Add mouse scrolling support to room list (ref #34)

2 files changed, 118 insertions, 33 deletions

diff --git a/ui/room-list.go b/ui/room-list.go
index 1cb71c9..3a43872 100644
--- a/ui/room-list.go
+++ b/ui/room-list.go
@@ -46,6 +46,8 @@ type RoomList struct {
 	selected    *rooms.Room
 	selectedTag string
 
+	scrollOffset int
+
 	// The item main text color.
 	mainTextColor tcell.Color
 	// The text color for selected items.
@@ -60,6 +62,8 @@ func NewRoomList() *RoomList {
 		items: make(map[string][]*rooms.Room),
 		tags:  []string{"m.favourite", "net.maunium.gomuks.fake.direct", "", "m.lowpriority"},
 
+		scrollOffset: 0,
+
 		mainTextColor:           tcell.ColorWhite,
 		selectedTextColor:       tcell.ColorWhite,
 		selectedBackgroundColor: tcell.ColorDarkGreen,
@@ -217,6 +221,12 @@ func (list *RoomList) Clear() {
 func (list *RoomList) SetSelected(tag string, room *rooms.Room) {
 	list.selected = room
 	list.selectedTag = tag
+	pos := list.index(tag, room)
+	_, _, _, height := list.GetRect()
+	if pos < list.scrollOffset || pos > list.scrollOffset+height {
+		// TODO this does weird stuff sometimes, needs to be fixed
+		//list.scrollOffset = pos
+	}
 	debug.Print("Selecting", room.GetTitle(), "in", list.GetTagDisplayName(tag))
 }
 
@@ -232,6 +242,18 @@ func (list *RoomList) SelectedRoom() *rooms.Room {
 	return list.selected
 }
 
+func (list *RoomList) AddScrollOffset(offset int) {
+	list.scrollOffset += offset
+	if list.scrollOffset < 0 {
+		list.scrollOffset = 0
+	}
+	_, _, _, viewHeight := list.GetRect()
+	contentHeight := list.ContentHeight()
+	if list.scrollOffset > contentHeight-viewHeight {
+		list.scrollOffset = contentHeight - viewHeight
+	}
+}
+
 func (list *RoomList) First() (string, *rooms.Room) {
 	for _, tag := range list.tags {
 		items := list.items[tag]
@@ -326,7 +348,52 @@ func (list *RoomList) indexInTag(tag string, room *rooms.Room) int {
 	return roomIndex
 }
 
+func (list *RoomList) index(tag string, room *rooms.Room) int {
+	tagIndex := list.IndexTag(tag)
+	if tagIndex == -1 {
+		return -1
+	}
+
+	localIndex := list.indexInTag(tag, room)
+	if localIndex == -1 {
+		return -1
+	}
+
+	// Tag header
+	localIndex += 1
+
+	if tagIndex > 0 {
+		for i := 0; i < tagIndex; i++ {
+			previousTag := list.tags[i]
+			previousItems := list.items[previousTag]
+
+			tagDisplayName := list.GetTagDisplayName(previousTag)
+			if len(tagDisplayName) > 0 {
+				// Previous tag header + space
+				localIndex += 2
+				// Previous tag items
+				localIndex += len(previousItems)
+			}
+		}
+	}
+
+	return localIndex
+}
+
+func (list *RoomList) ContentHeight() (height int) {
+	for _, tag := range list.tags {
+		items := list.items[tag]
+		tagDisplayName := list.GetTagDisplayName(tag)
+		if len(tagDisplayName) == 0 {
+			continue
+		}
+		height += 2 + len(items)
+	}
+	return
+}
+
 func (list *RoomList) Get(n int) (string, *rooms.Room) {
+	n += list.scrollOffset
 	if n < 0 {
 		return "", nil
 	}
@@ -377,12 +444,7 @@ func (list *RoomList) Draw(screen tcell.Screen) {
 	x, y, width, height := list.GetInnerRect()
 	bottomLimit := y + height
 
-	var offset int
-	/* TODO fix offset
-	currentItemIndex := list.Index(list.selected)
-	if currentItemIndex >= height {
-		offset = currentItemIndex + 1 - height
-	}*/
+	handledOffset := 0
 
