tiny.ui.style.element

1const std = @import("std");2const css = @import("css");3const abi = @import("../abi/root.zig");4const tree = @import("../tree/root.zig");56pub const Interaction = struct {7    hovered: u64 = 0,8    focused: u64 = 0,9    active: u64 = 0,10    keyboard_focus: bool = false,11};1213pub const Adapter = struct {14    view: tree.View,15    sheet: *const css.StyleSheet,16    interaction: Interaction = .{},17    hovered_index: ?u32 = null,18    focused_index: ?u32 = null,19    active_index: ?u32 = null,20    resolved: bool = false,21    ancestor_steps: u64 = 0,2223    pub fn element(self: *Adapter) css.match.Element {24        if (!self.resolved) {25            self.hovered_index = self.find(self.interaction.hovered);26            self.focused_index = self.find(self.interaction.focused);27            self.active_index = self.find(self.interaction.active);28            self.resolved = true;29        }30        return .{31            .context = self,32            .parent = parent,33            .previous = previous,34            .kind = kind,35            .role = role,36            .identifier = identifier,37            .classes = classes,38            .pseudo = pseudo,39            .sibling_index = siblingIndex,40        };41    }4243    fn selfOf(context: ?*anyopaque) *Adapter {44        return @ptrCast(@alignCast(context.?));45    }4647    fn parent(context: ?*anyopaque, index: u32) callconv(.c) u32 {48        const self = selfOf(context);49        self.ancestor_steps += 1;50        std.debug.assert(index < self.view.nodes.len);51        return self.view.nodes[index].parent;52    }5354    fn previous(context: ?*anyopaque, index: u32) callconv(.c) u32 {55        const self = selfOf(context);56        self.ancestor_steps += 1;57        std.debug.assert(index < self.view.nodes.len);58        if (index == 0) return index;59        const wanted = self.view.nodes[index].parent;60        var candidate = index;61        while (candidate > 0) {62            candidate -= 1;63            if (self.view.nodes[candidate].parent == wanted and candidate != wanted and64                candidate + self.view.nodes[candidate].subtree_count < index) return candidate;65            if (candidate == wanted) break;66        }67        return index;68    }6970    fn kind(context: ?*anyopaque, index: u32) callconv(.c) u16 {71        const self = selfOf(context);72        const value: abi.Kind = @fromBackingInt(@intCast(self.view.nodes[index].kind));73        return @intCast(self.sheet.token(@tagName(value)));74    }7576    fn role(context: ?*anyopaque, index: u32) callconv(.c) u16 {77        const self = selfOf(context);78        const value: abi.Role = @fromBackingInt(@intCast(self.view.nodes[index].role));79        return @intCast(self.sheet.token(@tagName(value)));80    }8182    fn identifier(context: ?*anyopaque, index: u32) callconv(.c) u32 {83        const self = selfOf(context);84        return self.sheet.token(self.view.text(self.view.nodes[index].identifier));85    }8687    fn classes(context: ?*anyopaque, index: u32, out: [*]u32, capacity: u32) callconv(.c) u32 {88        const self = selfOf(context);89        const source = self.view.classesOf(index);90        std.debug.assert(source.len <= capacity);91        for (source, 0..) |atom, at| out[at] = self.sheet.token(self.view.text(atom));92        return @intCast(source.len);93    }9495    fn hasAncestor(self: *const Adapter, index: u32, start: ?u32) bool {96        var candidate = start orelse return false;97        while (true) {98            if (candidate == index) return true;99            if (candidate == 0) return false;100            candidate = self.view.nodes[candidate].parent;101        }102    }103104    fn pseudo(context: ?*anyopaque, index: u32) callconv(.c) u32 {105        const self = selfOf(context);106        const node = self.view.nodes[index];107        var word: u32 = 0;108        inline for (@typeInfo(abi.State).@"enum".field_names, 0..) |name, at| {109            const state: abi.State = @fromBackingInt(@intCast(at));110            const class = @field(css.selector.PseudoClass, name);111            if (abi.active(node.state, state)) word |= css.selector.bit(class);112        }113        if (index == 0) word |= css.selector.bit(.root);114        if (node.subtree_count == 0 and node.text == abi.text_absent) word |= css.selector.bit(.empty);115        if (!abi.active(node.state, .disabled)) word |= css.selector.bit(.enabled);116        if (abi.holds(node.flags, .modal)) word |= css.selector.bit(.modal);117        if (self.hasAncestor(index, self.hovered_index)) word |= css.selector.bit(.hover);118        if (self.hasAncestor(index, self.active_index)) word |= css.selector.bit(.active);119        if (self.view.nodes[index].id == self.interaction.focused and self.interaction.focused != 0) {120            word |= css.selector.bit(.focus);121            if (self.interaction.keyboard_focus) word |= css.selector.bit(.focus_visible);122        }123        if (self.focused_index) |focused| {124            if (self.isAncestor(index, focused)) word |= css.selector.bit(.focus_within);125        }126        return word;127    }128129    pub fn find(self: *const Adapter, id: u64) ?u32 {130        if (id == 0) return null;131        if (self.view.identity) |identity| return identity.lookup(self.view.nodes, id);132        for (self.view.nodes, 0..) |node, at| if (node.id == id) return @intCast(at);133        return null;134    }135136    fn isAncestor(self: *const Adapter, ancestor: u32, child: u32) bool {137        var index = child;138        while (true) {139            if (index == ancestor) return true;140            if (index == 0) return false;141            index = self.view.nodes[index].parent;142        }143    }144145    fn siblingIndex(context: ?*anyopaque, index: u32, of_type: bool) callconv(.c) u32 {146        const self = selfOf(context);147        const node = self.view.nodes[index];148        var first: u32 = if (index == 0) 0 else node.parent + 1;149        var ordinal: u32 = 0;150        var total: u32 = 0;151        while (first < self.view.nodes.len and152            (index == 0 or first <= node.parent + self.view.nodes[node.parent].subtree_count))153        {154            const candidate = self.view.nodes[first];155            if (!of_type or candidate.kind == node.kind) {156                total += 1;157                if (first <= index) ordinal = total;158            }159            first += candidate.subtree_count + 1;160        }161        return css.match.packSibling(ordinal, total);162    }163};

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