Add Button.SetCursorRune and CheckBox.SetCursorRune

Cursors are now shown within Buttons and CheckBoxes by default.

Resolves #62.

CHANGELOG

@@ -1,8 +1,10 @@
 v1.5.6 (WIP)
 - Add TrueColorTags option and do not use TrueColor tag values by default
 - Add TextView.SetHighlightForegroundColor and TextView.SetHighlightBackgroundColor
+- Add Button.SetCursorRune (cursors are now shown within Buttons when focused by default)
+- Add CheckBox.SetCursorRune (cursors are now shown within CheckBoxes when focused by default)
+- Add DropDown.SetAlwaysDrawDropDownSymbol (DropDown symbols are now shown only when focused by default)
 - Add DropDown.SetDropDownOpenSymbolRune
-- Add DropDown.SetAlwaysDrawDropDownSymbol (DropDown symbols are now only drawn when focused by default)
 - Draw additional accents when rendering a list divider
 - Update List, Table and TreeView to not handle Tab or Backtab
 - Allow specifying TabbedPanels switcher height

README.md

@@ -67,10 +67,10 @@ func main() {
 ```
 
 Examples are available via [godoc](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview#pkg-examples)
-and in the [demos](https://code.rocketnine.space/tslocum/cview/src/branch/master/demos) subdirectory.
+and in the [demos](https://code.rocketnine.space/tslocum/cview/src/branch/master/demos) directory.
 
 For a presentation highlighting the features of this package, compile and run
-the program in the [demos/presentation](https://code.rocketnine.space/tslocum/cview/src/branch/master/demos/presentation) subdirectory.
+the program in the [demos/presentation](https://code.rocketnine.space/tslocum/cview/src/branch/master/demos/presentation) directory.
 
 ## Documentation
 

button.go

@@ -4,6 +4,7 @@ import (
 	"sync"
 
 	"github.com/gdamore/tcell/v2"
+	"github.com/mattn/go-runewidth"
 )
 
 // Button is labeled box that triggers an action when selected.
@@ -29,6 +30,9 @@ type Button struct {
 	// key is provided indicating which key was pressed to leave (tab or backtab).
 	blur func(tcell.Key)
 
+	// An optional rune which is drawn after the label when the button is focused.
+	cursorRune rune
+
 	sync.RWMutex
 }
 
@@ -36,13 +40,14 @@ type Button struct {
 func NewButton(label string) *Button {
 	box := NewBox()
 	box.SetRect(0, 0, TaggedStringWidth(label)+4, 1)
-	box.SetBackgroundColor(Styles.ContrastBackgroundColor)
+	box.SetBackgroundColor(Styles.MoreContrastBackgroundColor)
 	return &Button{
 		Box:                    box,
 		label:                  []byte(label),
 		labelColor:             Styles.PrimaryTextColor,
 		labelColorFocused:      Styles.PrimaryTextColor,
-		backgroundColorFocused: Styles.MoreContrastBackgroundColor,
+		cursorRune:             Styles.ButtonCursorRune,
+		backgroundColorFocused: Styles.ContrastBackgroundColor,
 	}
 }
 
@@ -79,6 +84,14 @@ func (b *Button) SetLabelColorFocused(color tcell.Color) {
 	b.labelColorFocused = color
 }
 
+// SetCursorRune sets the rune to show within the button when it is focused.
+func (b *Button) SetCursorRune(rune rune) {
+	b.Lock()
+	defer b.Unlock()
+
+	b.cursorRune = rune
+}
+
 // SetBackgroundColorFocused sets the background color of the button text when
 // the button is in focus.
 func (b *Button) SetBackgroundColorFocused(color tcell.Color) {
@@ -141,6 +154,10 @@ func (b *Button) Draw(screen tcell.Screen) {
 		labelColor := b.labelColor
 		if b.focus.HasFocus() {
 			labelColor = b.labelColorFocused
+			// Draw cursor.
