ScrollLayout added and various improvements

draw_buffer.go

@@ -9,6 +9,7 @@ func drawBuffer(scr tcell.Screen, buf *ViewBuffer) {
 	// 	scr.SetContent(x, y, rn.Rn, nil, rn.Style)
 	// })
 
+	// TODO use runewidth.RuneWidth(rn)?
 	buf.ForEachLine(func(y int, content []Rune) {
 		for x := 0; x < buf.Width(); x++ {
 			rn := content[x]

events.go

@@ -2,7 +2,11 @@ package tui
 
 type Events interface {
 
-	// KeyPressed is called every time a key or key-combination is pressed.
-	// If KeyPressed returns true, the event will not be passed onto child views
+	// OnKeyPressed is called every time a key or key-combination is pressed.
+	// If OnKeyPressed returns true, the event will not be passed onto child views
 	OnKeyPressed(event *KeyEvent) (consumed bool)
+
+	// OnMouseClicked is called every time a mouse button was pressed on the view.
+	// If OnMouseClicked returns true, the event will not be passed onto child views
+	OnMouseClicked(event *MouseEvent) (consumed bool)
 }

go.mod

@@ -3,7 +3,7 @@ module git.tordarus.net/Tordarus/tui
 go 1.18
 
 require (
-	git.tordarus.net/Tordarus/buf2d v1.1.1
+	git.tordarus.net/Tordarus/buf2d v1.1.2
 	github.com/gdamore/tcell v1.4.0
 	golang.org/x/text v0.3.7
 )

go.sum

@@ -1,5 +1,5 @@
-git.tordarus.net/Tordarus/buf2d v1.1.1 h1:rYvQ2YveqogCoKy5andQxuORPusWbUhpnqJhzVkTlRs=
-git.tordarus.net/Tordarus/buf2d v1.1.1/go.mod h1:XXPpS8nQK0gUI0ki7ftV/qlprsGCRWFVSD4ybvDuUL8=
+git.tordarus.net/Tordarus/buf2d v1.1.2 h1:mmK3tARa30gCh4WaYoSEF5e7qk0C+1ODhxerUcfXN5M=
+git.tordarus.net/Tordarus/buf2d v1.1.2/go.mod h1:XXPpS8nQK0gUI0ki7ftV/qlprsGCRWFVSD4ybvDuUL8=
 github.com/gdamore/encoding v1.0.0 h1:+7OoQ1Bc6eTm5niUzBa0Ctsh6JbMW6Ra+YNuAtDBdko=
 github.com/gdamore/encoding v1.0.0/go.mod h1:alR0ol34c49FCSBLjhosxzcPHQbf2trDkoo5dl+VrEg=
 github.com/gdamore/tcell v1.4.0 h1:vUnHwJRvcPQa3tzi+0QI4U9JINXYJlOz9yiaiPQ2wMU=

screen.go

@@ -16,6 +16,9 @@ type Screen struct {
 
 	// KeyPressed is called every time a key or key-combination is pressed.
 	KeyPressed func(event *KeyEvent) (consumed bool)
+
+	// MouseClicked is called every time a mouse button was pressed.
+	MouseClicked func(event *MouseEvent) (consumed bool)
 }
 
 func NewScreen(root View) (*Screen, error) {
@@ -42,6 +45,8 @@ func (s *Screen) eventloop() {
 			go s.Redraw()
 		case *tcell.EventKey:
 			go s.onKeyPressed(event)
+		case *tcell.EventMouse:
+			go s.onMouseClicked(convertMouseEvent(event))
 		default:
 			s.StopWithError(errors.New(fmt.Sprintf("%#v", event)))
 		}
@@ -56,7 +61,7 @@ func (s *Screen) Start() error {
 	}
 	defer s.scr.Fini()
 
-	s.Redraw()
+	s.scr.EnableMouse()
 	return <-s.stopCh
 }
 
@@ -75,6 +80,22 @@ func (s *Screen) onKeyPressed(event *KeyEvent) {
 	s.Redraw()
 }
 
