Implement streaming preview window (#2215)

Fix #2212

    # Will start rendering after 200ms, update every 100ms
    fzf --preview 'for i in $(seq 100); do echo $i; sleep 0.01; done'

    # Should print "Loading .." message after 500ms
    fzf --preview 'sleep 1; for i in $(seq 100); do echo $i; sleep 0.01; done'

    # The first line should appear after 200ms
    fzf --preview 'date; sleep 2; date'

    # Should not render before enough lines for the scroll offset are ready
    rg --line-number --no-heading --color=always ^ |
      fzf --delimiter : --ansi --preview-window '+{2}-/2' \
          --preview 'sleep 1; bat --style=numbers --color=always --pager=never --highlight-line={2} {1}'

4 files changed, 3 insertions, 13 deletions

diff --git a/src/tui/dummy.go b/src/tui/dummy.go
index 8fce77e5..a6df8550 100644
--- a/src/tui/dummy.go
+++ b/src/tui/dummy.go
@@ -32,10 +32,9 @@ func (r *FullscreenRenderer) Clear()            {}
 func (r *FullscreenRenderer) Refresh()          {}
 func (r *FullscreenRenderer) Close()            {}
 
-func (r *FullscreenRenderer) DoesAutoWrap() bool { return false }
-func (r *FullscreenRenderer) GetChar() Event     { return Event{} }
-func (r *FullscreenRenderer) MaxX() int          { return 0 }
-func (r *FullscreenRenderer) MaxY() int          { return 0 }
+func (r *FullscreenRenderer) GetChar() Event { return Event{} }
+func (r *FullscreenRenderer) MaxX() int      { return 0 }
+func (r *FullscreenRenderer) MaxY() int      { return 0 }
 
 func (r *FullscreenRenderer) RefreshWindows(windows []Window) {}
 
diff --git a/src/tui/light.go b/src/tui/light.go
index 9af19b83..3062ab45 100644
--- a/src/tui/light.go
+++ b/src/tui/light.go
@@ -624,10 +624,6 @@ func (r *LightRenderer) MaxY() int {
 	return r.height
 }
 
-func (r *LightRenderer) DoesAutoWrap() bool {
-	return false
-}
-
 func (r *LightRenderer) NewWindow(top int, left int, width int, height int, preview bool, borderStyle BorderStyle) Window {
 	w := &LightWindow{
 		renderer: r,
diff --git a/src/tui/tcell.go b/src/tui/tcell.go
index 4d8096d3..a4c599bb 100644
--- a/src/tui/tcell.go
+++ b/src/tui/tcell.go
@@ -166,10 +166,6 @@ func (w *TcellWindow) Y() int {
 	return w.lastY
 }
 
-func (r *FullscreenRenderer) DoesAutoWrap() bool {
-	return false
-}
-
 func (r *FullscreenRenderer) Clear() {
 	_screen.Sync()
 	_screen.Clear()
diff --git a/src/tui/tui.go b/src/tui/tui.go
index 3ed794f7..146aafac 100644
--- a/src/tui/tui.go
+++ b/src/tui/tui.go
@@ -286,7 +286,6 @@ type Renderer interface {
 
 	MaxX() int
 	MaxY() int
-	DoesAutoWrap() bool
 
 	NewWindow(top int, left int, width int, height int, preview bool, borderStyle BorderStyle) Window
 }