diff --git a/src/termui/linegraph.go b/src/termui/linegraph.go
index e803c43..32bc89e 100644
--- a/src/termui/linegraph.go
+++ b/src/termui/linegraph.go
@@ -97,7 +97,7 @@ func (self *LineGraph) Draw(buf *Buffer) {
 				}
 				if char != 10240 { // empty braille character
 					buf.SetCell(
-						Cell{char, NewStyle(colors[x][y])},
+						NewCell(char, NewStyle(colors[x][y])),
 						image.Pt(self.Inner.Min.X+x-1, self.Inner.Min.Y+y-1),
 					)
 				}
@@ -120,7 +120,7 @@ func (self *LineGraph) Draw(buf *Buffer) {
 		for k, char := range str {
 			if char != ' ' {
 				buf.SetCell(
-					Cell{char, NewStyle(seriesLineColor)},
+					NewCell(char, NewStyle(seriesLineColor)),
 					image.Pt(self.Inner.Min.X+2+k, self.Inner.Min.Y+i+1),
 				)
 			}
diff --git a/src/termui/sparkline.go b/src/termui/sparkline.go
index 8fc6890..d2c8d01 100644
--- a/src/termui/sparkline.go
+++ b/src/termui/sparkline.go
@@ -2,6 +2,7 @@ package termui
 
 import (
 	"image"
+	"log"
 
 	. "github.com/gizak/termui"
 )
@@ -84,12 +85,16 @@ func (self *Sparklines) Draw(buf *Buffer) {
 				percent := float64(curItem) / float64(max)
 				index := int(percent * 7)
 				if index < 0 || index >= len(BARS) {
-					panic("TODO")
+					log.Printf(
+						"invalid sparkline data value. index: %v, percent: %v, curItem: %v, offset: %v",
+						index, percent, curItem, offset,
+					)
+					continue
 				}
 				char = BARS[index]
 			}
 			buf.SetCell(
-				Cell{char, NewStyle(line.LineColor)},
+				NewCell(char, NewStyle(line.LineColor)),
 				image.Pt(self.Inner.Min.X+x-1, self.Inner.Min.Y+sparkY-1),
 			)
 		}
diff --git a/src/termui/table.go b/src/termui/table.go
index 9c4141a..0b8c71e 100644
--- a/src/termui/table.go
+++ b/src/termui/table.go
@@ -2,6 +2,7 @@ package termui
 
 import (
 	"image"
+	"log"
 	"strings"
 
 	. "github.com/gizak/termui"
@@ -77,11 +78,13 @@ func (self *Table) Draw(buf *Buffer) {
 		)
 	}
 
+	if self.TopRow < 0 {
+		log.Printf("table widget TopRow value less than 0. TopRow: %v", self.TopRow)
+		return
+	}
+
 	// prints each row
 	for rowNum := self.TopRow; rowNum < self.TopRow+self.Inner.Dy()-1 && rowNum < len(self.Rows); rowNum++ {
-		if rowNum < 0 || rowNum >= len(self.Rows) {
-			panic("TODO")
-		}
 		row := self.Rows[rowNum]
 		y := (rowNum + 2) - self.TopRow
 
@@ -149,12 +152,12 @@ func (self *Table) calcPos() {
 }
 
 func (self *Table) Up() {
-	self.SelectedRow -= 1
+	self.SelectedRow--
 	self.calcPos()
 }
 
 func (self *Table) Down() {
-	self.SelectedRow += 1
+	self.SelectedRow++
 	self.calcPos()
 }