widget

package
v0.0.0-...-e111b83 Latest Latest
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 Go to latest Published: Mar 16, 2015 License: BSD-3-Clause Imports: 17 Imported by: 0

Documentation

Overview

Package widget contains classes for widgets and the main window of a program.

Index

Constants

This section is empty.

Variables

View Source 
var (
	Mm   int = 10 * dpi / 254
	Cm   int = 100 * dpi / 254
	Inch int = dpi
	// Recommended height of capital letters (cap height) for standard font.
	Cap int = distanceToScreen * 7 * Mm / 1000
	// Recommended height of em (about the same as type height) for standard font.
	Rem int = distanceToScreen * Mm / 100
)

Length units in pixel units.

View Source 
var ComponentRegistry = make(map[string]Drawable)

ComponentRegistry is a registry for all components that can be drawn onto the screen. The purpose is to access widgets through an id, for example Button("okButton").SetText("All Right"), where Button is a function that asks the registry for the appropriate widget. This is very useful when the widgets are to be identified by an id, like in web applications or a textual UI description. Newly created widgets should register at this registry and provide an access function like func Label(id string) *Label.

View Source 
var ConstructorRegistry = make(map[string]func(json []byte) Drawable)

ContructorRegistry maps component names to component constructors that use a JSON definition.

Functions

func FindResourcesDir 

func FindResourcesDir(resDir string) (dir string, err error)

FindResourcesDir tries to locate a subdirectory that resides within the GOPATH environment variable.

If the functions finds the specified subdirectory in one of the GOPATH directories it returns the full path of the directory.

func IdlToJson 

func IdlToJson(idl string) []byte

IdlToJson converts a string in Interface Description Language (Idl) to Json. At the moment Idl is just Json with newlines, cursor returns and tabs allowed. This makes the interface descriptions more readable.

func LoadImage 

func LoadImage(filename string) (*extimage.BGRA, error)

LoadImage loads an image from a file. For good drawing performance it returns an *extimage.BGRA. extimage.BGRA can be used directly for cairo image surfaces.

func NewId 

func NewId() string

NewId creates a unique string as an identifier.

func RectSize 

func RectSize(area image.Rectangle) (x, y, dx, dy float64)

RectSize returns the dimensions of a Rectangle as float64 values.

Types

type Accessible 

type Accessible interface {
	Caption() string
	Tip() string
	Description() string
}

Accessible is a simple interface for accessibility purposes.

type BlankWidget 

type BlankWidget struct {
	event.Sender
	event.Receiver
	// contains filtered or unexported fields
}

BlankWidget is a simple widget that is used as a default in Combigridlayout. It draws a frame and implements the Widget interface.

func NewBlankWidget 

func NewBlankWidget() *BlankWidget

func (*BlankWidget) Area 

func (w *BlankWidget) Area() image.Rectangle

func (*BlankWidget) Draw 

func (w *BlankWidget) Draw()

func (*BlankWidget) MinSize 

func (w *BlankWidget) MinSize() image.Point

func (*BlankWidget) ReceiveEvent 

func (w *BlankWidget) ReceiveEvent(evt interface{})

ReceiveEvent receives a single event. It overwrites event.Receiver.ReceiveEvent().

func (*BlankWidget) SetArea 

func (w *BlankWidget) SetArea(drawRect image.Rectangle)

func (*BlankWidget) SetSurface 

func (w *BlankWidget) SetSurface(surface *cairo.Surface)

func (*BlankWidget) Surface 

func (w *BlankWidget) Surface() *cairo.Surface

type Button 

type Button struct {
	WidgetPart
	Caption string
	Command string
	// contains filtered or unexported fields
}

Button is a simple Button that is able to display an image.

func GetButton 

func GetButton(name string) *Button

func NewButton 

func NewButton(caption string) *Button

func (*Button) Draw 

func (b *Button) Draw()

func (*Button) LoadImage 

func (b *Button) LoadImage(filename string) error

func (*Button) MinSize 

func (b *Button) MinSize() image.Point

func (*Button) SetImage 

func (b *Button) SetImage(img image.Image)

type Canvas 

type Canvas struct {
	WidgetPart
	// contains filtered or unexported fields
}

func GetCanvas 

func GetCanvas(name string) *Canvas

func NewCanvas 

func NewCanvas() *Canvas

func (*Canvas) Draw 

func (c *Canvas) Draw()

Draw draws the canvas onto the surface.

func (*Canvas) LineTo 

func (c *Canvas) LineTo(p image.Point)

func (*Canvas) MoveTo 

func (c *Canvas) MoveTo(p image.Point)

func (*Canvas) ReceiveEvent 

func (c *Canvas) ReceiveEvent(evt interface{})

ReceiveEvent receives a single event. It overwrites event.Receiver.ReceiveEvent().

