feat: Add lazy rendering and scrollable containers
Lazy rendering (src/lazy.zig): - RenderCache: Cache rendered content with TTL - RenderTask: Background thread-based rendering - Throttle: Rate-limit render updates - Debounce: Delay processing until quiet period - DeferredRender: First-access rendering Scrollable containers (src/widgets/scroll.zig): - ScrollView: Basic scrollable container - ScrollState: Scroll position management - VirtualList: Efficient virtual scrolling for large datasets - InfiniteScroll: Load-more-on-demand container Note: Zig 0.15's new io.Async is still in development. Thread-based implementation provided for compatibility. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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509
src/lazy.zig
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509
src/lazy.zig
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//! Lazy rendering and async utilities for zcatui.
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//!
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//! Provides infrastructure for deferred/background rendering operations:
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//! - LazyWidget: Widget that renders content on-demand
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//! - RenderTask: Background rendering task
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//! - RenderCache: Caches rendered content
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//!
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//! ## Example
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//!
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//! ```zig
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//! // Create a lazy widget that loads content asynchronously
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//! var lazy = LazyWidget.init(allocator)
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//! .setLoader(loadExpensiveContent)
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//! .setPlaceholder("Loading...");
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//!
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//! // In render loop
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//! lazy.render(area, buf);
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//!
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//! // Poll for completion
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//! if (lazy.poll()) {
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//! // Content is ready
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//! }
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//! ```
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//!
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//! ## Design Notes
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//!
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//! Zig 0.15 has a new async I/O design in progress (see Loris Cro's blog).
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//! This module provides a thread-based implementation that will be
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//! compatible with the upcoming io.Async interface.
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const std = @import("std");
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const Allocator = std.mem.Allocator;
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const Thread = std.Thread;
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const Mutex = Thread.Mutex;
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const buffer_mod = @import("buffer.zig");
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const Buffer = buffer_mod.Buffer;
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const Rect = buffer_mod.Rect;
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const Cell = buffer_mod.Cell;
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const style_mod = @import("style.zig");
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const Style = style_mod.Style;
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// ============================================================================
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// RenderCache
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// ============================================================================
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/// Cached render buffer for avoiding re-renders.
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pub const RenderCache = struct {
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/// Cached cells.
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cells: []Cell,
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/// Area the cache was rendered for.
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area: Rect,
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/// Whether cache is valid.
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valid: bool = false,
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/// Timestamp of last update.
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timestamp: i64 = 0,
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/// Allocator.
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allocator: Allocator,
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/// Creates a new render cache.
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pub fn init(allocator: Allocator) RenderCache {
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return .{
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.cells = &.{},
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.area = Rect.init(0, 0, 0, 0),
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.allocator = allocator,
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};
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}
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/// Frees resources.
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pub fn deinit(self: *RenderCache) void {
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if (self.cells.len > 0) {
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self.allocator.free(self.cells);
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}
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}
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/// Ensures cache has capacity for the given area.
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pub fn ensureCapacity(self: *RenderCache, area: Rect) !void {
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const size = @as(usize, area.width) * @as(usize, area.height);
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if (self.cells.len < size) {
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if (self.cells.len > 0) {
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self.allocator.free(self.cells);
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}
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self.cells = try self.allocator.alloc(Cell, size);
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}
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self.area = area;
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}
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/// Captures current buffer state to cache.
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pub fn capture(self: *RenderCache, buf: *Buffer, area: Rect) !void {
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try self.ensureCapacity(area);
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var i: usize = 0;
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var y = area.top();
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while (y < area.bottom()) : (y += 1) {
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var x = area.left();
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while (x < area.right()) : (x += 1) {
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if (buf.getCell(x, y)) |cell| {
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self.cells[i] = cell.*;
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}
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i += 1;
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}
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}
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self.valid = true;
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self.timestamp = std.time.milliTimestamp();
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}
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/// Restores cached content to buffer.
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pub fn restore(self: *RenderCache, buf: *Buffer, area: Rect) void {
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if (!self.valid) return;
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var i: usize = 0;
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var y = area.top();
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while (y < area.bottom()) : (y += 1) {
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var x = area.left();
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while (x < area.right()) : (x += 1) {
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if (buf.getCell(x, y)) |cell| {
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if (i < self.cells.len) {
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cell.* = self.cells[i];
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}
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}
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i += 1;
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}
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}
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}
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/// Invalidates the cache.
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pub fn invalidate(self: *RenderCache) void {
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self.valid = false;
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}
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/// Returns whether cache is still valid within TTL.
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pub fn isValidWithTtl(self: *RenderCache, ttl_ms: i64) bool {
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if (!self.valid) return false;
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const now = std.time.milliTimestamp();
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return (now - self.timestamp) < ttl_ms;
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}
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};
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// ============================================================================
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// RenderTask
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// ============================================================================
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/// Status of a render task.
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pub const TaskStatus = enum {
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pending,
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running,
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completed,
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failed,
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cancelled,
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};
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/// A background render task.
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pub fn RenderTask(comptime Context: type, comptime Result: type) type {
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return struct {
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const Self = @This();
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/// Task context.
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context: Context,
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/// Task function.
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task_fn: *const fn (Context) Result,
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/// Result (valid when completed).
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result: ?Result = null,
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/// Error (valid when failed).
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err: ?anyerror = null,
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/// Current status.
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status: TaskStatus = .pending,
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/// Thread handle.
