Fix bugs and add MessageView widget

4 files changed, 305 insertions, 29 deletions

diff --git a/matrix.go b/matrix.go
index 5992a60..d611bb0 100644
--- a/matrix.go
+++ b/matrix.go
@@ -160,7 +160,7 @@ func (c *MatrixContainer) HandleMessage(evt *gomatrix.Event) {
 		timestamp = time.Unix(timestampInt64/1000, timestampInt64%1000*1000)
 	}
 
-	c.ui.MainView().AddMessage(evt.RoomID, evt.Sender, message, timestamp)
+	c.ui.MainView().AddRealMessage(evt.RoomID, evt.ID, evt.Sender, message, timestamp)
 }
 
 func (c *MatrixContainer) HandleMembership(evt *gomatrix.Event) {
diff --git a/message-view.go b/message-view.go
new file mode 100644
index 0000000..633c551
--- /dev/null
+++ b/message-view.go
@@ -0,0 +1,260 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2018 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/gdamore/tcell"
+	"github.com/mattn/go-runewidth"
+	"maunium.net/go/tview"
+)
+
+type Message struct {
+	ID           string
+	Sender       string
+	Text         string
+	Timestamp    string
+	RenderSender bool
+
+	buffer      []string
+	senderColor tcell.Color
+}
+
+var (
+	boundaryPattern = regexp.MustCompile("([[:punct:]]\\s*|\\s+)")
+	spacePattern    = regexp.MustCompile(`\s+`)
+)
+
+func (message *Message) calculateBuffer(width int) {
+	if width < 1 {
+		return
+	}
+	message.buffer = []string{}
+	forcedLinebreaks := strings.Split(message.Text, "\n")
+	newlines := 0
+	for _, str := range forcedLinebreaks {
+		if len(str) == 0 && newlines < 1 {
+			message.buffer = append(message.buffer, "")
+			newlines++
+		} else {
+			newlines = 0
+		}
+		// From tview/textview.go#reindexBuffer()
+		for len(str) > 0 {
+			extract := runewidth.Truncate(str, width, "")
+			if len(extract) < len(str) {
+				if spaces := spacePattern.FindStringIndex(str[len(extract):]); spaces != nil && spaces[0] == 0 {
+					extract = str[:len(extract)+spaces[1]]
+				}
+
+				matches := boundaryPattern.FindAllStringIndex(extract, -1)
+				if len(matches) > 0 {
+					extract = extract[:matches[len(matches)-1][1]]
+				}
+			}
+			message.buffer = append(message.buffer, extract)
+			str = str[len(extract):]
+		}
+	}
+}
+
+type MessageView struct {
+	*tview.Box
+
+	ScrollOffset    int
+	MaxSenderWidth  int
+	TimestampFormat string
+	TimestampWidth  int
+	Separator       rune
+
+	widestSender        int
+	prevWidth           int
+	prevHeight          int
+	prevScrollOffset    int
+	firstDisplayMessage int
+	lastDisplayMessage  int
+	totalHeight         int
+
+	messages []*Message
+
+	debug DebugPrinter
+}
+
+func NewMessageView(debug DebugPrinter) *MessageView {
+	return &MessageView{
+		Box:             tview.NewBox(),
+		MaxSenderWidth:  20,
+		TimestampFormat: "15:04:05",
+		TimestampWidth:  8,
+		Separator:       '|',
+		ScrollOffset:    0,
+
+		widestSender:        5,
+		prevWidth:           -1,
+		prevHeight:          -1,
+		prevScrollOffset:    -1,
+		firstDisplayMessage: -1,
+		lastDisplayMessage:  -1,
+		totalHeight:         -1,
+
+		debug: debug,
+	}
+}
+
+func (view *MessageView) recalculateBuffers(width int) {
+	width -= view.TimestampWidth + TimestampSenderGap + view.widestSender + SenderMessageGap
+	for _, message := range view.messages {
+		message.calculateBuffer(width)
+	}
+	view.prevWidth = width
+}
+
+func (view *MessageView) AddMessage(id, sender, text string, timestamp time.Time) {
+	if len(sender) > view.widestSender {
+		view.widestSender = len(sender)
+		if view.widestSender > view.MaxSenderWidth {
+			view.widestSender = view.MaxSenderWidth
+		}
+	}
+	message := &Message{
+		ID:           id,
+		Sender:       sender,
+		RenderSender: true,
+		Text:         text,
+		Timestamp:    timestamp.Format(view.TimestampFormat),
+		senderColor:  getColor(sender),
+	}
