fixes gdamore#62 windows console may have FIFO hang

fixes gdamore#63 Initial views API integration

Author: gdamore

console_win.go

@@ -123,7 +123,7 @@ func NewConsoleScreen() (Screen, error) {
 
 func (s *cScreen) Init() error {
 
-	s.evch = make(chan Event, 2)
+	s.evch = make(chan Event, 10)
 	s.quit = make(chan struct{})
 
 	if in, e := syscall.Open("CONIN$", syscall.O_RDWR, 0); e != nil {
@@ -196,10 +196,16 @@ func (s *cScreen) Fini() {
 	syscall.Close(s.out)
 }
 
-func (s *cScreen) PostEvent(ev Event) {
+func (s *cScreen) PostEventWait(ev Event) {
+	s.evch <- ev
+}
+
+func (s *cScreen) PostEvent(ev Event) error {
 	select {
-	case <-s.quit:
 	case s.evch <- ev:
+		return nil
+	default:
+		return ErrEventQFull
 	}
 }
 
@@ -977,3 +983,5 @@ func (s *cScreen) CanDisplay(r rune, checkFallbacks bool) bool {
 	// poorly supported under Windows.)
 	return true
 }
+
+func (s *cScreen) Resize(int, int, int, int) {}

errors.go

@@ -42,6 +42,10 @@ var (
 	// encoding was found for it.  This problem never occurs if
 	// the environment is UTF-8 or UTF-16.
 	ErrNoCharset = errors.New("character set not supported")
+
+	// ErrEventQFull indicates that the event queue is full, and
+	// cannot accept more events.
+	ErrEventQFull = errors.New("event queue full")
 )
 
 // An EventError is an event representing some sort of error, and carries

event.go

@@ -24,3 +24,27 @@ type Event interface {
 	// When reports the time when the event was generated.
 	When() time.Time
 }
+
+// EventTime is a simple base event class, suitable for easy reuse.
+// It can be used to deliver actual timer events as well.
+type EventTime struct {
+	when time.Time
+}
+
+func (e *EventTime) When() time.Time {
+	return e.when
+}
+
+func (e *EventTime) SetEventTime(t time.Time) {
+	e.when = t
+}
+
+func (e *EventTime) SetEventNow() {
+	e.SetEventTime(time.Now())
+}
+
+// EventHandler is anything that handles events.  If the handler has
+// consumed the event, it should return true.  False otherwise.
+type EventHandler interface {
+	HandleEvent(Event) bool
+}

screen.go

@@ -80,8 +80,20 @@ type Screen interface {
 	// Furthermore, this will return nil if the Screen is finalized.
 	PollEvent() Event
 
-	// PostEvent posts an event into the event stream.
-	PostEvent(Event)
+	// PostEvent tries to post an event into the event stream.  This
+	// can fail if the event queue is full.  In that case, the event
+	// is dropped, and ErrEventQFull is returned.
+	PostEvent(ev Event) error
+
+	// PostEventWait is like PostEvent, but if the queue is full, it
+	// blocks until there is space in the queue, making delivery
+	// reliable.  However, it is VERY important that this function
+	// never be called from within whatever event loop is polling
+	// with PollEvent(), otherwise a deadlock may arise.
+	//
+	// For this reason, when using this function, the use of a
+	// Goroutine is recommended to ensure no deadlock can occur.
+	PostEventWait(ev Event)
 
 	// EnableMouse enables the mouse.  (If your terminal supports it.)
 	EnableMouse()
@@ -157,6 +169,11 @@ type Screen interface {
 	// also return true if the terminal can replace the glyph with
 	// one that is visually indistinguishable from the one requested.
 	CanDisplay(r rune, checkFallbacks bool) bool
+
+	// Resize does nothing, since its generally not possible to
+	// ask a screen to resize, but it allows the Screen to implement
+	// the View interface.
+	Resize(int, int, int, int)
 }
 
 // NewScreen returns a default Screen suitable for the user's terminal

sim_test.go

@@ -132,7 +132,7 @@ func TestResize(t *testing.T) {
 		So(sc.Style, ShouldEqual, st)
 
