tiny.gui.model

1const std = @import("std");2const filigree = @import("filigree");3const flex_layout = @import("arrange");45pub const WidgetKind = enum(u8) {6    container,7    label,8    button,9    text_input,10};1112pub const ui_state_selected: u64 = 1 << 0;13pub const ui_state_disabled: u64 = 1 << 1;14pub const ui_state_expanded: u64 = 1 << 2;15pub const ui_state_checked: u64 = 1 << 3;16pub const ui_state_default: u64 = 1 << 4;17pub const ui_state_danger: u64 = 1 << 5;1819pub const UiOverflow = enum(u8) {20    visible,21    clip,22};2324pub const UiColor = struct {25    r: u8 = 0,26    g: u8 = 0,27    b: u8 = 0,28    a: u8 = 255,29};3031pub const UiPoint = struct {32    x: f32 = 0,33    y: f32 = 0,34};3536pub const UiLinearGradient = struct {37    start: UiPoint = .{},38    end: UiPoint = .{ .x = 1 },39    start_color: UiColor = .{},40    end_color: UiColor = .{},41};4243pub const UiPaint = struct {44    background: ?UiColor = null,45    linear_gradient: ?UiLinearGradient = null,46    foreground: ?UiColor = null,47    border: ?UiColor = null,48    border_width: f32 = 0,49    corner_roundness: f32 = 0,50    border_edges: UiBorderPaint = .{},51    shadow: UiShadowPaint = .{},52    image: ?UiImagePaint = null,53};5455pub const UiImagePaint = struct {56    index: u32,57    source: flex_layout.Rect = .{},58    tint: ?UiColor = null,59    opacity: u8 = 255,60};6162pub const UiImage = struct {63    width: u32,64    height: u32,65    pixels: []const u32,6667    pub fn pixelCount(self: UiImage) usize {68        return @as(usize, self.width) * @as(usize, self.height);69    }7071    pub fn validate(self: UiImage) !void {72        if (self.width == 0 or self.height == 0) return error.InvalidImage;73        if (self.pixels.len < self.pixelCount()) return error.BufferTooSmall;74    }75};7677pub const UiImageSet = struct {78    images: []const UiImage = &.{},79};8081pub const UiBorderEdgePaint = struct {82    color: ?UiColor = null,83    width: f32 = 0,84};8586pub const UiBorderPaint = struct {87    top: UiBorderEdgePaint = .{},88    right: UiBorderEdgePaint = .{},89    bottom: UiBorderEdgePaint = .{},90    left: UiBorderEdgePaint = .{},91};9293pub const UiShadowPaint = struct {94    color: ?UiColor = null,95    offset_x: f32 = 0,96    offset_y: f32 = 0,97    blur_radius: f32 = 0,98    spread: f32 = 0,99};100101pub const UiScroll = struct {102    overflow_x: UiOverflow = .visible,103    overflow_y: UiOverflow = .visible,104    scroll_x: f32 = 0,105    scroll_y: f32 = 0,106};107108pub fn nonNegativeFinite(value: f32) f32 {109    if (!std.math.isFinite(value) or value <= 0) return 0;110    return value;111}112113pub const UiTextStyle = struct {114    font_asset_id: u64 = 0,115    point_size: f64 = 16.0,116};117118pub const UiTextRun = struct {119    byte_start: usize,120    byte_end: usize,121    style_slot: u16 = 0,122    foreground: ?UiColor = null,123    background: ?UiColor = null,124    underline: bool = false,125    strikethrough: bool = false,126};127128pub const UiText = struct {129    content: []const u8,130    runs: []const UiTextRun = &.{},131    styles: []const UiTextStyle = &.{},132    font_asset_id: u64 = 0,133    font_weight: u16 = ui_font_weight_normal,134    point_size: f64 = 16.0,135    line_height: f64 = 1.2,136    wrap_width: f64 = 0.0,137    horizontal_align: UiTextAlign = .start,138    vertical_align: UiTextAlign = .start,139};140141pub const UiTextAlign = enum(u8) {142    start,143    center,144    end,145};146147pub const UiTextSelection = struct {148    cursor_visible: bool = false,149    cursor_block: bool = false,150    cursor_byte_offset: usize = 0,151    selection_active: bool = false,152    selection_anchor_byte_offset: usize = 0,153    selection_focus_byte_offset: usize = 0,154};155156pub const ui_font_weight_normal: u16 = 400;157pub const ui_font_weight_min: u16 = 100;158pub const ui_font_weight_max: u16 = 900;159160pub const TextRunValidator = struct {161    previous_end: usize = 0,162163    pub fn validate(164        self: *TextRunValidator,165        content: []const u8,166        byte_start: usize,167        byte_end: usize,168    ) error{InvalidTextRun}!void {169        if (byte_start < self.previous_end or byte_start >= byte_end) return error.InvalidTextRun;170        if (byte_end > content.len) return error.InvalidTextRun;171        if (!textByteBoundary(content, byte_start) or !textByteBoundary(content, byte_end)) return error.InvalidTextRun;172        self.previous_end = byte_end;173    }174};175176pub fn validateTextRuns(content: []const u8, runs: []const UiTextRun) error{InvalidTextRun}!void {177    var validator = TextRunValidator{};178    for (runs) |run| {179        try validator.validate(content, run.byte_start, run.byte_end);180    }181}182183pub fn validateText(text: UiText) error{InvalidTextRun}!void {184    if (text.styles.len > std.math.maxInt(u16)) return error.InvalidTextRun;185    for (text.styles) |style| {186        if (!validTextPointSize(style.point_size)) return error.InvalidTextRun;187    }188    try validateTextRuns(text.content, text.runs);189    for (text.runs, 0..) |run, index| {190        if (run.style_slot > text.styles.len) return error.InvalidTextRun;191        const style = resolvedTextStyle(text, run.style_slot);192        const before = if (index > 0 and text.runs[index - 1].byte_end == run.byte_start)193            resolvedTextStyle(text, text.runs[index - 1].style_slot)194        else195            resolvedTextStyle(text, 0);196        const after = if (index + 1 < text.runs.len and text.runs[index + 1].byte_start == run.byte_end)197            resolvedTextStyle(text, text.runs[index + 1].style_slot)198        else199            resolvedTextStyle(text, 0);200        if (!textStylesEqual(before, style) and201            !textGraphemeBoundary(text.content, run.byte_start))202        {203            return error.InvalidTextRun;204        }205        if (!textStylesEqual(style, after) and206            !textGraphemeBoundary(text.content, run.byte_end))207        {208            return error.InvalidTextRun;209        }210    }211}212213pub fn resolvedTextStyle(text: UiText, style_slot: u16) UiTextStyle {214    if (style_slot == 0 or style_slot > text.styles.len) {215        return .{216            .font_asset_id = text.font_asset_id,217            .point_size = normalizedTextPointSize(text.point_size),218        };219    }220    return text.styles[style_slot - 1];221}222223pub fn textStylesEqual(left: UiTextStyle, right: UiTextStyle) bool {224    return left.font_asset_id == right.font_asset_id and225        @as(u64, @bitCast(left.point_size)) == @as(u64, @bitCast(right.point_size));226}227228pub fn normalizedTextPointSize(value: f64) f64 {229    return if (validTextPointSize(value)) value else 16.0;230}231232pub fn validTextPointSize(value: f64) bool {233    return std.math.isFinite(value) and value > 0;234}235236pub fn textGraphemeBoundary(content: []const u8, index: usize) bool {237    if (index == 0 or index == content.len) return true;238    if (index > content.len) return false;239    var iterator = filigree.unicode.SourceIterator.init(.{ .utf8 = content }, 0) catch return false;240    var state: filigree.unicode.GraphemeState = .{};241    while (iterator.next() catch return false) |scalar| {242        const boundary = !state.consume(scalar.codepoint);243        const offset: usize = @intCast(scalar.source.start);244        if (offset == index) return boundary;245        if (offset > index) return false;246    }247    return false;248}249250fn textByteBoundary(content: []const u8, index: usize) bool {251    if (index == 0 or index == content.len) return true;252    return content[index] & 0b1100_0000 != 0b1000_0000;253}254255pub const UiNode = struct {256    widget_id: u64,257    kind: WidgetKind = .container,258    style: flex_layout.Style = .{},259    size: flex_layout.Dimensions = .{},260    paint: UiPaint = .{},261    scroll: UiScroll = .{},262    focusable: bool = false,263    layer: u8 = 0,264    text: ?UiText = null,265    text_selection: UiTextSelection = .{},266    action: []const u8 = &.{},267    role: []const u8 = &.{},268    state_flags: u64 = 0,269    children: []const UiNode = &.