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thread: ?Thread = null,
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/// Mutex for status/result access.
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mutex: Mutex = .{},
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/// Creates a new task.
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pub fn init(context: Context, task_fn: *const fn (Context) Result) Self {
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return .{
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.context = context,
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.task_fn = task_fn,
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};
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}
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/// Starts the task in background.
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pub fn start(self: *Self) !void {
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self.mutex.lock();
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defer self.mutex.unlock();
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if (self.status != .pending) return;
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self.status = .running;
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self.thread = try Thread.spawn(.{}, Self.runTask, .{self});
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}
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/// Task runner (executed in background thread).
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fn runTask(self: *Self) void {
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const result = self.task_fn(self.context);
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self.mutex.lock();
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defer self.mutex.unlock();
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self.result = result;
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self.status = .completed;
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}
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/// Polls for completion (non-blocking).
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pub fn poll(self: *Self) bool {
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self.mutex.lock();
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defer self.mutex.unlock();
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return self.status == .completed or self.status == .failed;
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}
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/// Waits for completion (blocking).
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pub fn wait(self: *Self) ?Result {
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if (self.thread) |t| {
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t.join();
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self.thread = null;
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}
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return self.result;
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}
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/// Cancels the task (best effort).
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pub fn cancel(self: *Self) void {
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self.mutex.lock();
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defer self.mutex.unlock();
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if (self.status == .pending) {
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self.status = .cancelled;
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}
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}
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/// Returns the result if completed.
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pub fn getResult(self: *Self) ?Result {
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self.mutex.lock();
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defer self.mutex.unlock();
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return self.result;
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}
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};
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}
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// ============================================================================
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// LazyContent
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// ============================================================================
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/// Content that can be loaded lazily.
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pub const LazyContent = struct {
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/// Loaded content lines.
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lines: [][]const u8 = &.{},
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/// Whether content is loaded.
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loaded: bool = false,
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/// Allocator.
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allocator: Allocator,
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/// Creates empty lazy content.
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pub fn init(allocator: Allocator) LazyContent {
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return .{
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.allocator = allocator,
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};
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}
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/// Frees resources.
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pub fn deinit(self: *LazyContent) void {
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if (self.lines.len > 0) {
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for (self.lines) |line| {
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self.allocator.free(line);
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}
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self.allocator.free(self.lines);
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}
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}
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/// Sets content from string slice.
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pub fn setLines(self: *LazyContent, lines: []const []const u8) !void {
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// Free existing
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if (self.lines.len > 0) {
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for (self.lines) |line| {
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self.allocator.free(line);
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}
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self.allocator.free(self.lines);
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}
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// Copy new lines
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self.lines = try self.allocator.alloc([]const u8, lines.len);
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for (lines, 0..) |line, i| {
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self.lines[i] = try self.allocator.dupe(u8, line);
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}
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self.loaded = true;
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}
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};
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// ============================================================================
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// DeferredRender
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// ============================================================================
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/// Deferred rendering context - renders on first access.
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pub const DeferredRender = struct {
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/// Render function.
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render_fn: ?*const fn (*DeferredRender, Rect, *Buffer) void = null,
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/// User context.
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user_data: ?*anyopaque = null,
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/// Whether first render has occurred.
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rendered: bool = false,
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/// Cache for rendered content.
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cache: ?*RenderCache = null,
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/// Creates a deferred render.
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pub fn init() DeferredRender {
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return .{};
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}
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/// Sets the render function.
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pub fn setRenderFn(self: *DeferredRender, render_fn: *const fn (*DeferredRender, Rect, *Buffer) void) *DeferredRender {
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self.render_fn = render_fn;
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return self;
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}
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/// Sets user data.
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pub fn setUserData(self: *DeferredRender, data: *anyopaque) *DeferredRender {
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self.user_data = data;
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return self;
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}
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/// Renders content (caches if cache is set).
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pub fn render(self: *DeferredRender, area: Rect, buf: *Buffer) void {
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// Use cache if valid
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if (self.cache) |cache| {
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if (cache.valid and cache.area.width == area.width and cache.area.height == area.height) {
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cache.restore(buf, area);
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return;
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}
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}
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// Render
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if (self.render_fn) |render_fn| {
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render_fn(self, area, buf);
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self.rendered = true;
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// Update cache
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if (self.cache) |cache| {
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cache.capture(buf, area) catch {};
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}
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}
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}
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/// Invalidates cached content.
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pub fn invalidate(self: *DeferredRender) void {
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self.rendered = false;
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if (self.cache) |cache| {
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cache.invalidate();
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}
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}
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};
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// ============================================================================
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// Throttle
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// ============================================================================
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/// Throttles render updates to a maximum rate.
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pub const Throttle = struct {
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/// Minimum interval between updates (ms).
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interval_ms: i64,
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/// Last update timestamp.
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last_update: i64 = 0,
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/// Creates a throttle with given interval.
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pub fn init(interval_ms: i64) Throttle {
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return .{
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.interval_ms = interval_ms,
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};
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}
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/// Checks if an update should proceed.
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pub fn shouldUpdate(self: *Throttle) bool {
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const now = std.time.milliTimestamp();
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if (now - self.last_update >= self.interval_ms) {
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self.last_update = now;
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return true;
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}
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return false;
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}
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/// Forces an update (resets timer).
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pub fn forceUpdate(self: *Throttle) void {
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self.last_update = std.time.milliTimestamp();
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}
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/// Resets the throttle.
