Add a Theme type that is more easy to edit in a configuration file

examples/raylib-ontop.zig

@@ -1,6 +1,8 @@
 const std = @import("std");
 const dvui = @import("dvui");
-comptime { std.debug.assert(dvui.backend_kind == .raylib); }
+comptime {
+    std.debug.assert(dvui.backend_kind == .raylib);
+}
 const RaylibBackend = dvui.backend;
 const ray = RaylibBackend.c;
 
@@ -29,7 +31,7 @@ pub fn main() !void {
 
     // init dvui Window (maps onto a single OS window)
     // OS window is managed by raylib, not dvui
-    var win = try dvui.Window.init(@src(), gpa, backend.backend(), .{ .theme = &dvui.Theme.Jungle });
+    var win = try dvui.Window.init(@src(), gpa, backend.backend(), .{});
     defer win.deinit();
 
     var selected_color: dvui.Color = dvui.Color.white;

src/Color.zig

@@ -8,6 +8,15 @@ g: u8 = 0xff,
 b: u8 = 0xff,
 a: u8 = 0xff,
 
+/// Returns brightness of the color as a value between 0 and 1
+pub fn brightness(self: @This()) f32 {
+    const red: f32 = @as(f32, @floatFromInt(self.r)) / 255.0;
+    const green: f32 = @as(f32, @floatFromInt(self.g)) / 255.0;
+    const blue: f32 = @as(f32, @floatFromInt(self.b)) / 255.0;
+
+    return 0.2126 * red + 0.7152 * green + 0.0722 * blue;
+}
+
 pub const HSLuv = struct {
     h: f32 = 0.0,
     s: f32 = 100.0,
@@ -83,7 +92,9 @@ pub fn extract(self: Color, field: FieldEnum) u16 {
         .r => self.r,
         .g => self.g,
         .b => self.b,
-        .a => @compileError("cannot extract alpha field from color"),
+        .a => {
+            @panic("This should never be called");
+        },
     });
     const result = normalized_a * value;
     return @intFromFloat(@floor(result));
@@ -99,8 +110,34 @@ pub fn alphaAdd(self: Color, other: Color) Color {
     };
 }
 
-pub fn toHexString(self: Color) ![7]u8 {
+/// Adds two colors rgb component-wise premultiplied by alpha
+pub fn alphaAverage(self: Color, other: Color) Color {
+    return Color{
+        .r = @intCast((self.extract(.r) + other.extract(.r)) / (255 * 2)),
+        .g = @intCast((self.extract(.g) + other.extract(.g)) / (255 * 2)),
+        .b = @intCast((self.extract(.b) + other.extract(.b)) / (255 * 2)),
+        .a = 255,
+    };
+}
+
+pub const HexString = [7]u8;
+
+pub fn toHexString(self: Color) !HexString {
     var result: [7]u8 = .{0} ** 7;
     _ = try std.fmt.bufPrint(&result, "#{x:0>2}{x:0>2}{x:0>2}", .{ self.r, self.g, self.b });
     return result;
 }
+
+/// Converts slice of HexString to Color
+pub fn fromHex(hex: HexString) !Color {
+    //if (hex[0] != '#') return error.NotAColor;
+    //if (hex.len != 7) return error.WrongStringLength;
+
+    const num: u24 = try std.fmt.parseInt(u24, hex[1..], 16);
+    const result = Color{
+        .r = @intCast(num >> 16 & 0xff),
+        .g = @intCast(num >> 8 & 0xff),
+        .b = @intCast(num & 0xff),
+    };
+    return result;
+}

src/Examples.zig

@@ -267,28 +267,7 @@ pub fn demo() !void {
             dvui.toggleDebugWindow();
         }
 
-        const theme_choice: usize = blk: {
-            for (dvui.Theme.ptrs, 0..) |tptr, i| {
-                if (dvui.themeGet() == tptr) {
-                    break :blk i;
-                }
-            }
-            break :blk 0;
-        };
-
-        var dd = dvui.DropdownWidget.init(@src(), .{ .selected_index = theme_choice, .label = dvui.themeGet().name }, .{ .min_size_content = .{ .w = 120 } });
-        try dd.install();
-
-        if (try dd.dropped()) {
-            for (dvui.Theme.ptrs) |tptr| {
-                if (try dd.addChoiceLabel(tptr.name)) {
-                    dvui.themeSet(tptr);
-                    break;
-                }
-            }
-        }
-
-        dd.deinit();
+        try dvui.currentWindow().themes.picker(@src());
     }
 
     {
@@ -364,10 +343,10 @@ pub fn demo() !void {
         try animations();
     }
 
-    if (try dvui.expander(@src(), "Theme Serialization and Parsing", .{}, .{ .expand = .horizontal })) {
+    if (try dvui.expander(@src(), "Theme Parsing", .{}, .{ .expand = .horizontal })) {
         var b = try dvui.box(@src(), .vertical, .{ .expand = .horizontal, .margin = .{ .x = 10 } });
         defer b.deinit();
-        try themeSerialization(float.data().id);
+        try themeSerialization();
     }
 
     if (try dvui.expander(@src(), "Struct UI Widget (Experimental)", .{}, .{ .expand = .horizontal })) {
@@ -459,36 +438,11 @@ pub fn demo() !void {
     }
 }
 
-pub fn themeSerialization(demo_win_id: u32) !void {
-    {
-        var serialize_box = try dvui.box(@src(), .vertical, .{ .expand = .horizontal, .margin = .{ .x = 10 } });
-        defer serialize_box.deinit();
+pub fn themeSerialization() !void {
+    var serialize_box = try dvui.box(@src(), .vertical, .{ .expand = .horizontal, .margin = .{ .x = 10 } });
+    defer serialize_box.deinit();
 
-        // Demonstrate serializing a theme
-        const Static = struct {
-            var bytes: [4096]u8 = undefined;
-            var buffer = std.io.fixedBufferStream(&bytes);
-        };
-
-        if (try dvui.button(@src(), "Serialize Active Theme", .{}, .{})) {
-            Static.buffer.reset();
-            _ = try std.json.stringify(dvui.themeGet(), .{}, Static.buffer.writer());
-        }
-
-        if (try dvui.expander(@src(), "Serialized Theme", .{}, .{ .expand = .horizontal })) {
-            var b = try dvui.box(@src(), .vertical, .{ .expand = .horizontal, .margin = .{ .x = 10 } });
-            defer b.deinit();
-
-            if (try dvui.button(@src(), "Copy To Clipboard", .{}, .{})) {
-                try dvui.clipboardTextSet(Static.buffer.getWritten());
-                try dvui.toast(@src(), .{ .subwindow_id = demo_win_id, .message = "Copied!" });
-            }
-
-            var tl = try dvui.textLayout(@src(), .{}, .{ .expand = .horizontal, .background = false });
-            try tl.addText(Static.buffer.getWritten(), .{});
-            tl.deinit();
-        }
-    }
+    try dvui.labelNoFmt(@src(), "TODO: demonstrate loading a quicktheme here", .{});
 }
 
 pub fn basicWidgets() !void {