cmd/gio: support app icons

If there is an appicon.png file in the main package the gio tool
will use it for Android and iOS apps in buildmode exe.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

cmd/gio/androidbuild.go

@@ -242,6 +242,20 @@ func exeAndroid(tmpDir string, tools *androidTools, bi *buildInfo) (err error) {
 			return err
 		}
 	}
+	icon := filepath.Join(bi.dir, "appicon.png")
+	iconSnip := ""
+	if _, err := os.Stat(icon); err == nil {
+		err := buildIcons(resDir, icon, []iconVariant{
+			{filepath.Join("mipmap-hdpi", "ic_launcher.png"), 72},
+			{filepath.Join("mipmap-xhdpi", "ic_launcher.png"), 96},
+			{filepath.Join("mipmap-xxhdpi", "ic_launcher.png"), 144},
+			{filepath.Join("mipmap-xxxhdpi", "ic_launcher.png"), 192},
+		})
+		if err != nil {
+			return err
+		}
+		iconSnip = `android:icon="@mipmap/ic_launcher"`
+	}
 	themes := `<?xml version="1.0" encoding="utf-8"?>
 <resources>
 	<style name="Theme.GioApp" parent="android:style/Theme.NoTitleBar">
@@ -284,7 +298,7 @@ func exeAndroid(tmpDir string, tools *androidTools, bi *buildInfo) (err error) {
 	<uses-sdk android:minSdkVersion="16" android:targetSdkVersion="28" />
 	<uses-permission android:name="android.permission.INTERNET" />
 	<uses-feature android:glEsVersion="0x00030000"/>
-	<application android:label="Gio">
+	<application %s android:label="%s">
 		<activity android:name="org.gioui.GioActivity"
 			android:label="%s"
 			android:theme="@style/Theme.GioApp"
@@ -296,7 +310,7 @@ func exeAndroid(tmpDir string, tools *androidTools, bi *buildInfo) (err error) {
 			</intent-filter>
 		</activity>
 	</application>
-</manifest>`, *appID, bi.version, bi.version, appName)
+</manifest>`, *appID, bi.version, bi.version, iconSnip, appName, appName)
 	manifest := filepath.Join(tmpDir, "AndroidManifest.xml")
 	if err := ioutil.WriteFile(manifest, []byte(manifestSrc), 0660); err != nil {
 		return err

cmd/gio/gio.go

@@ -6,12 +6,17 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
+	"image"
+	"image/png"
 	"io"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
+
+	"golang.org/x/image/draw"
+	"golang.org/x/sync/errgroup"
 )
 
 var (
@@ -32,6 +37,7 @@ type buildInfo struct {
 	target  string
 	appID   string
 	version int
+	dir     string
 	archs   []string
 }
 
@@ -68,11 +74,16 @@ func main() {
 		errorf("gio: %v", err)
 	}
 	name = filepath.Base(name)
+	dir, err := runCmd(exec.Command("go", "list", "-f", "{{.Dir}}", pkg))
+	if err != nil {
+		errorf("gio: %v", err)
+	}
 	bi := &buildInfo{
 		name:    name,
 		pkg:     pkg,
 		target:  *target,
 		appID:   *appID,
+		dir:     dir,
 		version: *version,
 	}
 	switch *target {
@@ -189,3 +200,43 @@ var allArchs = map[string]arch{
 		clang:   "x86_64-linux-android21-clang",
 	},
 }
+
+type iconVariant struct {
+	path string
+	size int
+}
+
+func buildIcons(baseDir, icon string, variants []iconVariant) error {
+	f, err := os.Open(icon)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	img, _, err := image.Decode(f)
+	if err != nil {
+		return err
+	}
+	var resizes errgroup.Group
+	for _, v := range variants {
+		v := v
+		resizes.Go(func() (err error) {
+			scaled := image.NewNRGBA(image.Rectangle{Max: image.Point{X: v.size, Y: v.size}})
+			draw.CatmullRom.Scale(scaled, scaled.Bounds(), img, img.Bounds(), draw.Src, nil)
+			path := filepath.Join(baseDir, v.path)
+			if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
+				return err
+			}
+			f, err := os.Create(path)
+			if err != nil {
+				return err
+			}
+			defer func() {
+				if cerr := f.Close(); err == nil {
+					err = cerr
+				}
+			}()
+			return png.Encode(f, scaled)
+		})
+	}
+	return resizes.Wait()
+}

cmd/gio/iosbuild.go

@@ -18,6 +18,8 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+const minIOSVersion = "9.0"
+
 func buildIOS(tmpDir, target string, bi *buildInfo) error {
 	appName := bi.name
 	switch *buildMode {
@@ -199,21 +201,86 @@ int main(int argc, char * argv[]) {
 	if err := ioutil.WriteFile(plistFile, []byte(infoPlist), 0660); err != nil {
 		return err
 	}
+	icon := filepath.Join(bi.dir, "appicon.png")
+	if _, err := os.Stat(icon); err == nil {
+		assetPlist, err := iosIcons(bi, tmpDir, app, icon)
+		if err != nil {
+			return err
+		}
+		// Merge assets plist with Info.plist
+		cmd := exec.Command(
+			"/usr/libexec/PlistBuddy",
+			"-c", "Merge "+assetPlist,
+			plistFile,
+		)
+		if _, err := runCmd(cmd); err != nil {
+			return err
+		}
+	}
 	if _, err := runCmd(exec.Command("plutil", "-convert", "binary1", plistFile)); err != nil {
 		return err
 	}
 	return nil
 }
 
