add(example/elements): distinct different scrollable containers

README.md

@@ -133,13 +133,18 @@ the primary use-case for myself to create this library in the first place.
     - [x] Button
     - [x] Text Input field
     - [ ] Popup-menu
-    - [ ] Scrollable Content (i.e. show long text of an except of something and other smaller `Container`)
+    - [x] Scrollable Content (i.e. show long text of an except of something and other smaller `Container`)
-      - [ ] min size
+      - [x] min size
-      - [ ] mouse scrolling aware of mouse position (i.e. through multiple different scrollable `Container`)
+      - [x] mouse scrolling aware of mouse position (i.e. through multiple different scrollable `Container`)
     - [ ] Launch sub-applications (not inside of a `Container` but during the application workflow, like an editor)
   - [ ] Styles
     - [ ] Text styles
     - [ ] Color palette
+  - [ ] Error Handling
+    - [ ] log and show error's without crashing the application
+    - [ ] show application error that will cause a crash
+  - [ ] Demo
+    - [ ] use another tui application to launch and come back to (showcase the interrupt behavior)
 - [ ] Testability
   - [ ] snapshot ability to safe current screen (from `Renderer`) to test against
   - [ ] try to integrate them into the library itself such that they also serve as examples on how to test

examples/elements/scrollable.zig

@@ -23,7 +23,7 @@ pub const HelloWorldText = packed struct {
         // NOTE: error should only be returned here in case an in-recoverable exception has occurred
         const row = size.rows / 2;
         const col = size.cols / 2 -| (text.len / 2);
-        const anchor = (row * size.rows) + col;
+        const anchor = (row * size.cols) + col;
 
         for (0.., text) |idx, char| {
             cells[anchor + idx].style.fg = .black;
@@ -52,7 +52,7 @@ pub fn main() !void {
     var element_wrapper: HelloWorldText = .{};
     const element = element_wrapper.element();
 
-    var box = try App.Container.init(allocator, .{
+    var top_box = try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .blue },
         .layout = .{
             .gap = 1,
@@ -61,21 +61,36 @@ pub fn main() !void {
         },
         .min_size = .{ .rows = 50 },
     }, .{});
-    try box.append(try App.Container.init(allocator, .{
+    try top_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
     }, .{}));
-    try box.append(try App.Container.init(allocator, .{
+    try top_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
     }, element));
-    try box.append(try App.Container.init(allocator, .{
+    try top_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
     }, .{}));
-    defer box.deinit();
+    defer top_box.deinit();
 
-    var scrollable: App.Scrollable = .{
+    var bottom_box = try App.Container.init(allocator, .{
-        .container = box,
+        .border = .{ .separator = .{ .enabled = true } },
-        .vertical = true,
+        .rectangle = .{ .fill = .blue },
-    };
+        .layout = .{
+            .direction = .vertical,
+            .padding = .vertical(1),
+        },
+        .min_size = .{ .rows = 30 },
+    }, .{});
+    try bottom_box.append(try App.Container.init(allocator, .{
+        .rectangle = .{ .fill = .grey },
+    }, .{}));
+    try bottom_box.append(try App.Container.init(allocator, .{
+        .rectangle = .{ .fill = .grey },
+    }, element));
+    try bottom_box.append(try App.Container.init(allocator, .{
+        .rectangle = .{ .fill = .grey },
+    }, .{}));
+    defer bottom_box.deinit();
 
     var container = try App.Container.init(allocator, .{
         .border = .{
@@ -87,21 +102,17 @@ pub fn main() !void {
         .layout = .{
             .gap = 2,
             .padding = .all(5),
-            .direction = .horizontal,
+            .direction = .vertical,
         },
     }, .{});
-    try container.append(try App.Container.init(allocator, .{}, scrollable.element()));
+    defer container.deinit();
 
