Adds side-by-side diff for images (#6784)

* Adds side-by-side diff for images

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Explain blank imports

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Use complete word for width and height labels on image compare

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Update index.css from master

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Moves ImageInfo to git commit file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Assign ImageInfo function for template and sets correct target for BeforeSourcePath

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adds missing comment

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Return error if ImageInfo failed

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Avoid template panic when ImageInfo failed for some reason

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Show file size on image diff

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Removes unused helper function

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Reverts copyright year change

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Close file reader

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Update commit.go

Sets correct data key

* Moves reader.Close() up a few lines

* Updates index.css

* Updates CSS file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Transfers adjustments for image compare to compare.go file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adjusts variable name

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Apply lesshint recommendations

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Do not show old image on image compare if it is not in index of base commit

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Change file size text

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/modules/git/commit.go b/modules/git/commit.go
index 2f7f53e7ce..83e03c2795 100644
--- a/modules/git/commit.go
+++ b/modules/git/commit.go
@@ -10,6 +10,11 @@ import (
 	"bytes"
 	"container/list"
 	"fmt"
+	"image"
+	"image/color"
+	_ "image/gif"  // for processing gif images
+	_ "image/jpeg" // for processing jpeg images
+	_ "image/png"  // for processing png images
 	"io"
 	"net/http"
 	"strconv"
@@ -158,6 +163,43 @@ func (c *Commit) IsImageFile(name string) bool {
 	return isImage
 }
 
+// ImageMetaData represents metadata of an image file
+type ImageMetaData struct {
+	ColorModel color.Model
+	Width      int
+	Height     int
+	ByteSize   int64
+}
+
+// ImageInfo returns information about the dimensions of an image
+func (c *Commit) ImageInfo(name string) (*ImageMetaData, error) {
+	if !c.IsImageFile(name) {
+		return nil, nil
+	}
+
+	blob, err := c.GetBlobByPath(name)
+	if err != nil {
+		return nil, err
+	}
+	reader, err := blob.DataAsync()
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+	config, _, err := image.DecodeConfig(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	metadata := ImageMetaData{
+		ColorModel: config.ColorModel,
+		Width:      config.Width,
+		Height:     config.Height,
+		ByteSize:   blob.Size(),
+	}
+	return &metadata, nil
+}
+
 // GetCommitByPath return the commit of relative path object.
 func (c *Commit) GetCommitByPath(relpath string) (*Commit, error) {
 	return c.repo.getCommitByPathWithID(c.ID, relpath)
@@ -310,6 +352,13 @@ func (c *Commit) FileChangedSinceCommit(filename, pastCommit string) (bool, erro
 	return c.repo.FileChangedBetweenCommits(filename, pastCommit, c.ID.String())
 }
 
+// HasFile returns true if the file given exists on this commit
+// This does only mean it's there - it does not mean the file was changed during the commit.
+func (c *Commit) HasFile(filename string) (bool, error) {
+	result, err := c.repo.LsFiles(filename)
+	return result[0] == filename, err
+}
+
 // GetSubModules get all the sub modules of current revision git tree
 func (c *Commit) GetSubModules() (*ObjectCache, error) {
 	if c.submoduleCache != nil {