termui/block.go
Caleb Bassi eaec27d1df Add sync.Locker interface to Drawable interface
Many widget implementations will want to update asynchronously, so now termui performs locks a widget when drawing. Users should call `Lock()` on their widgets when performing an asynchronous update.
2019-03-07 02:14:11 -08:00

106 lines
2.7 KiB
Go

// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
// Use of this source code is governed by a MIT license that can
// be found in the LICENSE file.
package termui
import (
"image"
"sync"
)
// Block is the base struct inherited by most widgets.
// Block manages size, position, border, and title.
// It implements all 3 of the methods needed for the `Drawable` interface.
// Custom widgets will override the Draw method.
type Block struct {
Border bool
BorderStyle Style
BorderLeft, BorderRight, BorderTop, BorderBottom bool
PaddingLeft, PaddingRight, PaddingTop, PaddingBottom int
image.Rectangle
Inner image.Rectangle
Title string
TitleStyle Style
sync.Mutex
}
func NewBlock() *Block {
return &Block{
Border: true,
BorderStyle: Theme.Block.Border,
BorderLeft: true,
BorderRight: true,
BorderTop: true,
BorderBottom: true,
TitleStyle: Theme.Block.Title,
}
}
func (self *Block) drawBorder(buf *Buffer) {
verticalCell := Cell{VERTICAL_LINE, self.BorderStyle}
horizontalCell := Cell{HORIZONTAL_LINE, self.BorderStyle}
// draw lines
if self.BorderTop {
buf.Fill(horizontalCell, image.Rect(self.Min.X, self.Min.Y, self.Max.X, self.Min.Y+1))
}
if self.BorderBottom {
buf.Fill(horizontalCell, image.Rect(self.Min.X, self.Max.Y-1, self.Max.X, self.Max.Y))
}
if self.BorderLeft {
buf.Fill(verticalCell, image.Rect(self.Min.X, self.Min.Y, self.Min.X+1, self.Max.Y))
}
if self.BorderRight {
buf.Fill(verticalCell, image.Rect(self.Max.X-1, self.Min.Y, self.Max.X, self.Max.Y))
}
// draw corners
if self.BorderTop && self.BorderLeft {
buf.SetCell(Cell{TOP_LEFT, self.BorderStyle}, self.Min)
}
if self.BorderTop && self.BorderRight {
buf.SetCell(Cell{TOP_RIGHT, self.BorderStyle}, image.Pt(self.Max.X-1, self.Min.Y))
}
if self.BorderBottom && self.BorderLeft {
buf.SetCell(Cell{BOTTOM_LEFT, self.BorderStyle}, image.Pt(self.Min.X, self.Max.Y-1))
}
if self.BorderBottom && self.BorderRight {
buf.SetCell(Cell{BOTTOM_RIGHT, self.BorderStyle}, self.Max.Sub(image.Pt(1, 1)))
}
}
// Draw implements the Drawable interface.
func (self *Block) Draw(buf *Buffer) {
if self.Border {
self.drawBorder(buf)
}
buf.SetString(
self.Title,
self.TitleStyle,
image.Pt(self.Min.X+2, self.Min.Y),
)
}
// SetRect implements the Drawable interface.
func (self *Block) SetRect(x1, y1, x2, y2 int) {
self.Rectangle = image.Rect(x1, y1, x2, y2)
self.Inner = image.Rect(
self.Min.X+1+self.PaddingLeft,
self.Min.Y+1+self.PaddingTop,
self.Max.X-1-self.PaddingRight,
self.Max.Y-1-self.PaddingBottom,
)
}
// GetRect implements the Drawable interface.
func (self *Block) GetRect() image.Rectangle {
return self.Rectangle
}