+			if b.cursorRune != 0 {
+				Print(screen, []byte(string(b.cursorRune)), x+width-(width-runewidth.StringWidth(string(b.label)))/2+1, y, width, AlignLeft, labelColor)
+			}
 		}
 		Print(screen, b.label, x, y, width, AlignCenter, labelColor)
 	}

checkbox.go

@@ -58,6 +58,9 @@ type CheckBox struct {
 	// The rune to show when the checkbox is checked
 	checkedRune rune
 
+	// An optional rune to show within the checkbox when it is focused
+	cursorRune rune
+
 	sync.RWMutex
 }
 
@@ -66,11 +69,12 @@ func NewCheckBox() *CheckBox {
 	return &CheckBox{
 		Box:                         NewBox(),
 		labelColor:                  Styles.SecondaryTextColor,
-		fieldBackgroundColor:        Styles.ContrastBackgroundColor,
+		fieldBackgroundColor:        Styles.MoreContrastBackgroundColor,
+		fieldBackgroundColorFocused: Styles.ContrastBackgroundColor,
 		fieldTextColor:              Styles.PrimaryTextColor,
 		checkedRune:                 Styles.CheckBoxCheckedRune,
+		cursorRune:                  Styles.CheckBoxCursorRune,
 		labelColorFocused:           ColorUnset,
-		fieldBackgroundColorFocused: ColorUnset,
 		fieldTextColorFocused:       ColorUnset,
 	}
 }
@@ -91,6 +95,14 @@ func (c *CheckBox) SetCheckedRune(rune rune) {
 	c.checkedRune = rune
 }
 
+// SetCursorRune sets the rune to show within the checkbox when it is focused.
+func (c *CheckBox) SetCursorRune(rune rune) {
+	c.Lock()
+	defer c.Unlock()
+
+	c.cursorRune = rune
+}
+
 // IsChecked returns whether or not the box is checked.
 func (c *CheckBox) IsChecked() bool {
 	c.RLock()
@@ -248,11 +260,13 @@ func (c *CheckBox) Draw(screen tcell.Screen) {
 	c.Lock()
 	defer c.Unlock()
 
+	hasFocus := c.GetFocusable().HasFocus()
+
 	// Select colors
 	labelColor := c.labelColor
 	fieldBackgroundColor := c.fieldBackgroundColor
 	fieldTextColor := c.fieldTextColor
-	if c.GetFocusable().HasFocus() {
+	if hasFocus {
 		if c.labelColorFocused != ColorUnset {
 			labelColor = c.labelColorFocused
 		}
@@ -291,9 +305,13 @@ func (c *CheckBox) Draw(screen tcell.Screen) {
 	if !c.checked {
 		checkedRune = ' '
 	}
+	rightRune := ' '
+	if c.cursorRune != 0 && hasFocus {
+		rightRune = c.cursorRune
+	}
 	screen.SetContent(x, y, ' ', nil, fieldStyle)
 	screen.SetContent(x+1, y, checkedRune, nil, fieldStyle)
-	screen.SetContent(x+2, y, ' ', nil, fieldStyle)
+	screen.SetContent(x+2, y, rightRune, nil, fieldStyle)
 
 	if len(c.message) > 0 {
 		Print(screen, c.message, x+4, y, len(c.message), AlignLeft, labelColor)

demos/button/main.go

@@ -8,7 +8,6 @@ func main() {
 	app.EnableMouse(true)
 
 	button := cview.NewButton("Hit Enter to close")
-	button.SetBorder(true)
 	button.SetRect(0, 0, 22, 3)
 	button.SetSelectedFunc(func() {
 		app.Stop()

demos/presentation/introduction.go

@@ -8,8 +8,8 @@ func Introduction(nextSlide func()) (title string, info string, content cview.Pr
 
 	listText := [][]string{
 		{"A Go package for terminal based UIs", "with a special focus on rich interactive widgets"},
-		{"Based on github.com/gdamore/tcell", "Like termbox but better (see tcell docs)"},
-		{"Designed to be simple", `"Hello world" is 5 lines of code`},
+		{"Based on github.com/gdamore/tcell", "Supports Linux, FreeBSD, MacOS and Windows"},
+		{"Designed to be simple", `"Hello world" is less than 20 lines of code`},
 		{"Good for data entry", `For charts, use "termui" - for low-level views, use "gocui" - ...`},
