github.com/hugh712/snapd@v0.0.0-20200910133618-1a99902bd583/wrappers/icons.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2019 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package wrappers
    21  
    22  import (
    23  	"fmt"
    24  	"os"
    25  	"path/filepath"
    26  	"strings"
    27  
    28  	"github.com/snapcore/snapd/dirs"
    29  	"github.com/snapcore/snapd/osutil"
    30  	"github.com/snapcore/snapd/snap"
    31  )
    32  
    33  func findIconFiles(snapName string, rootDir string) (icons []string, err error) {
    34  	if !osutil.IsDirectory(rootDir) {
    35  		return nil, nil
    36  	}
    37  	iconGlob := fmt.Sprintf("snap.%s.*", snapName)
    38  	forbiddenDirGlob := "snap.*"
    39  	err = filepath.Walk(rootDir, func(path string, info os.FileInfo, err error) error {
    40  		if err != nil {
    41  			return err
    42  		}
    43  		rel, err := filepath.Rel(rootDir, path)
    44  		if err != nil {
    45  			return err
    46  		}
    47  		base := filepath.Base(path)
    48  		if info.IsDir() {
    49  			// Ignore directories that could match an icon glob
    50  			if ok, err := filepath.Match(forbiddenDirGlob, base); ok || err != nil {
    51  				return filepath.SkipDir
    52  			}
    53  		} else {
    54  			if ok, err := filepath.Match(iconGlob, base); err != nil {
    55  				return err
    56  			} else if ok {
    57  				ext := filepath.Ext(base)
    58  				if ext == ".png" || ext == ".svg" {
    59  					icons = append(icons, rel)
    60  				}
    61  			}
    62  		}
    63  		return nil
    64  	})
    65  	return icons, err
    66  }
    67  
    68  func deriveIconContent(instanceName string, rootDir string, icons []string) (content map[string]map[string]osutil.FileState, err error) {
    69  	content = make(map[string]map[string]osutil.FileState)
    70  	snapPrefix := fmt.Sprintf("snap.%s.", snap.InstanceSnap(instanceName))
    71  	instancePrefix := fmt.Sprintf("snap.%s.", instanceName)
    72  
    73  	for _, iconFile := range icons {
    74  		base := filepath.Base(iconFile)
    75  		if !strings.HasPrefix(base, snapPrefix) {
    76  			return nil, fmt.Errorf("cannot use icon file %q: must start with snap prefix %q", iconFile, snapPrefix)
    77  		}
    78  		dir := filepath.Dir(iconFile)
    79  		dirContent := content[dir]
    80  		if dirContent == nil {
    81  			dirContent = make(map[string]osutil.FileState)
    82  			content[dir] = dirContent
    83  		}
    84  		// rename icons to match snap instance name
    85  		base = instancePrefix + base[len(snapPrefix):]
    86  		dirContent[base] = &osutil.FileReferencePlusMode{
    87  			FileReference: osutil.FileReference{Path: filepath.Join(rootDir, iconFile)},
    88  			Mode:          0644,
    89  		}
    90  	}
    91  	return content, nil
    92  }
    93  
    94  func AddSnapIcons(s *snap.Info) error {
    95  	if err := os.MkdirAll(dirs.SnapDesktopIconsDir, 0755); err != nil {
    96  		return err
    97  	}
    98  
    99  	rootDir := filepath.Join(s.MountDir(), "meta", "gui", "icons")
   100  	icons, err := findIconFiles(s.SnapName(), rootDir)
   101  	if err != nil {
   102  		return err
   103  	}
   104  
   105  	content, err := deriveIconContent(s.InstanceName(), rootDir, icons)
   106  	if err != nil {
   107  		return err
   108  	}
   109  	iconGlob := fmt.Sprintf("snap.%s.*", s.InstanceName())
   110  	_, _, err = osutil.EnsureTreeState(dirs.SnapDesktopIconsDir, []string{iconGlob}, content)
   111  	return err
   112  }
   113  
   114  func RemoveSnapIcons(s *snap.Info) error {
   115  	if !osutil.IsDirectory(dirs.SnapDesktopIconsDir) {
   116  		return nil
   117  	}
   118  	iconGlob := fmt.Sprintf("snap.%s.*", s.InstanceName())
   119  	_, _, err := osutil.EnsureTreeState(dirs.SnapDesktopIconsDir, []string{iconGlob}, nil)
   120  	return err
   121  }