mod(example/input): ellipse rendering with scrolling for text field contents

examples/continuous.zig

@@ -87,10 +87,6 @@ const InputField = struct {
             .key => |key| {
                 if (key.isAscii()) try this.input.append(key.cp);
 
-                // TODO support arrow keys for navigation?
-                // TODO support readline keybindings (i.e. ctrl-k, ctrl-u, ctrl-b, ctrl-f, etc. and the equivalent alt bindings)
-                // create an own `Element` implementation from this
-
                 if (key.eql(.{ .cp = zterm.input.Enter }) or key.eql(.{ .cp = zterm.input.KpEnter }))
                     this.queue.push(.{ .accept = try this.input.toOwnedSlice() });
 

examples/elements/input.zig

@@ -28,16 +28,24 @@ const QuitText = struct {
 const InputField = struct {
     /// Offset from the end describing the current position of the cursor.
     cursor_offset: usize = 0,
+    /// Configuration for the InputField.
+    configuration: Configuration,
     /// Array holding the value of the input.
     input: std.ArrayList(u21),
     /// Reference to the app's queue to issue the associated event to trigger when completing the input.
     queue: *App.Queue,
 
+    /// Configuration for InputField's.
+    pub const Configuration = struct {
+        color: Color = .default,
+    };
+
     // TODO make the event to trigger user defined (needs to be `comptime`)
     // - can this even be agnostic to `u8` / `u21`?
 
-    pub fn init(allocator: std.mem.Allocator, queue: *App.Queue) @This() {
+    pub fn init(allocator: std.mem.Allocator, queue: *App.Queue, configuration: Configuration) @This() {
         return .{
+            .configuration = configuration,
             .input = .init(allocator),
             .queue = queue,
         };
@@ -63,7 +71,7 @@ const InputField = struct {
             .key => |key| {
                 assert(this.cursor_offset >= 0 and this.cursor_offset <= this.input.items.len);
 
-                // see *form* implementation in `zk`, which might become part of the library
+                // readline commands
                 if (key.eql(.{ .cp = zterm.input.Left }) or key.eql(.{ .cp = zterm.input.KpLeft }) or key.eql(.{ .cp = 'b', .mod = .{ .ctrl = true } })) {
                     if (this.cursor_offset < this.input.items.len) this.cursor_offset += 1;
                 }
@@ -75,22 +83,6 @@ const InputField = struct {
 
                 if (key.eql(.{ .cp = 'a', .mod = .{ .ctrl = true } })) this.cursor_offset = this.input.items.len;
 
-                if (key.eql(.{ .cp = zterm.input.Backspace })) {
-                    if (this.cursor_offset < this.input.items.len) {
-                        _ = if (this.cursor_offset == 0) this.input.pop() else this.input.orderedRemove(this.input.items.len - this.cursor_offset - 1);
-                    }
-                }
-
-                if (key.eql(.{ .cp = zterm.input.Delete }) or key.eql(.{ .cp = zterm.input.KpDelete })) {
-                    if (this.cursor_offset > 0) {
-                        _ = this.input.orderedRemove(this.input.items.len - this.cursor_offset);
-                        this.cursor_offset -= 1;
-                    }
-                }
-
-                // TODO support readline keybindings (i.e. alt bindings alt-b, alt-f
-                // TODO maybe even ctrl-left, ctrl-right?)
-                // readline commands
                 if (key.eql(.{ .cp = 'k', .mod = .{ .ctrl = true } })) {
                     while (this.cursor_offset > 0) {
                         _ = this.input.pop();
@@ -115,10 +107,52 @@ const InputField = struct {
                     }
                 }
 
+                if (key.eql(.{ .cp = 'b', .mod = .{ .alt = true } }) or key.eql(.{ .cp = zterm.input.Left, .mod = .{ .ctrl = true } }) or key.eql(.{ .cp = zterm.input.KpLeft, .mod = .{ .ctrl = true } })) {
+                    var non_whitespace = false;
+                    while (this.cursor_offset < this.input.items.len) {
+                        if (non_whitespace and this.input.items[this.input.items.len - this.cursor_offset - 1] == ' ') break;
+
+                        // see backspace
+                        this.cursor_offset += 1;
+                        if (this.cursor_offset == this.input.items.len) break;
+                        const next = this.input.items[this.input.items.len - this.cursor_offset - 1];
+                        if (next != ' ') non_whitespace = true;
+                    }
+                }
+
+                if (key.eql(.{ .cp = 'f', .mod = .{ .alt = true } }) or key.eql(.{ .cp = zterm.input.Right, .mod = .{ .ctrl = true } }) or key.eql(.{ .cp = zterm.input.KpRight, .mod = .{ .ctrl = true } })) {
+                    var non_whitespace = false;
+                    while (this.cursor_offset > 0) {
+                        if (non_whitespace and this.input.items[this.input.items.len - this.cursor_offset - 1] == ' ') {
+                            this.cursor_offset += 1; // correct cursor position back again to make sure the cursor is not on the whitespace, but at the end of the jumped word
+                            break;
+                        }
+
+                        // see backspace
+                        this.cursor_offset -= 1;
+                        const next = this.input.items[this.input.items.len - this.cursor_offset - 1];
+                        if (next != ' ') non_whitespace = true;
+                    }
+                }
+
                 // usual input keys
                 if (key.isAscii()) try this.input.insert(this.input.items.len - this.cursor_offset, key.cp);
 
