) = wl.Listener(void).init(handleSetTitle),
 set_app_id: wl.Listener(void) = wl.Listener(void).init(handleSetAppId),
 
-/// The View will add itself to the output's view stack on map
 pub fn create(output: *Output, xdg_toplevel: *wlr.XdgToplevel) error{OutOfMemory}!void {
-    const node = try util.gpa.create(ViewStack(View).Node);
-    errdefer util.gpa.destroy(node);
-    const view = &node.view;
-
-    const tree = try output.layers.views.createSceneTree();
-    _ = try tree.createSceneXdgSurface(xdg_toplevel.base);
-
-    try view.init(output, tree, .{ .xdg_toplevel = .{
-        .view = view,
+    const view = try View.create(output, .{ .xdg_toplevel = .{
+        .view = undefined,
         .xdg_toplevel = xdg_toplevel,
+        .geometry = undefined,
     } });
+    errdefer view.destroy();
+
+    view.impl.xdg_toplevel.view = view;
+    xdg_toplevel.base.getGeometry(&view.impl.xdg_toplevel.geometry);
+
+    _ = try view.surface_tree.createSceneXdgSurface(xdg_toplevel.base);
 
     xdg_toplevel.base.data = @ptrToInt(view);
 
@@ -273,14 +273,14 @@ fn handleCommit(listener: *wl.Listener(*wlr.Surface), _: *wlr.Surface) void {
     const self = @fieldParentPtr(Self, "commit", listener);
     const view = self.view;
 
-    var new_box: wlr.Box = undefined;
-    self.xdg_toplevel.base.getGeometry(&new_box);
+    var new_geometry: wlr.Box = undefined;
+    self.xdg_toplevel.base.getGeometry(&new_geometry);
+
+    const size_changed = !std.meta.eql(self.geometry, new_geometry);
+    self.geometry = new_geometry;
 
     // If we have sent a configure changing the size
     if (view.pending_serial != null) {
-        // Update the stored dimensions of the surface
-        view.surface_box = new_box;
-
         if (self.acked_pending_serial) {
             // If this commit is in response to our configure and the
             // transaction code is tracking this configure, notify it.
@@ -307,16 +307,12 @@ fn handleCommit(listener: *wl.Listener(*wlr.Surface), _: *wlr.Surface) void {
             // stashed buffer from when the transaction started.
             view.sendFrameDone();
         }
-    } else {
-        const size_changed = !std.meta.eql(view.surface_box, new_box);
-        view.surface_box = new_box;
+    } else if ((self.view.pending.float or self.view.output.pending.layout == null) and size_changed) {
         // If the client has decided to resize itself and the view is floating,
         // then respect that resize.
-        if ((self.view.pending.float or self.view.output.pending.layout == null) and size_changed) {
-            view.pending.box.width = new_box.width;
-            view.pending.box.height = new_box.height;
-            view.applyPending();
-        }
+        view.pending.box.width = new_geometry.width;
+        view.pending.box.height = new_geometry.height;
+        view.applyPending();
     }
 }
 
diff --git a/river/XwaylandView.zig b/river/XwaylandView.zig
index f5de473..e17ac0a 100644
--- a/river/XwaylandView.zig
+++ b/river/XwaylandView.zig
@@ -33,7 +33,7 @@ const XwaylandOverrideRedirect = @import("XwaylandOverrideRedirect.zig");
 
 const log = std.log.scoped(.xwayland);
 
-/// The view this xwayland view implements
+/// TODO(zig): get rid of this and use @fieldParentPtr(), https://github.com/ziglang/zig/issues/6611
 view: *View,
 
 xwayland_surface: *wlr.XwaylandSurface,
@@ -55,7 +55,6 @@ set_override_redirect: wl.Listener(*wlr.XwaylandSurface) =
     wl.Listener(*wlr.XwaylandSurface).init(handleSetOverrideRedirect),
 
 // Listeners that are only active while the view is mapped
-commit: wl.Listener(*wlr.Surface) = wl.Listener(*wlr.Surface).init(handleCommit),
 set_title: wl.Listener(*wlr.XwaylandSurface) = wl.Listener(*wlr.XwaylandSurface).init(handleSetTitle),
 set_class: wl.Listener(*wlr.XwaylandSurface) = wl.Listener(*wlr.XwaylandSurface).init(handleSetClass),
 request_fullscreen: wl.Listener(*wlr.XwaylandSurface) =
@@ -64,17 +63,14 @@ request_minimize: wl.Listener(*wlr.XwaylandSurface.event.Minimize) =
     wl.Listener(*wlr.XwaylandSurface.event.Minimize).init(handleRequestMinimize),
 
 pub fn create(output: *Output, xwayland_surface: *wlr.XwaylandSurface) error{OutOfMemory}!void {
-    const node = try util.gpa.create(ViewStack(View).Node);
-    const view = &node.view;
-
-    const tree = try output.layers.views.createSceneTree();
-
-    try view.init(output, tree, .{ .xwayland_view = .{
-        .view = view,
+    const view = try View.create(output, .{ .xwayland_view = .{
+        .view = undefined,
         .xwayland_surface = xwayland_surface,
     } });
+    errdefer view.destroy();
 
-    const self = &node.view.impl.xwayland_view;
+    const self = &view.impl.xwayland_view;
+    self.view = view;
     xwayland_surface.data = @ptrToInt(self);
 
     // Add listeners that are active over the view's entire lifetime
@@ -189,19 +185,16 @@ pub fn handleMap(listener: *wl.Listener(*wlr.XwaylandSurface), xwayland_surface:
 
     // Add listeners that are only active while mapped
     const surface = xwayland_surface.surface.?;
-    surface.events.commit.add(&self.commit);
     xwayland_surface.events.set_title.add(&self.set_title);
     xwayland_surface.events.set_class.add(&self.set_class);
     xwayland_surface.events.request_fullscreen.add(&self.request_fullscreen);
     xwayland_surface.events.request_minimize.add(&self.request_minimize);
 
-    self.surface_tree = view.tree.createSceneSubsurfaceTree(surface) catch {
+    self.surface_tree = view.surface_tree.createSceneSubsurfaceTree(surface) catch {
         log.err("out of memory", .{});
         surface.resource.getClient().postNoMemory();
         return;
     };
-    // Place the node below the view's border nodes
-    self.surface_tree.?.node.lowerToBottom();
 
     // Use the view's "natural" size centered on the output as the default
     // floating dimensions
@@ -240,7 +233,6 @@ fn handleUnmap(listener: *wl.Listener(*wlr.XwaylandSurface), _: *wlr.XwaylandSur
     self.surface_tree = null;
 
     // Remove listeners that are only active while mapped
-    self.commit.link.remove();
     self.set_title.link.remove();
     self.set_class.link.remove();
     self.request_fullscreen.link.remove();
@@ -288,17 +280,6 @@ fn handleSetOverrideRedirect(
     };
 }
 
-fn handleCommit(listener: *wl.Listener(*wlr.Surface), surface: *wlr.Surface) void {
-    const self = @fieldParentPtr(Self, "commit", listener);
-
-    self.view.surface_box = .{
-        .x = 0,
-        .y = 0,
-        .width = surface.current.width,
-        .height = surface.current.height,
-    };
-}
-
 fn handleSetTitle(listener: *wl.Listener(*wlr.XwaylandSurface), _: *wlr.XwaylandSurface) void {
     const self = @fieldParentPtr(Self, "set_title", listener);
     self.view.notifyTitle();