+func (s *Screen) onMouseClicked(event *MouseEvent) {
+	if s.MouseClicked == nil || !s.MouseClicked(event) {
+		s.Root.OnMouseClicked(event)
+	}
+	s.Redraw()
+}
+
+func convertMouseEvent(original *tcell.EventMouse) *MouseEvent {
+	x, y := original.Position()
+	return &MouseEvent{
+		X: x, Y: y,
+		Button:    convertMouseButton(original.Buttons()),
+		Modifiers: original.Modifiers(),
+	}
+}
+
 func (s *Screen) Redraw() {
 	w, h := s.scr.Size()
 

tests/screen_test.go

@@ -3,6 +3,10 @@ package tui
 import (
 	"errors"
 	"fmt"
+	"log"
+	"math/rand"
+	"os"
+	"strconv"
 	"testing"
 
 	"git.tordarus.net/Tordarus/tui"
@@ -10,6 +14,72 @@ import (
 	"github.com/gdamore/tcell"
 )
 
+var logger *log.Logger
+
+func initDebugLogger() func() {
+	out, err := os.Create("output.log")
+	if err != nil {
+		panic(err)
+	}
+	logger = log.New(out, "", log.LstdFlags|log.Lmicroseconds)
+
+	return func() {
+		out.Close()
+	}
+}
+
+func TestScrollView(t *testing.T) {
+	//defer initDebugLogger()()
+
+	textViews := make([]tui.View, 0, 50)
+
+	for i := 0; i < cap(textViews); i++ {
+		textViews = append(textViews, views.NewTextView(strconv.Itoa(i)))
+		textViews[i].SetStyle(textViews[i].Style().Foreground(tcell.ColorBlack).Background(tcell.Color(rand.Intn(int(tcell.ColorYellowGreen)))))
+	}
+
+	flowLayout := views.NewFlowLayout(tui.Vertical)
+	flowLayout.AppendViews(textViews...)
+
+	scrollView := views.NewScrollView(flowLayout)
+
+	screen, err := tui.NewScreen(scrollView)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	screen.KeyPressed = func(event *tui.KeyEvent) (consumed bool) {
+		switch event.Key() {
+		case tcell.KeyCtrlC:
+			screen.StopWithError(errors.New(fmt.Sprintf("key: %#v | rune: %s", event.Key(), string(event.Rune()))))
+		case tcell.KeyPgDn:
+			scrollView.Scroll(10, 0)
+		case tcell.KeyPgUp:
+			scrollView.Scroll(-10, 0)
+		}
+		return true
+	}
+
+	screen.MouseClicked = func(event *tui.MouseEvent) (consumed bool) {
+		//textViews[0].(*views.TextView).Text = fmt.Sprintf("mouse position: %d | %d", event.X, event.Y)
+		//textViews[1].(*views.TextView).Text = fmt.Sprintf("mouse button: %d", event.Button)
+
+		if event.Button == tui.MouseWheelUp {
+			scrollView.Scroll(-1, 0)
+			return true
+		} else if event.Button == tui.MouseWheelDown {
+			scrollView.Scroll(1, 0)
+			return true
+		}
+
+		return false
+	}
+
+	err = screen.Start()
+	fmt.Println(err)
+}
+
 func TestFlowLayout(t *testing.T) {
 	textView := views.NewTextView("hello world!")
 	textView.SetStyle(tui.StyleDefault.Background(tcell.ColorRed).Foreground(tcell.ColorBlack))

types.go

@@ -54,3 +54,49 @@ const (
 	AnchorBottom
 	AnchorBottomRight
 )
+
+type MouseEvent struct {
+	X, Y      int
+	Button    MouseButton
+	Modifiers tcell.ModMask
+}
+
+type MouseButton uint8
+
+const (
+	MouseButtonNone MouseButton = iota
+	MouseButtonLeft
+	MouseButtonMiddle
+	MouseButtonRight
+	MouseButtonNext
+	MouseButtonPrev
+
+	MouseWheelUp
+	MouseWheelDown
+	MouseWheelLeft
+	MouseWheelRight
+)
+
+func convertMouseButton(mask tcell.ButtonMask) MouseButton {
+	if mask&tcell.Button1 == tcell.Button1 {
+		return MouseButtonLeft
+	} else if mask&tcell.Button2 == tcell.Button2 {
+		return MouseButtonMiddle
+	} else if mask&tcell.Button3 == tcell.Button3 {
+		return MouseButtonRight
+	} else if mask&tcell.Button4 == tcell.Button4 {
+		return MouseButtonNext
+	} else if mask&tcell.Button5 == tcell.Button5 {
+		return MouseButtonPrev
+	} else if mask&tcell.WheelUp == tcell.WheelUp {
+		return MouseWheelUp
+	} else if mask&tcell.WheelDown == tcell.WheelDown {
+		return MouseWheelDown
+	} else if mask&tcell.WheelLeft == tcell.WheelLeft {
+		return MouseWheelLeft
+	} else if mask&tcell.WheelRight == tcell.WheelRight {
+		return MouseWheelRight
+	}
+
+	return MouseButtonNone
+}

utils.go

@@ -3,7 +3,7 @@ package tui
 import (
 	"strings"
 
