tools/present/video.go

52 строки
1.1 KiB
Go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package present
import (
"fmt"
"strings"
)
func init() {
Register("video", parseVideo)
}
type Video struct {
URL string
SourceType string
Width int
Height int
}
func (v Video) TemplateName() string { return "video" }
func parseVideo(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
args := strings.Fields(text)
vid := Video{URL: args[1], SourceType: args[2]}
a, err := parseArgs(fileName, lineno, args[3:])
if err != nil {
return nil, err
}
switch len(a) {
case 0:
// no size parameters
case 2:
// If a parameter is empty (underscore) or invalid
// leave the field set to zero. The "video" action
// template will then omit that vid tag attribute and
// the browser will calculate the value to preserve
// the aspect ratio.
if v, ok := a[0].(int); ok {
vid.Height = v
}
if v, ok := a[1].(int); ok {
vid.Width = v
}
default:
return nil, fmt.Errorf("incorrect video invocation: %q", text)
}
return vid, nil
}