From 3897f23bc4dd24cf54ba39fad544d10feb273120 Mon Sep 17 00:00:00 2001 From: Tulir Asokan Date: Tue, 20 Mar 2018 12:16:32 +0200 Subject: Add support for loading more history --- ui/widget/message-view.go | 222 +++++++++++++++++++++++----------------------- 1 file changed, 112 insertions(+), 110 deletions(-) (limited to 'ui/widget/message-view.go') diff --git a/ui/widget/message-view.go b/ui/widget/message-view.go index 3503a5f..953dd7d 100644 --- a/ui/widget/message-view.go +++ b/ui/widget/message-view.go @@ -18,7 +18,6 @@ package widget import ( "fmt" - "strings" "time" "github.com/gdamore/tcell" @@ -36,17 +35,17 @@ type MessageView struct { TimestampFormat string TimestampWidth int Separator rune + LoadingMessages bool - widestSender int - prevWidth int - prevHeight int - prevScrollOffset int - firstDisplayMessage int - lastDisplayMessage int - totalHeight int + widestSender int + prevWidth int + prevHeight int messageIDs map[string]bool messages []*types.Message + + metaBuffer []*types.Message + textBuffer []string } func NewMessageView() *MessageView { @@ -61,14 +60,12 @@ func NewMessageView() *MessageView { messages: make([]*types.Message, 0), messageIDs: make(map[string]bool), + textBuffer: make([]string, 0), + metaBuffer: make([]*types.Message, 0), - widestSender: 5, - prevWidth: -1, - prevHeight: -1, - prevScrollOffset: -1, - firstDisplayMessage: -1, - lastDisplayMessage: -1, - totalHeight: -1, + widestSender: 5, + prevWidth: -1, + prevHeight: -1, } } @@ -79,17 +76,6 @@ func (view *MessageView) NewMessage(id, sender, text string, timestamp time.Time GetHashColor(sender)) } -func (view *MessageView) recalculateBuffers() { - _, _, width, _ := view.GetInnerRect() - width -= view.TimestampWidth + TimestampSenderGap + view.widestSender + SenderMessageGap - if width != view.prevWidth { - for _, message := range view.messages { - message.CalculateBuffer(width) - } - view.prevWidth = width - } -} - func (view *MessageView) updateWidestSender(sender string) { if len(sender) > view.widestSender { view.widestSender = len(sender) @@ -100,7 +86,7 @@ func (view *MessageView) updateWidestSender(sender string) { } const ( - AppendMessage int = iota + AppendMessage = iota PrependMessage ) @@ -126,53 +112,87 @@ func (view *MessageView) AddMessage(message *types.Message, direction int) { } view.messageIDs[message.ID] = true - view.recalculateHeight() + view.appendBuffer(message) } -func (view *MessageView) recalculateHeight() { - _, _, width, height := view.GetInnerRect() - if height != view.prevHeight || width != view.prevWidth || view.ScrollOffset != view.prevScrollOffset { - view.firstDisplayMessage = -1 - view.lastDisplayMessage = -1 - view.totalHeight = 0 - prevDate := "" - for i := len(view.messages) - 1; i >= 0; i-- { - prevTotalHeight := view.totalHeight - message := view.messages[i] - view.totalHeight += len(message.Buffer) - if message.Date != prevDate { - if len(prevDate) != 0 { - view.totalHeight++ - } - prevDate = message.Date - } +func (view *MessageView) recalculateMessageBuffers() { + _, _, width, _ := view.GetInnerRect() + width -= view.TimestampWidth + TimestampSenderGap + view.widestSender + SenderMessageGap + if width != view.prevWidth { + for _, message := range view.messages { + message.CalculateBuffer(width) + } + view.prevWidth = width + } +} - if view.totalHeight < view.ScrollOffset { - continue - } else if view.firstDisplayMessage == -1 { - view.lastDisplayMessage = i - view.firstDisplayMessage = i - } +func (view *MessageView) appendBuffer(message *types.Message) { + if len(view.metaBuffer) > 0 { + prevMeta := view.metaBuffer[len(view.metaBuffer)-1] + if prevMeta != nil && prevMeta.Date != message.Date { + view.textBuffer = append(view.textBuffer, fmt.Sprintf("Date changed to %s", message.Date)) + view.metaBuffer = append(view.metaBuffer, nil) + } + } - if prevTotalHeight < height+view.ScrollOffset { - view.lastDisplayMessage = i - } + view.textBuffer = append(view.textBuffer, message.Buffer...) + for range message.Buffer { + view.metaBuffer = append(view.metaBuffer, message) + } +} + +func (view *MessageView) recalculateBuffer() { + _, _, width, height := view.GetInnerRect() + view.textBuffer = make([]string, 0) + view.metaBuffer = make([]*types.Message, 0) + + if height != view.prevHeight || width != view.prevWidth { + for _, message := range view.messages { + view.appendBuffer(message) } - view.prevScrollOffset = view.ScrollOffset + view.prevHeight = height } } -func (view *MessageView) PageUp() { +const