closes #68

README.md

@@ -7,7 +7,7 @@ Command Line User Interface (Console UI inspired by TurboVision) with built-in t
 
 
 ## Current version
-The current version is 0.9.0 RC1. Please see details in [changelog](./changelog).
+The current version is 0.9.0 RC2. Please see details in [changelog](./changelog).
 
 ## Applications that uses the library
 * Terminal FB2 reader(termfb2): https://github.com/VladimirMarkelov/termfb2
@@ -39,6 +39,7 @@ The current version is 0.9.0 RC1. Please see details in [changelog](./changelog)
 * SparkChart (Show tabular data as a bar graph)
 * GridView (Table to show structured data - only virtual and readonly mode with scroll support)
 * ![FilePicker](/docs/fselect.md)
+* LoginDialog - a simple authorization dialog with two fields: Username and Password
 
 ## Screenshots
 The main demo (theme changing and radio group control)

changelog

@@ -1,3 +1,6 @@
+2018-08-13 - version 0.9.0 RC2
+[+] New control: LoginDialog (a dialog with username and password fields)
+
 2018-08-04 - version 0.9.0 RC1
 [+] New control: File Picker (a dialog for file save/load operations)
 [+] New property for Label: TextDisplay. It defines which part of Label title

demos/logindlg/logindlg.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	ui "github.com/VladimirMarkelov/clui"
+)
+
+func createView() {
+	view := ui.AddWindow(0, 0, 30, 7, "Login dialog")
+	view.SetPack(ui.Vertical)
+	view.SetGaps(0, 1)
+	view.SetPaddings(2, 2)
+
+	frmOpts := ui.CreateFrame(view, 1, 1, ui.BorderNone, ui.Fixed)
+	frmOpts.SetPack(ui.Horizontal)
+	cbCheck := ui.CreateCheckBox(frmOpts, ui.AutoSize, "Use callback to test data", ui.Fixed)
+
+	ui.CreateLabel(view, ui.AutoSize, ui.AutoSize, "Correct credentials", ui.Fixed)
+
+	frmCreds := ui.CreateFrame(view, 1, 1, ui.BorderNone, ui.Fixed)
+	frmCreds.SetPack(ui.Horizontal)
+	frmCreds.SetGaps(1, 0)
+	ui.CreateLabel(frmCreds, ui.AutoSize, ui.AutoSize, "Username", ui.Fixed)
+	edUser := ui.CreateEditField(frmCreds, 8, "", 1)
+	ui.CreateLabel(frmCreds, ui.AutoSize, ui.AutoSize, "Password", ui.Fixed)
+	edPass := ui.CreateEditField(frmCreds, 8, "", 1)
+
+	lbRes := ui.CreateLabel(view, ui.AutoSize, ui.AutoSize, "Result:", ui.Fixed)
+
+	frmBtns := ui.CreateFrame(view, 1, 1, ui.BorderNone, ui.Fixed)
+	frmBtns.SetPack(ui.Horizontal)
+	btnDlg := ui.CreateButton(frmBtns, ui.AutoSize, 4, "Login", ui.Fixed)
+	btnQuit := ui.CreateButton(frmBtns, ui.AutoSize, 4, "Quit", ui.Fixed)
+	ui.CreateFrame(frmBtns, 1, 1, ui.BorderNone, 1)
+
+	ui.ActivateControl(view, edUser)
+
+	btnDlg.OnClick(func(ev ui.Event) {
+		dlg := ui.CreateLoginDialog(
+			"Enter credentials",
+			edUser.Title(),
+		)
+
+		if cbCheck.State() == 1 {
+			dlg.OnCheck(func(u, p string) bool {
+				return u == edUser.Title() && p == edPass.Title()
+			})
+		} else {
+			dlg.OnCheck(nil)
+		}
+
+		dlg.OnClose(func() {
+			if dlg.Action == ui.LoginCanceled {
+				lbRes.SetTitle("Result:\nDialog canceled")
+				return
+			}
+
+			if dlg.Action == ui.LoginInvalid {
+				lbRes.SetTitle("Result:\nInvalid username or password")
+				return
+			}
+
+			if dlg.Action == ui.LoginOk {
+				if cbCheck.State() == 1 {
+					lbRes.SetTitle("Result:\nLogged in successfully")
+				} else {
+					lbRes.SetTitle("Result:\nEntered [" + dlg.Username + ":" + dlg.Password + "]")
+				}
+				return
+			}
+		})
+	})
+
+	btnQuit.OnClick(func(ev ui.Event) {
+		go ui.Stop()
+	})
+}
+
+func mainLoop() {
+	// Every application must create a single Composer and
+	// call its intialize method
+	ui.InitLibrary()
+	defer ui.DeinitLibrary()
+
+	createView()
+
+	// start event processing loop - the main core of the library
+	ui.MainLoop()
+}
+
+func main() {
+	mainLoop()
+}