-	"golang.org/x/text/width"
+	"github.com/mattn/go-runewidth"
 )
 
 // WriteString writes a whole string to the buffer at position (x,y)
@@ -56,15 +56,16 @@ func MeasureMultiLineString(str string) (maxLineWidth, lineCount int) {
 }
 
 func runeWidth(r rune) int {
+	return runewidth.RuneWidth(r)
 	//fmt.Println(r, width.LookupRune(r).Kind())
-	switch width.LookupRune(r).Kind() {
-	case width.EastAsianFullwidth:
-		fallthrough
-	case width.EastAsianWide:
-		return 2
-	default:
-		return 1
-	}
+	// switch width.LookupRune(r).Kind() {
+	// case width.EastAsianFullwidth:
+	// 	fallthrough
+	// case width.EastAsianWide:
+	// 	return 2
+	// default:
+	// 	return 1
+	// }
 }
 
 func min(x, y int) int {

views/layout_flow.go

@@ -58,6 +58,9 @@ func (g *FlowLayout) Draw(buf *tui.ViewBuffer) {
 
 	if g.Orientation == tui.Horizontal {
 		remainingSpacePerView := buf.Width() - layout.Sum.Width
+		if remainingSpacePerView < 0 {
+			remainingSpacePerView = 0
+		}
 		if layout.HorizontalNegativeCount > 0 {
 			remainingSpacePerView /= layout.HorizontalNegativeCount
 		}
@@ -72,10 +75,17 @@ func (g *FlowLayout) Draw(buf *tui.ViewBuffer) {
 			}
 
 			view.Draw(buf.Sub(x, 0, size.Width, size.Height))
+
 			x += size.Width
+			if x >= buf.Width() {
+				break
+			}
 		}
 	} else if g.Orientation == tui.Vertical {
 		remainingSpacePerView := buf.Height() - layout.Sum.Height
+		if remainingSpacePerView < 0 {
+			remainingSpacePerView = 0
+		}
 		if layout.VerticalNegativeCount > 0 {
 			remainingSpacePerView /= layout.VerticalNegativeCount
 		}
@@ -90,7 +100,11 @@ func (g *FlowLayout) Draw(buf *tui.ViewBuffer) {
 			}
 
 			view.Draw(buf.Sub(0, y, size.Width, size.Height))
+
 			y += size.Height
+			if y >= buf.Height() {
+				break
+			}
 		}
 	}
 
@@ -106,7 +120,7 @@ func (g *FlowLayout) Layout() (prefWidth, prefHeight int) {
 		prefHeight = iff(layout.VerticalNegativeCount == 0, layout.Max.Height, -1)
 	} else if g.Orientation == tui.Vertical {
 		prefWidth = iff(layout.HorizontalNegativeCount == 0, layout.Max.Width, -1)
-		prefHeight = iff(layout.VerticalNegativeCount == 0, layout.Sum.Width, -1)
+		prefHeight = iff(layout.VerticalNegativeCount == 0, layout.Sum.Height, -1)
 	}
 
 	layout.Pref = tui.Size{Width: prefWidth, Height: prefHeight}

views/utils.go

@@ -20,6 +20,10 @@ func max(x, y int) int {
 	return y
 }
 
+func limit(v, minv, maxv int) int {
+	return min(max(v, minv), maxv)
+}
+
 func iff[T any](condition bool, trueValue, falseValue T) T {
 	if condition {
 		return trueValue

views/view_border.go

@@ -10,7 +10,7 @@ type BorderView struct {
 	Border BorderBox
 }
 
-var _ tui.View = &BorderView{}
+var _ tui.Wrapper = &BorderView{}
 
 func NewBorderView(view tui.View) *BorderView {
 	v := new(BorderView)
@@ -46,10 +46,6 @@ func (v *BorderView) Layout() (prefWidth, prefHeight int) {
 	return w, h
 }
 
