Add Bubble Tea TUI with interactive treemap

Cell canvas renderer with frame cache and a perceptual 256-colour
quantizer; responsive geometry (large/medium/small/too-small);
squarified treemap with nested previews, LOD grouping, category
colouring and adaptive labels; spatial arrow navigation with stable
NodeID selection; zoom and breadcrumbs; modal system (info, help,
confirm, save); list, file-type, top-N, scan-info, duplicate and
comparison views; live search/filter; mouse support; move-to-trash.

internal/tui/mouse.go

@@ -0,0 +1,110 @@
+package tui
+
+import (
+	"time"
+
+	tea "charm.land/bubbletea/v2"
+
+	"github.com/andydixon/mapsize/internal/inventory"
+)
+
+const doubleClick = 400 * time.Millisecond
+
+func (m *Model) mouseClick(ev tea.Mouse) tea.Cmd {
+	t := m.tree
+	t.RLock()
+	defer t.RUnlock()
+	m.dirty = true
+	if len(m.modals) > 0 {
+		// Clicking outside the modal closes it.
+		if len(m.hits) > 0 && !m.hits[0].r.Contains(ev.X, ev.Y) {
+			m.closeModal()
+		}
+		return nil
+	}
+	if ev.Button == tea.MouseRight {
+		for _, h := range m.hits {
+			if h.r.Contains(ev.X, ev.Y) {
+				h.fn(m, false)
+				return m.inspectSelection()
+			}
+		}
+		return nil
+	}
+	if ev.Button != tea.MouseLeft {
+		return nil
+	}
+	for i := len(m.hits) - 1; i >= 0; i-- {
+		h := m.hits[i]
+		if h.r.Contains(ev.X, ev.Y) {
+			key := int64(ev.Y)<<32 | int64(i)
+			double := time.Since(m.lastClick) < doubleClick && m.lastClickI == key
+			m.lastClick, m.lastClickI = time.Now(), key
+			if double {
+				m.lastClickI = noSel
+			}
+			return h.fn(m, double)
+		}
+	}
+	return nil
+}
+
+// clickBlock selects a treemap block; a double click zooms (or inspects).
+func (m *Model) clickBlock(id int64, double bool) tea.Cmd {
+	m.sel = id
+	if !double {
+		return nil
+	}
+	if !isGroup(id) && !m.tree.Node(inventory.NodeID(id)).IsDir() {
+		return m.inspectSelection()
+	}
+	return m.zoomIntoSelection()
+}
+
+func (m *Model) mouseWheel(ev tea.Mouse) tea.Cmd {
+	t := m.tree
+	t.RLock()
+	defer t.RUnlock()
+	m.dirty = true
+	up := ev.Button == tea.MouseWheelUp
+	if ev.Button != tea.MouseWheelUp && ev.Button != tea.MouseWheelDown {
+		return nil
+	}
+	if len(m.modals) > 0 {
+		f := m.modals[len(m.modals)-1].(*modalFrame)
+		if up {
+			f.scroll -= 3
+		} else {
+			f.scroll += 3
+		}
+		f.clampScroll()
+		return nil
+	}
+	if up {
+		// Zoom towards the block under the pointer.
+		if l := m.tm; l != nil && m.view == 0 {
+			for _, b := range l.blocks {
+				if b.Contains(ev.X, ev.Y) {
+					m.sel = b.ID
+				}
+			}
+		}
+	}
+	return m.views[m.view].wheel(m, up)
+}
+
+func (m *Model) mouseMotion(ev tea.Mouse) {
+	h := noSel
+	if l := m.tm; l != nil && m.view == 0 && len(m.modals) == 0 {
+		for _, b := range l.blocks {
+			if b.Contains(ev.X, ev.Y) {
+				h = b.ID
+				break
+			}
+		}
+	}
+	if h != m.hover {
+		m.hover = h
+		m.dirty = true
+	}
+}