 		{"Supports context menus", "Right click on one of these items or press Alt+Enter"},
 		{"Extensive documentation", "Demo code is available for each widget"},

dropdown.go

@@ -154,14 +154,14 @@ func NewDropDown() *DropDown {
 	list.SetSelectedTextColor(Styles.PrimitiveBackgroundColor)
 	list.SetSelectedBackgroundColor(Styles.PrimaryTextColor)
 	list.SetHighlightFullLine(true)
-	list.SetBackgroundColor(Styles.MoreContrastBackgroundColor)
+	list.SetBackgroundColor(Styles.ContrastBackgroundColor)
 
 	d := &DropDown{
 		Box:                         NewBox(),
 		currentOption:               -1,
 		list:                        list,
 		labelColor:                  Styles.SecondaryTextColor,
-		fieldBackgroundColor:        Styles.ContrastBackgroundColor,
+		fieldBackgroundColor:        Styles.MoreContrastBackgroundColor,
 		fieldTextColor:              Styles.PrimaryTextColor,
 		prefixTextColor:             Styles.ContrastSecondaryTextColor,
 		dropDownSymbol:              Styles.DropDownSymbol,

form.go

@@ -151,12 +151,12 @@ func NewForm() *Form {
 		Box:                          box,
 		itemPadding:                  1,
 		labelColor:                   Styles.SecondaryTextColor,
-		fieldBackgroundColor:         Styles.ContrastBackgroundColor,
-		fieldBackgroundColorFocused:  Styles.MoreContrastBackgroundColor,
+		fieldBackgroundColor:         Styles.MoreContrastBackgroundColor,
+		fieldBackgroundColorFocused:  Styles.ContrastBackgroundColor,
 		fieldTextColor:               Styles.PrimaryTextColor,
 		fieldTextColorFocused:        Styles.PrimaryTextColor,
-		buttonBackgroundColor:        Styles.ContrastBackgroundColor,
-		buttonBackgroundColorFocused: Styles.MoreContrastBackgroundColor,
+		buttonBackgroundColor:        Styles.MoreContrastBackgroundColor,
+		buttonBackgroundColorFocused: Styles.ContrastBackgroundColor,
 		buttonTextColor:              Styles.PrimaryTextColor,
 		buttonTextColorFocused:       Styles.PrimaryTextColor,
 		labelColorFocused:            ColorUnset,

styles.go

@@ -22,8 +22,12 @@ type Theme struct {
 	ContrastBackgroundColor     tcell.Color // Background color for contrasting elements.
 	MoreContrastBackgroundColor tcell.Color // Background color for even more contrasting elements.
 
+	// Button
+	ButtonCursorRune rune // The symbol to draw at the end of button labels when focused.
+
 	// Check box
 	CheckBoxCheckedRune rune
+	CheckBoxCursorRune  rune // The symbol to draw within the checkbox when focused.
 
 	// Context menu
 	ContextMenuPaddingTop    int
@@ -63,7 +67,10 @@ var Styles = Theme{
 	ContrastBackgroundColor:     tcell.ColorGreen.TrueColor(),
 	MoreContrastBackgroundColor: tcell.ColorDarkGreen.TrueColor(),
 
+	ButtonCursorRune: '◀',
+
 	CheckBoxCheckedRune: 'X',
+	CheckBoxCursorRune:  '◀',
 
 	ContextMenuPaddingTop:    0,
 	ContextMenuPaddingBottom: 0,

textview.go

@@ -14,14 +14,15 @@ import (
 )
 
 var (
-	openColorRegex  = regexp.MustCompile(`\[([a-zA-Z]*|#[0-9a-zA-Z]*)$`)
-	openRegionRegex = regexp.MustCompile(`\["[a-zA-Z0-9_,;: \-\.]*"?$`)
-	newLineRegex    = regexp.MustCompile(`\r?\n`)
-
 	// TabSize is the number of spaces with which a tab character will be replaced.
 	TabSize = 4
 )
 
+var (
+	openColorRegex  = regexp.MustCompile(`\[([a-zA-Z]*|#[0-9a-zA-Z]*)$`)
+	openRegionRegex = regexp.MustCompile(`\["[a-zA-Z0-9_,;: \-\.]*"?$`)
+)
+
 // textViewIndex contains information about each line displayed in the text
 // view.
 type textViewIndex struct {