cview/frame.go

169 lines
4.2 KiB
Go

package tview
import (
"github.com/gdamore/tcell"
)
// frameText holds information about a line of text shown in the frame.
type frameText struct {
Text string // The text to be displayed.
Header bool // true = place in header, false = place in footer.
Align int // One of the Align constants.
Color tcell.Color // The text color.
}
// Frame is a wrapper which adds a border around another box. The top area
// (header) and the bottom area (footer) may also contain text.
type Frame struct {
*Box
// The contained primitive.
primitive Primitive
// The lines of text to be displayed.
text []*frameText
// Border spacing.
top, bottom, header, footer, left, right int
}
// NewFrame returns a new frame around the given primitive. The primitive's
// size will be changed to fit within this frame.
func NewFrame(primitive Primitive) *Frame {
box := NewBox()
f := &Frame{
Box: box,
primitive: primitive,
top: 1,
bottom: 1,
header: 1,
footer: 1,
left: 1,
right: 1,
}
f.focus = f
return f
}
// AddText adds text to the frame. Set "header" to true if the text is to appear
// in the header, above the contained primitive. Set it to false for it to
// appear in the footer, below the contained primitive. "align" must be one of
// the Align constants. Rows in the header are printed top to bottom, rows in
// the footer are printed bottom to top. Note that long text can overlap as
// different alignments will be placed on the same row.
func (f *Frame) AddText(text string, header bool, align int, color tcell.Color) *Frame {
f.text = append(f.text, &frameText{
Text: text,
Header: header,
Align: align,
Color: color,
})
return f
}
// ClearText removes all text from the frame.
func (f *Frame) ClearText() *Frame {
f.text = nil
return f
}
// SetBorders sets the width of the frame borders as well as "header" and
// "footer", the vertical space between the header and footer text and the
// contained primitive (does not apply if there is no text).
func (f *Frame) SetBorders(top, bottom, header, footer, left, right int) *Frame {
f.top, f.bottom, f.header, f.footer, f.left, f.right = top, bottom, header, footer, left, right
return f
}
// Draw draws this primitive onto the screen.
func (f *Frame) Draw(screen tcell.Screen) {
f.Box.Draw(screen)
// Calculate start positions.
left, top, width, height := f.GetInnerRect()
right := left + width - 1
bottom := top + height - 1
left += f.left
right -= f.right
top += f.top
bottom -= f.bottom
center := (left + right) / 2
if left >= right || top >= bottom {
return // No space left.
}
// Draw text.
var rows [6]int // top-left, top-center, top-right, bottom-left, bottom-center, bottom-right.
topMax := top
bottomMin := bottom
for _, text := range f.text {
// Where do we place this text?
var y int
if text.Header {
y = top + rows[text.Align]
rows[text.Align]++
if y >= bottomMin {
continue
}
if y+1 > topMax {
topMax = y + 1
}
} else {
y = bottom - rows[3+text.Align]
rows[3+text.Align]++
if y <= topMax {
continue
}
if y-1 < bottomMin {
bottomMin = y - 1
}
}
x := left
if text.Align == AlignCenter {
x = center
} else if text.Align == AlignRight {
x = right
}
// Draw text.
Print(screen, text.Text, x, y, right-left+1, text.Align, text.Color)
}
// Set the size of the contained primitive.
if topMax > top {
top = topMax + f.header
}
if bottomMin < bottom {
bottom = bottomMin - f.footer
}
if top > bottom {
return // No space for the primitive.
}
f.primitive.SetRect(left, top, right+1-left, bottom+1-top)
// Finally, draw the contained primitive.
f.primitive.Draw(screen)
}
// Focus is called when this primitive receives focus.
func (f *Frame) Focus(delegate func(p Primitive)) {
delegate(f.primitive)
}
// InputHandler returns the handler for this primitive.
func (f *Frame) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
return func(event *tcell.EventKey, setFocus func(p Primitive)) {}
}
// HasFocus returns whether or not this primitive has focus.
func (f *Frame) HasFocus() bool {
focusable, ok := f.primitive.(Focusable)
if ok {
return focusable.HasFocus()
}
return false
}