Merge pull request #595 from peco/gh-445

Add new layout, refactr layout lookup/registration

action.go

@@ -437,8 +437,7 @@ func doToggleSelectionAndSelectNext(ctx context.Context, state *Peco, e Event) {
 	state.Hub().Batch(ctx, func(ctx context.Context) {
 		ctx = context.WithValue(ctx, isTopLevelActionCall, false)
 		doToggleSelection(ctx, state, e)
-		// XXX This is sucky. Fix later
-		if state.LayoutType() == "top-down" {
+		if state.LayoutType() != LayoutTypeBottomUp {
 			doSelectDown(ctx, state, e)
 		} else {
 			doSelectUp(ctx, state, e)

interface.go

@@ -33,9 +33,10 @@ const (
 )
 
 const (
-	DefaultLayoutType  = LayoutTypeTopDown // LayoutTypeTopDown makes the layout so the items read from top to bottom
-	LayoutTypeTopDown  = "top-down"        // LayoutTypeBottomUp changes the layout to read from bottom to up
-	LayoutTypeBottomUp = "bottom-up"
+	DefaultLayoutType            = LayoutTypeTopDown       // LayoutTypeTopDown makes the layout so the items read from top to bottom
+	LayoutTypeTopDown            = "top-down"              // LayoutTypeTopDown displays prompt at top, list top-to-bottom
+	LayoutTypeBottomUp           = "bottom-up"             // LayoutTypeBottomUp displays prompt at bottom, list bottom-to-top
+	LayoutTypeTopDownQueryBottom = "top-down-query-bottom"  // LayoutTypeTopDownQueryBottom displays list top-to-bottom, prompt at bottom
 )
 
 const (
@@ -195,6 +196,7 @@ type Layout interface {
 	DrawScreen(*Peco, *DrawOptions)
 	MovePage(*Peco, PagingRequest) (moved bool)
 	PurgeDisplayCache()
+	SortTopDown() bool
 }
 
 // AnchorSettings groups items that are required to control
@@ -457,7 +459,7 @@ type CLIOptions struct {
 	OptInitialMatcher  string `long:"initial-matcher" description:"specify the default matcher (deprecated)"`
 	OptInitialFilter   string `long:"initial-filter" description:"specify the default filter"`
 	OptPrompt          string `long:"prompt" description:"specify the prompt string"`
-	OptLayout          string `long:"layout" description:"layout to be used. 'top-down' or 'bottom-up'. default is 'top-down'"`
+	OptLayout          string `long:"layout" description:"layout to be used. 'top-down', 'bottom-up', or 'top-down-query-bottom'. default is 'top-down'"`
 	OptSelect1         bool   `long:"select-1" description:"select first item and immediately exit if the input contains only 1 item"`
 	OptExitZero        bool   `long:"exit-0" description:"exit immediately with status 1 if the input is empty"`
 	OptSelectAll       bool   `long:"select-all" description:"select all items and immediately exit"`

layout.go

@@ -15,9 +15,28 @@ import (
 
 var extraOffset int = 0
 
+// LayoutFactory is a function that creates a BasicLayout for the given Peco state.
+type LayoutFactory func(*Peco) *BasicLayout
+
+var layoutRegistry = map[LayoutType]LayoutFactory{}
+
+// RegisterLayout registers a layout factory under the given name.
+func RegisterLayout(name LayoutType, factory LayoutFactory) {
+	layoutRegistry[name] = factory
+}
+
+// NewLayout creates a layout by looking up the registry. Falls back to top-down.
+func NewLayout(layoutType LayoutType, state *Peco) *BasicLayout {
+	if factory, ok := layoutRegistry[layoutType]; ok {
+		return factory(state)
+	}
+	return layoutRegistry[LayoutTypeTopDown](state)
+}
+
 // IsValidLayoutType checks if a string is a supported layout type
 func IsValidLayoutType(v LayoutType) bool {
-	return v == LayoutTypeTopDown || v == LayoutTypeBottomUp
+	_, ok := layoutRegistry[v]
+	return ok
 }
 
 // IsValidVerticalAnchor checks if the specified anchor is supported
@@ -656,6 +675,31 @@ func NewBottomUpLayout(state *Peco) *BasicLayout {
 	}
 }
 
