Keyboard events are now propagated down the hierarchy, allowing users to intercept them. Closes #421

application.go

@@ -305,17 +305,19 @@ EventLoop:
 			switch event := event.(type) {
 			case *tcell.EventKey:
 				a.RLock()
-				p := a.focus
+				root := a.root
 				inputCapture := a.inputCapture
 				a.RUnlock()
 
 				// Intercept keys.
+				var draw bool
 				if inputCapture != nil {
 					event = inputCapture(event)
 					if event == nil {
 						a.draw()
 						continue // Don't forward event.
 					}
+					draw = true
 				}
 
 				// Ctrl-C closes the application.
@@ -323,15 +325,20 @@ EventLoop:
 					a.Stop()
 				}
 
-				// Pass other key events to the currently focused primitive.
-				if p != nil {
-					if handler := p.InputHandler(); handler != nil {
+				// Pass other key events to the root primitive.
+				if root != nil && root.GetFocusable().HasFocus() {
+					if handler := root.InputHandler(); handler != nil {
 						handler(event, func(p Primitive) {
 							a.SetFocus(p)
 						})
-						a.draw()
+						draw = true
 					}
 				}
+
+				// Redraw.
+				if draw {
+					a.draw()
+				}
 			case *tcell.EventResize:
 				if time.Since(lastRedraw) < redrawPause {
 					if redrawTimer != nil {

demos/presentation/flex.go

@@ -9,25 +9,24 @@ import (
 func Flex(nextSlide func()) (title string, content tview.Primitive) {
 	modalShown := false
 	pages := tview.NewPages()
-	textView := tview.NewTextView().
-		SetDoneFunc(func(key tcell.Key) {
-			if modalShown {
-				nextSlide()
-				modalShown = false
-			} else {
-				pages.ShowPage("modal")
-				modalShown = true
-			}
-		})
-	textView.SetBorder(true).SetTitle("Flexible width, twice of middle column")
 	flex := tview.NewFlex().
-		AddItem(textView, 0, 2, true).
+		AddItem(tview.NewBox().SetBorder(true).SetTitle("Flexible width, twice of middle column"), 0, 2, true).
 		AddItem(tview.NewFlex().
 			SetDirection(tview.FlexRow).
 			AddItem(tview.NewBox().SetBorder(true).SetTitle("Flexible width"), 0, 1, false).
 			AddItem(tview.NewBox().SetBorder(true).SetTitle("Fixed height"), 15, 1, false).
 			AddItem(tview.NewBox().SetBorder(true).SetTitle("Flexible height"), 0, 1, false), 0, 1, false).
 		AddItem(tview.NewBox().SetBorder(true).SetTitle("Fixed width"), 30, 1, false)
+	flex.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
+		if modalShown {
+			nextSlide()
+			modalShown = false
+		} else {
+			pages.ShowPage("modal")
+			modalShown = true
+		}
+		return event
+	})
 	modal := tview.NewModal().
 		SetText("Resize the window to see the effect of the flexbox parameters").
 		AddButtons([]string{"Ok"}).SetDoneFunc(func(buttonIndex int, buttonLabel string) {

demos/presentation/grid.go

@@ -11,18 +11,9 @@ func Grid(nextSlide func()) (title string, content tview.Primitive) {
 	pages := tview.NewPages()
 
 	newPrimitive := func(text string) tview.Primitive {
-		return tview.NewTextView().
-			SetTextAlign(tview.AlignCenter).
-			SetText(text).
-			SetDoneFunc(func(key tcell.Key) {
-				if modalShown {
-					nextSlide()
-					modalShown = false
-				} else {
-					pages.ShowPage("modal")
-					modalShown = true
-				}
-			})
+		return tview.NewFrame(nil).
+			SetBorders(0, 0, 0, 0, 0, 0).
+			AddText(text, true, tview.AlignCenter, tcell.ColorWhite)
 	}
 
 	menu := newPrimitive("Menu")
@@ -35,6 +26,16 @@ func Grid(nextSlide func()) (title string, content tview.Primitive) {
 		SetBorders(true).
 		AddItem(newPrimitive("Header"), 0, 0, 1, 3, 0, 0, true).
 		AddItem(newPrimitive("Footer"), 2, 0, 1, 3, 0, 0, false)
+	grid.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
+		if modalShown {
+			nextSlide()
+			modalShown = false
+		} else {
+			pages.ShowPage("modal")
+			modalShown = true
+		}
+		return event
+	})
 
 	// Layout for screens narrower than 100 cells (menu and side bar are hidden).
 	grid.AddItem(menu, 0, 0, 0, 0, 0, 0, false).