+                if (key.eql(.{ .cp = zterm.input.Backspace })) {
+                    if (this.cursor_offset < this.input.items.len) {
+                        _ = if (this.cursor_offset == 0) this.input.pop() else this.input.orderedRemove(this.input.items.len - this.cursor_offset - 1);
+                    }
+                }
+
+                if (key.eql(.{ .cp = zterm.input.Delete }) or key.eql(.{ .cp = zterm.input.KpDelete })) {
+                    if (this.cursor_offset > 0) {
+                        _ = this.input.orderedRemove(this.input.items.len - this.cursor_offset);
+                        this.cursor_offset -= 1;
+                    }
+                }
+
                 // TODO enter to accept?
+                // - shift+enter is not recognized by the input reader of `zterm`, so currently it is not possible to add newlines into the text box?
                 if (key.eql(.{ .cp = zterm.input.Enter }) or key.eql(.{ .cp = zterm.input.KpEnter })) {
                     this.queue.push(.{ .accept = try this.input.toOwnedSlice() });
                     this.cursor_offset = 0;
@@ -132,17 +166,24 @@ const InputField = struct {
         const this: *@This() = @ptrCast(@alignCast(ctx));
         assert(cells.len == @as(usize, size.x) * @as(usize, size.y));
 
-        // TODO add configuration for coloring the text!
-        for (this.input.items, 0..) |cp, idx| {
-            cells[idx].style.fg = .black;
+        const offset = if (this.input.items.len - this.cursor_offset + 1 >= cells.len) this.input.items.len + 1 - cells.len else 0;
+        for (this.input.items[offset..], 0..) |cp, idx| {
+            cells[idx].style.fg = this.configuration.color;
             cells[idx].cp = cp;
+            // display ellipse at the beginning
+            if (offset > 0 and idx == 0) cells[idx].cp = '…';
 
             // NOTE do not write over the contents of this `Container`'s `Size`
-            if (idx == cells.len - 1) break;
+            if (idx == cells.len - 1) {
+                // display ellipse at the end
+                if (this.input.items.len >= cells.len and this.cursor_offset > 0) cells[idx].cp = '…';
+                break;
             }
-        // TODO show ellipse `..` (maybe with configuration where - start, middle, end)
-        // show cursor after text (if there is still space available)
-        if (this.input.items.len < cells.len) cells[this.input.items.len - this.cursor_offset].style.cursor = true;
+        }
+        if (this.input.items.len < cells.len)
+            cells[this.input.items.len - this.cursor_offset].style.cursor = true
+        else
+            cells[this.input.items.len - offset - this.cursor_offset].style.cursor = true;
     }
 };
 
@@ -191,7 +232,9 @@ pub fn main() !void {
     var renderer = zterm.Renderer.Buffered.init(allocator);
     defer renderer.deinit();
 
-    var input_field: InputField = .init(allocator, &app.queue);
+    var input_field: InputField = .init(allocator, &app.queue, .{
+        .color = .black,
+    });
     defer input_field.deinit();
 
     var mouse_draw: MouseDraw = .{};
@@ -211,7 +254,7 @@ pub fn main() !void {
         .rectangle = .{ .fill = .light_grey },
         .size = .{
             .grow = .horizontal,
-            .dim = .{ .y = 10 },
+            .dim = .{ .y = 1 },
         },
     }, input_field.element()));
 
@@ -284,6 +327,8 @@ const log = std.log.scoped(.default);
 const std = @import("std");
 const assert = std.debug.assert;
 const zterm = @import("zterm");
+const Color = zterm.Color;
+
 const App = zterm.App(union(enum) {
     accept: []u21,
 });