Add a ton more doc comments

canvas/canvas.go

@@ -8,24 +8,24 @@ import "image/color"
 
 // Cap represents a stroke cap type.
 type Cap int; const (
-	CapButt Cap = iota
-	CapRound
-	CapSquare
+	CapButt Cap = iota // Square cap that ends at the point
+	CapRound           // Round cap that surrounds the point
+	CapSquare          // square cap that surrounds the point
 )
 
 // Joint represents a stroke joint type.
 type Joint int; const (
-	JointRount Joint = iota
-	JointSharp
-	JointMiter
+	JointRount Joint = iota // Rounded joint
+	JointSharp              // Sharp joint
+	JointMiter              // Clipped/beveled joint
 )
 
 // StrokeAlign determines whether a stroke is drawn inside, outside, or on a
 // path.
 type StrokeAlign int; const (
-	StrokeAlignCenter StrokeAlign = iota
-	StrokeAlignInner
-	StrokeAlignOuter
+	StrokeAlignCenter StrokeAlign = iota // Centered on the path
+	StrokeAlignInner                     // Inset into the path
+	StrokeAlignOuter                     // Outset around the path
 )
 
 // Pen represents a drawing context that is linked to a canvas. Each canvas can
@@ -44,9 +44,8 @@ type Pen interface {
 	StrokeWeight (int)         // how thick the stroke is
 	StrokeAlign  (StrokeAlign) // where the stroke is drawn
 
-	// set the stroke/fill to a solid color
-	Stroke (color.Color)
-	Fill   (color.Color)
+	Stroke (color.Color) // Sets the stroke to a solid color
+	Fill   (color.Color) // Sets the fill to a solid color
 }
 
 // Canvas is an image that supports drawing paths.
@@ -62,6 +61,7 @@ type Canvas interface {
 
 // Drawer is an object that can draw to a canvas.
 type Drawer interface {
+	// Draw draws to the given canvas.
 	Draw (Canvas)
 }
 

data/data.go

@@ -27,7 +27,10 @@ func (mime Mime) String () string {
 	return mime.Type + "/" + mime.Subtype
 }
 
+// MimePlain returns the MIME type of plain text.
 func MimePlain () Mime { return Mime { "text", "plain"    } }
+
+// MimeFile returns the MIME type of a file path/URI.
 func MimeFile  () Mime { return Mime { "text", "uri-list" } }
 
 type byteReadCloser struct { *bytes.Reader }

object.go

@@ -111,25 +111,66 @@ type Object interface {
 type Box interface {
 	Object
 
+	// Window returns the Window this Box is a part of.
 	Window         () Window
+	// Bounds returns the outer bounding rectangle of the Box relative to
+	// the Window.
 	Bounds         () image.Rectangle
+	// InnerBounds returns the inner bounding rectangle of the box. It is
+	// the value of Bounds inset by the Box's border and padding.
 	InnerBounds    () image.Rectangle
+	// MinimumSize returns the minimum width and height this Box's bounds
+	// can be set to. This will return the value of whichever of these is
+	// greater:
+	//   - The size as set by SetMinimumSize
+	//   - The size taken up by the Box's border and padding. If there is
+	//     internal content that does not overflow, the size of that is also
+	//     taken into account here.
 	MinimumSize    () image.Point
+	// SetBounds sets the bounding rectangle of this Box relative to the
+	// Window.
 	SetBounds      (image.Rectangle)
+	// SetColor sets the background color of this Box.
 	SetColor       (color.Color)
+	// SetBorder sets the Border(s) of the box. The first Border will be the
+	// most outset, and the last Border will be the most inset.
 	SetBorder      (...Border)
+	// SetMinimumSize sets the minimum width and height of the box, as
+	// described in MinimumSize.
 	SetMinimumSize (image.Point)
+	// SetPadding sets the padding between the Box's innermost Border and
+	// its content.
 	SetPadding     (Inset)
 
