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/components/InfoLine.zig

@@ -18,6 +18,7 @@ const Message = struct {
     fg: u32,
 };
 
+instance: ?Widget = null,
 label: *MessageLabel,
 
 pub fn init(
@@ -28,6 +29,7 @@ pub fn init(
     arrow_bg: u32,
 ) !InfoLine {
     return .{
+        .instance = null,
         .label = try MessageLabel.init(
             allocator,
             buffer,
@@ -46,8 +48,9 @@ pub fn deinit(self: *InfoLine) void {
     self.label.deinit();
 }
 
-pub fn widget(self: *InfoLine) Widget {
-    return Widget.init(
+pub fn widget(self: *InfoLine) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "InfoLine",
         self.label.keybinds,
         self,
@@ -58,6 +61,7 @@ pub fn widget(self: *InfoLine) Widget {
         handle,
         null,
     );
+    return &self.instance.?;
 }
 
 pub fn addMessage(self: *InfoLine, text: []const u8, bg: u32, fg: u32) !void {

src/components/Session.zig

@@ -18,6 +18,7 @@ const EnvironmentLabel = CyclableLabel(Env, *UserList);
 
 const Session = @This();
 
+instance: ?Widget = null,
 label: *EnvironmentLabel,
 user_list: *UserList,
 
@@ -31,6 +32,7 @@ pub fn init(
     bg: u32,
 ) !Session {
     return .{
+        .instance = null,
         .label = try EnvironmentLabel.init(
             allocator,
             buffer,
@@ -55,8 +57,9 @@ pub fn deinit(self: *Session) void {
     self.label.deinit();
 }
 
-pub fn widget(self: *Session) Widget {
-    return Widget.init(
+pub fn widget(self: *Session) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "Session",
         self.label.keybinds,
         self,
@@ -67,6 +70,7 @@ pub fn widget(self: *Session) Widget {
         handle,
         null,
     );
+    return &self.instance.?;
 }
 
 pub fn addEnvironment(self: *Session, environment: Environment) !void {

src/components/UserList.zig

@@ -21,6 +21,7 @@ const UserLabel = CyclableLabel(User, *Session);
 
 const UserList = @This();
 
+instance: ?Widget = null,
 label: *UserLabel,
 
 pub fn init(
@@ -35,6 +36,7 @@ pub fn init(
     bg: u32,
 ) !UserList {
     var user_list = UserList{
+        .instance = null,
         .label = try UserLabel.init(
             allocator,
             buffer,
@@ -89,8 +91,9 @@ pub fn deinit(self: *UserList) void {
     self.label.deinit();
 }
 
-pub fn widget(self: *UserList) Widget {
-    return Widget.init(
+pub fn widget(self: *UserList) *Widget {
+    if (self.instance) |*instance| return instance;
+    self.instance = Widget.init(
         "UserList",
         self.label.keybinds,
         self,
@@ -101,6 +104,7 @@ pub fn widget(self: *UserList) Widget {
         handle,
         null,
     );
+    return &self.instance.?;
 }
 
 pub fn getCurrentUsername(self: UserList) []const u8 {