 		Convey("Do resize", func() {
-			s.Resize(30, 10)
+			s.SetSize(30, 10)
 			s.Show()
 			b2, x2, y2 := s.GetContents()
 			So(b2, ShouldNotEqual, b)

simulation.go

@@ -49,16 +49,16 @@ type SimulationScreen interface {
 	// InjectMouse injects a mouse event.
 	InjectMouse(x, y int, buttons ButtonMask, mod ModMask)
 
-	// Resize resizes the underlying physical screen.  It also causes
+	// SetSize resizes the underlying physical screen.  It also causes
 	// a resize event to be injected during the next Show() or Sync().
 	// A new physical contents array will be allocated (with data from
 	// the old copied), so any prior value obtained with GetContents
 	// won't be used anymore
-	Resize(width, height int)
+	SetSize(width, height int)
 
 	// GetContents returns screen contents as an array of
 	// cells, along with the physical width & height.   Note that the
-	// physical contents will be used until the next time Resize()
+	// physical contents will be used until the next time SetSize()
 	// is called.
 	GetContents() (cells []SimCell, width int, height int)
 
@@ -351,11 +351,16 @@ func (s *simscreen) PollEvent() Event {
 	}
 }
 
-func (s *simscreen) PostEvent(ev Event) {
+func (s *simscreen) PostEventWait(ev Event) {
+	s.evch <- ev
+}
+
+func (s *simscreen) PostEvent(ev Event) error {
 	select {
 	case s.evch <- ev:
+		return nil
 	default:
-		// drop the event on the floor
+		return ErrEventQFull
 	}
 }
 
@@ -459,7 +464,7 @@ func (s *simscreen) CharacterSet() string {
 	return s.charset
 }
 
-func (s *simscreen) Resize(w, h int) {
+func (s *simscreen) SetSize(w, h int) {
 	s.Lock()
 	newc := make([]SimCell, w*h)
 	for row := 0; row < h && row < s.physh; row++ {
@@ -519,3 +524,5 @@ func (s *simscreen) CanDisplay(r rune, checkFallbacks bool) bool {
 	}
 	return false
 }
+
+func (s *simscreen) Resize(int, int, int, int) {}

tscreen.go

@@ -654,11 +654,16 @@ func (t *tScreen) buildAcsMap() {
 	}
 }
 
-func (t *tScreen) PostEvent(ev Event) {
+func (t *tScreen) PostEventWait(ev Event) {
+	t.evch <- ev
+}
+
+func (t *tScreen) PostEvent(ev Event) error {
 	select {
 	case t.evch <- ev:
+		return nil
 	default:
-		// drop the event on the floor
+		return ErrEventQFull
 	}
 }
 
@@ -1106,3 +1111,5 @@ func (t *tScreen) CanDisplay(r rune, checkFallbacks bool) bool {
 	}
 	return false
 }
+
+func (t *tScreen) Resize(int, int, int, int) {}

views/README.md

@@ -0,0 +1,7 @@
+## tcell views
+
+This package provides some enhanced functionality on top of base tcell.
+In particular, support for logical views, and a few different kinds of
+widgets like title bars, and scrollable areas, are provided.
+
+These make up a higher level interface than tcell itself.

