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Diffstat (limited to 'ui/context.go')
-rw-r--r--ui/context.go95
1 files changed, 95 insertions, 0 deletions
diff --git a/ui/context.go b/ui/context.go
new file mode 100644
index 00000000..9f2e2fe5
--- /dev/null
+++ b/ui/context.go
@@ -0,0 +1,95 @@
+package ui
+
+import (
+ "fmt"
+
+ "github.com/nsf/termbox-go"
+)
+
+// A context allows you to draw in a sub-region of the terminal
+type Context struct {
+ x int
+ y int
+ width int
+ height int
+}
+
+func (ctx *Context) Width() int {
+ return ctx.width
+}
+
+func (ctx *Context) Height() int {
+ return ctx.height
+}
+
+func NewContext() *Context {
+ width, height := termbox.Size()
+ return &Context{0, 0, width, height}
+}
+
+func (ctx *Context) Subcontext(x, y, width, height int) *Context {
+ if x+width > ctx.width || y+height > ctx.height {
+ panic(fmt.Errorf("Attempted to create context larger than parent"))
+ }
+ return &Context{
+ x: ctx.x + x,
+ y: ctx.y + y,
+ width: width,
+ height: height,
+ }
+}
+
+func (ctx *Context) SetCell(x, y int, ch rune, fg, bg termbox.Attribute) {
+ if x >= ctx.width || y >= ctx.height {
+ panic(fmt.Errorf("Attempted to draw outside of context"))
+ }
+ termbox.SetCell(ctx.x+x, ctx.y+y, ch, fg, bg)
+}
+
+func (ctx *Context) Printf(x, y int, ref termbox.Cell,
+ format string, a ...interface{}) {
+
+ if x >= ctx.width || y >= ctx.height {
+ panic(fmt.Errorf("Attempted to draw outside of context"))
+ }
+
+ str := fmt.Sprintf(format, a...)
+
+ x += ctx.x
+ y += ctx.y
+ old_x := x
+
+ newline := func() bool {
+ x = old_x
+ y++
+ return y < ctx.height
+ }
+ for _, ch := range str {
+ switch ch {
+ case '\n':
+ if !newline() {
+ return
+ }
+ case '\r':
+ x = old_x
+ default:
+ termbox.SetCell(x, y, ch, ref.Fg, ref.Bg)
+ x++
+ if x == old_x+ctx.width {
+ if !newline() {
+ return
+ }
+ }
+ }
+ }
+}
+
+func (ctx *Context) Fill(x, y, width, height int, ref termbox.Cell) {
+ _x := x
+ for ; y < height && y < ctx.height; y++ {
+ for ; x < width && x < ctx.width; x++ {
+ ctx.SetCell(x, y, ref.Ch, ref.Fg, ref.Bg)
+ }
+ x = _x
+ }
+}