+	_, _, width, height := view.GetInnerRect()
+	width -= view.TimestampWidth + TimestampSenderGap + view.widestSender + SenderMessageGap
+	message.calculateBuffer(width)
+	if view.ScrollOffset > 0 {
+		view.ScrollOffset += len(message.buffer)
+	}
+	if len(view.messages) > 0 && view.messages[len(view.messages)-1].Sender == message.Sender {
+		message.RenderSender = false
+	}
+	view.messages = append(view.messages, message)
+	view.recalculateHeight(height)
+}
+
+func (view *MessageView) recalculateHeight(height int) {
+	view.firstDisplayMessage = -1
+	view.lastDisplayMessage = -1
+	view.totalHeight = 0
+	for i := len(view.messages) - 1; i >= 0; i-- {
+		prevTotalHeight := view.totalHeight
+		view.totalHeight += len(view.messages[i].buffer)
+
+		if view.totalHeight < view.ScrollOffset {
+			continue
+		} else if view.firstDisplayMessage == -1 {
+			view.lastDisplayMessage = i
+			view.firstDisplayMessage = i
+		}
+
+		if prevTotalHeight < height+view.ScrollOffset {
+			view.lastDisplayMessage = i
+		}
+	}
+	view.prevScrollOffset = view.ScrollOffset
+}
+
+func (view *MessageView) PageUp() {
+	_, _, _, height := view.GetInnerRect()
+	view.ScrollOffset += height / 2
+	if view.ScrollOffset > view.totalHeight-height {
+		view.ScrollOffset = view.totalHeight - height + 5
+	}
+}
+
+func (view *MessageView) PageDown() {
+	_, _, _, height := view.GetInnerRect()
+	view.ScrollOffset -= height / 2
+	if view.ScrollOffset < 0 {
+		view.ScrollOffset = 0
+	}
+}
+
+func (view *MessageView) writeLine(screen tcell.Screen, line string, x, y int, color tcell.Color) {
+	offsetX := 0
+	for _, ch := range line {
+		chWidth := runewidth.RuneWidth(ch)
+		if chWidth == 0 {
+			continue
+		}
+
+		for localOffset := 0; localOffset < chWidth; localOffset++ {
+			screen.SetContent(x+offsetX+localOffset, y, ch, nil, tcell.StyleDefault.Foreground(color))
+		}
+		offsetX += chWidth
+	}
+}
+
+const (
+	TimestampSenderGap = 1
+	SenderSeparatorGap = 1
+	SenderMessageGap   = 3
+)
+
+func (view *MessageView) Draw(screen tcell.Screen) {
+	view.Box.Draw(screen)
+
+	x, y, width, height := view.GetInnerRect()
+	if width != view.prevWidth {
+		view.recalculateBuffers(width)
+	}
+	if height != view.prevHeight || width != view.prevWidth || view.ScrollOffset != view.prevScrollOffset {
+		view.recalculateHeight(height)
+	}
+	usernameOffsetX := view.TimestampWidth + TimestampSenderGap
+	messageOffsetX := usernameOffsetX + view.widestSender + SenderMessageGap
+
+	separatorX := x + usernameOffsetX + view.widestSender + SenderSeparatorGap
+	for separatorY := y; separatorY < y+height; separatorY++ {
+		screen.SetContent(separatorX, separatorY, view.Separator, nil, tcell.StyleDefault)
+	}
+
+	if view.firstDisplayMessage == -1 || view.lastDisplayMessage == -1 {
+		return
+	}
+
+	writeOffset := 0
+	for i := view.firstDisplayMessage; i >= view.lastDisplayMessage; i-- {
+		message := view.messages[i]
+		messageHeight := len(message.buffer)
+
+		senderAtLine := y + height - writeOffset - messageHeight
+		if senderAtLine < y {
+			senderAtLine = y
+		}
+		view.writeLine(screen, message.Timestamp, x, senderAtLine, tcell.ColorDefault)
+		if message.RenderSender || i == view.lastDisplayMessage {
+			view.writeLine(screen, message.Sender, x+usernameOffsetX, senderAtLine, message.senderColor)
+		}
+
+		for num, line := range message.buffer {
+			offsetY := height - messageHeight - writeOffset + num
+			if offsetY >= 0 {
+				view.writeLine(screen, line, x+messageOffsetX, y+offsetY, tcell.ColorDefault)
+			}
+		}
+		writeOffset += messageHeight
+	}
+}
diff --git a/room-view.go b/room-view.go
index d5b9ca2..6764e85 100644
--- a/room-view.go
+++ b/room-view.go
@@ -19,9 +19,8 @@ package main
 import (
 	"fmt"
 	"hash/fnv"
-	"regexp"
+	"sort"
 	"strings"
-	"time"
 