func (*Canvas) SetBackgroundColor 

func (c *Canvas) SetBackgroundColor(color color.Color)

func (*Canvas) SetBackgroundImage 

func (c *Canvas) SetBackgroundImage(img image.Image)

func (*Canvas) SetBrushColor 

func (c *Canvas) SetBrushColor(color color.Color)

func (*Canvas) SetBrushWidth 

func (c *Canvas) SetBrushWidth(width int)

SetBrushWidth sets the width of the drawing brush in pixel units. For all drawing operations a circular brush is used.

type CombiGridEntry 

type CombiGridEntry struct {
	// contains filtered or unexported fields
}

type CombiGridLayout 

type CombiGridLayout struct {
	// contains filtered or unexported fields
}

CombiGridLayout implements Layout. It is a layout that supports laying out components in a grid and docking them together. CombiGridLayout was heavily inspired by MigLayout http://miglayout.com/.

CombiGridLayout is a series of components (Drawables) arranged is a grid or docked together (which also results in a grid). Each component may be a Container consisting of other components.

func NewCombiGridLayout 

func NewCombiGridLayout() *CombiGridLayout

func (*CombiGridLayout) AddWithLayout 

func (l *CombiGridLayout) AddWithLayout(component Drawable, layout *LayoutDef)

func (*CombiGridLayout) Addf 

func (l *CombiGridLayout) Addf(layoutDef string, components ...Drawable)

func (*CombiGridLayout) Area 

func (l *CombiGridLayout) Area() image.Rectangle

func (*CombiGridLayout) Draw 

func (l *CombiGridLayout) Draw()

func (*CombiGridLayout) Gaps 

func (l *CombiGridLayout) Gaps() GridGaps

func (*CombiGridLayout) MinSize 

func (l *CombiGridLayout) MinSize() image.Point

func (*CombiGridLayout) SetArea 

func (l *CombiGridLayout) SetArea(drawRect image.Rectangle)

func (*CombiGridLayout) SetGaps 

func (l *CombiGridLayout) SetGaps(gaps GridGaps)

func (*CombiGridLayout) SetSurface 

func (l *CombiGridLayout) SetSurface(surface *cairo.Surface)

func (*CombiGridLayout) Surface 

func (l *CombiGridLayout) Surface() *cairo.Surface

func (*CombiGridLayout) Wrap 

func (l *CombiGridLayout) Wrap()

Wrap jumps to the beginning of the next line.

type Container 

type Container interface {
	Layout
	event.Receiver
	event.Sender
}

Container is a container for other widgets that should be displayed. A typical container is a window.

func NewContainer 

func NewContainer() Container

type DefaultContainer 

type DefaultContainer struct {
	CombiGridLayout
	event.Sender
	event.Receiver
	// contains filtered or unexported fields
}

DefaultContainer is a sample implementation that satisfies the Container interface.

func NewDefaultContainer 

func NewDefaultContainer() *DefaultContainer

func NewDefaultContainerFromJson 

func NewDefaultContainerFromJson(jsonDef []byte) *DefaultContainer

func (*DefaultContainer) Addf 

func (c *DefaultContainer) Addf(layoutDef string, components ...Drawable)

Addf overwrites Addf in Layout.

func (*DefaultContainer) ReceiveEvent 

func (c *DefaultContainer) ReceiveEvent(evt interface{})

ReceiveEvent receives a single event.

func (*DefaultContainer) ReceiveFromEmbedded 

func (c *DefaultContainer) ReceiveFromEmbedded(evt interface{})

ReceiveFromEmbedded receives events from embedded components.

type Drawable 

type Drawable interface {
	Draw()
	SetArea(image.Rectangle)
	Area() image.Rectangle
	SetSurface(*cairo.Surface)
	Surface() *cairo.Surface

	// MinSize is the minimum space the object needs to
	// to be displayed. It is calculated by the object itself.
	MinSize() image.Point
}

Drawable is anything that could be drawn onto the screen.

func NewButtonFromJson 

func NewButtonFromJson(jsonDef []byte) Drawable

func NewCanvasFromJson 

func NewCanvasFromJson(jsonDef []byte) Drawable

func NewSpacerFromJson 

func NewSpacerFromJson(jsonDef []byte) Drawable

type GridGaps 

type GridGaps struct {
	Top            int
	Begin          int
	End            int
	Bottom         int
	BetweenRows    int
	BetweenColumns int
}

func (GridGaps) Unit 

func (g GridGaps) Unit(unit int) GridGaps

Unit converts grid gaps in a defined length unit to pixel units.

The unit parameter is a factor with which GridGaps are multiplied to get the length in pixel units.

