From bcd03c4c4a94e73b2545bf5dfc404082a674c76e Mon Sep 17 00:00:00 2001 From: Ben Burwell Date: Fri, 20 Dec 2019 13:21:32 -0500 Subject: [PATCH] Add popovers A popover is a special UI element which can be layered over the rest of the UI (i.e. it is painted last) and can fall anywhere on the screen, not just with the bounds of its parent's viewport/context. With these special abilities comes the restriction that only one popover may be visible on screen at once. Popovers are requested from the UI context passed to Draw calls and specify the anchor point and the desired dimensions. The popover is then fit to the available space and placed relative to the anchor point. --- lib/ui/context.go | 23 +++++++++++++----- lib/ui/popover.go | 62 +++++++++++++++++++++++++++++++++++++++++++++++ lib/ui/ui.go | 26 +++++++++++++++++--- 3 files changed, 102 insertions(+), 9 deletions(-) create mode 100644 lib/ui/popover.go diff --git a/lib/ui/context.go b/lib/ui/context.go index d450fd8..6bdf76a 100644 --- a/lib/ui/context.go +++ b/lib/ui/context.go @@ -10,9 +10,10 @@ import ( // A context allows you to draw in a sub-region of the terminal type Context struct { - screen tcell.Screen - viewport *views.ViewPort - x, y int + screen tcell.Screen + viewport *views.ViewPort + x, y int + onPopover func(*Popover) } func (ctx *Context) X() int { @@ -35,9 +36,9 @@ func (ctx *Context) Height() int { return height } -func NewContext(width, height int, screen tcell.Screen) *Context { +func NewContext(width, height int, screen tcell.Screen, p func(*Popover)) *Context { vp := views.NewViewPort(screen, 0, 0, width, height) - return &Context{screen, vp, 0, 0} + return &Context{screen, vp, 0, 0, p} } func (ctx *Context) Subcontext(x, y, width, height int) *Context { @@ -49,7 +50,7 @@ func (ctx *Context) Subcontext(x, y, width, height int) *Context { panic(fmt.Errorf("Attempted to create context larger than parent")) } vp := views.NewViewPort(ctx.viewport, x, y, width, height) - return &Context{ctx.screen, vp, ctx.x + x, ctx.y + y} + return &Context{ctx.screen, vp, ctx.x + x, ctx.y + y, ctx.onPopover} } func (ctx *Context) SetCell(x, y int, ch rune, style tcell.Style) { @@ -113,3 +114,13 @@ func (ctx *Context) SetCursor(x, y int) { func (ctx *Context) HideCursor() { ctx.screen.HideCursor() } + +func (ctx *Context) Popover(x, y, width, height int, d Drawable) { + ctx.onPopover(&Popover{ + x: ctx.x + x, + y: ctx.y + y, + width: width, + height: height, + content: d, + }) +} diff --git a/lib/ui/popover.go b/lib/ui/popover.go new file mode 100644 index 0000000..a76f222 --- /dev/null +++ b/lib/ui/popover.go @@ -0,0 +1,62 @@ +package ui + +import "github.com/gdamore/tcell" + +type Popover struct { + x, y, width, height int + content Drawable +} + +func (p *Popover) Draw(ctx *Context) { + var subcontext *Context + + // trim desired width to fit + width := p.width + if p.x+p.width > ctx.Width() { + width = ctx.Width() - p.x + } + + if p.y+p.height+1 < ctx.Height() { + // draw below + subcontext = ctx.Subcontext(p.x, p.y+1, width, p.height) + } else if p.y-p.height >= 0 { + // draw above + subcontext = ctx.Subcontext(p.x, p.y-p.height, width, p.height) + } else { + // can't fit entirely above or below, so find the largest available + // vertical space and shrink to fit + if p.y > ctx.Height()-p.y { + // there is more space above than below + height := p.y + subcontext = ctx.Subcontext(p.x, 0, width, height) + } else { + // there is more space below than above + height := ctx.Height() - p.y + subcontext = ctx.Subcontext(p.x, p.y+1, width, height-1) + } + } + p.content.Draw(subcontext) +} + +func (p *Popover) Event(e tcell.Event) bool { + if di, ok := p.content.(DrawableInteractive); ok { + return di.Event(e) + } + return false +} + +func (p *Popover) Focus(f bool) { + if di, ok := p.content.(DrawableInteractive); ok { + di.Focus(f) + } +} + +func (p *Popover) Invalidate() { + p.content.Invalidate() +} + +func (p *Popover) OnInvalidate(f func(Drawable)) { + p.content.OnInvalidate(func(_ Drawable) { + f(p) + }) +} diff --git a/lib/ui/ui.go b/lib/ui/ui.go index 01d12dc..16b176d 100644 --- a/lib/ui/ui.go +++ b/lib/ui/ui.go @@ -11,6 +11,7 @@ type UI struct { exit atomic.Value // bool ctx *Context screen tcell.Screen + popover *Popover tcEvents chan tcell.Event invalid int32 // access via atomic @@ -34,11 +35,11 @@ func Initialize(content DrawableInteractiveBeeper) (*UI, error) { state := UI{ Content: content, - ctx: NewContext(width, height, screen), screen: screen, tcEvents: make(chan tcell.Event, 10), } + state.ctx = NewContext(width, height, screen, state.onPopover) state.exit.Store(false) go func() { @@ -57,6 +58,10 @@ func Initialize(content DrawableInteractiveBeeper) (*UI, error) { return &state, nil } +func (state *UI) onPopover(p *Popover) { + state.popover = p +} + func (state *UI) ShouldExit() bool { return state.exit.Load().(bool) } @@ -78,17 +83,32 @@ func (state *UI) Tick() bool { case *tcell.EventResize: state.screen.Clear() width, height := event.Size() - state.ctx = NewContext(width, height, state.screen) + state.ctx = NewContext(width, height, state.screen, state.onPopover) state.Content.Invalidate() } - state.Content.Event(event) + // if we have a popover, and it can handle the event, it does so + if state.popover == nil || !state.popover.Event(event) { + // otherwise, we send the event to the main content + state.Content.Event(event) + } more = true default: } wasInvalid := atomic.SwapInt32(&state.invalid, 0) if wasInvalid != 0 { + if state.popover != nil { + // if the previous frame had a popover, rerender the entire display + state.Content.Invalidate() + atomic.StoreInt32(&state.invalid, 0) + } + // reset popover for the next Draw + state.popover = nil state.Content.Draw(state.ctx) + if state.popover != nil { + // if the Draw resulted in a popover, draw it + state.popover.Draw(state.ctx) + } state.screen.Show() more = true }