-func (v *BorderView) Style() tui.Style {
-	return v.ViewTmpl.Style()
-}
-
 type BorderBox struct {
 	TopLeft     rune
 	TopRight    rune

views/view_constrain.go

@@ -11,7 +11,7 @@ type ConstrainView struct {
 	MaxHeight int
 }
 
-var _ tui.View = &ConstrainView{}
+var _ tui.Wrapper = &ConstrainView{}
 
 func NewConstrainView(view tui.View) *ConstrainView {
 	v := new(ConstrainView)

views/view_frame.go

@@ -8,7 +8,7 @@ type FrameView struct {
 	Anchor tui.Anchor
 }
 
-var _ tui.View = &FrameView{}
+var _ tui.Wrapper = &FrameView{}
 
 func NewFrameView(view tui.View) *FrameView {
 	v := new(FrameView)
@@ -29,7 +29,3 @@ func (g *FrameView) Draw(buf *tui.ViewBuffer) {
 func (v *FrameView) Layout() (prefWidth, prefHeight int) {
 	return -1, -1
 }
-
-func (v *FrameView) Style() tui.Style {
-	return v.ViewTmpl.Style()
-}

views/view_margin.go

@@ -8,7 +8,7 @@ type MarginView struct {
 	Margin map[tui.Side]int
 }
 
-var _ tui.View = &MarginView{}
+var _ tui.Wrapper = &MarginView{}
 
 func NewMarginView(view tui.View) *MarginView {
 	v := new(MarginView)
@@ -34,10 +34,6 @@ func (v *MarginView) Layout() (prefWidth, prefHeight int) {
 	return w, h
 }
 
-func (v *MarginView) Style() tui.Style {
-	return v.ViewTmpl.Style()
-}
-
 func (v *MarginView) SetMargin(top, right, bottom, left int) {
 	v.Margin = map[tui.Side]int{
 		tui.SideTop:    top,

views/view_scroll.go

@@ -0,0 +1,140 @@
+package views
+
+import (
+	"math"
+
+	"git.tordarus.net/Tordarus/buf2d"
+	"git.tordarus.net/Tordarus/tui"
+	"github.com/gdamore/tcell"
+)
+
+// ScrollView is a tui.View which can hold an arbitrary large view.
+// If the sub view does not fit into its bounds, scroll bars will be shown
+type ScrollView struct {
+	tui.WrapperTmpl
+	buf *tui.ViewBuffer
+
+	width, height int
+
+	verticalScrollOffset   int
+	horizontalScrollOffset int
+}
+
+var _ tui.Wrapper = &ScrollView{}
+
+func NewScrollView(view tui.View) *ScrollView {
+	v := new(ScrollView)
+	v.SetView(view)
+	return v
+}
+
+func (v *ScrollView) Draw(buf *tui.ViewBuffer) {
+	w, h := v.View().Layout()
+
+	if v.buf == nil || v.buf.Width() != w || v.buf.Height() != h {
+		v.buf = buf2d.NewBuffer(w, h, tui.DefaultRune)
+	}
+
+	v.Scroll(0, 0) // limit scroll offset boundaries
+	v.View().Draw(v.buf)
+
+	scrollH, scrollV := v.determineViewportSize(buf)
+	copyBufferWidth, copyBufferHeight := 0, 0
+
+	if scrollH {
+		copyBufferWidth = v.width
+	} else {
+		copyBufferWidth = v.buf.Width()
+	}
+
+	if scrollV {
+		copyBufferHeight = v.height
+	} else {
+		copyBufferHeight = v.buf.Height()
+	}
+
+	scrollVHeight := int(float64(buf.Height()) / float64(v.buf.Height()) * float64(v.height))
+	scrollVStart := int(math.Ceil(float64(v.verticalScrollOffset) / float64(v.buf.Height()) * float64(v.height)))
+
+	scrollHStart := int(float64(v.horizontalScrollOffset) / float64(v.buf.Width()) * float64(v.width))
+	scrollHWidth := int(math.Ceil(float64(buf.Width()) / float64(v.buf.Width()) * float64(v.width)))
+
+	// guarantee minimum scroll bar thumb size of 1 TODO inaccurate for small scales
+	if scrollVHeight <= 0 {
+		scrollVHeight = 1
+		if scrollVStart >= v.height {
+			scrollVStart = v.height - 1
+		}
+	}
+	if scrollHWidth <= 0 {
+		scrollHWidth = 1
+		if scrollHStart >= v.width {
+			scrollHStart = v.width - 1
+		}
+	}
+
+	// copy buffer
+	for x := 0; x < copyBufferWidth; x++ {
+		for y := 0; y < copyBufferHeight; y++ {
+			buf.Set(x, y, v.buf.Get(v.horizontalScrollOffset+x, v.verticalScrollOffset+y))
+		}
+	}
+
+	// vertical scrollbar
+	if scrollV {
+		for y := 0; y < v.height; y++ {
+			var style tcell.Style
+			if y >= scrollVStart && y < scrollVStart+scrollVHeight {
+				style = tui.StyleDefault.Background(tcell.ColorWhite)
+			} else {
+				style = tui.StyleDefault.Background(tcell.ColorDarkSlateGray)
+			}
+			buf.Set(v.width, y, tui.Rune{Rn: ' ', Style: style})
+		}
+	}
+
+	// horizontal scrollbar
+	if scrollH {
+		for x := 0; x < v.width; x++ {
+			var style tcell.Style
+			if x >= scrollHStart && x < scrollHStart+scrollHWidth {
+				style = tui.StyleDefault.Background(tcell.ColorWhite)
+			} else {
+				style = tui.StyleDefault.Background(tcell.ColorDarkSlateGray)
+			}
+			buf.Set(x, v.height, tui.Rune{Rn: ' ', Style: style})
+		}
+	}
+}
+
+func (v *ScrollView) Layout() (prefWidth, prefHeight int) {
+	return -1, -1
+}
+
+func (v *ScrollView) Scroll(verticalOffset, horizontalOffset int) {
+	if v.buf != nil {
+		v.verticalScrollOffset = limit(v.verticalScrollOffset+verticalOffset, 0, max(v.buf.Height()-v.height, 0))
+		v.horizontalScrollOffset = limit(v.horizontalScrollOffset+horizontalOffset, 0, max(v.buf.Width()-v.width, 0))
+	} else {
+		v.verticalScrollOffset = v.verticalScrollOffset + verticalOffset
+		v.horizontalScrollOffset = v.horizontalScrollOffset + horizontalOffset
+	}
+}
+
+func (v *ScrollView) determineViewportSize(buf *tui.ViewBuffer) (scrollbarH, scrollbarV bool) {
+	v.width, v.height = buf.Width()-1, buf.Height()-1
+	scrollbarV = v.buf.Height() > v.height
+	scrollbarH = v.buf.Width() > v.width
+
+	if scrollbarV && !scrollbarH {
+		v.height++
+		scrollbarV = v.buf.Height() > v.height
+	}
+
+	if !scrollbarV && scrollbarH {
+		v.width++
+		scrollbarH = v.buf.Width() > v.width
+	}
+
+	return
+}

