makepad-2.0-theme（makepad 2 0 主题）

Makepad 2.0 Theme System

Overview

The Makepad 2.0 theme system provides a comprehensive set of design tokens accessed through theme.* variables in Splash scripts. It delivers consistent styling for colors, typography, spacing, and widget states across your entire application.

Three built-in themes are available:

• mod.themes.dark -- dark desktop theme (default)
• mod.themes.light -- light desktop theme
• mod.themes.skeleton -- minimal skeleton theme with hardcoded values

Golden rule: Always use theme.* variables instead of hardcoded values for any color, font size, or spacing in production UIs. This ensures your app automatically supports theme switching and maintains visual consistency.

Theme Setup in App::run

The theme must be loaded before widgets are loaded. The standard pattern is:

impl App {
    fn run(vm: &mut ScriptVm) -> Self {
        // Step 1: Load theme definitions (dark, light, skeleton)
        crate::makepad_widgets::theme_mod(vm);

        // Step 2: Select active theme (MUST come before widgets_mod)
        script_eval!(vm, {
            mod.theme = mod.themes.light  // or mod.themes.dark
        });

        // Step 3: Load widget definitions (they reference mod.theme)
        crate::makepad_widgets::widgets_mod(vm);

        // Step 4: Load your app's script_mod
        App::from_script_mod(vm, self::script_mod)
    }
}

If you skip steps 1-2, the default theme is dark (set inside theme_mod). The counter example uses the simplified one-liner crate::makepad_widgets::script_mod(vm) which bundles steps 1-3 with the default dark theme.

How It Works Internally

theme_mod() does the following:

1. Calls makepad_draw::script_mod(vm) to load drawing primitives
2. Creates the mod.themes module
3. Loads theme_desktop_dark, theme_desktop_light, and theme_desktop_skeleton
4. Sets mod.theme = mod.themes.dark as the default

Then widgets_mod() creates mod.prelude.widgets_internal with theme: mod.theme, making theme.* available in all widget scripts that use mod.prelude.widgets.*.

Theme Global Parameters

Each theme defines tunable global parameters that control the overall feel:

Theme Color Variables -- Primary

These are the colors you will use most often in application code:

Theme Color Variables -- Text and Labels

Theme Color Variables -- Widget States

Outset colors (buttons, raised elements):

Inset colors (text inputs, checkboxes, radio buttons):

Selection and highlight:

Theme Color Variables -- Semantic/Status

Theme Color Variables -- Bevel System

The theme has a layered bevel system for 3D-like widget effects:

Theme Color Variables -- Additional Widget Colors

Theme Font Variables

Font Sizes

Font sizes are computed from font_size_base and font_size_contrast:

Font Styles (TextStyle objects)

Each font style includes multi-language support:

• Latin: IBM Plex Sans family
• Chinese: LXGW WenKai family
• Emoji: Noto Color Emoji

Line Spacing Constants

Theme Spacing Variables

Base Spacing

Spacing is derived from space_factor (default 6.0):

Margin/Padding Presets (Inset objects)

All-sides presets:

Horizontal-only presets:

Vertical-only presets:

Dimension Variables

Using Theme Variables in Splash

Colors

// Background color
draw_bg.color: theme.color_bg_container

// Text color
draw_text.color: theme.color_label_inner

// Muted/secondary text
draw_text.color: theme.color_label_inner_inactive

// Color math -- multiply for opacity
draw_text.color: theme.color_label_inner_inactive * 0.8

// Semantic colors
draw_bg.color: theme.color_warning
draw_bg.color: theme.color_error

Font Sizes

// Body text size
draw_text.text_style.font_size: theme.font_size_p

// Heading sizes
draw_text.text_style.font_size: theme.font_size_1   // Largest
draw_text.text_style.font_size: theme.font_size_2   // Medium
draw_text.text_style.font_size: theme.font_size_3   // Small
draw_text.text_style.font_size: theme.font_size_4   // Sub-heading

// Code font size
draw_text.text_style.font_size: theme.font_size_code

Font Styles

// Bold text with custom size (override with {} syntax)
draw_text.text_style: theme.font_bold{font_size: theme.font_size_2}

// Bold text keeping default size
draw_text.text_style: theme.font_bold{}

// Code font
draw_text.text_style: theme.font_code{}

// Override font size using +: merge syntax
draw_text +: {text_style +: {font_size: theme.font_size_3}}

Spacing

// Uniform padding
padding: theme.mspace_2

// Padding with overrides
padding: theme.mspace_2{left: theme.space_3, right: theme.space_3}

// Horizontal-only padding with custom values
padding: theme.mspace_h_1{left: theme.space_2, right: theme.space_2}

// Spacing between children
spacing: theme.space_2

// Computed spacing
width: Fill height: 9. * theme.space_1
padding: theme.mspace_3{left: theme.space_3 * 2, right: theme.space_3 * 2}

Color Syntax Reference

Splash supports multiple color formats (not theme-specific but essential):

Important: When a hex color starts with the letter e, use the #x prefix to avoid ambiguity with scientific notation. For example, #x2ecc71 not #2ecc71.

