// 7 july 2014

package ui

// Window represents a top-level window on screen that contains other Controls.
// Windows in package ui can only contain one control; the Stack and Grid layout Controls allow you to pack multiple Controls in a Window.
// Note that a Window is not itself a Control.
type Window interface {
	// SetControl creates a Request to the Window's child Control.
	SetControl(c Control) *Request

	// Title and SetTitle create Requests to get and set the Window's title, respectively.
	Title() *Request
	SetTitle(title string) *Request

	// Show and Hide create Requests to bring the Window on-screen and off-screen, respectively.
	Show() *Request
	Hide() *Request

	// Close creates a Request to close the Window.
	// Any Controls within the Window are destroyed, and the Window itself is also destroyed.
	// Attempting to use a Window after it has been closed results in undefined behavior.
	// Close unconditionally closes the Window; it neither raises OnClosing nor checks for a return from OnClosing.
	// TODO make sure the above happens on GTK+ and Mac OS X; it does on Windows
	Close() *Request

	// OnClosing creates a Request to register an event handler that is triggered when the user clicks the Window's close button.
	// On systems where whole applications own windows, OnClosing is also triggered when the user asks to close the application.
	// If this handler returns true, the Window is closed as defined by Close above.
	// If this handler returns false, the Window is not closed.
	OnClosing(func(c Doer) bool) *Request

	// TODO SetSize (TODO remove?)
	// TODO Center
}

// NewWindow returns a Request to create a new Window with the given title text and size.
func NewWindow(title string, width int, height int) *Request {
	return newWindow(title, width, height)
}

// GetNewWindow is like NewWindow but sends the Request along the given Doer and returns the resultant Window.
// Example:
// 	w := ui.GetNewWindow(ui.Do, "Main Window")
func GetNewWindow(c Doer, title string, width int, height int) Window {
	req := newWindow(title, width, height)
	c <- req
	return (<-req.resp).(Window)
}