Switch to single-instance Widget model

And make widget() functions return pointers to widgets instead of just
widgets

Signed-off-by: AnErrupTion <anerruption@disroot.org>

src/animations/Cascade.zig

@@ -8,6 +8,7 @@ const Widget = ly_ui.Widget;
 
 const Cascade = @This();
 
+instance: ?Widget = null,
 buffer: *TerminalBuffer,
 current_auth_fails: *usize,
 max_auth_fails: usize,
@@ -18,14 +19,16 @@ pub fn init(
     max_auth_fails: usize,
 ) Cascade {
     return .{
+        .instance = null,
         .buffer = buffer,
         .current_auth_fails = current_auth_fails,
         .max_auth_fails = max_auth_fails,
     };
 }
 
-pub fn widget(self: *Cascade) Widget {
-    return Widget.init(
+pub fn widget(self: *Cascade) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "Cascade",
         null,
         self,
@@ -36,6 +39,7 @@ pub fn widget(self: *Cascade) Widget {
         null,
         null,
     );
+    return &self.instance.?;
 }
 
 fn draw(self: *Cascade) void {

src/animations/ColorMix.zig

@@ -21,6 +21,7 @@ fn length(vec: Vec2) f32 {
     return math.sqrt(vec[0] * vec[0] + vec[1] * vec[1]);
 }
 
+instance: ?Widget = null,
 start_time: TimeOfDay,
 terminal_buffer: *TerminalBuffer,
 animate: *bool,
@@ -41,6 +42,7 @@ pub fn init(
     frame_delay: u16,
 ) !ColorMix {
     return .{
+        .instance = null,
         .start_time = try interop.getTimeOfDay(),
         .terminal_buffer = terminal_buffer,
         .animate = animate,
@@ -66,8 +68,9 @@ pub fn init(
     };
 }
 
-pub fn widget(self: *ColorMix) Widget {
-    return Widget.init(
+pub fn widget(self: *ColorMix) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "ColorMix",
         null,
         self,
@@ -78,6 +81,7 @@ pub fn widget(self: *ColorMix) Widget {
         null,
         calculateTimeout,
     );
+    return &self.instance.?;
 }
 
 fn draw(self: *ColorMix) void {

src/animations/Doom.zig

@@ -16,6 +16,7 @@ pub const STEPS = 12;
 pub const HEIGHT_MAX = 9;
 pub const SPREAD_MAX = 4;
 
+instance: ?Widget = null,
 start_time: TimeOfDay,
 allocator: Allocator,
 terminal_buffer: *TerminalBuffer,
@@ -60,6 +61,7 @@ pub fn init(
         };
 
     return .{
+        .instance = null,
         .start_time = try interop.getTimeOfDay(),
         .allocator = allocator,
         .terminal_buffer = terminal_buffer,
@@ -73,8 +75,9 @@ pub fn init(
     };
 }
 
-pub fn widget(self: *Doom) Widget {
-    return Widget.init(
+pub fn widget(self: *Doom) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "Doom",
         null,
         self,
@@ -85,6 +88,7 @@ pub fn widget(self: *Doom) Widget {
         null,
         calculateTimeout,
     );
+    return &self.instance.?;
 }
 
 fn deinit(self: *Doom) void {

src/animations/DurFile.zig

@@ -304,6 +304,7 @@ const VEC_Y = 1;
 
 const DurFile = @This();
 
+instance: ?Widget = null,
 start_time: TimeOfDay,
 allocator: Allocator,
 terminal_buffer: *TerminalBuffer,
@@ -408,6 +409,7 @@ pub fn init(
     const frame_time: u32 = @intFromFloat(1000 / dur_movie.framerate.?);
 
     return .{
+        .instance = null,
         .start_time = try interop.getTimeOfDay(),
         .allocator = allocator,
         .terminal_buffer = terminal_buffer,
@@ -427,8 +429,9 @@ pub fn init(
     };
 }
 
-pub fn widget(self: *DurFile) Widget {
-    return Widget.init(
+pub fn widget(self: *DurFile) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "DurFile",
         null,
         self,
@@ -439,6 +442,7 @@ pub fn widget(self: *DurFile) Widget {
         null,
         calculateTimeout,
     );
+    return &self.instance.?;
 }
 
 fn deinit(self: *DurFile) void {

src/animations/GameOfLife.zig

@@ -21,6 +21,7 @@ const NEIGHBOR_DIRS = [_][2]i8{
     .{ 1, 0 },   .{ 1, 1 },
 };
 
+instance: ?Widget = null,
 start_time: TimeOfDay,
 allocator: Allocator,
 terminal_buffer: *TerminalBuffer,
@@ -58,6 +59,7 @@ pub fn init(
     const next_grid = try allocator.alloc(bool, grid_size);
 
     var game = GameOfLife{
+        .instance = null,
         .start_time = try interop.getTimeOfDay(),
         .allocator = allocator,
         .terminal_buffer = terminal_buffer,
@@ -83,8 +85,9 @@ pub fn init(
     return game;
 }
 
-pub fn widget(self: *GameOfLife) Widget {
-    return Widget.init(
+pub fn widget(self: *GameOfLife) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "GameOfLife",
         null,
         self,
@@ -95,6 +98,7 @@ pub fn widget(self: *GameOfLife) Widget {
         null,
         calculateTimeout,
     );
+    return &self.instance.?;
 }
 
 fn deinit(self: *GameOfLife) void {

src/animations/Matrix.zig

@@ -29,6 +29,7 @@ pub const Line = struct {
     update: usize,
 };
 
+instance: ?Widget = null,
 start_time: TimeOfDay,
 allocator: Allocator,
 terminal_buffer: *TerminalBuffer,
@@ -62,6 +63,7 @@ pub fn init(
     initBuffers(dots, lines, terminal_buffer.width, terminal_buffer.height, terminal_buffer.random);
 
     return .{
+        .instance = null,
         .start_time = try interop.getTimeOfDay(),
         .allocator = allocator,
         .terminal_buffer = terminal_buffer,
@@ -80,8 +82,9 @@ pub fn init(
     };
 }
 
-pub fn widget(self: *Matrix) Widget {
-    return Widget.init(
+pub fn widget(self: *Matrix) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "Matrix",
         null,
         self,
@@ -92,6 +95,7 @@ pub fn widget(self: *Matrix) Widget {
         null,
         calculateTimeout,
     );
+    return &self.instance.?;
 }
 
 fn deinit(self: *Matrix) void {