feat: enable variable channel importance

android/NotificationHelper.java

@@ -10,9 +10,8 @@ import android.graphics.drawable.Icon;
 
 public class NotificationHelper {
     private final static String tag = "NotificationHelper";
-    public static void newChannel(Context ctx, String channelID, String name, String description) {
+    public static void newChannel(Context ctx, int importance, String channelID, String name, String description) {
         Log.w(tag,String.format("newChannel invoked"));
-        int importance = NotificationManager.IMPORTANCE_DEFAULT;
         NotificationChannel channel = new NotificationChannel(channelID, name, importance);
     	Log.e(tag,String.format("channel: %s",channel));
         channel.setDescription(description);

android/notify_android.go

@@ -2,21 +2,73 @@ package android
 
 import (
 	"fmt"
+	"log"
 	"sync"
 
 	"gioui.org/app"
-	"github.com/tailscale/tailscale-android/jni"
+	"git.wow.st/gmp/jni"
 )
 
+type Importance int
+
+const (
+	ImportanceDefault Importance = iota
+	ImportanceHigh
+	ImportanceLow
+	ImportanceMax
+	ImportanceMin
+	ImportanceNone
+	ImportanceUnspecified
+	importanceEnd // compile-time hack to track the number of importance constants and size the
+	// array holding their values correctly. If new constants need to be added, add them above
+	// this.
+)
+
+// value returns the JVM value for this importance constant. It must not be invoked before the
+// importances have been resolved.
+func (i Importance) value() int32 {
+	return importances[i]
+}
+
 const (
 	helperClass               = "ht/sr/git/whereswaldon/niotify/NotificationHelper"
+	importanceDefaultName     = "IMPORTANCE_DEFAULT"
+	importanceHighName        = "IMPORTANCE_HIGH"
+	importanceLowName         = "IMPORTANCE_LOW"
+	importanceMaxName         = "IMPORTANCE_MAX"
+	importanceMinName         = "IMPORTANCE_MIN"
+	importanceNoneName        = "IMPORTANCE_NONE"
+	importanceUnspecifiedName = "IMPORTANCE_UNSPECIFIED"
 )
 
 var (
+	// idlock protects the nextNotificationID to ensure that no notification is ever
+	// sent with a duplicate id.
+	//
+	// BUG(whereswaldon): does not handle integer overflow
 	idlock             sync.Mutex
 	nextNotificationID int32
+
+	// jvmConstLock protects the mapping of JVM constants that must be resolved at runtime
+	jvmConstLock sync.Once
+	// importances tracks the IMPORTANCE_* constants from the JVM's values. Since they must
+	// be resolved at runtime, this array tracks their actual runtime values and the exported
+	// constants are simply indicies into this array.
+	importances [importanceEnd]int32
+	// map the JVM constant name to the index in the array
+	importancesMap = map[string]Importance{
+		importanceDefaultName:     ImportanceDefault,
+		importanceHighName:        ImportanceHigh,
+		importanceLowName:         ImportanceLow,
+		importanceMaxName:         ImportanceMax,
+		importanceMinName:         ImportanceMin,
+		importanceNoneName:        ImportanceNone,
+		importanceUnspecifiedName: ImportanceUnspecified,
+	}
 )
 
+// nextID safely returns the next unused notification id number. This function should
+// always be used to get a notificationID.
 func nextID() int32 {
 	idlock.Lock()
 	defer idlock.Unlock()
@@ -34,7 +86,7 @@ type NotificationChannel struct {
 
 // NewChannel creates a new notification channel identified by the provided id
 // and with the given user-visible name and description.
-func NewChannel(id, name, description string) (*NotificationChannel, error) {
+func NewChannel(importance Importance, id, name, description string) (*NotificationChannel, error) {
 	if err := jni.Do(jni.JVMFor(app.JavaVM()), func(env jni.Env) error {
 		appCtx := jni.Object(app.AppContext())
 		classLoader := jni.ClassLoaderFor(env, appCtx)
@@ -42,11 +94,25 @@ func NewChannel(id, name, description string) (*NotificationChannel, error) {
 		if err != nil {
 			return err
 		}
-		newChannelMethod := jni.GetStaticMethodID(env, notifyClass, "newChannel", "(Landroid/content/Context;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V")
+		jvmConstLock.Do(func() {
+			var managerClass jni.Class
+			managerClass, err = jni.LoadClass(env, classLoader, "android/app/NotificationManager")
+			if err != nil {
+				return
+			}
+			for name, index := range importancesMap {
+				fieldID := jni.GetStaticFieldID(env, managerClass, name, "I")
+				importances[index] = jni.GetStaticIntField(env, managerClass, fieldID)
+			}
+			log.Printf("importances: %v", importances)
+
+		})
+		newChannelMethod := jni.GetStaticMethodID(env, notifyClass, "newChannel", "(Landroid/content/Context;ILjava/lang/String;Ljava/lang/String;Ljava/lang/String;)V")
 		jname := jni.Value(jni.JavaString(env, name))
 		jdescription := jni.Value(jni.JavaString(env, description))
 		jID := jni.Value(jni.JavaString(env, id))
-		err = jni.CallStaticVoidMethod(env, notifyClass, newChannelMethod, jni.Value(app.AppContext()), jID, jname, jdescription)
+		jimportance := jni.Value(importance.value())
+		err = jni.CallStaticVoidMethod(env, notifyClass, newChannelMethod, jni.Value(app.AppContext()), jimportance, jID, jname, jdescription)
 		if err != nil {
 			return err
 		}