 	// Draw the list items.
 	for _, tag := range list.tags {
@@ -392,20 +454,32 @@ func (list *RoomList) Draw(screen tcell.Screen) {
 			continue
 		}
 
+		localOffset := 0
+
+		if handledOffset < list.scrollOffset {
+			if handledOffset+len(items) < list.scrollOffset {
+				handledOffset += len(items) + 2
+				continue
+			} else {
+				localOffset = list.scrollOffset - handledOffset
+				handledOffset += localOffset
+			}
+		}
+
 		widget.WriteLine(screen, tview.AlignLeft, tagDisplayName, x, y, width, tcell.StyleDefault.Underline(true).Bold(true))
 		y++
 		for i := len(items) - 1; i >= 0; i-- {
 			item := items[i]
 			index := len(items) - 1 - i
 
-			if index < offset {
-				continue
-			}
-
 			if y >= bottomLimit {
 				break
 			}
 
+			if index < localOffset {
+				continue
+			}
+
 			text := item.GetTitle()
 
 			lineWidth := width
diff --git a/ui/view-main.go b/ui/view-main.go
index 4b01829..b7bbf6d 100644
--- a/ui/view-main.go
+++ b/ui/view-main.go
@@ -213,39 +213,47 @@ func (view *MainView) MouseEventHandler(roomView *RoomView, event *tcell.EventMo
 	msgView := roomView.MessageView()
 	x, y := event.Position()
 
-	switch event.Buttons() {
-	case tcell.WheelUp:
-		if msgView.IsAtTop() {
-			go view.LoadHistory(roomView.Room.ID)
-		} else {
-			msgView.AddScrollOffset(WheelScrollOffsetDiff)
+	switch {
+	case isInArea(x, y, msgView):
+		mx, my, _, _ := msgView.GetRect()
+		switch event.Buttons() {
+		case tcell.WheelUp:
+			if msgView.IsAtTop() {
+				go view.LoadHistory(roomView.Room.ID)
+			} else {
+				msgView.AddScrollOffset(WheelScrollOffsetDiff)
 
-			view.parent.Render()
-		}
-	case tcell.WheelDown:
-		msgView.AddScrollOffset(-WheelScrollOffsetDiff)
+				view.parent.Render()
+			}
+		case tcell.WheelDown:
+			msgView.AddScrollOffset(-WheelScrollOffsetDiff)
 
-		view.parent.Render()
+			view.parent.Render()
 
-		if msgView.ScrollOffset == 0 {
-			roomView.Room.MarkRead()
-		}
-	default:
-		if isInArea(x, y, msgView) {
-			mx, my, _, _ := msgView.GetRect()
+			if msgView.ScrollOffset == 0 {
+				roomView.Room.MarkRead()
+			}
+		default:
 			if msgView.HandleClick(x-mx, y-my, event.Buttons()) {
 				view.parent.Render()
 			}
-		} else if isInArea(x, y, view.roomList) && event.Buttons() == tcell.Button1 {
+		}
+	case isInArea(x, y, view.roomList):
+		switch event.Buttons() {
+		case tcell.WheelUp:
+			view.roomList.AddScrollOffset(-WheelScrollOffsetDiff)
+			view.parent.Render()
+		case tcell.WheelDown:
+			view.roomList.AddScrollOffset(WheelScrollOffsetDiff)
+			view.parent.Render()
+		case tcell.Button1:
 			_, rly, _, _ := msgView.GetRect()
 			n := y - rly + 1
 			view.SwitchRoom(view.roomList.Get(n))
-		} else {
-			debug.Print("Unhandled mouse event:", event.Buttons(), event.Modifiers(), x, y)
 		}
-		return event
+	default:
+		debug.Print("Unhandled mouse event:", event.Buttons(), event.Modifiers(), x, y)
 	}
-
 	return event
 }
 
@@ -305,7 +313,10 @@ func (view *MainView) GetRoom(roomID string) ifc.RoomView {
 	room, ok := view.rooms[roomID]
 	if !ok {
 		view.AddRoom(roomID)
-		room, _ := view.rooms[roomID]
+		room, ok := view.rooms[roomID]
+		if !ok {
+			return nil
+		}
 		return room
 	}
 	return room