PaddingAtTop = 5 + +func (view *MessageView) MoveUp(page bool) { _, _, _, height := view.GetInnerRect() - view.ScrollOffset += height / 2 - if view.ScrollOffset > view.totalHeight-height { - view.ScrollOffset = view.totalHeight - height + 5 + + totalHeight := len(view.textBuffer) + if view.ScrollOffset >= totalHeight-height { + // If the user is at the top and presses page up again, add a bit of blank space. + if page { + view.ScrollOffset = totalHeight - height + PaddingAtTop + } else if view.ScrollOffset < totalHeight-height+PaddingAtTop { + view.ScrollOffset++ + } + return + } + + if page { + view.ScrollOffset += height / 2 + } else { + view.ScrollOffset++ } + if view.ScrollOffset > totalHeight-height { + view.ScrollOffset = totalHeight - height + } +} + +func (view *MessageView) IsAtTop() bool { + _, _, _, height := view.GetInnerRect() + totalHeight := len(view.textBuffer) + return view.ScrollOffset >= totalHeight-height+PaddingAtTop } -func (view *MessageView) PageDown() { +func (view *MessageView) MoveDown(page bool) { _, _, _, height := view.GetInnerRect() - view.ScrollOffset -= height / 2 + if page { + view.ScrollOffset -= height / 2 + } else { + view.ScrollOffset-- + } if view.ScrollOffset < 0 { view.ScrollOffset = 0 } @@ -224,10 +244,10 @@ func (view *MessageView) Draw(screen tcell.Screen) { view.Box.Draw(screen) x, y, _, height := view.GetInnerRect() - view.recalculateBuffers() - view.recalculateHeight() + view.recalculateMessageBuffers() + view.recalculateBuffer() - if view.firstDisplayMessage == -1 || view.lastDisplayMessage == -1 { + if len(view.textBuffer) == 0 { view.writeLine(screen, "It's quite empty in here.", x, y+height, tcell.ColorDefault) return } @@ -239,55 +259,37 @@ func (view *MessageView) Draw(screen tcell.Screen) { screen.SetContent(separatorX, separatorY, view.Separator, nil, tcell.StyleDefault) } - writeOffset := 0 - prevDate := "" - prevSender := "" - prevSenderLine := -1 - for i := view.firstDisplayMessage; i >= view.lastDisplayMessage; i-- { - message := view.messages[i] - messageHeight := len(message.Buffer) - - // Show message when the date changes. - if message.Date != prevDate { - if len(prevDate) > 0 { - writeOffset++ - view.writeLine( - screen, fmt.Sprintf("Date changed to %s", prevDate), - x+messageOffsetX, y+height-writeOffset, tcell.ColorGreen) - } - prevDate = message.Date + var prevMeta *types.Message + var prevSender string + indexOffset := len(view.textBuffer) - view.ScrollOffset - height + if indexOffset <= -PaddingAtTop { + message := "Scroll up to load more messages." + if view.LoadingMessages { + message = "Loading more messages..." } - - senderAtLine := y + height - writeOffset - messageHeight - // The message may be only partially on screen, so we need to make sure the sender - // is on screen even when the message is not shown completely. - if senderAtLine < y { - senderAtLine = y - } - - view.writeLine(screen, message.Timestamp, x, senderAtLine, tcell.ColorDefault) - view.writeLineRight(screen, message.Sender, - x+usernameOffsetX, senderAtLine, - view.widestSender, message.SenderColor) - - if message.Sender == prevSender { - // Sender is same as previous. We're looping from bottom to top, and we want the - // sender name only on the topmost message, so clear out the duplicate sender name - // below. - view.writeLineRight(screen, strings.Repeat(" ", view.widestSender), - x+usernameOffsetX, prevSenderLine, - view.widestSender, message.SenderColor) + view.writeLine(screen, message, x+messageOffsetX, y, tcell.ColorGreen) + } + for line := 0; line < height; line++ { + index := indexOffset + line + if index < 0 { + continue + } else if index > len(view.textBuffer) { + break } - prevSender = message.Sender - prevSenderLine = senderAtLine - - for num, line := range message.Buffer { - offsetY := height - messageHeight - writeOffset + num - // Only render message if it's within the message view. - if offsetY >= 0 { - view.writeLine(screen, line, x+messageOffsetX, y+offsetY, tcell.ColorDefault) + text, meta := view.textBuffer[index], view.metaBuffer[index] + if meta != prevMeta { + if meta != nil { + view.writeLine(screen, meta.Timestamp, x, y+line, tcell.ColorDefault) + if meta.Sender != prevSender { + view.writeLineRight( + screen, meta.Sender, + x+usernameOffsetX, y+line, + view.widestSender, meta.SenderColor) + prevSender = meta.Sender + } } + prevMeta = meta } - writeOffset += messageHeight + view.writeLine(screen, text, x+messageOffsetX, y+line, tcell.ColorDefault) } } -- cgit v1.2.3