Add the ability to close splits and change splits using the mouse

This commits adds split navigation with the mouse and the ability to
close splits. You can now also open a file directly with the hsplit
and vsplit commands.

cmd/micro/bindings.go

@@ -915,11 +915,13 @@ func (v *View) OpenFile() bool {
 		filename = strings.Replace(filename, "~", home, 1)
 		file, err := ioutil.ReadFile(filename)
 
+		var buf *Buffer
 		if err != nil {
-			messenger.Error(err.Error())
-			return false
+			// File does not exist -- create an empty buffer with that name
+			buf = NewBuffer([]byte{}, filename)
+		} else {
+			buf = NewBuffer(file, filename)
 		}
-		buf := NewBuffer(file, filename)
 		v.OpenBuffer(buf)
 		return true
 	}
@@ -1090,7 +1092,27 @@ func (v *View) Quit() bool {
 	// Make sure not to quit if there are unsaved changes
 	if v.CanClose("Quit anyway? (yes, no, save) ") {
 		v.CloseBuffer()
-		if len(tabs) > 1 {
+		if len(tabs[curTab].views) > 1 {
+			var view *View
+			if v.splitChild != nil {
+				view = v.splitChild
+				view.splitParent = v.splitParent
+			} else if v.splitParent != nil {
+				view = v.splitParent
+				v.splitParent.splitChild = nil
+			}
+			view.x, view.y = view.splitOrigPos[0], view.splitOrigPos[1]
+			view.widthPercent, view.heightPercent = view.splitOrigDimensions[0], view.splitOrigDimensions[1]
+			view.Resize(screen.Size())
+			if settings["syntax"].(bool) {
+				view.matches = Match(view)
+			}
+			tabs[curTab].views = tabs[curTab].views[:v.Num+copy(tabs[curTab].views[v.Num:], tabs[curTab].views[v.Num+1:])]
+			for i, v := range tabs[curTab].views {
+				v.Num = i
+			}
+			tabs[curTab].curView = view.Num
+		} else if len(tabs) > 1 {
 			if len(tabs[v.TabNum].views) == 1 {
 				tabs = tabs[:v.TabNum+copy(tabs[v.TabNum:], tabs[v.TabNum+1:])]
 				for i, t := range tabs {

cmd/micro/command.go

@@ -2,11 +2,14 @@ package main
 
 import (
 	"bytes"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"os/signal"
 	"regexp"
 	"strings"
+
+	"github.com/mitchellh/go-homedir"
 )
 
 var commands map[string]func([]string)
@@ -63,11 +66,48 @@ func DefaultCommands() map[string]string {
 	}
 }
 
+// VSplit opens a vertical split with file given in the first argument
+// If no file is given, it opens an empty buffer in a new split
 func VSplit(args []string) {
-	CurView().VSplit()
+	if len(args) == 0 {
+		CurView().VSplit(NewBuffer([]byte{}, ""))
+	} else {
+		filename := args[0]
+		home, _ := homedir.Dir()
+		filename = strings.Replace(filename, "~", home, 1)
+		file, err := ioutil.ReadFile(filename)
+
+		var buf *Buffer
+		if err != nil {
+			// File does not exist -- create an empty buffer with that name
+			buf = NewBuffer([]byte{}, filename)
+		} else {
+			buf = NewBuffer(file, filename)
+		}
+		CurView().VSplit(buf)
+	}
 }
+
+// HSplit opens a horizontal split with file given in the first argument
+// If no file is given, it opens an empty buffer in a new split
 func HSplit(args []string) {
-	CurView().HSplit()
+	if len(args) == 0 {
+		CurView().HSplit(NewBuffer([]byte{}, ""))
+	} else {
+		filename := args[0]
+		home, _ := homedir.Dir()
+		filename = strings.Replace(filename, "~", home, 1)
+		file, err := ioutil.ReadFile(filename)
+
+		var buf *Buffer
+		if err != nil {
+			// File does not exist -- create an empty buffer with that name
+			buf = NewBuffer([]byte{}, filename)
+		} else {
+			buf = NewBuffer(file, filename)
+		}
+		CurView().HSplit(buf)
+	}
 }
 