+// NewTopDownQueryBottomLayout creates a new Layout with list top-to-bottom
+// and the query prompt at the bottom.
+func NewTopDownQueryBottomLayout(state *Peco) *BasicLayout {
+	return &BasicLayout{
+		statusBar: newStatusBar(state),
+		screen:    state.Screen(),
+		// The prompt is at the bottom, above the status bar
+		prompt: NewUserPrompt(state.Screen(), AnchorBottom, 1+extraOffset, state.Prompt(), state.Styles()),
+		// The list area is at the top
+		// It's displayed in top-to-bottom order
+		list: NewListArea(state.Screen(), AnchorTop, 0, true, state.Styles()),
+	}
+}
+
+// SortTopDown returns whether this layout sorts lines from top to bottom.
+func (l *BasicLayout) SortTopDown() bool {
+	return l.list.sortTopDown
+}
+
+func init() {
+	RegisterLayout(LayoutTypeTopDown, NewDefaultLayout)
+	RegisterLayout(LayoutTypeBottomUp, NewBottomUpLayout)
+	RegisterLayout(LayoutTypeTopDownQueryBottom, NewTopDownQueryBottomLayout)
+}
+
 func (l *BasicLayout) PurgeDisplayCache() {
 	l.list.purgeDisplayCache()
 }

layout_test.go

@@ -17,6 +17,7 @@ func TestLayoutType(t *testing.T) {
 	}{
 		{LayoutTypeTopDown, true},
 		{LayoutTypeBottomUp, true},
+		{LayoutTypeTopDownQueryBottom, true},
 		{"foobar", false},
 	}
 	for _, l := range layouts {
@@ -366,3 +367,71 @@ func TestGHIssue455_DrawScreenForceSync(t *testing.T) {
 		require.Empty(t, syncEvents, "expected no Sync calls with nil options")
 	})
 }
+
+// TestNewLayout verifies the layout registry returns correct layout types.
+func TestNewLayout(t *testing.T) {
+	makeState := func() *Peco {
+		state := New()
+		state.screen = NewDummyScreen()
+		state.skipReadConfig = true
+		state.Filters().Add(filter.NewIgnoreCase())
+		return state
+	}
+
+	t.Run("top-down", func(t *testing.T) {
+		state := makeState()
+		layout := NewLayout(LayoutTypeTopDown, state)
+		require.NotNil(t, layout)
+		require.True(t, layout.SortTopDown(), "top-down layout should sort top-down")
+		require.Equal(t, AnchorTop, layout.prompt.anchor, "top-down prompt should be anchored at top")
+	})
+
+	t.Run("bottom-up", func(t *testing.T) {
+		state := makeState()
+		layout := NewLayout(LayoutTypeBottomUp, state)
+		require.NotNil(t, layout)
+		require.False(t, layout.SortTopDown(), "bottom-up layout should not sort top-down")
+		require.Equal(t, AnchorBottom, layout.prompt.anchor, "bottom-up prompt should be anchored at bottom")
+	})
+
+	t.Run("top-down-query-bottom", func(t *testing.T) {
+		state := makeState()
+		layout := NewLayout(LayoutTypeTopDownQueryBottom, state)
+		require.NotNil(t, layout)
+		require.True(t, layout.SortTopDown(), "top-down-query-bottom layout should sort top-down")
+		require.Equal(t, AnchorBottom, layout.prompt.anchor, "top-down-query-bottom prompt should be anchored at bottom")
+		require.Equal(t, AnchorTop, layout.list.anchor, "top-down-query-bottom list should be anchored at top")
+	})
+
+	t.Run("unknown falls back to top-down", func(t *testing.T) {
+		state := makeState()
+		layout := NewLayout("unknown-layout", state)
+		require.NotNil(t, layout)
+		require.True(t, layout.SortTopDown(), "fallback layout should sort top-down")
+		require.Equal(t, AnchorTop, layout.prompt.anchor, "fallback prompt should be anchored at top")
+	})
+}
+
+// TestTopDownQueryBottomLayout verifies the specific properties of the
+// top-down-query-bottom layout.
+func TestTopDownQueryBottomLayout(t *testing.T) {
+	state := New()
+	state.screen = NewDummyScreen()
+	state.skipReadConfig = true
+	state.Filters().Add(filter.NewIgnoreCase())
+
+	layout := NewTopDownQueryBottomLayout(state)
+
+	require.Equal(t, AnchorBottom, layout.prompt.anchor,
+		"prompt should be anchored at bottom")
+	require.Equal(t, 1+extraOffset, layout.prompt.anchorOffset,
+		"prompt anchor offset should be 1+extraOffset")
+	require.Equal(t, AnchorTop, layout.list.anchor,
+		"list should be anchored at top")
+	require.Equal(t, 0, layout.list.anchorOffset,
+		"list anchor offset should be 0")
+	require.True(t, layout.list.sortTopDown,
+		"list should sort top-down")
+	require.True(t, layout.SortTopDown(),
+		"SortTopDown() should return true")
+}

view.go

@@ -25,13 +25,7 @@ func (jlr JumpToLineRequest) Line() int {
 }
 
 func NewView(state *Peco) *View {
-	var layout Layout
-	switch state.LayoutType() {
-	case LayoutTypeBottomUp:
-		layout = NewBottomUpLayout(state)
-	default:
-		layout = NewDefaultLayout(state)
-	}
+	layout := NewLayout(LayoutType(state.LayoutType()), state)
 	return &View{
 		state:  state,
 		layout: layout,