keep View() pure by moving state transitions into Update() handlers

The dashboard model's View() was mutating sub-model state on every render:
it called streamModel.SetFooterVisible() and flameModel.SetViewport() on
local copies instead of keeping those fields in sync through Update().

Moved the sync points to the Update() handlers that trigger each change:
- handleWindowSize: syncs stream footer visibility alongside SetViewport
- handleHelpToggleKey: already updated flame viewport; now also updates
  stream footer visibility when the help bar is toggled
- handleKey: syncs flame viewport when switching to the flame tab, covering
  the case that window-resize and help-toggle do not

Aligned the stream model's initial showFooter value with the dashboard's
default showHelp=false in NewModelWithConfig so there is no mismatch on
the first render.

Also extracted numeric tab shortcuts into the tab registry via ShortcutKey
fields so handleShortcutKey no longer needs updating when tabs are added.

Updated two tests that bypassed Update() to set dimensions directly; they
now use WindowSizeMsg so sub-model viewports are initialised correctly
under the new pure-View contract.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/internal/tui/dashboard/tabregistry.go b/internal/tui/dashboard/tabregistry.go
index d16a363..2a5c7ff 100644
--- a/internal/tui/dashboard/tabregistry.go
+++ b/internal/tui/dashboard/tabregistry.go
@@ -9,6 +9,7 @@ import (
 	flamegraphtui "ior/internal/tui/flamegraph"
 	"ior/internal/tui/messages"
 
+	"charm.land/bubbles/v2/key"
 	tea "charm.land/bubbletea/v2"
 )
 
@@ -47,6 +48,11 @@ type tabDescriptor struct {
 	// HandleScroll handles direction keys for this tab when bubbles are off.
 	// Nil means the tab does not process scroll/navigation keys.
 	HandleScroll tabScrollFn
+	// ShortcutKey extracts the numeric shortcut key binding for this tab from
+	// a KeyMap. It is called at runtime against the model's configured key map
+	// so that custom key maps (e.g. in tests) are respected. Nil means the tab
+	// has no direct numeric shortcut; it is still reachable via tab/shift+tab.
+	ShortcutKey func(keys common.KeyMap) key.Binding
 }
 
 // tabDescriptors is the central registry mapping every known Tab to its
@@ -61,6 +67,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		InitCmd:         flameTickCmd,
 		Render:          tabRenderFlame,
 		HandleScroll:    nil,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.One },
 	},
 	TabOverview: {
 		Name:            "Overview",
@@ -69,6 +76,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		AllowedVizModes: []tabVizMode{tabVizModeTable},
 		Render:          tabRenderOverview,
 		HandleScroll:    nil,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.Two },
 	},
 	TabSyscalls: {
 		Name:            "Syscalls",
@@ -77,6 +85,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		AllowedVizModes: []tabVizMode{tabVizModeTable, tabVizModeBubbles, tabVizModeTreemap},
 		Render:          tabRenderSyscalls,
 		HandleScroll:    tabScrollSyscalls,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.Three },
 	},
 	TabFiles: {
 		Name:            "Files",
@@ -85,6 +94,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		AllowedVizModes: []tabVizMode{tabVizModeTable},
 		Render:          tabRenderFiles,
 		HandleScroll:    tabScrollFiles,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.Four },
 	},
 	TabProcesses: {
 		Name:            "Processes",
@@ -93,6 +103,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		AllowedVizModes: []tabVizMode{tabVizModeTable, tabVizModeBubbles, tabVizModeTreemap},
 		Render:          tabRenderProcesses,
 		HandleScroll:    tabScrollProcesses,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.Five },
 	},
 	TabLatency: {
 		Name:            "Latency+Gaps",
@@ -101,6 +112,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		AllowedVizModes: []tabVizMode{tabVizModeTable},
 		Render:          tabRenderLatency,
 		HandleScroll:    nil,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.Six },
 	},
 	TabStream: {
 		Name:            "Stream",
@@ -110,6 +122,7 @@ var tabDescriptors = map[Tab]tabDescriptor{
 		InitCmd:         streamTickCmd,
 		Render:          tabRenderStream,
 		HandleScroll:    tabScrollStream,
+		ShortcutKey:     func(k common.KeyMap) key.Binding { return k.Seven },
 	},
 }
 
@@ -137,6 +150,24 @@ func lookupTab(tab Tab) tabDescriptor {
 	return tabDescriptor{Name: "Unknown", ShortName: "Unk", AllowedVizModes: []tabVizMode{tabVizModeTable}}
 }
 
+// tabForShortcutKey searches the registry for the first tab whose ShortcutKey
+// matches the given key press message. It returns the tab and true when a match
+// is found; otherwise the zero Tab value and false. Using the registry here
+// means adding a new tab with a shortcut only requires a new entry in
+// tabDescriptors — handleShortcutKey in model.go never needs updating.
+func tabForShortcutKey(msg tea.KeyPressMsg, keys common.KeyMap) (Tab, bool) {
+	for _, tab := range orderedTabs() {
+		d := tabDescriptors[tab]
+		if d.ShortcutKey == nil {
+			continue
+		}
+		if key.Matches(msg, d.ShortcutKey(keys)) {
+			return tab, true
+		}
+	}
+	return 0, false
+}
+
 // tabAllowedVizModes returns the visualisation modes allowed for tab,
 // respecting any runtime conditions (e.g. Files requires dir-grouped mode for
 // non-table views). This replaces the former allowedVizModes switch statement.