example/hello.go

@@ -53,7 +53,7 @@ func loop(w *app.Window) error {
 			if first {
 				first = false
 				go func() {
-					channel, err := android.NewChannel("CHANNEL", "hello", "description")
+					channel, err := android.NewChannel(android.ImportanceMax, "CHANNEL", "hello", "description")
 					if err != nil {
 						log.Printf("channel creation failed: %v", err)
 					}

go.mod

@@ -4,5 +4,8 @@ go 1.14
 
 require (
 	gioui.org v0.0.0-20200619180744-e2f3bbdfc367
-	github.com/tailscale/tailscale-android v0.1.9
+	gioui.org/cmd v0.0.0-20200619180744-e2f3bbdfc367 // indirect
+	git.wow.st/gmp/jni v0.0.0-20200619201040-d0d3f316ae09
 )
+
+replace git.wow.st/gmp/jni => git.wow.st/whereswaldon/jni v0.0.0-20200620152723-b380472956a0

go.sum

@@ -2,10 +2,15 @@ cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMT
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 eliasnaur.com/font v0.0.0-20200617114307-e02d32decb4b/go.mod h1:CYwJpIhpzVfoHpFXGlXjSx9mXMWtHt4XXmZb6RjumRc=
 gioui.org v0.0.0-20200530124200-1377bea3cdc5/go.mod h1:AHI9rFr6AEEHCb8EPVtb/p5M+NMJRKH58IOp8O3Je04=
+gioui.org v0.0.0-20200619103721-0b713032fbff/go.mod h1:jiUwifN9cRl/zmco43aAqh0aV+s9GbhG13KcD+gEpkU=
 gioui.org v0.0.0-20200619180744-e2f3bbdfc367 h1:uLmvlsenFUA5XkLheXgdQnX3T/oeYzO9aokBrbSsi/w=
 gioui.org v0.0.0-20200619180744-e2f3bbdfc367/go.mod h1:jiUwifN9cRl/zmco43aAqh0aV+s9GbhG13KcD+gEpkU=
 gioui.org/cmd v0.0.0-20200530141830-d2c67cdf8039 h1:mO1CTk+PwcDQGMXpN1JJiFflYBvwqSQ6+3Gvp64IKHo=
 gioui.org/cmd v0.0.0-20200530141830-d2c67cdf8039/go.mod h1:B1g+HOceSj7g3S4Yao3skwInTpcK978KANys5YuapMc=
+gioui.org/cmd v0.0.0-20200619180744-e2f3bbdfc367 h1:YClsDYIOzphBRi6t9N9wjPhQKTnW+B7oxxIK+DtlbJc=
+gioui.org/cmd v0.0.0-20200619180744-e2f3bbdfc367/go.mod h1:ECXnwbmqh7yrY50m4xQfFws2TsErFAXgiRmj8UHkb2U=
+git.wow.st/whereswaldon/jni v0.0.0-20200620152723-b380472956a0 h1:+S/LqMv8h+w4LE/3XtAq1roX8OAZ/E6rqsl/EQ1eaK8=
+git.wow.st/whereswaldon/jni v0.0.0-20200620152723-b380472956a0/go.mod h1:ro8WfqxHdXc4wFC+3uP98fVT5uZqrq3yQPMV+LjP6MA=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/Masterminds/semver/v3 v3.0.3/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
@@ -92,6 +97,7 @@ golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20200301022130-244492dfa37a/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58 h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e h1:vcxGaoTs7kV8m5Np9uUNQin4BrLOthgV7252N8V+FwY=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -110,6 +116,7 @@ golang.org/x/sys v0.0.0-20200124204421-9fbb57f87de9/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200501052902-10377860bb8e h1:hq86ru83GdWTlfQFZGO4nZJTU4Bs2wfHl8oFHRaXsfc=
 golang.org/x/sys v0.0.0-20200501052902-10377860bb8e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=