Predefined are: Mm, Cm, Inch.

type Layout 

type Layout interface {
	Drawable
	Addf(layoutDef string, components ...Drawable)
}

Layout positions drawable objects.

type LayoutDef 

type LayoutDef struct {
	GrowX int
	GrowY int
	SpanX int
	SpanY int
}

LayoutDef defines the layout of a component in CombiGridLayout.

type Spacer 

type Spacer struct {
	// contains filtered or unexported fields
}

Spacer is a Drawable object that can be used to add some space in a layout. Apart from that, a spacer does nothing.

func GetSpacer 

func GetSpacer(name string) *Spacer

func NewSpacer 

func NewSpacer() *Spacer

func (*Spacer) Area 

func (s *Spacer) Area() image.Rectangle

func (*Spacer) Draw 

func (s *Spacer) Draw()

func (*Spacer) MinSize 

func (s *Spacer) MinSize() image.Point

func (*Spacer) SetArea 

func (s *Spacer) SetArea(drawRect image.Rectangle)

func (*Spacer) SetSurface 

func (s *Spacer) SetSurface(surface *cairo.Surface)

func (*Spacer) Surface 

func (s *Spacer) Surface() *cairo.Surface

type Style 

type Style struct {
	FontSize float64

	Color      color.Color
	Background color.Color

	MarginTop    int
	MarginLeft   int
	MarginRight  int
	MarginBottom int

	PaddingTop    int
	PaddingLeft   int
	PaddingRight  int
	PaddingBottom int

	BorderTopColor    color.Color
	BorderLeftColor   color.Color
	BorderRightColor  color.Color
	BorderBottomColor color.Color

	BorderTopWidth    int
	BorderLeftWidth   int
	BorderRightWidth  int
	BorderBottomWidth int
}

Style determines the drawing style like CSS.

func (*Style) ContentPosition 

func (s *Style) ContentPosition() (x, y int)

ContentPosition() returns the top left postion for content after the borders, paddings and margins are drawn.

func (*Style) Draw 

func (s *Style) Draw(surface *cairo.Surface, area image.Rectangle)

func (*Style) Size 

func (s *Style) Size() (dx, dy int)

Size returns the size that is needed to draw the style without the inner content.

type TestWidget 

type TestWidget struct {
	event.Sender
	event.Receiver
	// contains filtered or unexported fields
}

TestWidget is a simple widget for testing purposes. It implements the Widget interface.

func NewTestWidget 

func NewTestWidget() *TestWidget

func (*TestWidget) Area 

func (w *TestWidget) Area() image.Rectangle

func (*TestWidget) Draw 

func (w *TestWidget) Draw()

func (*TestWidget) MinSize 

func (w *TestWidget) MinSize() image.Point

func (*TestWidget) ReceiveEvent 

func (w *TestWidget) ReceiveEvent(evt interface{})

ReceiveEvent receives a single event. It overwrites event.Receiver.ReceiveEvent().

func (*TestWidget) SetArea 

func (w *TestWidget) SetArea(drawRect image.Rectangle)

func (*TestWidget) SetSurface 

func (w *TestWidget) SetSurface(surface *cairo.Surface)

func (*TestWidget) Surface 

func (w *TestWidget) Surface() *cairo.Surface

type Widget 

type Widget interface {
	Drawable
	event.Receiver
	event.Sender
}

Widget is something that can be drawn onto the screen and is capable to send and receive events.

type WidgetPart 

type WidgetPart struct {
	event.Sender
	event.Receiver
	// contains filtered or unexported fields
}

WidgetPart implements most methods of the Widget interface. To fully implement the widget interface the Draw() method must be added. WidgetPart can be used to construct new widgets by mixing it into the new widget class. WidgetPart replaces the old WidgetPart to avoid overwriting methods in prototype based inheritence.

func NewWidgetPart 

func NewWidgetPart() *WidgetPart

func (*WidgetPart) Area 

func (w *WidgetPart) Area() image.Rectangle

func (*WidgetPart) MinSize 

func (w *WidgetPart) MinSize() image.Point

func (*WidgetPart) SetArea 

func (w *WidgetPart) SetArea(drawRect image.Rectangle)

func (*WidgetPart) SetSurface 

func (w *WidgetPart) SetSurface(surface *cairo.Surface)

func (*WidgetPart) Surface 

func (w *WidgetPart) Surface() *cairo.Surface

type Window 

type Window struct {
	DefaultContainer
	// contains filtered or unexported fields
}

Window represents a typical graphical window. It usually encapsulates a native system window. In this version of the code it is a wde window.

func GetWindow 

func GetWindow(name string) *Window

func NewWindow 

func NewWindow() *Window

func NewWindowFromJson 

func NewWindowFromJson(jsonDef []byte) *Window

func (*Window) Close 

func (w *Window) Close()

func (*Window) Draw 

func (w *Window) Draw()

Draw completely draws the contents of a window. This includes a recalculation of the position of widgets.

func (*Window) ReceiveFromEmbeddedChan 

func (w *Window) ReceiveFromEmbeddedChan(ec <-chan interface{})

ReceiveFromEmbeddedChan receives events from embedded components.

func (*Window) Run 

func (w *Window) Run()

Run just starts the main event loop.

func (*Window) Show 

func (w *Window) Show()

Show draws the contents of the window and makes it visible on the screen.

Source Files

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