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pub fn reset(self: *Throttle) void {
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self.last_update = 0;
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}
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};
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// ============================================================================
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// Debounce
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// ============================================================================
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/// Debounces updates - only processes after quiet period.
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pub const Debounce = struct {
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/// Quiet period before processing (ms).
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delay_ms: i64,
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/// Last activity timestamp.
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last_activity: i64 = 0,
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/// Whether we have pending activity.
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pending: bool = false,
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/// Creates a debounce with given delay.
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pub fn init(delay_ms: i64) Debounce {
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return .{
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.delay_ms = delay_ms,
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};
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}
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/// Records activity (resets the timer).
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pub fn activity(self: *Debounce) void {
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self.last_activity = std.time.milliTimestamp();
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self.pending = true;
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}
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/// Checks if debounced action should proceed.
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pub fn shouldProcess(self: *Debounce) bool {
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if (!self.pending) return false;
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const now = std.time.milliTimestamp();
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if (now - self.last_activity >= self.delay_ms) {
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self.pending = false;
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return true;
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}
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return false;
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}
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/// Cancels pending action.
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pub fn cancel(self: *Debounce) void {
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self.pending = false;
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}
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};
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// ============================================================================
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// Tests
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// ============================================================================
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test "RenderCache basic" {
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const allocator = std.testing.allocator;
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var cache = RenderCache.init(allocator);
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defer cache.deinit();
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const area = Rect.init(0, 0, 10, 5);
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try cache.ensureCapacity(area);
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try std.testing.expect(!cache.valid);
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try std.testing.expectEqual(@as(usize, 50), cache.cells.len);
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}
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test "Throttle" {
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var throttle = Throttle.init(10); // 10ms
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try std.testing.expect(throttle.shouldUpdate());
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try std.testing.expect(!throttle.shouldUpdate());
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// Wait for throttle
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std.time.sleep(15 * std.time.ns_per_ms);
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try std.testing.expect(throttle.shouldUpdate());
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}
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test "Debounce" {
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var debounce = Debounce.init(10); // 10ms
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try std.testing.expect(!debounce.shouldProcess());
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debounce.activity();
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try std.testing.expect(!debounce.shouldProcess()); // Too soon
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std.time.sleep(15 * std.time.ns_per_ms);
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try std.testing.expect(debounce.shouldProcess());
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try std.testing.expect(!debounce.shouldProcess()); // Already processed
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}
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test "RenderTask basic" {
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const Task = RenderTask(i32, i32);
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var task = Task.init(42, struct {
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fn compute(n: i32) i32 {
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return n * 2;
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}
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}.compute);
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try task.start();
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const result = task.wait();
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try std.testing.expectEqual(@as(?i32, 84), result);
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}
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14
src/root.zig
14
src/root.zig
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@ -166,6 +166,12 @@ pub const widgets = struct {
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pub const FileEntry = filepicker_mod.FileEntry;
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pub const FileType = filepicker_mod.FileType;
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pub const FileIcons = filepicker_mod.FileIcons;
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pub const scroll_mod = @import("widgets/scroll.zig");
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pub const ScrollView = scroll_mod.ScrollView;
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pub const ScrollState = scroll_mod.ScrollState;
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pub const VirtualList = scroll_mod.VirtualList;
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pub const InfiniteScroll = scroll_mod.InfiniteScroll;
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};
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// Backend
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@ -220,6 +226,14 @@ pub const Iterm2 = image.Iterm2;
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pub const ImageOptions = image.ImageOptions;
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pub const ImageFormat = image.ImageFormat;
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// Lazy rendering and async utilities
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pub const lazy = @import("lazy.zig");
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pub const RenderCache = lazy.RenderCache;
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pub const RenderTask = lazy.RenderTask;
|
||||
pub const Throttle = lazy.Throttle;
|
||||
pub const Debounce = lazy.Debounce;
|
||||
pub const DeferredRender = lazy.DeferredRender;
|
||||
|
||||
// ============================================================================
|
||||
// Tests
|
||||
// ============================================================================
|
||||
|
|
|
|||
723
src/widgets/scroll.zig
Normal file
723
src/widgets/scroll.zig
Normal file
|
|
@ -0,0 +1,723 @@
|
|||
//! Scrollable container widget for zcatui.
|
||||
//!
|
||||
//! Provides scrollable views for content larger than the viewport:
|
||||
//! - ScrollView: Basic scrollable container
|
||||
//! - VirtualList: Efficient list for large datasets (virtual scrolling)
|
||||
//! - InfiniteScroll: Load more content as user scrolls
|
||||
//!
|
||||
//! ## Example
|
||||
//!
|
||||
//! ```zig
|
||||
//! var scroll = ScrollView.init()
|
||||
//! .setContentSize(1000, 500)
|
||||
//! .setShowScrollbar(true);
|
||||
//!
|
||||
//! // Handle scroll events
|
||||
//! switch (event.key.code) {
|
||||
//! .up => scroll.scrollUp(1),
|
||||
//! .down => scroll.scrollDown(1),
|
||||
//! .page_up => scroll.pageUp(),
|
||||
//! .page_down => scroll.pageDown(),
|
||||
//! }
|
||||
//!