 	"github.com/gdamore/tcell"
 	"maunium.net/go/gomatrix"
@@ -32,10 +31,12 @@ type RoomView struct {
 	*tview.Box
 
 	topic    *tview.TextView
-	content  *tview.TextView
+	content  *MessageView
 	status   *tview.TextView
 	userList *tview.TextView
 	room     *gomatrix.Room
+
+	debug DebugPrinter
 }
 
 var colorNames []string
@@ -47,27 +48,30 @@ func init() {
 		colorNames[i] = name
 		i++
 	}
+	sort.Sort(sort.StringSlice(colorNames))
 }
 
-func NewRoomView(room *gomatrix.Room) *RoomView {
+func NewRoomView(debug DebugPrinter, room *gomatrix.Room) *RoomView {
 	view := &RoomView{
 		Box:      tview.NewBox(),
 		topic:    tview.NewTextView(),
-		content:  tview.NewTextView(),
+		content:  NewMessageView(debug),
 		status:   tview.NewTextView(),
 		userList: tview.NewTextView(),
 		room:     room,
+		debug:    debug,
 	}
 	view.topic.
 		SetText(strings.Replace(room.GetTopic(), "\n", " ", -1)).
 		SetBackgroundColor(tcell.ColorDarkGreen)
 	view.status.SetBackgroundColor(tcell.ColorDimGray)
 	view.userList.SetDynamicColors(true)
-	view.content.SetDynamicColors(true)
 	return view
 }
 
 func (view *RoomView) Draw(screen tcell.Screen) {
+	view.Box.Draw(screen)
+
 	x, y, width, height := view.GetRect()
 	view.topic.SetRect(x, y, width, 1)
 	view.content.SetRect(x, y+1, width-30, height-2)
@@ -104,26 +108,24 @@ func (view *RoomView) SetTyping(users []string) {
 	}
 }
 
-var colorPattern = regexp.MustCompile(`\[([a-zA-Z]+|#[0-9a-zA-Z]{6})\]`)
+func (view *RoomView) MessageView() *MessageView {
+	return view.content
+}
 
-func color(s string) string {
+func getColorName(s string) string {
 	h := fnv.New32a()
 	h.Write([]byte(s))
-	color := colorNames[int(h.Sum32())%len(colorNames)]
-	return fmt.Sprintf("[%s]%s[white]", color, s)
+	return colorNames[int(h.Sum32())%len(colorNames)]
 }
 