demos/presentation/main.go

@@ -88,8 +88,10 @@ func main() {
 	app.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
 		if event.Key() == tcell.KeyCtrlN {
 			nextSlide()
+			return nil
 		} else if event.Key() == tcell.KeyCtrlP {
 			previousSlide()
+			return nil
 		}
 		return event
 	})

dropdown.go

@@ -396,6 +396,14 @@ func (d *DropDown) Draw(screen tcell.Screen) {
 // InputHandler returns the handler for this primitive.
 func (d *DropDown) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
 	return d.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		// If the list has focus, let it process its own key events.
+		if d.list.GetFocusable().HasFocus() {
+			if handler := d.list.InputHandler(); handler != nil {
+				handler(event, setFocus)
+			}
+			return
+		}
+
 		// Process key event.
 		switch key := event.Key(); key {
 		case tcell.KeyEnter, tcell.KeyRune, tcell.KeyDown:

flex.go

@@ -223,3 +223,17 @@ func (f *Flex) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 		return
 	})
 }
+
+// InputHandler returns the handler for this primitive.
+func (f *Flex) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
+	return f.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		for _, item := range f.items {
+			if item != nil && item.Item.GetFocusable().HasFocus() {
+				if handler := item.Item.InputHandler(); handler != nil {
+					handler(event, setFocus)
+					return
+				}
+			}
+		}
+	})
+}

form.go

@@ -661,3 +661,26 @@ func (f *Form) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 		return
 	})
 }
+
+// InputHandler returns the handler for this primitive.
+func (f *Form) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
+	return f.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		for _, item := range f.items {
+			if item != nil && item.GetFocusable().HasFocus() {
+				if handler := item.InputHandler(); handler != nil {
+					handler(event, setFocus)
+					return
+				}
+			}
+		}
+
+		for _, button := range f.buttons {
+			if button.GetFocusable().HasFocus() {
+				if handler := button.InputHandler(); handler != nil {
+					handler(event, setFocus)
+					return
+				}
+			}
+		}
+	})
+}

frame.go

@@ -19,7 +19,7 @@ type frameText struct {
 type Frame struct {
 	*Box
 
-	// The contained primitive.
+	// The contained primitive. May be nil.
 	primitive Primitive
 
 	// The lines of text to be displayed.
@@ -30,7 +30,8 @@ type Frame struct {
 }
 
 // NewFrame returns a new frame around the given primitive. The primitive's
-// size will be changed to fit within this frame.
+// size will be changed to fit within this frame. The primitive may be nil, in
+// which case no other primitive is embedded in the frame.
 func NewFrame(primitive Primitive) *Frame {
 	box := NewBox()
 
@@ -127,33 +128,42 @@ func (f *Frame) Draw(screen tcell.Screen) {
 	}
 
 	// Set the size of the contained primitive.
-	if topMax > top {
-		top = topMax + f.header
-	}
-	if bottomMin < bottom {
-		bottom = bottomMin - f.footer
-	}
-	if top > bottom {
-		return // No space for the primitive.
-	}
-	f.primitive.SetRect(x, top, width, bottom+1-top)
+	if f.primitive != nil {
+		if topMax > top {
+			top = topMax + f.header
+		}
+		if bottomMin < bottom {
+			bottom = bottomMin - f.footer
+		}
+		if top > bottom {
+			return // No space for the primitive.
+		}
+		f.primitive.SetRect(x, top, width, bottom+1-top)
 
-	// Finally, draw the contained primitive.
-	f.primitive.Draw(screen)
+		// Finally, draw the contained primitive.
+		f.primitive.Draw(screen)
+	}
 }
 
 // Focus is called when this primitive receives focus.
 func (f *Frame) Focus(delegate func(p Primitive)) {
-	delegate(f.primitive)
+	if f.primitive != nil {
+		delegate(f.primitive)
+	} else {
+		f.hasFocus = true
+	}
 }
 
 // HasFocus returns whether or not this primitive has focus.
 func (f *Frame) HasFocus() bool {
+	if f.primitive == nil {
+		return f.hasFocus
+	}
 	focusable, ok := f.primitive.(Focusable)
 	if ok {
 		return focusable.HasFocus()
 	}
-	return false
+	return f.hasFocus
 }
 
 // MouseHandler returns the mouse handler for this primitive.
@@ -164,6 +174,25 @@ func (f *Frame) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 		}
 