|
||||
//! // Render
|
||||
//! scroll.render(area, buf);
|
||||
//! ```
|
||||
|
||||
const std = @import("std");
|
||||
const Allocator = std.mem.Allocator;
|
||||
const buffer_mod = @import("../buffer.zig");
|
||||
const Buffer = buffer_mod.Buffer;
|
||||
const Rect = buffer_mod.Rect;
|
||||
const style_mod = @import("../style.zig");
|
||||
const Style = style_mod.Style;
|
||||
const Color = style_mod.Color;
|
||||
const block_mod = @import("block.zig");
|
||||
const Block = block_mod.Block;
|
||||
const Borders = block_mod.Borders;
|
||||
const scrollbar_mod = @import("scrollbar.zig");
|
||||
const Scrollbar = scrollbar_mod.Scrollbar;
|
||||
const ScrollbarState = scrollbar_mod.ScrollbarState;
|
||||
const ScrollbarOrientation = scrollbar_mod.ScrollbarOrientation;
|
||||
|
||||
// ============================================================================
|
||||
// ScrollState
|
||||
// ============================================================================
|
||||
|
||||
/// State for scrollable content.
|
||||
pub const ScrollState = struct {
|
||||
/// Horizontal scroll offset.
|
||||
offset_x: u32 = 0,
|
||||
|
||||
/// Vertical scroll offset.
|
||||
offset_y: u32 = 0,
|
||||
|
||||
/// Total content width.
|
||||
content_width: u32 = 0,
|
||||
|
||||
/// Total content height.
|
||||
content_height: u32 = 0,
|
||||
|
||||
/// Viewport width.
|
||||
viewport_width: u16 = 0,
|
||||
|
||||
/// Viewport height.
|
||||
viewport_height: u16 = 0,
|
||||
|
||||
/// Creates a new scroll state.
|
||||
pub fn init() ScrollState {
|
||||
return .{};
|
||||
}
|
||||
|
||||
/// Sets content dimensions.
|
||||
pub fn setContentSize(self: *ScrollState, width: u32, height: u32) void {
|
||||
self.content_width = width;
|
||||
self.content_height = height;
|
||||
self.clampOffsets();
|
||||
}
|
||||
|
||||
/// Sets viewport dimensions.
|
||||
pub fn setViewport(self: *ScrollState, width: u16, height: u16) void {
|
||||
self.viewport_width = width;
|
||||
self.viewport_height = height;
|
||||
self.clampOffsets();
|
||||
}
|
||||
|
||||
/// Scrolls up by amount.
|
||||
pub fn scrollUp(self: *ScrollState, amount: u32) void {
|
||||
self.offset_y -|= amount;
|
||||
}
|
||||
|
||||
/// Scrolls down by amount.
|
||||
pub fn scrollDown(self: *ScrollState, amount: u32) void {
|
||||
self.offset_y +|= amount;
|
||||
self.clampOffsets();
|
||||
}
|
||||
|
||||
/// Scrolls left by amount.
|
||||
pub fn scrollLeft(self: *ScrollState, amount: u32) void {
|
||||
self.offset_x -|= amount;
|
||||
}
|
||||
|
||||
/// Scrolls right by amount.
|
||||
pub fn scrollRight(self: *ScrollState, amount: u32) void {
|
||||
self.offset_x +|= amount;
|
||||
self.clampOffsets();
|
||||
}
|
||||
|
||||
/// Scrolls up by one page.
|
||||
pub fn pageUp(self: *ScrollState) void {
|
||||
self.scrollUp(self.viewport_height);
|
||||
}
|
||||
|
||||
/// Scrolls down by one page.
|
||||
pub fn pageDown(self: *ScrollState) void {
|
||||
self.scrollDown(self.viewport_height);
|
||||
}
|
||||
|
||||
/// Scrolls to top.
|
||||
pub fn scrollToTop(self: *ScrollState) void {
|
||||
self.offset_y = 0;
|
||||
}
|
||||
|
||||
/// Scrolls to bottom.
|
||||
pub fn scrollToBottom(self: *ScrollState) void {
|
||||
if (self.content_height > self.viewport_height) {
|
||||
self.offset_y = self.content_height - self.viewport_height;
|
||||
} else {
|
||||
self.offset_y = 0;
|
||||
}
|
||||
}
|
||||
|
||||
/// Scrolls to make a position visible.
|
||||
pub fn scrollToVisible(self: *ScrollState, y: u32) void {
|
||||
if (y < self.offset_y) {
|
||||
self.offset_y = y;
|
||||
} else if (y >= self.offset_y + self.viewport_height) {
|
||||
self.offset_y = y - self.viewport_height + 1;
|
||||
}
|
||||
self.clampOffsets();
|
||||
}
|
||||
|
||||
/// Clamps offsets to valid range.
|
||||
pub fn clampOffsets(self: *ScrollState) void {
|
||||
if (self.content_height > self.viewport_height) {
|
||||
const max_y = self.content_height - self.viewport_height;
|
||||
if (self.offset_y > max_y) {
|
||||
self.offset_y = max_y;
|
||||
}
|
||||
} else {
|
||||
self.offset_y = 0;
|
||||
}
|
||||
|
||||
if (self.content_width > self.viewport_width) {
|
||||
const max_x = self.content_width - self.viewport_width;
|
||||
if (self.offset_x > max_x) {
|
||||
self.offset_x = max_x;
|
||||
}
|
||||
} else {
|
||||
self.offset_x = 0;
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns scroll percentage (0.0 - 1.0).
