feat: custom shell highlight (#50)

* no large gaps between prompts on empty input due to NewlineBefore and NewlineAfter

* removed lastLine placeholder

* don't print lastLine

* check firstRead in newlineAfter

* set lastLine every iteration

* custom ansi code for flag and command highlight color

* docstring

Author: pygrum

console.go

@@ -12,14 +12,16 @@ import (
 // Console is an integrated console application instance.
 type Console struct {
 	// Application
-	name        string           // Used in the prompt, and for readline `.inputrc` application-specific settings.
-	shell       *readline.Shell  // Provides readline functionality (inputs, completions, hints, history)
-	printLogo   func(c *Console) // Simple logo printer.
-	menus       map[string]*Menu // Different command trees, prompt engines, etc.
-	filters     []string         // Hide commands based on their attributes and current context.
-	isExecuting bool             // Used by log functions, which need to adapt behavior (print the prompt, , etc)
-	printed     bool             // Used to adjust asynchronous messages too.
-	mutex       *sync.RWMutex    // Concurrency management.
+	name          string           // Used in the prompt, and for readline `.inputrc` application-specific settings.
+	shell         *readline.Shell  // Provides readline functionality (inputs, completions, hints, history)
+	printLogo     func(c *Console) // Simple logo printer.
+	cmdHighlight  string           // Ansi code for highlighting of command in default highlighter. Green by default.
+	flagHighlight string           // Ansi code for highlighting of flag in default highlighter. Grey by default.
+	menus         map[string]*Menu // Different command trees, prompt engines, etc.
+	filters       []string         // Hide commands based on their attributes and current context.
+	isExecuting   bool             // Used by log functions, which need to adapt behavior (print the prompt, etc.)
+	printed       bool             // Used to adjust asynchronous messages too.
+	mutex         *sync.RWMutex    // Concurrency management.
 
 	// Execution
 
@@ -93,6 +95,8 @@ func New(app string) *Console {
 	}
 
 	// Syntax highlighting, multiline callbacks, etc.
+	console.cmdHighlight = seqFgGreen
+	console.flagHighlight = seqBrightWigth
 	console.shell.AcceptMultiline = console.acceptMultiline
 	console.shell.SyntaxHighlighter = console.highlightSyntax
 

highlighter.go

@@ -31,6 +31,22 @@ var (
 	reverseReset    = "\x1b[27m"
 )
 
+// SetDefaultCommandHighlight allows the user to change the highlight color for a command in the default syntax
+// highlighter using an ansi code.
+// This action has no effect if a custom syntax highlighter for the shell is set.
+// By default, the highlight code is green ("\x1b[32m").
+func (c *Console) SetDefaultCommandHighlight(seq string) {
+	c.cmdHighlight = seq
+}
+
+// SetDefaultFlagHighlight allows the user to change the highlight color for a flag in the default syntax
+// highlighter using an ansi color code.
+// This action has no effect if a custom syntax highlighter for the shell is set.
+// By default, the highlight code is grey ("\x1b[38;05;244m").
+func (c *Console) SetDefaultFlagHighlight(seq string) {
+	c.flagHighlight = seq
+}
+
 // highlightSyntax - Entrypoint to all input syntax highlighting in the Wiregost console.
 func (c *Console) highlightSyntax(input []rune) (line string) {
 	// Split the line as shellwords
@@ -82,7 +98,7 @@ func (c *Console) highlightCommand(done, args []string, _ *cobra.Command) ([]str
 		}
 
 		if cmdFound {
-			highlighted = append(highlighted, bold+seqFgGreen+args[0]+seqFgReset+boldReset)
+			highlighted = append(highlighted, bold+c.cmdHighlight+args[0]+seqFgReset+boldReset)
 			rest = args[1:]
 
 			return append(done, highlighted...), rest
@@ -102,7 +118,7 @@ func (c *Console) highlightCommandFlags(done, args []string, _ *cobra.Command) (
 
 	for _, arg := range args {
 		if strings.HasPrefix(arg, "-") || strings.HasPrefix(arg, "--") {
-			highlighted = append(highlighted, bold+seqBrightWigth+arg+seqFgReset+boldReset)
+			highlighted = append(highlighted, bold+c.flagHighlight+arg+seqFgReset+boldReset)
 		} else {
 			highlighted = append(highlighted, arg)
 		}