+// iosIcons builds an asset catalog and compile it with the Xcode command actool.
+// iosIcons returns the asset plist file to be merged into Info.plist.
+func iosIcons(bi *buildInfo, tmpDir, appDir, icon string) (string, error) {
+	assets := filepath.Join(tmpDir, "Assets.xcassets")
+	if err := os.Mkdir(assets, 0700); err != nil {
+		return "", err
+	}
+	appIcon := filepath.Join(assets, "AppIcon.appiconset")
+	err := buildIcons(appIcon, icon, []iconVariant{
+		{"ios_2x.png", 120},
+		{"ios_3x.png", 180},
+		{"ios_store.png", 1024},
+	})
+	if err != nil {
+		return "", err
+	}
+	contentJson := `{
+	"images" : [
+		{
+			"size" : "60x60",
+			"idiom" : "iphone",
+			"filename" : "ios_2x.png",
+			"scale" : "2x"
+		},
+		{
+			"size" : "60x60",
+			"idiom" : "iphone",
+			"filename" : "ios_3x.png",
+			"scale" : "3x"
+		},
+		{
+			"size" : "1024x1024",
+			"idiom" : "ios-marketing",
+			"filename" : "ios_store.png",
+			"scale" : "1x"
+		}
+	]
+}`
+	contentFile := filepath.Join(appIcon, "Contents.json")
+	if err := ioutil.WriteFile(contentFile, []byte(contentJson), 0600); err != nil {
+		return "", err
+	}
+	assetPlist := filepath.Join(tmpDir, "assets.plist")
+	compile := exec.Command(
+		"actool",
+		"--compile", appDir,
+		"--platform", iosPlatformFor(bi.target),
+		"--minimum-deployment-target", minIOSVersion,
+		"--app-icon", "AppIcon",
+		"--output-partial-info-plist", assetPlist,
+		assets)
+	_, err = runCmd(compile)
+	return assetPlist, err
+}
+
 func buildInfoPlist(bi *buildInfo) string {
 	appName := strings.Title(bi.name)
-	var platform string
+	platform := iosPlatformFor(bi.target)
-	switch bi.target {
-	case "ios":
-		platform = "iphoneos"
-	case "tvos":
-		platform = "appletvos"
-	}
 	return fmt.Sprintf(`<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
@@ -243,7 +310,7 @@ func buildInfoPlist(bi *buildInfo) string {
 	<key>DTPlatformVersion</key>
 	<string>12.4</string>
 	<key>MinimumOSVersion</key>
-	<string>9.0</string>
+	<string>%s</string>
 	<key>UIDeviceFamily</key>
 	<array>
 		<integer>1</integer>
@@ -255,7 +322,18 @@ func buildInfoPlist(bi *buildInfo) string {
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
 </dict>
-</plist>`, bi.appID, appName, bi.version, bi.version, platform)
+</plist>`, bi.appID, appName, bi.version, bi.version, platform, minIOSVersion)
+}
+
+func iosPlatformFor(target string) string {
+	switch target {
+	case "ios":
+		return "iphoneos"
+	case "tvos":
+		return "appletvos"
+	default:
+		panic("invalid platform " + target)
+	}
 }
 
 func archiveIOS(tmpDir, target, frameworkRoot string, bi *buildInfo) error {
@@ -379,7 +457,7 @@ func iosCompilerFor(target, arch string) (string, []string, error) {
 		"-Werror",
 		"-arch", allArchs[arch].iosArch,
 		"-isysroot", sdkPath,
-		"-m" + platformOS + "-version-min=9.0",
+		"-m" + platformOS + "-version-min=" + minIOSVersion,
 	}
 	return clang, cflags, nil
 }

cmd/go.mod

@@ -2,4 +2,7 @@ module gioui.org/cmd
 
 go 1.12
 
-require golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4
+require (
+	golang.org/x/image v0.0.0-20190802002840-cff245a6509b
+	golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4
+)

cmd/go.sum

@@ -1,2 +1,5 @@
+golang.org/x/image v0.0.0-20190802002840-cff245a6509b h1:+qEpEAPhDZ1o0x3tHzZTQDArnOixOzGD9HUJfcg0mb4=
+golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 h1:YUO/7uOKsKeq9UokNS62b8FYywz3ker1l1vDZRCRefw=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=