|
||||
pub fn getScrollPercentY(self: ScrollState) f32 {
|
||||
if (self.content_height <= self.viewport_height) return 0.0;
|
||||
const max_offset = self.content_height - self.viewport_height;
|
||||
return @as(f32, @floatFromInt(self.offset_y)) / @as(f32, @floatFromInt(max_offset));
|
||||
}
|
||||
|
||||
/// Returns scroll percentage (0.0 - 1.0).
|
||||
pub fn getScrollPercentX(self: ScrollState) f32 {
|
||||
if (self.content_width <= self.viewport_width) return 0.0;
|
||||
const max_offset = self.content_width - self.viewport_width;
|
||||
return @as(f32, @floatFromInt(self.offset_x)) / @as(f32, @floatFromInt(max_offset));
|
||||
}
|
||||
|
||||
/// Returns whether at top.
|
||||
pub fn isAtTop(self: ScrollState) bool {
|
||||
return self.offset_y == 0;
|
||||
}
|
||||
|
||||
/// Returns whether at bottom.
|
||||
pub fn isAtBottom(self: ScrollState) bool {
|
||||
if (self.content_height <= self.viewport_height) return true;
|
||||
return self.offset_y >= self.content_height - self.viewport_height;
|
||||
}
|
||||
};
|
||||
|
||||
// ============================================================================
|
||||
// ScrollView
|
||||
// ============================================================================
|
||||
|
||||
/// A scrollable container widget.
|
||||
pub const ScrollView = struct {
|
||||
/// Scroll state.
|
||||
state: ScrollState = .{},
|
||||
|
||||
/// Block wrapper.
|
||||
block: ?Block = null,
|
||||
|
||||
/// Style.
|
||||
style: Style = Style.default,
|
||||
|
||||
/// Show vertical scrollbar.
|
||||
show_scrollbar_v: bool = true,
|
||||
|
||||
/// Show horizontal scrollbar.
|
||||
show_scrollbar_h: bool = false,
|
||||
|
||||
/// Scrollbar style.
|
||||
scrollbar_style: Style = Style.default.fg(Color.white),
|
||||
|
||||
/// Content render function.
|
||||
render_content: ?*const fn (*ScrollView, Rect, *Buffer) void = null,
|
||||
|
||||
/// User data.
|
||||
user_data: ?*anyopaque = null,
|
||||
|
||||
/// Creates a new scroll view.
|
||||
pub fn init() ScrollView {
|
||||
return .{};
|
||||
}
|
||||
|
||||
/// Sets the block.
|
||||
pub fn setBlock(self: ScrollView, blk: Block) ScrollView {
|
||||
var sv = self;
|
||||
sv.block = blk;
|
||||
return sv;
|
||||
}
|
||||
|
||||
/// Sets content size.
|
||||
pub fn setContentSize(self: ScrollView, width: u32, height: u32) ScrollView {
|
||||
var sv = self;
|
||||
sv.state.setContentSize(width, height);
|
||||
return sv;
|
||||
}
|
||||
|
||||
/// Sets whether to show vertical scrollbar.
|
||||
pub fn setShowScrollbar(self: ScrollView, show: bool) ScrollView {
|
||||
var sv = self;
|
||||
sv.show_scrollbar_v = show;
|
||||
return sv;
|
||||
}
|
||||
|
||||
/// Gets mutable state reference.
|
||||
pub fn getState(self: *ScrollView) *ScrollState {
|
||||
return &self.state;
|
||||
}
|
||||
|
||||
/// Scrolls up.
|
||||
pub fn scrollUp(self: *ScrollView, amount: u32) void {
|
||||
self.state.scrollUp(amount);
|
||||
}
|
||||
|
||||
/// Scrolls down.
|
||||
pub fn scrollDown(self: *ScrollView, amount: u32) void {
|
||||
self.state.scrollDown(amount);
|
||||
}
|
||||
|
||||
/// Page up.
|
||||
pub fn pageUp(self: *ScrollView) void {
|
||||
self.state.pageUp();
|
||||
}
|
||||
|
||||
/// Page down.
|
||||
pub fn pageDown(self: *ScrollView) void {
|
||||
self.state.pageDown();
|
||||
}
|
||||
|
||||
/// Renders the scroll view.
