feat(tree): make left side of the tree only take as much space as necessary

build.zig.zon

@@ -3,8 +3,8 @@
     .version = "0.0.1",
     .dependencies = .{
         .zterm = .{
-            .url = "git+https://gitea.yves-biener.de/yves-biener/zterm#e972a2ea0f7a9f8caffd439ef206474b46475f91",
-            .hash = "zterm-0.3.0-1xmmENkhHAB2rmNJFH-9rRqiRLnT673xwuMrqLwOnlT_",
+            .url = "git+https://gitea.yves-biener.de/yves-biener/zterm#b1a0d60ae379bb91b862d7c4a8a2210cd74c4387",
+            .hash = "zterm-0.3.0-1xmmEMotHACXUXNtsX1P2iz3XQgabNz1PfF7oazYtNam",
         },
     },
     .minimum_zig_version = "0.16.0-dev.1254+bf15c791f",

src/elements.zig

@@ -59,6 +59,7 @@ pub fn Tree(App: type) type {
                 .ptr = this,
                 .vtable = &.{
                     .resize = resize,
+                    .minSize = minSize,
                     .handle = handle,
                     .content = content,
                 },
@@ -70,6 +71,19 @@ pub fn Tree(App: type) type {
             this.size = size;
         }
 
+        fn minSize(ctx: *anyopaque, model: *const App.Model, _: Point) Point {
+            // NOTE as we assume the model contents do not change we could calculate the
+            // maximum width required for this `Element` and return that, instead of
+            // calculating the width every time anew. For now this works fine.
+            const this: *@This() = @ptrCast(@alignCast(ctx));
+            const changes: []const Model.Index = model.changes.keys();
+            const files = changes[this.scrollback..];
+            var width: u16 = 0;
+            for (files) |file| width = @max(@as(u16, @intCast(file.len)), width);
+            return .{ .x = width };
+        }
+
+
         fn handle(ctx: *anyopaque, model: *App.Model, event: App.Event) !void {
             const this: *@This() = @ptrCast(@alignCast(ctx));
             switch (event) {
@@ -112,7 +126,6 @@ pub fn Tree(App: type) type {
                 const row_color: zterm.Color = if (this.idx == idx) .blue else .default;
                 cell_idx = row * size.x;
                 for (0..size.x) |_| {
-                    cell_idx += 1;
                     if (value_idx >= value.len) break;
                     const cp = value[value_idx];
                     defer value_idx += 1;
@@ -128,6 +141,7 @@ pub fn Tree(App: type) type {
                         else => cp,
                     };
                     cells[cell_idx].style.fg = row_color;
+                    cell_idx += 1;
                 }
             }
         }

src/main.zig

@@ -33,7 +33,7 @@ pub fn main() !void {
     // tui creation
     errdefer |err| log.err("Application Error: {any}", .{err});
 
-    var threaded_io: std.Io.Threaded = .init(allocator);
+    var threaded_io: std.Io.Threaded = .init(allocator, .{});
     errdefer threaded_io.deinit();
     const io = threaded_io.io();
 

src/root.zig

@@ -17,7 +17,11 @@ pub fn Container(App: type, gpa: Allocator, element: *elements.Root(App), tree:
             },
         },
     }, element.element());
-    try root.append(try .init(gpa, .{}, tree.element()));
+    try root.append(try .init(gpa, .{
+        .size = .{
+            .grow = .vertical,
+        },
+    }, tree.element()));
     try root.append(try .init(gpa, .{}, .{})); // empty container holding the scrollable element for the diff of each file
     return root;
 }