1 files changed, 186 insertions, 0 deletions
diff --git a/decor/decorator.go b/decor/decorator.go
new file mode 100644
index 0000000..f537d3f
--- /dev/null
+++ b/decor/decorator.go
@@ -0,0 +1,186 @@
+package decor
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/mattn/go-runewidth"
+)
+
+const (
+	// DidentRight bit specifies identation direction.
+	//
+	//	|foo   |b     | With DidentRight
+	//	|   foo|     b| Without DidentRight
+	DidentRight = 1 << iota
+
+	// DextraSpace bit adds extra space, makes sense with DSyncWidth only.
+	// When DidentRight bit set, the space will be added to the right,
+	// otherwise to the left.
+	DextraSpace
+
+	// DSyncWidth bit enables same column width synchronization.
+	// Effective with multiple bars only.
+	DSyncWidth
+
+	// DSyncWidthR is shortcut for DSyncWidth|DidentRight
+	DSyncWidthR = DSyncWidth | DidentRight
+
+	// DSyncSpace is shortcut for DSyncWidth|DextraSpace
+	DSyncSpace = DSyncWidth | DextraSpace
+
+	// DSyncSpaceR is shortcut for DSyncWidth|DextraSpace|DidentRight
+	DSyncSpaceR = DSyncWidth | DextraSpace | DidentRight
+)
+
+// TimeStyle enum.
+type TimeStyle int
+
+// TimeStyle kinds.
+const (
+	ET_STYLE_GO TimeStyle = iota
+	ET_STYLE_HHMMSS
+	ET_STYLE_HHMM
+	ET_STYLE_MMSS
+)
+
+// Statistics contains fields which are necessary for implementing
+// `decor.Decorator` and `mpb.BarFiller` interfaces.
+type Statistics struct {
+	AvailableWidth int // calculated width initially equal to terminal width
+	RequestedWidth int // width set by `mpb.WithWidth`
+	ID             int
+	Total          int64
+	Current        int64
+	Refill         int64
+	Completed      bool
+	Aborted        bool
+}
+
+// Decorator interface.
+// Most of the time there is no need to implement this interface
+// manually, as decor package already provides a wide range of decorators
+// which implement this interface. If however built-in decorators don't
+// meet your needs, you're free to implement your own one by implementing
+// this particular interface. The easy way to go is to convert a
+// `DecorFunc` into a `Decorator` interface by using provided
+// `func Any(DecorFunc, ...WC) Decorator`.
+type Decorator interface {
+	Synchronizer
+	Formatter
+	Decor(Statistics) (str string, viewWidth int)
+}
+
+// DecorFunc func type.
+// To be used with `func Any(DecorFunc, ...WC) Decorator`.
+type DecorFunc func(Statistics) string
+
+// Synchronizer interface.
+// All decorators implement this interface implicitly. Its Sync
+// method exposes width sync channel, if DSyncWidth bit is set.
+type Synchronizer interface {
+	Sync() (chan int, bool)
+}
+
+// Formatter interface.
+// Format method needs to be called from within Decorator.Decor method
+// in order to format string according to decor.WC settings.
+// No need to implement manually as long as decor.WC is embedded.
+type Formatter interface {
+	Format(string) (str string, viewWidth int)
+}
+
+// Wrapper interface.
+// If you're implementing custom Decorator by wrapping a built-in one,
+// it is necessary to implement this interface to retain functionality
+// of built-in Decorator.
+type Wrapper interface {
+	Unwrap() Decorator
+}
+
+// EwmaDecorator interface.
+// EWMA based decorators should implement this one.
+type EwmaDecorator interface {
+	EwmaUpdate(int64, time.Duration)
+}
+
+// AverageDecorator interface.
+// Average decorators should implement this interface to provide start
+// time adjustment facility, for resume-able tasks.
+type AverageDecorator interface {
+	AverageAdjust(time.Time)
+}
+
+// ShutdownListener interface.
+// If decorator needs to be notified once upon bar shutdown event, so
+// this is the right interface to implement.
+type ShutdownListener interface {
+	OnShutdown()
+}
+
+// Global convenience instances of WC with sync width bit set.
+// To be used with multiple bars only, i.e. not effective for single bar usage.
+var (
+	WCSyncWidth  = WC{C: DSyncWidth}
+	WCSyncWidthR = WC{C: DSyncWidthR}
+	WCSyncSpace  = WC{C: DSyncSpace}
+	WCSyncSpaceR = WC{C: DSyncSpaceR}
+)
+
+// WC is a struct with two public fields W and C, both of int type.
+// W represents width and C represents bit set of width related config.
+// A decorator should embed WC, to enable width synchronization.
+type WC struct {
+	W     int
+	C     int
+	fill  func(s string, w int) string
+	wsync chan int
+}
+
+// Format should be called by any Decorator implementation.
+// Returns formatted string and its view (visual) width.
+func (wc WC) Format(str string) (string, int) {
+	viewWidth := runewidth.StringWidth(str)
+	if wc.W > viewWidth {
+		viewWidth = wc.W
+	}
+	if (wc.C & DSyncWidth) != 0 {
+		if (wc.C & DextraSpace) != 0 {
+			viewWidth++
+		}
+		wc.wsync <- viewWidth
+		viewWidth = <-wc.wsync
+	}
+	return wc.fill(str, viewWidth), viewWidth
+}
+
+// Init initializes width related config.
+func (wc *WC) Init() WC {
+	if (wc.C & DidentRight) != 0 {
+		wc.fill = runewidth.FillRight
+	} else {
+		wc.fill = runewidth.FillLeft
+	}
+	if (wc.C & DSyncWidth) != 0 {
+		// it's deliberate choice to override wsync on each Init() call,
+		// this way globals like WCSyncSpace can be reused
+		wc.wsync = make(chan int)
+	}
+	return *wc
+}
+
+// Sync is implementation of Synchronizer interface.
+func (wc WC) Sync() (chan int, bool) {
+	if (wc.C&DSyncWidth) != 0 && wc.wsync == nil {
+		panic(fmt.Sprintf("%T is not initialized", wc))
+	}
+	return wc.wsync, (wc.C & DSyncWidth) != 0
+}
+
+func initWC(wcc ...WC) WC {
+	var wc WC
+	for _, nwc := range wcc {
+		wc = nwc
+	}
+	return wc.Init()
+}