mirror of https://github.com/mum4k/termdash.git
94 lines
2.6 KiB
Go
94 lines
2.6 KiB
Go
// Copyright 2018 Google Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this 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 draw
|
|
|
|
// rectangle.go draws a rectangle.
|
|
|
|
import (
|
|
"fmt"
|
|
"image"
|
|
|
|
"github.com/mum4k/termdash/cell"
|
|
"github.com/mum4k/termdash/private/canvas"
|
|
)
|
|
|
|
// RectangleOption is used to provide options to the Rectangle function.
|
|
type RectangleOption interface {
|
|
// set sets the provided option.
|
|
set(*rectOptions)
|
|
}
|
|
|
|
// rectOptions stores the provided options.
|
|
type rectOptions struct {
|
|
cellOpts []cell.Option
|
|
char rune
|
|
}
|
|
|
|
// rectOption implements RectangleOption.
|
|
type rectOption func(rOpts *rectOptions)
|
|
|
|
// set implements RectangleOption.set.
|
|
func (ro rectOption) set(rOpts *rectOptions) {
|
|
ro(rOpts)
|
|
}
|
|
|
|
// RectCellOpts sets options on the cells that create the rectangle.
|
|
func RectCellOpts(opts ...cell.Option) RectangleOption {
|
|
return rectOption(func(rOpts *rectOptions) {
|
|
rOpts.cellOpts = append(rOpts.cellOpts, opts...)
|
|
})
|
|
}
|
|
|
|
// DefaultRectChar is the default value for the RectChar option.
|
|
const DefaultRectChar = ' '
|
|
|
|
// RectChar sets the character used in each of the cells of the rectangle.
|
|
func RectChar(c rune) RectangleOption {
|
|
return rectOption(func(rOpts *rectOptions) {
|
|
rOpts.char = c
|
|
})
|
|
}
|
|
|
|
// Rectangle draws a filled rectangle on the canvas.
|
|
func Rectangle(c *canvas.Canvas, r image.Rectangle, opts ...RectangleOption) error {
|
|
opt := &rectOptions{
|
|
char: DefaultRectChar,
|
|
}
|
|
for _, o := range opts {
|
|
o.set(opt)
|
|
}
|
|
|
|
if ar := c.Area(); !r.In(ar) {
|
|
return fmt.Errorf("the requested rectangle %v doesn't fit the canvas area %v", r, ar)
|
|
}
|
|
|
|
if r.Dx() < 1 || r.Dy() < 1 {
|
|
return fmt.Errorf("the rectangle must be at least 1x1 cell, got %v", r)
|
|
}
|
|
|
|
for col := r.Min.X; col < r.Max.X; col++ {
|
|
for row := r.Min.Y; row < r.Max.Y; row++ {
|
|
cells, err := c.SetCell(image.Point{col, row}, opt.char, opt.cellOpts...)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if cells != 1 {
|
|
return fmt.Errorf("invalid rectangle character %q, this character occupies %d cells, the implementation only supports half-width runes that occupy exactly one cell", opt.char, cells)
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|