 // Set sets an option

cmd/micro/micro.go

@@ -281,11 +281,17 @@ func main() {
 		case *tcell.EventMouse:
 			if e.Buttons() == tcell.Button1 {
 				_, h := screen.Size()
-				_, y := e.Position()
+				x, y := e.Position()
 				if y == h-1 && messenger.message != "" {
 					clipboard.WriteAll(messenger.message)
 					continue
 				}
+
+				for _, v := range tabs[curTab].views {
+					if x >= v.x && x < v.x+v.width && y >= v.y && y < v.y+v.height {
+						tabs[curTab].curView = v.Num
+					}
+				}
 			}
 		}
 

cmd/micro/view.go

@@ -87,6 +87,11 @@ type View struct {
 	matches SyntaxMatches
 	// The matches from the last frame
 	lastMatches SyntaxMatches
+
+	splitParent         *View
+	splitChild          *View
+	splitOrigDimensions [2]int
+	splitOrigPos        [2]int
 }
 
 // NewView returns a new fullscreen view
@@ -222,32 +227,56 @@ func (v *View) ReOpen() {
 	}
 }
 
-func (v *View) HSplit() bool {
+// HSplit opens a horizontal split with the given buffer
+func (v *View) HSplit(buf *Buffer) bool {
+	origDimensions := [2]int{v.widthPercent, v.heightPercent}
+	origPos := [2]int{v.x, v.y}
+
 	v.heightPercent /= 2
 	v.Resize(screen.Size())
 
-	newView := NewViewWidthHeight(NewBuffer([]byte{}, ""), v.widthPercent, v.heightPercent)
+	newView := NewViewWidthHeight(buf, v.widthPercent, v.heightPercent)
+
+	v.splitOrigDimensions = origDimensions
+	v.splitOrigPos = origPos
+	newView.splitOrigDimensions = origDimensions
+	newView.splitOrigPos = origPos
+
 	newView.TabNum = v.TabNum
 	newView.y = v.y + v.height + 1
 	newView.x = v.x
 	tab := tabs[v.TabNum]
 	tab.curView++
 	newView.Num = len(tab.views)
+	newView.splitParent = v
+	v.splitChild = newView
 	tab.views = append(tab.views, newView)
 	return false
 }
 
-func (v *View) VSplit() bool {
+// VSplit opens a vertical split with the given buffer
+func (v *View) VSplit(buf *Buffer) bool {
+	origDimensions := [2]int{v.widthPercent, v.heightPercent}
+	origPos := [2]int{v.x, v.y}
+
 	v.widthPercent /= 2
 	v.Resize(screen.Size())
 
-	newView := NewViewWidthHeight(NewBuffer([]byte{}, ""), v.widthPercent, v.heightPercent)
+	newView := NewViewWidthHeight(buf, v.widthPercent, v.heightPercent)
+
+	v.splitOrigDimensions = origDimensions
+	v.splitOrigPos = origPos
+	newView.splitOrigDimensions = origDimensions
+	newView.splitOrigPos = origPos
+
 	newView.TabNum = v.TabNum
 	newView.y = v.y
 	newView.x = v.x + v.width
 	tab := tabs[v.TabNum]
 	tab.curView++
 	newView.Num = len(tab.views)
+	newView.splitParent = v
+	v.splitChild = newView
 	tab.views = append(tab.views, newView)
 	return false
 }
@@ -638,7 +667,7 @@ func (v *View) DisplayView() {
 				lineStyle = highlightStyle
 			}
 
-			if settings["cursorline"].(bool) && !v.Cursor.HasSelection() && v.Cursor.Y == lineN+v.Topline {
+			if settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == lineN+v.Topline {
 				if style, ok := colorscheme["cursor-line"]; ok {
 					fg, _, _ := style.Decompose()
 					lineStyle = lineStyle.Background(fg)
@@ -742,7 +771,9 @@ func (v *View) DisplayCursor() {
 // Display renders the view, the cursor, and statusline
 func (v *View) Display() {
 	v.DisplayView()
-	v.DisplayCursor()
+	if v.Num == tabs[curTab].curView {
+		v.DisplayCursor()
+	}
 	if settings["statusline"].(bool) {
 		v.sline.Display()
 	}