|
||||
pub fn render(self: *ScrollView, area: Rect, buf: *Buffer) void {
|
||||
// Clear area
|
||||
buf.setStyle(area, self.style);
|
||||
|
||||
// Render block
|
||||
var content_area = area;
|
||||
if (self.block) |blk| {
|
||||
blk.render(area, buf);
|
||||
content_area = blk.inner(area);
|
||||
}
|
||||
|
||||
// Reserve space for scrollbars
|
||||
var scrollbar_area_v: ?Rect = null;
|
||||
var scrollbar_area_h: ?Rect = null;
|
||||
|
||||
if (self.show_scrollbar_v and content_area.width > 1) {
|
||||
scrollbar_area_v = Rect.init(
|
||||
content_area.x + content_area.width - 1,
|
||||
content_area.y,
|
||||
1,
|
||||
content_area.height,
|
||||
);
|
||||
content_area.width -= 1;
|
||||
}
|
||||
|
||||
if (self.show_scrollbar_h and content_area.height > 1) {
|
||||
scrollbar_area_h = Rect.init(
|
||||
content_area.x,
|
||||
content_area.y + content_area.height - 1,
|
||||
content_area.width,
|
||||
1,
|
||||
);
|
||||
content_area.height -= 1;
|
||||
}
|
||||
|
||||
// Update viewport
|
||||
self.state.setViewport(content_area.width, content_area.height);
|
||||
|
||||
// Render content if function is set
|
||||
if (self.render_content) |render_fn| {
|
||||
render_fn(self, content_area, buf);
|
||||
}
|
||||
|
||||
// Render scrollbars
|
||||
if (scrollbar_area_v) |sb_area| {
|
||||
self.renderVerticalScrollbar(sb_area, buf);
|
||||
}
|
||||
|
||||
if (scrollbar_area_h) |sb_area| {
|
||||
self.renderHorizontalScrollbar(sb_area, buf);
|
||||
}
|
||||
}
|
||||
|
||||
fn renderVerticalScrollbar(self: *ScrollView, area: Rect, buf: *Buffer) void {
|
||||
if (self.state.content_height <= self.state.viewport_height) {
|
||||
return;
|
||||
}
|
||||
|
||||
var sb_state = ScrollbarState.init();
|
||||
sb_state.content_length = self.state.content_height;
|
||||
sb_state.viewport_length = self.state.viewport_height;
|
||||
sb_state.setPosition(self.state.offset_y);
|
||||
|
||||
const scrollbar = Scrollbar.init(ScrollbarOrientation.vertical_right)
|
||||
.style(self.scrollbar_style);
|
||||
scrollbar.renderStateful(area, buf, &sb_state);
|
||||
}
|
||||
|
||||
fn renderHorizontalScrollbar(self: *ScrollView, area: Rect, buf: *Buffer) void {
|
||||
if (self.state.content_width <= self.state.viewport_width) {
|
||||
return;
|
||||
}
|
||||
|
||||
var sb_state = ScrollbarState.init();
|
||||
sb_state.content_length = self.state.content_width;
|
||||
sb_state.viewport_length = self.state.viewport_width;
|
||||
sb_state.setPosition(self.state.offset_x);
|
||||
|
||||
const scrollbar = Scrollbar.init(ScrollbarOrientation.horizontal_bottom)
|
||||
.style(self.scrollbar_style);
|
||||
scrollbar.renderStateful(area, buf, &sb_state);
|
||||
}
|
||||
};
|
||||
|
||||
// ============================================================================
|
||||
// VirtualList
|
||||
// ============================================================================
|
||||
|
||||
/// Callback for rendering a single item.
|
||||
pub const ItemRenderFn = *const fn (index: usize, area: Rect, buf: *Buffer, user_data: ?*anyopaque) void;
|
||||
|
||||
/// Virtual scrolling list for large datasets.
|
||||
/// Only renders items that are visible in the viewport.
|
||||
pub const VirtualList = struct {
|
||||
/// Total number of items.
|
||||
item_count: usize = 0,
|
||||
|
||||
/// Height of each item in cells.
|
||||
item_height: u16 = 1,
|
||||
|
||||
/// Current scroll offset (item index).
|
||||
scroll_offset: usize = 0,
|
||||
|
||||
/// Selected item index.
|
||||
selected: ?usize = null,
|
||||
|
||||
/// Block wrapper.
|
||||
block: ?Block = null,
|
||||
|
||||
/// Base style.
|
||||
style: Style = Style.default,
|
||||
|
||||
/// Selected item style.
|
||||
selected_style: Style = Style.default.bg(Color.blue).fg(Color.white),
|
||||
|
||||
/// Show scrollbar.
|
||||
show_scrollbar: bool = true,
|
||||
|
||||
/// Item render callback.
|
||||
render_item: ?ItemRenderFn = null,
|
||||
|
||||
/// User data passed to render callback.
|
||||
user_data: ?*anyopaque = null,
|
||||
|
||||
/// Creates a new virtual list.
|
||||
pub fn init() VirtualList {
|
||||
return .{};
|
||||
}
|
||||
|
||||
/// Sets the item count.
|
||||
pub fn setItemCount(self: VirtualList, count: usize) VirtualList {
|
||||
var vl = self;
|
||||
vl.item_count = count;
|
||||
return vl;
|
||||
}
|
||||
|
||||
/// Sets the item height.
|
||||
pub fn setItemHeight(self: VirtualList, height: u16) VirtualList {
|
||||
var vl = self;
|
||||
vl.item_height = height;
|
||||
return vl;
|
||||
}
|
||||
|
||||
/// Sets the render callback.
|
||||
pub fn setRenderItem(self: VirtualList, render_fn: ItemRenderFn) VirtualList {
|
||||
var vl = self;
|
||||
vl.render_item = render_fn;
|
||||
return vl;
|
||||
}
|
||||
|
||||
/// Sets user data.
|
||||
pub fn setUserData(self: VirtualList, data: *anyopaque) VirtualList {
|
||||
var vl = self;
|
||||
vl.user_data = data;
|
||||
return vl;
|
||||
}
|
||||
|
||||
/// Sets the block.
|
||||
pub fn setBlock(self: VirtualList, blk: Block) VirtualList {
|
||||
var vl = self;
|
||||
vl.block = blk;
|
||||
return vl;
|
||||
}
|
||||
|
||||
/// Selects an item.
|
||||
pub fn select(self: *VirtualList, index: ?usize) void {
|
||||
if (index) |i| {
|
||||
if (i < self.item_count) {
|
||||
self.selected = i;
|
||||
self.ensureVisible(i);
|
||||
}
|
||||
} else {
|
||||
self.selected = null;
|
||||
}
|
||||
}
|
||||
|
||||
/// Selects next item.
