| 1 | // Copyright 2012 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package present |
| 6 | |
| 7 | import ( |
| 8 | "fmt" |
| 9 | "strings" |
| 10 | ) |
| 11 | |
| 12 | func init() { |
| 13 | Register("image", parseImage) |
| 14 | } |
| 15 | |
| 16 | type Image struct { |
| 17 | Cmd string // original command from present source |
| 18 | URL string |
| 19 | Width int |
| 20 | Height int |
| 21 | } |
| 22 | |
| 23 | func (i Image) PresentCmd() string { return i.Cmd } |
| 24 | func (i Image) TemplateName() string { return "image" } |
| 25 | |
| 26 | func parseImage(ctx *Context, fileName string, lineno int, text string) (Elem, error) { |
| 27 | args := strings.Fields(text) |
| 28 | if len(args) < 2 { |
| 29 | return nil, fmt.Errorf("incorrect image invocation: %q", text) |
| 30 | } |
| 31 | img := Image{Cmd: text, URL: args[1]} |
| 32 | a, err := parseArgs(fileName, lineno, args[2:]) |
| 33 | if err != nil { |
| 34 | return nil, err |
| 35 | } |
| 36 | switch len(a) { |
| 37 | case 0: |
| 38 | // no size parameters |
| 39 | case 2: |
| 40 | // If a parameter is empty (underscore) or invalid |
| 41 | // leave the field set to zero. The "image" action |
| 42 | // template will then omit that img tag attribute and |
| 43 | // the browser will calculate the value to preserve |
| 44 | // the aspect ratio. |
| 45 | if v, ok := a[0].(int); ok { |
| 46 | img.Height = v |
| 47 | } |
| 48 | if v, ok := a[1].(int); ok { |
| 49 | img.Width = v |
| 50 | } |
| 51 | default: |
| 52 | return nil, fmt.Errorf("incorrect image invocation: %q", text) |
| 53 | } |
| 54 | return img, nil |
| 55 | } |
| 56 |
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