Automatically trim lines wider than the window width

charmbracelet · Jan 14, 2021 · 633886a · 633886a
1 parent cb8e902
commit 633886a
Show file tree

Hide file tree

Showing 3 changed files with 19 additions and 1 deletion.
diff --git a/go.mod b/go.mod
@@ -5,6 +5,7 @@ go 1.13
 require (
 	github.com/containerd/console v1.0.1
 	github.com/mattn/go-isatty v0.0.12
+	github.com/muesli/reflow v0.2.1-0.20201126184510-3bcb929042f2
 	github.com/muesli/termenv v0.7.2
 	golang.org/x/crypto v0.0.0-20201012173705-84dcc777aaee
 	golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634

diff --git a/go.sum b/go.sum
@@ -8,6 +8,8 @@ github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHX
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 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/muesli/reflow v0.2.1-0.20201126184510-3bcb929042f2 h1:+cpkcmASpeBn4qXz2tU+x+njyKe91NoHXqrJdhoDnZo=
+github.com/muesli/reflow v0.2.1-0.20201126184510-3bcb929042f2/go.mod h1:qT22vjVmM9MIUeLgsVYe/Ye7eZlbv9dZjL3dVhUqLX8=
 github.com/muesli/termenv v0.7.2 h1:r1raklL3uKE7rOvWgSenmEm2px+dnc33OTisZ8YR1fw=
 github.com/muesli/termenv v0.7.2/go.mod h1:ct2L5N2lmix82RaY3bMWwVu/jUFc9Ule0KGDCiKYPh8=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=

diff --git a/renderer.go b/renderer.go
@@ -6,6 +6,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/muesli/reflow/truncate"
 )
 
 const (
@@ -148,7 +150,20 @@ func (r *renderer) flush() {
 		if _, exists := r.ignoreLines[r.linesRendered]; exists {
 			cursorDown(out) // skip rendering for this line.
 		} else {
-			_, _ = io.WriteString(out, lines[i])
+			line := lines[i]
+
+			// Truncate lines wider than the width of the window to avoid
+			// rendering troubles. If we don't have the width of the window
+			// this will be ignored.
+			//
+			// Note that on Windows we can't get the width of the window
+			// (signal SIGWINCH is not supported), so this will be ignored.
+			if r.width > 0 {
+				line = truncate.String(line, uint(r.width))
+			}
+
+			_, _ = io.WriteString(out, line)
+
 			if i != len(lines)-1 {
 				_, _ = io.WriteString(out, "\r\n")
 			}