{},270};271272pub const UiSurfaceTree = struct {273    available_size: flex_layout.Size,274    root: UiNode,275};276277pub const RootFrame = struct {278    root_id: u64,279    surface_revision: u64,280    rect: flex_layout.Rect,281    widget_start: usize,282    widget_count: usize,283};284285pub const WidgetFrame = struct {286    root_id: u64,287    widget_id: u64,288    kind: WidgetKind,289    rect: flex_layout.Rect,290    visible_rect: flex_layout.Rect,291    paint: UiPaint,292    scroll: UiScroll,293    constraints: flex_layout.Constraints,294    content_size: flex_layout.Size,295    focusable: bool,296    layer: u8 = 0,297    hovered: bool = false,298    captured: bool = false,299    focused: bool = false,300    has_text: bool = false,301    action: []const u8 = &.{},302    role: []const u8 = &.{},303    state_flags: u64 = 0,304    text_ref: u64 = 0,305    text: ?UiText = null,306    text_selection: UiTextSelection = .{},307    subtree_size: usize = 1,308};309310pub const UiFrame = struct {311    revision: u64 = 0,312    root_count: usize = 0,313    roots: []const RootFrame = &.{},314    widget_count: usize = 0,315    widgets: []const WidgetFrame = &.{},316    text_layout_revision: u64 = 0,317    text_layout_ptr: ?*anyopaque = null,318};319320pub fn pointInRect(rect: flex_layout.Rect, x: f32, y: f32) bool {321    return x >= rect.x and y >= rect.y and x <= rect.x + rect.width and y <= rect.y + rect.height;322}323324test "text runs require ordered nonempty UTF-8 byte ranges" {325    const content = "a\u{00e9}z";326    const valid = [_]UiTextRun{327        .{ .byte_start = 0, .byte_end = 1 },328        .{ .byte_start = 1, .byte_end = 3 },329        .{ .byte_start = 3, .byte_end = 4 },330    };331    try validateTextRuns(content, &valid);332    try std.testing.expectError(error.InvalidTextRun, validateTextRuns(content, &.{333        .{ .byte_start = 1, .byte_end = 1 },334    }));335    try std.testing.expectError(error.InvalidTextRun, validateTextRuns(content, &.{336        .{ .byte_start = 1, .byte_end = 2 },337    }));338    try std.testing.expectError(error.InvalidTextRun, validateTextRuns(content, &.{339        .{ .byte_start = 0, .byte_end = 3 },340        .{ .byte_start = 2, .byte_end = 4 },341    }));342    try std.testing.expectError(error.InvalidTextRun, validateTextRuns(content, &.{343        .{ .byte_start = 3, .byte_end = 5 },344    }));345}346347test "metric text runs require valid slots and grapheme boundaries" {348    const content = "a\u{0301}b";349    const styles = [_]UiTextStyle{350        .{ .font_asset_id = 7, .point_size = 18 },351        .{ .point_size = 16 },352    };353    try validateText(.{354        .content = content,355        .styles = &styles,356        .runs = &.{357            .{ .byte_start = 0, .byte_end = 3, .style_slot = 1 },358            .{ .byte_start = 3, .byte_end = 4, .style_slot = 2 },359        },360    });361    try validateText(.{362        .content = content,363        .styles = &styles,364        .runs = &.{365            .{ .byte_start = 0, .byte_end = 1, .style_slot = 1 },366            .{ .byte_start = 1, .byte_end = 3, .style_slot = 1 },367        },368    });369    try std.testing.expectError(error.InvalidTextRun, validateText(.{370        .content = content,371        .styles = &styles,372        .runs = &.{373            .{ .byte_start = 0, .byte_end = 1, .style_slot = 1 },374            .{ .byte_start = 1, .byte_end = 3, .style_slot = 2 },375        },376    }));377    try std.testing.expectError(error.InvalidTextRun, validateText(.{378        .content = content,379        .styles = &styles,380        .runs = &.{381            .{ .byte_start = 1, .byte_end = 3, .style_slot = 1 },382        },383    }));384    try std.testing.expectError(error.InvalidTextRun, validateText(.{385        .content = content,386        .styles = &styles,387        .runs = &.{388            .{ .byte_start = 0, .byte_end = 3, .style_slot = 3 },389        },390    }));391    try std.testing.expectError(error.InvalidTextRun, validateText(.{392        .content = content,393        .styles = &.{.{ .point_size = std.math.nan(f64) }},394    }));395}

1pub const model = @import("model.zig");