Code optimisation (#1117)

[micro.git] / cmd / micro / cursor.go

diff --git a/cmd/micro/cursor.go b/cmd/micro/cursor.go
index a0d3477f19f84fe23e99eac6eff01e95fab1a355..452268ba12b1f3802623be7fca8c5d33097e81e0 100644 (file)
--- a/cmd/micro/cursor.go
+++ b/cmd/micro/cursor.go
@@ -28,13 +28,22 @@ type Cursor struct {
        Num int
 }
 
-// Goto puts the cursor at the given cursor's location and gives the current cursor its selection too
+// Goto puts the cursor at the given cursor's location and gives
+// the current cursor its selection too
 func (c *Cursor) Goto(b Cursor) {
        c.X, c.Y, c.LastVisualX = b.X, b.Y, b.LastVisualX
        c.OrigSelection, c.CurSelection = b.OrigSelection, b.CurSelection
 }
 
-// CopySelection copies the user's selection to either "primary" or "clipboard"
+// GotoLoc puts the cursor at the given cursor's location and gives
+// the current cursor its selection too
+func (c *Cursor) GotoLoc(l Loc) {
+       c.X, c.Y = l.X, l.Y
+       c.LastVisualX = c.GetVisualX()
+}
+
+// CopySelection copies the user's selection to either "primary"
+// or "clipboard"
 func (c *Cursor) CopySelection(target string) {
        if c.HasSelection() {
                if target != "primary" || c.buf.Settings["useprimary"].(bool) {
@@ -151,7 +160,8 @@ func (c *Cursor) SelectWord() {
        c.Loc = c.CurSelection[1]
 }
 
-// AddWordToSelection adds the word the cursor is currently on to the selection
+// AddWordToSelection adds the word the cursor is currently on
+// to the selection
 func (c *Cursor) AddWordToSelection() {
        if c.Loc.GreaterThan(c.OrigSelection[0]) && c.Loc.LessThan(c.OrigSelection[1]) {
                c.CurSelection = c.OrigSelection
@@ -183,7 +193,8 @@ func (c *Cursor) AddWordToSelection() {
        c.Loc = c.CurSelection[1]
 }
 
-// SelectTo selects from the current cursor location to the given location
+// SelectTo selects from the current cursor location to the given
+// location
 func (c *Cursor) SelectTo(loc Loc) {
        if loc.GreaterThan(c.OrigSelection[0]) {
                c.SetSelectionStart(c.OrigSelection[0])
@@ -250,19 +261,19 @@ func (c *Cursor) UpN(amount int) {
        proposedY := c.Y - amount
        if proposedY < 0 {
                proposedY = 0
+               c.LastVisualX = 0
        } else if proposedY >= c.buf.NumLines {
                proposedY = c.buf.NumLines - 1
        }
-       if proposedY == c.Y {
-               return
-       }
 
-       c.Y = proposedY
        runes := []rune(c.buf.Line(c.Y))
-       c.X = c.GetCharPosInLine(c.Y, c.LastVisualX)
-       if c.X > len(runes) {
+       c.X = c.GetCharPosInLine(proposedY, c.LastVisualX)
+
+       if c.X > len(runes) || (amount < 0 && proposedY == c.Y) {
                c.X = len(runes)
        }
+
+       c.Y = proposedY
 }
 
 // DownN moves the cursor down N lines (if possible)
@@ -280,7 +291,8 @@ func (c *Cursor) Down() {
        c.DownN(1)
 }
 
-// Left moves the cursor left one cell (if possible) or to the last line if it is at the beginning
+// Left moves the cursor left one cell (if possible) or to
+// the previous line if it is at the beginning
 func (c *Cursor) Left() {
        if c.Loc == c.buf.Start() {
                return
@@ -294,7 +306,8 @@ func (c *Cursor) Left() {
        c.LastVisualX = c.GetVisualX()
 }
 
-// Right moves the cursor right one cell (if possible) or to the next line if it is at the end
+// Right moves the cursor right one cell (if possible) or
+// to the next line if it is at the end
 func (c *Cursor) Right() {
        if c.Loc == c.buf.End() {
                return
@@ -320,7 +333,21 @@ func (c *Cursor) Start() {
        c.LastVisualX = c.GetVisualX()
 }
 
-// GetCharPosInLine gets the char position of a visual x y coordinate (this is necessary because tabs are 1 char but 4 visual spaces)
+// StartOfText moves the cursor to the first non-whitespace rune of 
+// the line it is on
+func (c *Cursor) StartOfText() {
+       c.Start()
+       for IsWhitespace(c.RuneUnder(c.X)) {
+               if c.X == Count(c.buf.Line(c.Y)) {
+                       break
+               }
+               c.Right()
+       }
+}
+
+// GetCharPosInLine gets the char position of a visual x y
+// coordinate (this is necessary because tabs are 1 char but
+// 4 visual spaces)
 func (c *Cursor) GetCharPosInLine(lineNum, visualPos int) int {
        // Get the tab size
        tabSize := int(c.buf.Settings["tabsize"].(float64))
@@ -355,8 +382,9 @@ func (c *Cursor) StoreVisualX() {
        c.LastVisualX = c.GetVisualX()
 }
 
-// Relocate makes sure that the cursor is inside the bounds of the buffer
-// If it isn't, it moves it to be within the buffer's lines
+// Relocate makes sure that the cursor is inside the bounds
+// of the buffer If it isn't, it moves it to be within the
+// buffer's lines
 func (c *Cursor) Relocate() {
        if c.Y < 0 {
                c.Y = 0