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/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