From 5070eb61f4d5614527f87f02154e21f69f3cf227 Mon Sep 17 00:00:00 2001
From: root <root@turin.home>
Date: Sun, 8 May 2022 12:04:37 +0100
Subject: [PATCH] Scrolling improvements and loading change.

Load market before quotes so something appears on screen quickly.

Using screen.max to prevent scrolling off the screen.
---
 cmd/mop/main.go | 18 ++++++++++--------
 screen.go       | 26 +++++++++++++++-----------
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/cmd/mop/main.go b/cmd/mop/main.go
index c0d14df..a150347 100644
--- a/cmd/mop/main.go
+++ b/cmd/mop/main.go
@@ -69,7 +69,8 @@ func mainLoop(screen *mop.Screen, profile *mop.Profile) {
 
 	market := mop.NewMarket()
 	quotes := mop.NewQuotes(market, profile)
-	screen.Draw(market, quotes)
+	screen.Draw(market)
+	screen.Draw(quotes)
 
 loop:
 	for {
@@ -102,7 +103,7 @@ loop:
 						screen.Clear().Draw(help)
 					} else if event.Key == termbox.KeyPgdn ||
 						event.Ch == 'J' {
-						screen.IncreaseOffset(upDownJump, len(profile.Tickers))
+						screen.IncreaseOffset(upDownJump)
 						redrawQuotesFlag = true
 					} else if event.Key == termbox.KeyPgup ||
 						event.Ch == 'K' {
@@ -112,13 +113,13 @@ loop:
 						screen.DecreaseOffset(1)
 						redrawQuotesFlag = true
 					} else if event.Key == termbox.KeyArrowDown || event.Ch == 'j' {
-						screen.IncreaseOffset(1, len(profile.Tickers))
+						screen.IncreaseOffset(1)
 						redrawQuotesFlag = true
 					} else if event.Key == termbox.KeyHome {
 						screen.ScrollTop()
 						redrawQuotesFlag = true
 					} else if event.Key == termbox.KeyEnd {
-						screen.ScrollBottom(len(profile.Tickers))
+						screen.ScrollBottom()
 						redrawQuotesFlag = true
 					}
 				} else if lineEditor != nil {
@@ -136,7 +137,8 @@ loop:
 			case termbox.EventResize:
 				screen.Resize()
 				if !showingHelp {
-					screen.Draw(market, quotes)
+					screen.Draw(market)
+                    redrawQuotesFlag = true
 				} else {
 					screen.Draw(help)
 				}
@@ -147,7 +149,7 @@ loop:
 						screen.DecreaseOffset(5)
 						redrawQuotesFlag = true
 					case termbox.MouseWheelDown:
-						screen.IncreaseOffset(5, len(profile.Tickers))
+						screen.IncreaseOffset(5)
 						redrawQuotesFlag = true
 					}
 				}
@@ -159,8 +161,8 @@ loop:
 			}
 
 		case <-quotesQueue.C:
-			if !showingHelp && !paused {
-				redrawQuotesFlag = true
+			if !showingHelp && !paused && len(keyboardQueue) == 0 {
+				screen.Draw(quotes)
 			}
 
 		case <-marketQueue.C:
diff --git a/screen.go b/screen.go
index 27f7118..5e62329 100644
--- a/screen.go
+++ b/screen.go
@@ -24,6 +24,7 @@ type Screen struct {
 	pausedAt   *time.Time // Timestamp of the pause request or nil if none.
 	offset     int        // Offset for scolling
 	headerLine int        // Line number of header for scroll feature
+	max        int        // highest offset
 }
 
 // Initializes Termbox, creates screen along with layout and markup, and
@@ -91,10 +92,12 @@ func (screen *Screen) ClearLine(x int, y int) *Screen {
 
 // Increase the offset for scrolling feature by n
 // Takes number of tickers as max, so not scrolling down forever
-func (screen *Screen) IncreaseOffset(n int, max int) {
-    if screen.offset + n < max - screen.height + screen.headerLine{
+func (screen *Screen) IncreaseOffset(n int) {
+	if screen.offset+n <= screen.max {
 		screen.offset += n
-	}
+	} else if screen.max > screen.height {
+        screen.offset = screen.max
+    }
 }
 
 // Decrease the offset for scrolling feature by n
@@ -110,17 +113,14 @@ func (screen *Screen) ScrollTop() {
 	screen.offset = 0
 }
 
-func (screen *Screen) ScrollBottom(max int) {
-	bottom := max - screen.height + screen.headerLine
-	if bottom > 0 {
-		screen.offset = bottom
-	} else {
-		screen.offset = 0
-	}
+func (screen *Screen) ScrollBottom() {
+    if screen.max > screen.height {
+        screen.offset = screen.max
+    }
 }
 
 func (screen *Screen) DrawOldQuotes(quotes *Quotes) {
-    screen.draw(screen.layout.Quotes(quotes), true)
+	screen.draw(screen.layout.Quotes(quotes), true)
 	termbox.Flush()
 }
 
@@ -202,6 +202,10 @@ func (screen *Screen) draw(str string, offset bool) {
 	blankLine := fmt.Sprintf(tempFormat, "")
 	allLines = strings.Split(str, "\n")
 
+	if offset {
+		screen.max = len(allLines) - screen.height
+	}
+
 	// Write the lines being updated.
 	for row := 0; row < len(allLines); row++ {
 		if offset {