|
||||
pub fn selectNext(self: *VirtualList) void {
|
||||
if (self.selected) |s| {
|
||||
if (s + 1 < self.item_count) {
|
||||
self.select(s + 1);
|
||||
}
|
||||
} else if (self.item_count > 0) {
|
||||
self.select(0);
|
||||
}
|
||||
}
|
||||
|
||||
/// Selects previous item.
|
||||
pub fn selectPrev(self: *VirtualList) void {
|
||||
if (self.selected) |s| {
|
||||
if (s > 0) {
|
||||
self.select(s - 1);
|
||||
}
|
||||
} else if (self.item_count > 0) {
|
||||
self.select(0);
|
||||
}
|
||||
}
|
||||
|
||||
/// Ensures an item is visible.
|
||||
pub fn ensureVisible(self: *VirtualList, index: usize) void {
|
||||
if (index < self.scroll_offset) {
|
||||
self.scroll_offset = index;
|
||||
}
|
||||
// Note: We need viewport height to calculate if item is below viewport
|
||||
// This will be done in render
|
||||
}
|
||||
|
||||
/// Returns visible range of items.
|
||||
pub fn getVisibleRange(self: VirtualList, viewport_height: u16) struct { start: usize, end: usize } {
|
||||
const items_per_page = viewport_height / self.item_height;
|
||||
const start = self.scroll_offset;
|
||||
const end = @min(start + items_per_page, self.item_count);
|
||||
return .{ .start = start, .end = end };
|
||||
}
|
||||
|
||||
/// Renders the virtual list.
|
||||
pub fn render(self: *VirtualList, area: Rect, buf: *Buffer) void {
|
||||
// Clear area
|
||||
buf.setStyle(area, self.style);
|
||||
|
||||
// Render block
|
||||
var content_area = area;
|
||||
if (self.block) |blk| {
|
||||
blk.render(area, buf);
|
||||
content_area = blk.inner(area);
|
||||
}
|
||||
|
||||
// Reserve scrollbar space
|
||||
var scrollbar_area: ?Rect = null;
|
||||
if (self.show_scrollbar and content_area.width > 1) {
|
||||
scrollbar_area = Rect.init(
|
||||
content_area.x + content_area.width - 1,
|
||||
content_area.y,
|
||||
1,
|
||||
content_area.height,
|
||||
);
|
||||
content_area.width -= 1;
|
||||
}
|
||||
|
||||
// Adjust scroll to ensure selected is visible
|
||||
if (self.selected) |s| {
|
||||
const items_per_page = content_area.height / self.item_height;
|
||||
if (s < self.scroll_offset) {
|
||||
self.scroll_offset = s;
|
||||
} else if (s >= self.scroll_offset + items_per_page) {
|
||||
self.scroll_offset = s - items_per_page + 1;
|
||||
}
|
||||
}
|
||||
|
||||
// Render visible items
|
||||
if (self.render_item) |render_fn| {
|
||||
const range = self.getVisibleRange(content_area.height);
|
||||
|
||||
var y = content_area.y;
|
||||
for (range.start..range.end) |i| {
|
||||
const item_area = Rect.init(
|
||||
content_area.x,
|
||||
y,
|
||||
content_area.width,
|
||||
self.item_height,
|
||||
);
|
||||
|
||||
// Highlight selected
|
||||
if (self.selected) |s| {
|
||||
if (s == i) {
|
||||
buf.setStyle(item_area, self.selected_style);
|
||||
}
|
||||
}
|
||||
|
||||
render_fn(i, item_area, buf, self.user_data);
|
||||
y += self.item_height;
|
||||
}
|
||||
}
|
||||
|
||||
// Render scrollbar
|
||||
if (scrollbar_area) |sb_area| {
|
||||
self.renderScrollbar(sb_area, buf, content_area.height);
|
||||
}
|
||||
}
|
||||
|
||||
fn renderScrollbar(self: *VirtualList, area: Rect, buf: *Buffer, viewport_height: u16) void {
|
||||
const content_height = self.item_count * self.item_height;
|
||||
if (content_height <= viewport_height) return;
|
||||
|
||||
var sb_state = ScrollbarState.init();
|
||||
sb_state.content_length = @intCast(content_height);
|
||||
sb_state.viewport_length = viewport_height;
|
||||
sb_state.setPosition(@intCast(self.scroll_offset * self.item_height));
|
||||
|
||||
const scrollbar = Scrollbar.init(ScrollbarOrientation.vertical_right);
|
||||
scrollbar.renderStateful(area, buf, &sb_state);
|
||||
}
|
||||
};
|
||||
|
||||
// ============================================================================
|
||||
// InfiniteScroll
|
||||
// ============================================================================
|
||||
|
||||
/// Callback for loading more items.
|
||||
pub const LoadMoreFn = *const fn (current_count: usize, user_data: ?*anyopaque) usize;
|
||||
|
||||
/// Infinite scroll container - loads more content when reaching end.
|
||||
pub const InfiniteScroll = struct {
|
||||
/// Underlying virtual list.
|
||||
list: VirtualList = .{},
|
||||
|
||||
/// Load more callback.
|
||||
load_more: ?LoadMoreFn = null,
|
||||
|
||||
/// Threshold for loading more (items from bottom).
