v/examples/js_dom_draw/draw.js.v

75 lines
1.9 KiB
V

import jsdom
import jsdom.ctx
fn get_2dcontext(canvas jsdom.IElement) ?ctx.CanvasRenderingContext2D {
if canvas is jsdom.HTMLCanvasElement {
c := canvas.get_context('2d')
match c {
ctx.CanvasRenderingContext2D {
return c
}
else {
return error('cannot fetch 2d context')
}
}
} else {
return error('canvas is not an HTMLCanvasElement')
}
}
fn draw_line(context ctx.CanvasRenderingContext2D, x1 int, y1 int, x2 int, y2 int) {
context.begin_path()
context.set_stroke_style('black')
context.set_line_width(1)
context.move_to(x1, y1)
context.line_to(x2, y2)
context.stroke()
context.close_path()
}
fn main() {
/*
document := jsdom.document
elem := document.get_element_by_id('myButton') ?
elemc := document.get_element_by_id('myCanvas') or { panic('no canvas') }
canv := jsdom.get_html_canvas_element(elemc) or { panic('expected canvas') }
context := get_2dcontext(canv) or { panic('wow') }
mut drawing := false
mut x := int(0)
mut y := int(0)
canv.add_event_listener('mousedown', fn [mut drawing, mut x, mut y] (_ jsdom.IEventTarget, event jsdom.IEvent) {
drawing = true
if event is jsdom.MouseEvent {
x = event.offset_x()
y = event.offset_y()
}
})
canv.add_event_listener('mousemove', fn [context, drawing, mut x, mut y] (_ jsdom.IEventTarget, event jsdom.IEvent) {
if drawing {
if event is jsdom.MouseEvent {
draw_line(context, x, y, event.offset_x(), event.offset_y())
x = event.offset_x()
y = event.offset_y()
}
}
})
jsdom.window.add_event_listener('mouseup', fn [context, mut drawing, mut x, mut y] (_ jsdom.IEventTarget, event jsdom.IEvent) {
if drawing {
if event is jsdom.MouseEvent {
draw_line(context, x, y, event.offset_x(), event.offset_y())
}
x = 0
y = 0
drawing = false
}
})
elem.add_event_listener('click', fn [context, canv] (_ jsdom.IEventTarget, _ jsdom.IEvent) {
context.clear_rect(0, 0, canv.width(), canv.height())
})
*/
}