v0.5.0

Added

• Menu items can be disabled. MenuItem::with_enabled attaches a predicate
  that is evaluated live on every paint and every attempt to fire, so a menu
  built once tracks changing application state (typically read through an
  Rc<RefCell<…>>). A disabled item renders greyed, shows no hover band, is
  skipped by arrow-key navigation and mnemonics, and never fires — by mouse,
  keyboard, or accelerator. (#46)
• Menu items can show a checkmark. MenuItem::with_checked attaches a
  predicate, also read live each paint, that draws a tick in the item's left
  gutter while true — for toggles and radio-style groups. The glyph is the
  same one Checkbox uses, tinted to the item's current text color, and it
  rides inside the existing label inset, so the layout never shifts between
  checked and unchecked. The mark is display-only: a checked item still fires
  its callback normally when picked. (#46)
• Menu accelerators are now live, not just decorative. MenuItem::with_accel
  takes the new Accel type (or its conventional string form: "Ctrl+R",
  "Ctrl+Shift+Enter"), and pressing a matching chord while the bar is closed
  fires the item directly. Accel names its modifiers as platform-independent
  roles (AccelMods): Accel::primary('r') means ⌘R on macOS and Ctrl+R
  everywhere else, resolved through a ModifierScheme both when matching
  input and when rendering the right-aligned hint. The scheme defaults to the
  build platform's; MenuBar::with_scheme pins it, e.g. for snapshot tests
  that must not drift between hosts. A chord whose only matches are disabled
  items falls through unconsumed, keeping its ordinary meaning in the focused
  widget (Ctrl+Left stays word-jump in an editor); while a menu is open it owns
  the keyboard, so chords wait. Breaking: MenuItem::Action's accel field is
  now Option<Accel> instead of Option<String> — with_accel("Ctrl+R")
  call sites keep compiling via From<&str>, which panics on a malformed
  chord so a typo fails loudly at first use. (#46)
• Text can now be drawn in three font families — sans-serif, serif, and
  monospace — each in bold, italic, and bold-italic, all using
  the host's real installed faces rather than a synthesized smear or shear of the
  regular one. Two new enums name the axes: FontFamily (Sans / Serif /
  Mono) and FontStyle (Regular / Bold / Italic / BoldItalic). Draw
  with Painter::text_styled(.., family, style) and measure with
  Painter::measure_text_styled(.., family, style); the existing text /
  measure_text stay sans-serif regular, so nothing already on screen moves. (#44)
• Font::load_sans (renamed from load_system), Font::load_serif, and
  Font::load_monospace load the three families, walking — for the serif — the
  classic Win 3.1 / Office serif families (Times New Roman, Georgia, …) down to
  modern Linux replacements. Each loader now also loads the bold, italic, and
  bold-italic faces of the chosen family alongside the regular one. Because real
  bold / italic / serif faces carry their own advance widths, measuring in the
  same family and style the text is drawn keeps word-wrap pixel-accurate. A
  family the host ships without a given face falls back to the nearest real
  face it does have (ultimately the regular face), and the loader verifies
  fontdb's match actually carries the requested weight/slant so a regular face is
  never passed off as bold or italic. (#44)
• For deterministic, font-bundling snapshot tests, Font::from_sans_bytes
  (renamed from from_bytes) gains with_bold_bytes, with_italic_bytes, and
  with_bold_italic_bytes builders to attach the emphasis faces from in-memory
  buffers, and MockBackend gains with_serif_font alongside with_sans_font
  (renamed from with_font) / with_mono_font.
• Painter::blit_argb blits a block of pre-composited, opaque ARGB pixels in
  one call — the bulk path for drawing a decoded or composed image, where a
  grid of per-pixel pixel() calls is the bottleneck. Each source pixel still
  snaps to the same physical block pixel() would produce and the physical
  clip rect is honored, but the logical→physical snap runs once per row and
  column instead of twice per pixel and the clip is resolved once for the whole
  blit. Alpha is ignored: the source is assumed already flattened to opaque, so
  no per-pixel blending happens. (#45)

Changed

• Breaking: Painter::new and Painter::with_popup_anchor now take a single
  FontSet { sans, serif, mono } in place of the two separate Option<&Font>
  arguments. A backend builds one FontSet from the fonts it owns; offscreen
  painters with no text pass FontSet::default(). This replaces three
  same-typed positional font arguments (easy to transpose) with one named bundle
  and makes room for the serif family. (#44)
• Breaking renames: Font::load_system → Font::load_sans,
  Font::from_bytes → Font::from_sans_bytes, and MockBackend::with_font →
  MockBackend::with_sans_font, so each name states the family it loads. (#44)
• Breaking: the monospace-specific painter methods mono_text,
  measure_mono_text, and mono_cumulative_widths are removed in favor of the
  general family+style API: draw with text_styled(.., FontFamily::Mono, FontStyle::Regular), measure with measure_text_styled(.., FontFamily::Mono, FontStyle::Regular), and get caret offsets with the new
  Painter::cumulative_widths(text, size, family, style). Font::cumulative_widths
  likewise gains a FontStyle argument. (#44)

Fixed

• TextEditor and List no longer jump their scroll position back to the
  caret / selected row when the window merely gains or loses focus. Their
  layout re-synced the scrollbar range and scrolled the caret/selection into
  view, but a layout pass also fires for reasons unrelated to editing — on
  Wayland the compositor sends a configure (hence a relayout) on every
  activation change — so a wheel-scrolled view snapped back the instant focus
  changed (visible in the notepad example as the caret jumping to the first
  line). layout now only re-clamps the scroll range to the new viewport;
  edits, keyboard navigation, and selection changes still scroll the
  caret/selection into view as before. (#43)