-func escapeColor(s string) string {
-	return colorPattern.ReplaceAllString(s, "[$1[]")
+func getColor(s string) tcell.Color {
+	h := fnv.New32a()
+	h.Write([]byte(s))
+	return tcell.ColorNames[colorNames[int(h.Sum32())%len(colorNames)]]
 }
 
-func (view *RoomView) AddMessage(sender, message string, timestamp time.Time) {
-	member := view.room.GetMember(sender)
-	if member != nil {
-		sender = member.DisplayName
-	}
-	fmt.Fprintf(view.content, "[%s] %s: %s\n",
-		timestamp.Format("15:04:05"), color(sender), escapeColor(message))
+func color(s string) string {
+	return fmt.Sprintf("[%s]%s[white]", getColorName(s), s)
 }
 
 func (view *RoomView) UpdateUserList() {
diff --git a/view-main.go b/view-main.go
index 58fbd80..d291754 100644
--- a/view-main.go
+++ b/view-main.go
@@ -126,28 +126,34 @@ func (view *MainView) HandleCommand(room, command string, args []string) {
 		view.matrix.client.LeaveRoom(room)
 	case "/join":
 		if len(args) == 0 {
-			view.AddMessage(room, "*", "Usage: /join <room>", time.Now())
+			view.AddMessage(room,  "Usage: /join <room>")
 			break
 		}
 		view.debug.Print(view.matrix.JoinRoom(args[0]))
 	default:
-		view.AddMessage(room, "*", "Unknown command.", time.Now())
+		view.AddMessage(room, "Unknown command.")
 	}
 }
 
 func (view *MainView) InputCapture(key *tcell.EventKey) *tcell.EventKey {
+	k := key.Key()
 	if key.Modifiers() == tcell.ModCtrl {
-		if key.Key() == tcell.KeyDown {
+		if k == tcell.KeyDown {
 			view.SwitchRoom(view.currentRoomIndex + 1)
 			view.roomList.SetCurrentItem(view.currentRoomIndex)
-		} else if key.Key() == tcell.KeyUp {
+		} else if k == tcell.KeyUp {
 			view.SwitchRoom(view.currentRoomIndex - 1)
 			view.roomList.SetCurrentItem(view.currentRoomIndex)
 		} else {
 			return key
 		}
-	} else if key.Key() == tcell.KeyPgUp || key.Key() == tcell.KeyPgDn {
-		view.rooms[view.CurrentRoomID()].InputHandler()(key, nil)
+	} else if k == tcell.KeyPgUp || k == tcell.KeyPgDn {
+		msgView := view.rooms[view.CurrentRoomID()].MessageView()
+		if k == tcell.KeyPgUp {
+			msgView.PageUp()
+		} else {
+			msgView.PageDown()
+		}
 	} else {
 		return key
 	}
@@ -178,7 +184,7 @@ func (view *MainView) addRoom(index int, room string) {
 		view.SwitchRoom(index)
 	})
 	if !view.roomView.HasPage(room) {
-		roomView := NewRoomView(roomStore)
+		roomView := NewRoomView(view.debug, roomStore)
 		view.rooms[room] = roomView
 		view.roomView.AddPage(room, roomView, true, false)
 		roomView.UpdateUserList()
@@ -231,10 +237,18 @@ func (view *MainView) SetTyping(room string, users []string) {
 	}
 }
 
-func (view *MainView) AddMessage(room, sender, message string, timestamp time.Time) {
+func (view *MainView) AddMessage(room, message string) {
+	view.AddRealMessage(room, "", "*", message, time.Now())
+}
+
+func (view *MainView) AddRealMessage(room, id, sender, message string, timestamp time.Time) {
 	roomView, ok := view.rooms[room]
 	if ok {
-		roomView.AddMessage(sender, message, timestamp)
+		member := roomView.room.GetMember(sender)
+		if member != nil {
+			sender = member.DisplayName
+		}
+		roomView.content.AddMessage(id, sender, message, timestamp)
 		view.parent.Render()
 	}
 }