+	// SetDNDData sets the data that will be picked up if this Box is
+	// dragged. If this is nil (which is the default), this Box will not be
+	// picked up.
 	SetDNDData   (data.Data)
+	// SetDNDAccept sets the type of data that can be dropped onto this Box.
+	// If this is nil (which is the default), this Box will reject all
+	// drops.
 	SetDNDAccept (...data.Mime)
+	// SetFocused sets whether or not this Box has keyboard focus. If set to
+	// true, this method will steal focus away from whichever Object
+	// currently has focus.
 	SetFocused   (bool)
+	// SetFocusable sets whether or not this Box can receive keyboard focus.
+	// If set to false and the Box is already focused. the focus is removed.
 	SetFocusable (bool)
-	
+
+	// Focused returns whether or not this Box has keyboard focus.
 	Focused       () bool
+	// Modifiers returns which modifier keys on the keyboard are currently
+	// being held down.
 	Modifiers     () input.Modifiers
+	// MousePosition returns the position of the mouse pointer relative to
+	// the Window.
 	MousePosition () image.Point
 
+	// These are event subscription functions that allow callbacks to be
+	// connected to particular events. Multiple callbacks may be connected
+	// to the same event at once. Callbacks can be removed by closing the
+	// returned cookie.
 	OnFocusEnter  (func ()) event.Cookie
 	OnFocusLeave  (func ()) event.Cookie
 	OnDNDEnter    (func ()) event.Cookie
@@ -148,7 +189,13 @@ type Box interface {
 // CanvasBox is a box that can be drawn to.
 type CanvasBox interface {
 	Box
+
+	// SetDrawer sets the Drawer that will be called upon to draw the Box's
+	// content when it is invalidated.
 	SetDrawer  (canvas.Drawer)
+
+	// Invalidate causes the Box's area to be redrawn at the end of the
+	// event cycle, even if it wouldn't be otherwise.
 	Invalidate ()
 }
 
@@ -156,77 +203,151 @@ type CanvasBox interface {
 // is to be embedded into TextBox and ContainerBox.
 type ContentBox interface {
 	Box
+
+	// SetOverflow sets whether or not the Box's content overflows
+	// horizontally and vertically. Overflowing content is clipped to the
+	// bounds of the Box inset by all Borders (but not padding).
 	SetOverflow           (horizontal, vertical bool)
-	ContentBounds         () image.Rectangle
-	ScrollTo              (image.Point)
-	OnContentBoundsChange (func ()) event.Cookie
+	// SetAlign sets how the Box's content is distributed horizontally and
+	// vertically.
 	SetAlign              (x, y Align)
+	// ContentBounds returns the bounds of the inner content of the Box
+	// relative to the window.
+	ContentBounds         () image.Rectangle
+	// ScrollTo shifts the origin of the Box's content to the origin of the
+	// Box's InnerBounds, offset by the given point.
+	ScrollTo              (image.Point)
+	// OnContentBoundsChange specifies a function to be called when the
+	// Box's ContentBounds or InnerBounds changes.
+	OnContentBoundsChange (func ()) event.Cookie
 }
 
 // TextBox is a box that contains text content.
 type TextBox interface {
 	ContentBox
 
+	// SetText sets the text content of the Box.
 	SetText       (string)
+	// SetTextColor sets the text color.
 	SetTextColor  (color.Color)
+	// SetFace sets the font face text is rendered in.
 	SetFace       (font.Face)
+	// SetWrap sets whether or not the text wraps.
 	SetWrap       (bool)
 
+	// SetSelectable sets whether or not the text content can be
+	// highlighted/selected.
 	SetSelectable (bool)
+	// Select sets the text cursor or selection.
 	Select        (text.Dot)
+	// Dot returns the text cursor or selection.
 	Dot           () text.Dot
+	// OnDotChange specifies a function to be called when the text cursor or
+	// selection changes.
 	OnDotChange   (func ()) event.Cookie
 }
 