Color math is supported:

// Multiply for opacity
theme.color_label_inner_inactive * 0.8

// Mix two colors
mix(theme.color_w, theme.color_b, 0.5)

Theme Switching at Runtime

You can switch themes dynamically in Rust event handlers:

impl MatchEvent for App {
    fn handle_actions(&mut self, cx: &mut Cx, actions: &Actions) {
        if self.ui.button(cx, ids!(toggle_theme)).clicked(actions) {
            script_eval!(cx, {
                mod.theme = mod.themes.dark  // or mod.themes.light
            });
            // All widgets using theme.* will pick up new values
            // You may need to trigger a re-render
        }
    }
}

Or switch before widgets load (in App::run) for a static theme choice:

fn run(vm: &mut ScriptVm) -> Self {
    crate::makepad_widgets::theme_mod(vm);
    script_eval!(vm, {
        mod.theme = mod.themes.light
    });
    crate::makepad_widgets::widgets_mod(vm);
    App::from_script_mod(vm, self::script_mod)
}

Complete Theme-Aware UI Example

This example demonstrates a themed card list using only theme variables:

script_mod! {
    use mod.prelude.widgets.*

    let CardItem = RoundedView{
        width: Fill height: Fit
        padding: theme.mspace_2{left: theme.space_3, right: theme.space_3}
        flow: Right spacing: theme.space_2
        align: Align{y: 0.5}
        draw_bg.color: theme.color_bg_container
        draw_bg.border_radius: theme.container_corner_radius

        icon := Label{
            width: 24 height: 24
            text: ""
        }
        content := View{
            width: Fill height: Fit
            flow: Down spacing: theme.space_1
            title := Label{
                text: "Title"
                draw_text.color: theme.color_label_inner
                draw_text.text_style: theme.font_bold{font_size: theme.font_size_4}
            }
            subtitle := Label{
                text: "Subtitle"
                draw_text.color: theme.color_label_inner_inactive
                draw_text.text_style.font_size: theme.font_size_p
            }
        }
        badge := RoundedView{
            width: Fit height: Fit
            padding: theme.mspace_h_1
            draw_bg.color: theme.color_bg_highlight_inline
            draw_bg.border_radius: 4.0
            badge_label := Label{
                text: "new"
                draw_text.color: theme.color_highlight
                draw_text.text_style.font_size: theme.font_size_code
                draw_text.text_style: theme.font_bold{}
            }
        }
    }

    startup() do #(App::script_component(vm)){
        ui: Root{
            main_window := Window{
                pass.clear_color: theme.color_bg_app
                window.inner_size: vec2(400, 600)
                body +: {
                    width: Fill height: Fill
                    flow: Down spacing: 0

                    // Header
                    SolidView{
                        width: Fill height: Fit
                        padding: theme.mspace_3
                        draw_bg.color: theme.color_app_caption_bar
                        Label{
                            text: "My Cards"
                            draw_text.color: theme.color_label_inner
                            draw_text.text_style: theme.font_bold{font_size: theme.font_size_2}
                        }
                    }

                    // Card list
                    ScrollYView{
                        width: Fill height: Fill
                        padding: theme.mspace_2
                        flow: Down spacing: theme.space_1
                        CardItem{title.text: "First Card" subtitle.text: "Description here"}
                        CardItem{title.text: "Second Card" subtitle.text: "Another card"}
                    }

                    // Footer
                    SolidView{
                        width: Fill height: Fit
                        padding: theme.mspace_2
                        draw_bg.color: theme.color_bg_container
                        Label{
                            text: "2 items"
                            draw_text.color: theme.color_label_inner_inactive
                            draw_text.text_style.font_size: theme.font_size_code
                        }
                    }
                }
            }
        }
    }
}

Best Practices

1. **ALWAYS use theme.* for colors in production apps** -- never hardcode #ff0000 when theme.color_error exists. This enables theme switching and accessibility.
2. Use theme fonts for consistent typography -- prefer theme.font_bold{font_size: theme.font_size_2} over manually specifying font families.
3. Use theme spacing for consistent layout -- theme.mspace_2 and theme.space_2 create a harmonious rhythm. Avoid magic numbers like padding: Inset{top: 8,...}.
4. Override with {} syntax -- extend theme values without replacing them: theme.font_bold{font_size: 20} keeps the bold font family but overrides size. theme.mspace_2{left: theme.space_3} keeps top/right/bottom but overrides left.
5. Use merge +: for partial overrides -- when you only want to change one nested property: draw_text +: {text_style +: {font_size: theme.font_size_3}}
6. Choose the right text color variable:

- theme.color_label_inner for primary UI text (buttons, labels) - theme.color_label_inner_inactive for secondary/muted text - theme.color_text for general content text - theme.color_text_placeholder for placeholder text

1. Use state-aware color variants -- widgets that change on hover/focus/press should use the matching _hover, _focus, _down suffixes.
2. Multiply for subtle opacity -- theme.color_label_inner_inactive * 0.8 creates a subtler variant without a new variable.
3. Select theme before widgets_mod -- the theme must be set between theme_mod() and widgets_mod() calls, so widget definitions pick up the correct theme values.
4. For simple apps, use crate::makepad_widgets::script_mod(vm) which loads everything with the default dark theme in one call.

Source Files

• Theme dark: widgets/src/theme_desktop_dark.rs
• Theme light: widgets/src/theme_desktop_light.rs
• Theme skeleton: widgets/src/theme_desktop_skeleton.rs
• Theme loader: widgets/src/lib.rs (theme_mod and widgets_mod functions)
• Example usage: examples/todo/src/app.rs (light theme with full theme variable usage)
• Example usage: examples/counter/src/app.rs (default dark theme)