views/view_text.go

@@ -12,17 +12,17 @@ type TextView struct {
 
 var _ tui.View = &TextView{}
 
-func (v *TextView) Draw(buf *tui.ViewBuffer) {
-	v.ViewTmpl.Draw(buf)
-	tui.WriteMultiLineString(buf, v.Text, v.Style(), 0, 0)
-}
-
 func NewTextView(text string) *TextView {
 	return &TextView{
 		Text: text,
 	}
 }
 
+func (v *TextView) Draw(buf *tui.ViewBuffer) {
+	v.ViewTmpl.Draw(buf)
+	tui.WriteMultiLineString(buf, v.Text, v.Style(), 0, 0)
+}
+
 func (v *TextView) Layout() (prefWidth, prefHeight int) {
 	return tui.MeasureMultiLineString(v.Text)
 }

viewtmpl.go

@@ -18,6 +18,10 @@ func (v *ViewTmpl) OnKeyPressed(event *KeyEvent) (consumed bool) {
 	return false
 }
 
+func (v *ViewTmpl) OnMouseClicked(event *MouseEvent) (consumed bool) {
+	return false
+}
+
 func (v *ViewTmpl) SetStyle(s Style) {
 	v.style = &s
 }

wrappertmpl.go

@@ -30,17 +30,10 @@ func (v *WrapperTmpl) OnKeyPressed(event *KeyEvent) (consumed bool) {
 }
 
 func (v *WrapperTmpl) SetStyle(s Style) {
-	if v.view != nil {
-		v.view.SetStyle(s)
-		return
-	}
 	v.ViewTmpl.SetStyle(s)
 }
 
 func (v *WrapperTmpl) Style() Style {
-	if v.view != nil {
-		return v.view.Style()
-	}
 	return v.ViewTmpl.Style()
 }