mirror of
https://github.com/unidoc/unioffice.git
synced 2025-04-25 13:48:53 +08:00
105 lines
2.9 KiB
Go
105 lines
2.9 KiB
Go
// Copyright 2017 Baliance. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by the terms of the Affero GNU General
|
|
// Public License version 3.0 as published by the Free Software Foundation and
|
|
// appearing in the file LICENSE included in the packaging of this file. A
|
|
// commercial license can be purchased by contacting sales@baliance.com.
|
|
|
|
package common
|
|
|
|
import (
|
|
"fmt"
|
|
"image"
|
|
"os"
|
|
|
|
"baliance.com/gooxml/measurement"
|
|
// Add image format support
|
|
_ "image/gif"
|
|
_ "image/jpeg"
|
|
_ "image/png"
|
|
)
|
|
|
|
// Image is a container for image information. It's used as we need format and
|
|
// and size information to use images.
|
|
type Image struct {
|
|
Size image.Point
|
|
Format string
|
|
Path string
|
|
}
|
|
|
|
// ImageRef is a reference to an image within a document.
|
|
type ImageRef struct {
|
|
d *DocBase
|
|
rels Relationships
|
|
img Image
|
|
relID string
|
|
}
|
|
|
|
// MakeImageRef constructs an image reference which is a reference to a
|
|
// particular image file inside a document. The same image can be used multiple
|
|
// times in a document by re-use the ImageRef.
|
|
func MakeImageRef(img Image, d *DocBase, rels Relationships) ImageRef {
|
|
return ImageRef{img: img, d: d, rels: rels}
|
|
}
|
|
|
|
func (i *ImageRef) SetRelID(id string) {
|
|
i.relID = id
|
|
}
|
|
|
|
// RelID returns the relationship ID.
|
|
func (i ImageRef) RelID() string {
|
|
return i.relID
|
|
}
|
|
|
|
// Format returns the format of the underlying image
|
|
func (i ImageRef) Format() string {
|
|
return i.img.Format
|
|
}
|
|
|
|
// Path returns the path to an image file
|
|
func (i ImageRef) Path() string {
|
|
return i.img.Path
|
|
}
|
|
|
|
// Size returns the size of an image
|
|
func (i ImageRef) Size() image.Point {
|
|
return i.img.Size
|
|
}
|
|
|
|
// RelativeHeight returns the relative height of an image given a fixed width.
|
|
// This is used when setting image to a fixed width to calculate the height
|
|
// required to keep the same image aspect ratio.
|
|
func (i ImageRef) RelativeHeight(w measurement.Distance) measurement.Distance {
|
|
hScale := float64(i.Size().Y) / float64(i.Size().X)
|
|
return w * measurement.Distance(hScale)
|
|
}
|
|
|
|
// RelativeWidth returns the relative width of an image given a fixed height.
|
|
// This is used when setting image to a fixed height to calculate the width
|
|
// required to keep the same image aspect ratio.
|
|
func (i ImageRef) RelativeWidth(h measurement.Distance) measurement.Distance {
|
|
wScale := float64(i.Size().X) / float64(i.Size().Y)
|
|
return h * measurement.Distance(wScale)
|
|
}
|
|
|
|
// ImageFromFile reads an image from a file on disk. It doesn't keep the image
|
|
// in memory and only reads it to determine the format and size. You can also
|
|
// construct an Image directly if the file and size are known.
|
|
func ImageFromFile(path string) (Image, error) {
|
|
f, err := os.Open(path)
|
|
r := Image{}
|
|
if err != nil {
|
|
return r, fmt.Errorf("error reading image: %s", err)
|
|
}
|
|
defer f.Close()
|
|
imgDec, ifmt, err := image.Decode(f)
|
|
if err != nil {
|
|
return r, fmt.Errorf("unable to parse image: %s", err)
|
|
}
|
|
|
|
r.Path = path
|
|
r.Format = ifmt
|
|
r.Size = imgDec.Bounds().Size()
|
|
return r, nil
|
|
}
|