Implement configurable view opacity with fade effect

river/command/opacity.zig

@@ -0,0 +1,79 @@
+// This file is part of river, a dynamic tiling wayland compositor.
+//
+// Copyright 2020 Leon Henrik Plickat
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+
+const Error = @import("../command.zig").Error;
+const Seat = @import("../Seat.zig");
+const View = @import("../View.zig");
+const ViewStack = @import("../view_stack.zig").ViewStack;
+
+fn opacityUpdateFilter(view: *View, context: void) bool {
+    // We want to update all views
+    return true;
+}
+
+pub fn opacity(
+    allocator: *std.mem.Allocator,
+    seat: *Seat,
+    args: []const []const u8,
+    out: *?[]const u8,
+) Error!void {
+    if (args.len < 6) return Error.NotEnoughArguments;
+    if (args.len > 6) return Error.TooManyArguments;
+
+    const server = seat.input_manager.server;
+
+    // Focused opacity
+    server.config.view_opacity_focused = try std.fmt.parseFloat(f32, args[1]);
+    if (server.config.view_opacity_focused < 0.0 or server.config.view_opacity_focused > 1.0)
+        return Error.InvalidValue;
+
+    // Unfocused opacity
+    server.config.view_opacity_unfocused = try std.fmt.parseFloat(f32, args[2]);
+    if (server.config.view_opacity_unfocused < 0.0 or server.config.view_opacity_unfocused > 1.0)
+        return Error.InvalidValue;
+
+    // Starting opacity for new views
+    server.config.view_opacity_initial = try std.fmt.parseFloat(f32, args[3]);
+    if (server.config.view_opacity_initial < 0.0 or server.config.view_opacity_initial > 1.0)
+        return Error.InvalidValue;
+
+    // Opacity transition step
+    server.config.view_opacity_delta = try std.fmt.parseFloat(f32, args[4]);
+    if (server.config.view_opacity_delta < 0.0 or server.config.view_opacity_delta > 1.0)
+        return Error.InvalidValue;
+
+    // Time between step
+    server.config.view_opacity_delta_t = try std.fmt.parseInt(u31, args[5], 10);
+    if (server.config.view_opacity_delta_t < 1) return Error.InvalidValue;
+
+    // Update opacity of all views
+    // Unmapped views will be skipped, however their opacity gets updated on map anyway
+    var oit = server.root.outputs.first;
+    while (oit) |onode| : (oit = onode.next) {
+        var vit = ViewStack(View).iter(onode.data.views.first, .forward, {}, opacityUpdateFilter);
+        while (vit.next()) |vnode| {
+            if (vnode.current.focus > 0) {
+                vnode.pending.target_opacity = server.config.view_opacity_focused;
+            } else {
+                vnode.pending.target_opacity = server.config.view_opacity_unfocused;
+            }
+        }
+    }
+    server.root.startTransaction();
+}