Basic Gossamy abstraction

gossamy.go

package gossamy


type Controller interface {
	// here go user events
}
type Arranger interface {
	func Arrange()
	// here go 
}
type Dragger interface {
	func CanDrag() bool
	func BeginDrag()
	func EndDrag()
	func DropInto(target Control) bool
}
type Dropper {
	CanDrop *func()
	OnDrop *func()
	
}
type DragAndDropper interface {
	Dragger
	Dropper
}

type Themable interface {
	func LoadTheme(name string, t {}interface) Theme
	func UnloadTheme(name string) 
	func ApplyTheme(name string)
}

// A Theme is a pre-designed collection of styles.
// A Theme can be loaded from an external theme definition
// much in the same way a browser loads a CSS file.
// A style can be altered for any given control.
// There is no concept of classes.
// A Style is a list of key/value pairs.
// Style values can be strings, ints, floats, or Style
// For example:  
// buttonstyle := &Style{ {"pen-width", 2},{"opacity", 0.5},
//                        {"fill", &Gradient{ 0x000000, 0xffffff } } } 
//
type Style map[string]interface{}
type Theme struct {
	name string  // short name
	description string // longer display name
	definition map[string]Style
}



type Control struct {
	id	int
	parent  Container

	x          int     // top
	y          int     // left
	width      int
	height     int

	visible    bool // true = control is displayed on screen
	focused    bool // true = control has focus
	readonly   bool // true = user can't change state
	enabled    bool // true = esponds to events

	// to be added later via dependency injection
	// I don't like to have all the drag and drop stuff
	// stuck here
	// dragsource bool // true = can be dragged
	// droptarget bool // true = can accept drops

	maxwidth    int
	maxheight   int
	minwidth    int
	minheight   int

	padding     int
	margin      int
	border      int

	hint        *Tooltip

	contextmenu *Menu
}

type Option struct {
	text     string
	value    {}interface // useful to hold associated values
	checkbox bool
	checked  bool
	visible  bool
	enabled  bool

	iconutf8 int          // icon codepage in system icon set
	iconbits Image.image  // icon as PNG image data

	submenu Menu
}


type Menu {
	[]Option
}
type MainMenu {
	Control

	[]Menu
}

type Label {
	Control

	text     string
	maxwidth int
	// background and font style
}

type Scrollbar {
	Control
	orientation int  // 0 horiztontal, 1 vertical
}

type Edit {
	Control

	text string
	maxlength int
	length int

	displayformat string
	editmask string
}

type TextBox {
	Control

	cursorline   int
	cursorcolumn int
	text         string
	maxlines     int
	maxcolumns   int
	vscrollbar   Scrollbar
	hscrollbar   Scrollbar
}

type Container struct {
	Control

	children []Control
}

type Form struct {
	Container

	title              string
	is_minimised       bool
	is_maximised       bool

	has_decoration     bool
	has_minimisebutton bool
	has_maximisebutton bool
	has_restorebutton  bool
	has_closebutton    bool

	is_resizable       bool
	is_snappy          bool

	is_modal           bool
	modalvalue         int
}

type Window struct {
	Form

	mintraybar bool // true = minimised to traybar
	minmenu    *Menu // context menu on traybar or minimised icon
	sysmenu    *Menu // window title menu in platforms that support it

	// should contain a proxy to the lower level glfw 
 	// window handling system, or a proxy to a remote
    // server providing similar functionality
	
	// syswindow glfw.Window
	// syswindow gossamy.Server
	
	screen *Screen // screen this
}

type Screen struct {
	title string
	width int
	height int

	layers []Layer  
	windows []Window
	// tiling data go here
}

type Display struct {
	// system device caps and low level  
	// glfw/opengl system data goes here.
	monitors []Screen
}

var (
	gxdark   Theme // gossamy default dark theme
	gxlight	 Theme // gossamy default light theme

	winold   Theme // Windows 95/2000/2003 theme
	winten   Theme // Windows 10  

	feline   Theme // Mac OS X Leopard theme
	capitano Theme // Mac OS X El Capitan theme
}