views/_demos/hbox.go

@@ -0,0 +1,87 @@
+// Copyright 2015 The Tops'l Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use file except in compliance with the License.
+// You may obtain a copy of the license at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/gdamore/tcell"
+	"github.com/gdamore/tcell/views"
+)
+
+type MyBox struct {
+	views.BoxLayout
+}
+
+func (m *MyBox) HandleEvent(ev tcell.Event) bool {
+	switch ev := ev.(type) {
+	case *tcell.EventKey:
+		if ev.Key() == tcell.KeyEscape {
+			views.AppQuit()
+			return true
+		}
+	}
+	return m.BoxLayout.HandleEvent(ev)
+}
+
+func main() {
+
+	if e := views.AppInit(); e != nil {
+		fmt.Fprintln(os.Stderr, e.Error())
+		os.Exit(1)
+	}
+
+	outer := &MyBox{}
+	outer.SetOrientation(views.Vertical)
+
+	title := views.NewTextBar()
+	title.SetStyle(tcell.StyleDefault.
+		Background(tcell.ColorYellow).
+		Foreground(tcell.ColorBlack))
+	title.SetCenter("Horizontal Boxes", tcell.StyleDefault)
+	title.SetLeft("ESC to exit", tcell.StyleDefault.
+		Background(tcell.ColorBlue).
+		Foreground(tcell.ColorWhite))
+	title.SetRight("==>X", tcell.StyleDefault)
+
+	box := views.NewBoxLayout(views.Horizontal)
+
+	l := views.NewText()
+	m := views.NewText()
+	r := views.NewText()
+
+	l.SetText("Left (0.0)")
+	m.SetText("Middle (0.7)")
+	r.SetText("Right (0.3)")
+	l.SetStyle(tcell.StyleDefault.Foreground(tcell.ColorWhite).
+		Background(tcell.ColorRed))
+	m.SetStyle(tcell.StyleDefault.Foreground(tcell.ColorWhite).
+		Background(tcell.ColorLime))
+	r.SetStyle(tcell.StyleDefault.Foreground(tcell.ColorWhite).
+		Background(tcell.ColorBlue))
+	l.SetAlignment(views.AlignBegin)
+	m.SetAlignment(views.AlignMiddle)
+	r.SetAlignment(views.AlignEnd)
+
+	box.AddWidget(l, 0)
+	box.AddWidget(m, 0.7)
+	box.AddWidget(r, 0.3)
+
+	outer.AddWidget(title, 0)
+	outer.AddWidget(box, 1)
+	views.SetApplication(outer)
+	views.RunApplication()
+}

views/_demos/vbox.go

@@ -0,0 +1,80 @@
+// Copyright 2015 The Tops'l Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use file except in compliance with the License.
+// You may obtain a copy of the license at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/gdamore/tcell"
+	"github.com/gdamore/tcell/views"
+)
+
+type MyBox struct {
+	views.BoxLayout
+}
+
+func (m *MyBox) HandleEvent(ev tcell.Event) bool {
+	switch ev := ev.(type) {
+	case *tcell.EventKey:
+		if ev.Key() == tcell.KeyEscape {
+			views.AppQuit()
+			return true
+		}
+	}
+	return m.BoxLayout.HandleEvent(ev)
+}
+
+func main() {
+
+	if e := views.AppInit(); e != nil {
+		fmt.Fprintln(os.Stderr, e.Error())
+		os.Exit(1)
+	}
+
+	box := &MyBox{}
+	box.SetOrientation(views.Vertical)
+
+	title := views.NewTextBar()
+	title.SetStyle(tcell.StyleDefault.
+		Foreground(tcell.ColorBlack).
+		Background(tcell.ColorYellow))
+	title.SetCenter("Vertical Layout", tcell.StyleDefault)
+	top := views.NewText()
+	mid := views.NewText()
+	bot := views.NewText()
+
+	top.SetText("Top-Right (0.0)\nLine Two")
+	mid.SetText("Center (0.7)")
+	bot.SetText("Bottom-Left (0.3)")
+	top.SetStyle(tcell.StyleDefault.Foreground(tcell.ColorWhite).
+		Background(tcell.ColorRed))
+	mid.SetStyle(tcell.StyleDefault.Foreground(tcell.ColorWhite).
+		Background(tcell.ColorLime))
+	bot.SetStyle(tcell.StyleDefault.Foreground(tcell.ColorWhite).
+		Background(tcell.ColorBlue))
+
+	top.SetAlignment(views.VAlignTop | views.HAlignRight)
+	mid.SetAlignment(views.VAlignCenter | views.HAlignCenter)
+	bot.SetAlignment(views.VAlignBottom | views.HAlignLeft)
+
+	box.AddWidget(title, 0)
+	box.AddWidget(top, 0)
+	box.AddWidget(mid, 0.7)
+	box.AddWidget(bot, 0.3)
+
+	views.SetApplication(box)
+	views.RunApplication()
+}