tcell/_demos/hello_world.go

85 lines
1.8 KiB
Go

// +build ignore
// Copyright 2020 The TCell 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/v2"
"github.com/gdamore/tcell/v2/encoding"
"github.com/mattn/go-runewidth"
)
func emitStr(s tcell.Screen, x, y int, style tcell.Style, str string) {
for _, c := range str {
var comb []rune
w := runewidth.RuneWidth(c)
if w == 0 {
comb = []rune{c}
c = ' '
w = 1
}
s.SetContent(x, y, c, comb, style)
x += w
}
}
func displayHelloWorld(s tcell.Screen) {
w, h := s.Size()
s.Clear()
emitStr(s, w/2-7, h/2, tcell.StyleDefault, "Hello, World!")
emitStr(s, w/2-9, h/2+1, tcell.StyleDefault, "Press ESC to exit.")
s.Show()
}
// This program just prints "Hello, World!". Press ESC to exit.
func main() {
encoding.Register()
s, e := tcell.NewScreen()
if e != nil {
fmt.Fprintf(os.Stderr, "%v\n", e)
os.Exit(1)
}
if e := s.Init(); e != nil {
fmt.Fprintf(os.Stderr, "%v\n", e)
os.Exit(1)
}
defStyle := tcell.StyleDefault.
Background(tcell.ColorBlack).
Foreground(tcell.ColorWhite)
s.SetStyle(defStyle)
displayHelloWorld(s)
for {
switch ev := s.PollEvent().(type) {
case *tcell.EventResize:
s.Sync()
displayHelloWorld(s)
case *tcell.EventKey:
if ev.Key() == tcell.KeyEscape {
s.Fini()
os.Exit(0)
}
}
}
}