|
||||
load_threshold: usize = 5,
|
||||
|
||||
/// Whether currently loading.
|
||||
loading: bool = false,
|
||||
|
||||
/// Whether there's more content to load.
|
||||
has_more: bool = true,
|
||||
|
||||
/// Creates a new infinite scroll.
|
||||
pub fn init() InfiniteScroll {
|
||||
return .{};
|
||||
}
|
||||
|
||||
/// Sets the load more callback.
|
||||
pub fn setLoadMore(self: InfiniteScroll, load_fn: LoadMoreFn) InfiniteScroll {
|
||||
var is = self;
|
||||
is.load_more = load_fn;
|
||||
return is;
|
||||
}
|
||||
|
||||
/// Sets the load threshold.
|
||||
pub fn setLoadThreshold(self: InfiniteScroll, threshold: usize) InfiniteScroll {
|
||||
var is = self;
|
||||
is.load_threshold = threshold;
|
||||
return is;
|
||||
}
|
||||
|
||||
/// Gets the underlying list.
|
||||
pub fn getList(self: *InfiniteScroll) *VirtualList {
|
||||
return &self.list;
|
||||
}
|
||||
|
||||
/// Checks if more content should be loaded.
|
||||
pub fn checkLoadMore(self: *InfiniteScroll) bool {
|
||||
if (self.loading or !self.has_more) return false;
|
||||
if (self.load_more == null) return false;
|
||||
|
||||
if (self.list.selected) |s| {
|
||||
const remaining = self.list.item_count -| s;
|
||||
if (remaining <= self.load_threshold) {
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
/// Triggers loading more content.
|
||||
pub fn loadMore(self: *InfiniteScroll) void {
|
||||
if (self.load_more) |load_fn| {
|
||||
self.loading = true;
|
||||
const new_count = load_fn(self.list.item_count, self.list.user_data);
|
||||
|
||||
if (new_count == self.list.item_count) {
|
||||
self.has_more = false;
|
||||
} else {
|
||||
self.list.item_count = new_count;
|
||||
}
|
||||
|
||||
self.loading = false;
|
||||
}
|
||||
}
|
||||
|
||||
/// Selects next item (loads more if needed).
|
||||
pub fn selectNext(self: *InfiniteScroll) void {
|
||||
self.list.selectNext();
|
||||
if (self.checkLoadMore()) {
|
||||
self.loadMore();
|
||||
}
|
||||
}
|
||||
|
||||
/// Selects previous item.
|
||||
pub fn selectPrev(self: *InfiniteScroll) void {
|
||||
self.list.selectPrev();
|
||||
}
|
||||
|
||||
/// Renders the infinite scroll.
|
||||
pub fn render(self: *InfiniteScroll, area: Rect, buf: *Buffer) void {
|
||||
self.list.render(area, buf);
|
||||
}
|
||||
};
|
||||
|
||||
// ============================================================================
|
||||
// Tests
|
||||
// ============================================================================
|
||||
|
||||
test "ScrollState basic" {
|
||||
var state = ScrollState.init();
|
||||
state.setContentSize(100, 200);
|
||||
state.setViewport(40, 20);
|
||||
|
||||
try std.testing.expectEqual(@as(u32, 0), state.offset_y);
|
||||
try std.testing.expect(state.isAtTop());
|
||||
|
||||
state.scrollDown(10);
|
||||
try std.testing.expectEqual(@as(u32, 10), state.offset_y);
|
||||
|
||||
state.scrollToBottom();
|
||||
try std.testing.expect(state.isAtBottom());
|
||||
try std.testing.expectEqual(@as(u32, 180), state.offset_y);
|
||||
}
|
||||
|
||||
test "ScrollState clamp" {
|
||||
var state = ScrollState.init();
|
||||
state.setContentSize(100, 50);
|
||||
state.setViewport(40, 100);
|
||||
|
||||
// Content fits in viewport
|
||||
state.scrollDown(1000);
|
||||
try std.testing.expectEqual(@as(u32, 0), state.offset_y);
|
||||
}
|
||||
|
||||
test "VirtualList visible range" {
|
||||
var list = VirtualList.init()
|
||||
.setItemCount(100)
|
||||
.setItemHeight(2);
|
||||
|
||||
list.scroll_offset = 10;
|
||||
const range = list.getVisibleRange(20);
|
||||
|
||||
try std.testing.expectEqual(@as(usize, 10), range.start);
|
||||
try std.testing.expectEqual(@as(usize, 20), range.end);
|
||||
}
|
||||
|
||||
test "VirtualList selection" {
|
||||
var list = VirtualList.init()
|
||||
.setItemCount(100)
|
||||
.setItemHeight(1);
|
||||
|
||||
try std.testing.expectEqual(@as(?usize, null), list.selected);
|
||||
|
||||
list.selectNext();
|
||||
try std.testing.expectEqual(@as(?usize, 0), list.selected);
|
||||
|
||||
list.selectNext();
|
||||
try std.testing.expectEqual(@as(?usize, 1), list.selected);
|
||||
|
||||
list.selectPrev();
|
||||
try std.testing.expectEqual(@as(?usize, 0), list.selected);
|
||||
|
||||
list.selectPrev();
|
||||
try std.testing.expectEqual(@as(?usize, 0), list.selected); // Stay at 0
|
||||
}
|
||||
Loading…
Reference in a new issue