-    try container.append(try App.Container.init(allocator, .{
+    // place empty container containing the element of the scrollable Container.
-        .border = .{
+    var scrollable_top: App.Scrollable = .init(top_box);
-            .color = .light_blue,
+    try container.append(try App.Container.init(allocator, .{}, scrollable_top.element()));
-            .sides = .vertical,
+
-        },
+    var scrollable_bottom: App.Scrollable = .init(bottom_box);
-    }, .{}));
+    try container.append(try App.Container.init(allocator, .{}, scrollable_bottom.element()));
-    try container.append(try App.Container.init(allocator, .{
-        .rectangle = .{ .fill = .blue },
-    }, .{}));
-    defer container.deinit(); // also de-initializes the children
 
     try app.start();
     defer app.stop() catch |err| log.err("Failed to stop application: {any}", .{err});
@@ -112,37 +123,14 @@ pub fn main() !void {
         log.debug("received event: {s}", .{@tagName(event)});
 
         switch (event) {
-            .init => {
+            .init => continue,
-                try container.handle(event);
-                continue; // do not render
-            },
             .quit => break,
             .resize => |size| try renderer.resize(size),
-            .key => |key| {
+            .key => |key| if (key.eql(.{ .cp = 'c', .mod = .{ .ctrl = true } })) app.quit(),
-                if (key.eql(.{ .cp = 'q' })) app.quit();
-
-                // corresponding element could even be changed from the 'outside' (not forced through the event system)
-                // event system however allows for cross element communication (i.e. broadcasting messages, etc.)
-                if (key.eql(.{ .cp = input.Escape })) element_wrapper.text_color = .black;
-
-                if (key.eql(.{ .cp = 'n', .mod = .{ .ctrl = true } })) {
-                    try app.interrupt();
-                    defer app.start() catch @panic("could not start app event loop");
-                    var child = std.process.Child.init(&.{"hx"}, allocator);
-                    _ = child.spawnAndWait() catch |err| app.postEvent(.{
-                        .err = .{
-                            .err = err,
-                            .msg = "Spawning $EDITOR failed",
-                        },
-                    });
-                }
-            },
-            // NOTE: errors could be displayed in another container in case one was received, etc. to provide the user with feedback
             .err => |err| log.err("Received {s} with message: {s}", .{ @errorName(err.err), err.msg }),
             else => {},
         }
 
-        // NOTE: returned errors should be propagated back to the application
         container.handle(event) catch |err| app.postEvent(.{
             .err = .{
                 .err = err,

src/element.zig

@@ -91,10 +91,6 @@ pub fn Scrollable(Event: type) type {
         anchor: Position = .{},
         /// The actual container, that is scrollable.
         container: Container(Event),
-        /// Enable horizontal scrolling. This also renders a scrollbar (along the bottom of the viewport).
-        horizontal: bool = false,
-        /// Enable vertical scrolling. This also renders a scrollbar (along the right of the viewport).
-        vertical: bool = false,
 
         pub fn element(this: *@This()) Element(Event) {
             return .{
@@ -106,11 +102,13 @@ pub fn Scrollable(Event: type) type {
             };
         }
 
+        pub fn init(container: Container(Event)) @This() {
+            return .{ .container = container };
+        }
+
         fn handle(ctx: *anyopaque, event: Event) !void {
             const this: *@This() = @ptrCast(@alignCast(ctx));
             switch (event) {
-                // TODO: emit `.resize` event for the container to set the size for the scrollable `Container`
-                // - how would I determine the required or necessary `Size`?
                 .resize => |size| {
                     this.size = size;
                     // TODO: scrollbar space - depending on configuration and only if necessary?
@@ -124,17 +122,17 @@ pub fn Scrollable(Event: type) type {
                 },
                 // TODO: other means to scroll except with the mouse? (i.e. Ctrl-u/d, k/j, etc.?)
                 .mouse => |mouse| switch (mouse.button) {
-                    Mouse.Button.wheel_up => if (this.vertical) {
+                    Mouse.Button.wheel_up => if (this.container_size.rows > this.size.rows) {
                         this.anchor.row -|= 1;
                     },
-                    Mouse.Button.wheel_down => if (this.vertical) {
+                    Mouse.Button.wheel_down => if (this.container_size.rows > this.size.rows) {
                         const max_anchor_row = this.container_size.rows -| this.size.rows;
                         this.anchor.row = @min(this.anchor.row + 1, max_anchor_row);
                     },
-                    Mouse.Button.wheel_left => if (this.horizontal) {
+                    Mouse.Button.wheel_left => if (this.container_size.cols > this.size.cols) {
                         this.anchor.col -|= 1;
                     },
-                    Mouse.Button.wheel_right => if (this.horizontal) {
+                    Mouse.Button.wheel_right => if (this.container_size.cols > this.size.cols) {
                         const max_anchor_col = this.container_size.cols -| this.size.cols;
                         this.anchor.col = @min(this.anchor.col + 1, max_anchor_col);
                     },