logindlg.go

@@ -0,0 +1,159 @@
+package clui
+
+const (
+	LoginOk = iota
+	LoginCanceled
+	LoginInvalid
+)
+
+// LoginDialog is a login dialog with fields to enter user name and password
+// Public properties:
+//   * Username - login entered by a user
+//   * Password - password entered by a user
+//   * Action - how the dialog was closed:
+//     - LoginOk - button "OK" was clicked
+//     - LoginCanceled - button "Cancel" was clicked or dialog was dismissed
+//     - LoginInvalid - invalid credentials were entered. This value appears
+//         only in case of callback is used and button "OK" is clicked
+//         while entered username or password is incorrect
+type LoginDialog struct {
+	View     *Window
+	Username string
+	Password string
+	Action   int
+
+	result  int
+	onClose func()
+	onCheck func(string, string) bool
+}
+
+// LoginDialog creates a new login dialog
+//  * title - custom dialog title
+//  * userName - initial username. Maybe useful if you want to implement
+//     a feature "remember me"
+// The active control depends on userName: if it is empty then the cursor is
+//  in Username field, and in Password field otherwise.
+// By default the dialog is closed when button "OK" is clicked. But if you set
+//  OnCheck callback the dialog closes only if callback returns true or
+//  button "Cancel" is clicked. This is helpful if you do not want to recreate
+//  the dialog after every incorrect credentials. So, you define a callback
+//  that checks whether pair of Usename and Password is correct and then the
+//  button "OK" closed the dialog only if the callback returns true. If the
+//  credentials are not valid, then the dialog shows a warning. The warning
+//  automatically disappears when a user starts typing in Password or Username
+//  field.
+func CreateLoginDialog(title, userName string) *LoginDialog {
+	dlg := new(LoginDialog)
+
+	dlg.View = AddWindow(15, 8, 10, 4, title)
+	WindowManager().BeginUpdate()
+	defer WindowManager().EndUpdate()
+
+	dlg.View.SetModal(true)
+	dlg.View.SetPack(Vertical)
+
+	userfrm := CreateFrame(dlg.View, 1, 1, BorderNone, Fixed)
+	userfrm.SetPaddings(1, 1)
+	userfrm.SetPack(Horizontal)
+	userfrm.SetGaps(1, 0)
+	CreateLabel(userfrm, AutoSize, AutoSize, "User name", Fixed)
+	edUser := CreateEditField(userfrm, 20, userName, 1)
+
+	passfrm := CreateFrame(dlg.View, 1, 1, BorderNone, 1)
+	passfrm.SetPaddings(1, 1)
+	passfrm.SetPack(Horizontal)
+	passfrm.SetGaps(1, 0)
+	CreateLabel(passfrm, AutoSize, AutoSize, "Password", Fixed)
+	edPass := CreateEditField(passfrm, 20, "", 1)
+	edPass.SetPasswordMode(true)
+
+	filler := CreateFrame(dlg.View, 1, 1, BorderNone, 1)
+	filler.SetPack(Horizontal)
+	lbRes := CreateLabel(filler, AutoSize, AutoSize, "", 1)
+
+	blist := CreateFrame(dlg.View, 1, 1, BorderNone, Fixed)
+	blist.SetPack(Horizontal)
+	blist.SetPaddings(1, 1)
+	btnOk := CreateButton(blist, 10, 4, "OK", Fixed)
+	btnCancel := CreateButton(blist, 10, 4, "Cancel", Fixed)
+
+	btnCancel.OnClick(func(ev Event) {
+		WindowManager().DestroyWindow(dlg.View)
+		WindowManager().BeginUpdate()
+		dlg.Action = LoginCanceled
+		closeFunc := dlg.onClose
+		WindowManager().EndUpdate()
+		if closeFunc != nil {
+			closeFunc()
+		}
+	})
+
+	btnOk.OnClick(func(ev Event) {
+		if dlg.onCheck != nil && !dlg.onCheck(edUser.Title(), edPass.Title()) {
+			lbRes.SetTitle("Invalid username or password")
+			dlg.Action = LoginInvalid
+			return
+		}
+
+		dlg.Action = LoginOk
+		if dlg.onCheck == nil {
+			dlg.Username = edUser.Title()
+			dlg.Password = edPass.Title()
+		}
+
+		WindowManager().DestroyWindow(dlg.View)
+		WindowManager().BeginUpdate()
+
+		closeFunc := dlg.onClose
+		WindowManager().EndUpdate()
+		if closeFunc != nil {
+			closeFunc()
+		}
+	})
+
+	dlg.View.OnClose(func(ev Event) bool {
+		if dlg.result == DialogAlive {
+			dlg.result = DialogClosed
+			if ev.X != 1 {
+				WindowManager().DestroyWindow(dlg.View)
+			}
+			if dlg.onClose != nil {
+				dlg.onClose()
+			}
+		}
+		return true
+	})
+
+	edUser.OnChange(func(ev Event) {
+		lbRes.SetTitle("")
+	})
+	edPass.OnChange(func(ev Event) {
+		lbRes.SetTitle("")
+	})
+
+	if userName == "" {
+		ActivateControl(dlg.View, edUser)
+	} else {
+		ActivateControl(dlg.View, edPass)
+	}
+	return dlg
+}
+
+// OnClose sets the callback that is called when the
+// dialog is closed
+func (d *LoginDialog) OnClose(fn func()) {
+	WindowManager().BeginUpdate()
+	defer WindowManager().EndUpdate()
+	d.onClose = fn
+}
+
+// OnCheck sets the callback that is called when the
+// button "OK" is clicked. The dialog sends to the callback two arguments:
+// username and password. The callback validates the arguments and if
+// the credentials are valid it returns true. That means the dialog can be
+// closed. If the callback returns false then the dialog remains on the screen.
+func (d *LoginDialog) OnCheck(fn func(string, string) bool) {
+	WindowManager().BeginUpdate()
+	defer WindowManager().EndUpdate()
+	d.onCheck = fn
+}