 		// Pass mouse events on to contained primitive.
-		return f.primitive.MouseHandler()(action, event, setFocus)
+		if f.primitive != nil {
+			return f.primitive.MouseHandler()(action, event, setFocus)
+		}
+
+		return false, nil
+	})
+}
+
+// InputHandler returns the handler for this primitive.
+func (f *Frame) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
+	return f.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		if f.primitive == nil {
+			return
+		}
+		if f.primitive.GetFocusable().HasFocus() {
+			if handler := f.primitive.InputHandler(); handler != nil {
+				handler(event, setFocus)
+				return
+			}
+		}
 	})
 }

go.mod

@@ -5,8 +5,8 @@ go 1.12
 require (
 	github.com/gdamore/tcell v1.3.0
 	github.com/lucasb-eyer/go-colorful v1.0.3
-	github.com/mattn/go-runewidth v0.0.8
+	github.com/mattn/go-runewidth v0.0.9
 	github.com/rivo/uniseg v0.1.0
-	golang.org/x/sys v0.0.0-20200212091648-12a6c2dcc1e4 // indirect
+	golang.org/x/sys v0.0.0-20200817155316-9781c653f443 // indirect
 	golang.org/x/text v0.3.2 // indirect
 )

go.sum

@@ -10,14 +10,14 @@ github.com/lucasb-eyer/go-colorful v1.0.3 h1:QIbQXiugsb+q10B+MI+7DI1oQLdmnep86tW
 github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mattn/go-runewidth v0.0.4 h1:2BvfKmzob6Bmd4YsL0zygOqfdFnK7GR4QL06Do4/p7Y=
 github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
-github.com/mattn/go-runewidth v0.0.8 h1:3tS41NlGYSmhhe/8fhGRzc+z3AYCw1Fe1WAyLuujKs0=
-github.com/mattn/go-runewidth v0.0.8/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
+github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/rivo/uniseg v0.1.0 h1:+2KBaVoUmb9XzDsrx/Ct0W/EYOSFf/nWTauy++DprtY=
 github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 golang.org/x/sys v0.0.0-20190626150813-e07cf5db2756 h1:9nuHUbU8dRnRRfj9KjWUVrJeoexdbeMjttk6Oh1rD10=
 golang.org/x/sys v0.0.0-20190626150813-e07cf5db2756/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200212091648-12a6c2dcc1e4 h1:sfkvUWPNGwSV+8/fNqctR5lS2AqCSqYwXdrjCxp/dXo=
-golang.org/x/sys v0.0.0-20200212091648-12a6c2dcc1e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200817155316-9781c653f443 h1:X18bCaipMcoJGm27Nv7zr4XYPKGUy92GtqboKC2Hxaw=
+golang.org/x/sys v0.0.0-20200817155316-9781c653f443/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=

grid.go

@@ -271,6 +271,20 @@ func (g *Grid) HasFocus() bool {
 // InputHandler returns the handler for this primitive.
 func (g *Grid) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
 	return g.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		if !g.hasFocus {
+			// Pass event on to child primitive.
+			for _, item := range g.items {
+				if item != nil && item.Item.GetFocusable().HasFocus() {
+					if handler := item.Item.InputHandler(); handler != nil {
+						handler(event, setFocus)
+						return
+					}
+				}
+			}
+			return
+		}
+
+		// Process our own key events if we have direct focus.
 		switch event.Key() {
 		case tcell.KeyRune:
 			switch event.Rune() {

modal.go

@@ -188,3 +188,15 @@ func (m *Modal) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 		return
 	})
 }
+
+// InputHandler returns the handler for this primitive.
+func (m *Modal) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
+	return m.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		if m.frame.GetFocusable().HasFocus() {
+			if handler := m.frame.InputHandler(); handler != nil {
+				handler(event, setFocus)
+				return
+			}
+		}
+	})
+}

pages.go

@@ -300,3 +300,17 @@ func (p *Pages) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 		return
 	})
 }
+
+// InputHandler returns the handler for this primitive.
+func (p *Pages) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
+	return p.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
+		for _, page := range p.pages {
+			if page.Item.GetFocusable().HasFocus() {
+				if handler := page.Item.InputHandler(); handler != nil {
+					handler(event, setFocus)
+					return
+				}
+			}
+		}
+	})
+}

table.go

@@ -1250,8 +1250,8 @@ func (t *Table) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 			if t.rowsSelectable || t.columnsSelectable {
 				t.Select(t.cellAt(x, y))
 			}
-			consumed = true
 			setFocus(t)
+			consumed = true
 		case MouseScrollUp:
 			t.trackEnd = false
 			t.rowOffset--

textview.go

@@ -1173,8 +1173,8 @@ func (t *TextView) MouseHandler() func(action MouseAction, event *tcell.EventMou
 					break
 				}
 			}
-			consumed = true
 			setFocus(t)
+			consumed = true
 		case MouseScrollUp:
 			t.trackEnd = false
 			t.lineOffset--