-// ContentBox is a box that can contain child objects. It arranges them
+// ContentBox is a box that can contain child Objects. It arranges them
 // according to a layout rule.
 type ContainerBox interface {
 	ContentBox
-	PropagateEvents (bool)
-	SetGap          (image.Point)
-	Add             (Object)
-	Delete          (Object)
-	Insert          (child Object, before Object)
-	Clear           ()
-	Length          () int
-	At              (int) Object
-	SetLayout       (Layout)
+
+	// SetPropagateEvents specifies whether or not child Objects will
+	// receive user input events. It is true by default. If it is false, all
+	// user input that would otherwise be directed to a child Box is
+	// directed to this Box.
+	SetPropagateEvents (bool)
+	// SetGap sets the gap between child Objects.
+	SetGap             (image.Point)
+	// Add appends a child Object.
+	Add                (Object)
+	// Delete removes a child Object, if it is a child of this Box.
+	Delete             (Object)
+	// Insert inserts a child Object before a specified Object. If the
+	// before Object is nil or is not contained within this Box, the
+	// inserted Object is appended.
+	Insert             (child Object, before Object)
+	// Clear removes all child Objects.
+	Clear              ()
+	// Length returns the amount of child objects.
+	Length             () int
+	// At returns the child Object at the specified index.
+	At                 (int) Object
+	// SetLayout sets the layout of this Box. Child Objects will be
+	// positioned according to it.
+	SetLayout          (Layout)
 }
 
 // LayoutHints are passed to a layout to tell it how to arrange child boxes.
 type LayoutHints struct {
+	// Bounds is the bounding rectangle that children should be placed
+	// within. Any padding values are already applied.
 	Bounds image.Rectangle
+	// OverflowX and OverflowY control wether child Boxes may be positioned
+	// outside of Bounds.
 	OverflowX bool
 	OverflowY bool
+	// AlignX and AlignY control how child Boxes are aligned horizontally
+	// and vertically. The effect of this may vary depending on the Layout.
 	AlignX    Align
 	AlignY    Align
+	// Gap controls the amount of horizontal and vertical spacing in-between
+	// child Boxes.
 	Gap image.Point
 }
 
-// Layout can be given to a ContainerBox to arrange child objects.
+// A Layout can be given to a ContainerBox to arrange child objects.
 type Layout interface {
+	// MinimumSize returns the minimum width and height of
+	// LayoutHints.Bounds needed to properly lay out all child Boxes.
 	MinimumSize (LayoutHints, []Box) image.Point
+	// Arrange arranges child boxes according to the given LayoutHints.
 	Arrange     (LayoutHints, []Box)
 }
 
 // Window is an operating system window. It can contain one object.
 type Window interface {
+	// SetRoot sets the root child of the window. There can only be one at
+	// a time, and setting it will remove the current child if there is one.
 	SetRoot  (Object)
+	// SetTitle sets the title of the window.
 	SetTitle (string)
-	SetIcon  (sizes []image.Image)
-	NewMenu  (image.Rectangle) (Window, error)
-	NewModal (image.Rectangle) (Window, error)
+	// SetIcon sets the icon of the window. When multiple icon sizes are
+	// provided, the best fitting one is chosen for display.
+	SetIcon  (... image.Image)
+	// Widget returns a window representing a smaller iconified form of this
+	// window. How exactly this window is used depends on the platform.
+	// Subsequent calls to this method on the same window will return the
+	// same window object.
 	Widget   () (Window, error)
+	// NewMenu creates a new menu window. This window is undecorated and
+	// will close once the user clicks outside of it.
+	NewMenu  (image.Rectangle) (Window, error)
+	// NewModal creates a new modal window that blocks all input to this
+	// window until it is closed.
+	NewModal (image.Rectangle) (Window, error)
+	// Copy copies data to the clipboard.
 	Copy     (data.Data)
+	// Paste reads data from the clipboard. When the data is available or an
+	// error has occurred, the provided function will be called.
 	Paste    (callback func (data.Data, error), accept ...data.Mime)
+	// Show shows the window.
 	Show     ()
+	// Hide hides the window.
 	Hide     ()
+	// Close closes the window.
 	Close    ()
+	// OnClose specifies a function to be called when the window is closed.
 	OnClose  (func ()) event.Cookie
 }
 
 // MainWindow is a top-level operating system window.
 type MainWindow interface {
 	Window
+
+	// NewChild creates a new window that is semantically a child of this
+	// window. It does not actually reside within this window, but it may be
+	// linked to it via some other means. This is intended for things like
+	// toolboxes and tear-off menus.
 	NewChild (image.Rectangle) (Window, error)
 }