Extract app UI platform glue

2026-04-09 06:50:16 -07:00
parent b593b1e6a7
commit c3a9c0fddb
6 changed files with 26 additions and 25 deletions
@@ -0,0 +1,184 @@
+//go:build android
+
+package platform
+
+/*
+#cgo CFLAGS: -Werror
+#cgo LDFLAGS: -landroid
+
+#include <jni.h>
+#include <stdlib.h>
+
+static jclass jni_GetObjectClass(JNIEnv *env, jobject obj) {
+	return (*env)->GetObjectClass(env, obj);
+}
+
+static jmethodID jni_GetMethodID(JNIEnv *env, jclass clazz, const char *name, const char *sig) {
+	return (*env)->GetMethodID(env, clazz, name, sig);
+}
+
+static jmethodID jni_GetStaticMethodID(JNIEnv *env, jclass clazz, const char *name, const char *sig) {
+	return (*env)->GetStaticMethodID(env, clazz, name, sig);
+}
+
+static jobject jni_CallObjectMethodA(JNIEnv *env, jobject obj, jmethodID method, jvalue *args) {
+	return (*env)->CallObjectMethodA(env, obj, method, args);
+}
+
+static void jni_CallStaticVoidMethodA(JNIEnv *env, jclass cls, jmethodID methodID, const jvalue *args) {
+	(*env)->CallStaticVoidMethodA(env, cls, methodID, args);
+}
+
+static jvalue jni_ValueObject(jobject obj) {
+	jvalue value;
+	value.l = obj;
+	return value;
+}
+
+static jthrowable jni_ExceptionOccurred(JNIEnv *env) {
+	return (*env)->ExceptionOccurred(env);
+}
+
+static void jni_ExceptionClear(JNIEnv *env) {
+	(*env)->ExceptionClear(env);
+}
+
+static jstring jni_NewString(JNIEnv *env, const jchar *unicodeChars, jsize len) {
+	return (*env)->NewString(env, unicodeChars, len);
+}
+
+static int jni_IsNull(jobject obj) {
+	return obj == NULL;
+}
+*/
+import "C"
+
+import (
+	"fmt"
+	"strings"
+	"unicode/utf16"
+	"unsafe"
+
+	"gioui.org/app"
+	_ "unsafe"
+)
+
+type androidVaultSharer struct{}
+
+//go:linkname gioJavaVM gioui.org/app.javaVM
+func gioJavaVM() *C.JavaVM
+
+//go:linkname gioRunInJVM gioui.org/app.runInJVM
+func gioRunInJVM(jvm *C.JavaVM, f func(env *C.JNIEnv))
+
+func NewVaultSharer(goos string) VaultSharer {
+	return androidVaultSharer{}
+}
+
+func (androidVaultSharer) ShareVault(path, title string) error {
+	if strings.TrimSpace(path) == "" {
+		return fmt.Errorf("vault path is required")
+	}
+	ctx := C.jobject(unsafe.Pointer(app.AppContext()))
+	if C.jni_IsNull(ctx) != 0 {
+		return fmt.Errorf("android app context is not available")
+	}
+	var callErr error
+	gioRunInJVM(gioJavaVM(), func(env *C.JNIEnv) {
+		sharerClass, err := androidLoadClass(env, ctx, "org.julianfamily.keepassgo.AndroidShare")
+		if err != nil {
+			callErr = err
+			return
+		}
+		methodName := cString("shareVault")
+		defer C.free(unsafe.Pointer(methodName))
+		methodSig := cString("(Landroid/content/Context;Ljava/lang/String;Ljava/lang/String;)V")
+		defer C.free(unsafe.Pointer(methodSig))
+		method := C.jni_GetStaticMethodID(env, sharerClass, methodName, methodSig)
+		if method == nil {
+			callErr = androidJNIError(env, "resolve shareVault method")
+			if callErr == nil {
+				callErr = fmt.Errorf("resolve shareVault method")
+			}
+			return
+		}
+
+		jPath := androidJavaString(env, path)
+		jTitle := androidJavaString(env, title)
+		args := [3]C.jvalue{}
+		args[0] = C.jni_ValueObject(ctx)
+		args[1] = C.jni_ValueObject(C.jobject(jPath))
+		args[2] = C.jni_ValueObject(C.jobject(jTitle))
+		C.jni_CallStaticVoidMethodA(env, sharerClass, method, &args[0])
+		callErr = androidJNIError(env, "share vault")
+	})
+	return callErr
+}
+
+func androidLoadClass(env *C.JNIEnv, ctx C.jobject, name string) (C.jclass, error) {
+	var zeroClass C.jclass
+	contextClass := C.jni_GetObjectClass(env, ctx)
+	getClassLoaderName := cString("getClassLoader")
+	defer C.free(unsafe.Pointer(getClassLoaderName))
+	getClassLoaderSig := cString("()Ljava/lang/ClassLoader;")
+	defer C.free(unsafe.Pointer(getClassLoaderSig))
+	getClassLoader := C.jni_GetMethodID(env, contextClass, getClassLoaderName, getClassLoaderSig)
+	if getClassLoader == nil {
+		if err := androidJNIError(env, "resolve getClassLoader"); err != nil {
+			return zeroClass, err
+		}
+		return zeroClass, fmt.Errorf("resolve getClassLoader")
+	}
+	classLoader := C.jni_CallObjectMethodA(env, ctx, getClassLoader, nil)
+	if err := androidJNIError(env, "load class loader"); err != nil {
+		return zeroClass, err
+	}
+	if C.jni_IsNull(classLoader) != 0 {
+		return zeroClass, fmt.Errorf("android class loader is nil")
+	}
+
+	classLoaderClass := C.jni_GetObjectClass(env, classLoader)
+	loadClassName := cString("loadClass")
+	defer C.free(unsafe.Pointer(loadClassName))
+	loadClassSig := cString("(Ljava/lang/String;)Ljava/lang/Class;")
+	defer C.free(unsafe.Pointer(loadClassSig))
+	loadClass := C.jni_GetMethodID(env, classLoaderClass, loadClassName, loadClassSig)
+	if loadClass == nil {
+		if err := androidJNIError(env, "resolve loadClass"); err != nil {
+			return zeroClass, err
+		}
+		return zeroClass, fmt.Errorf("resolve loadClass")
+	}
+
+	jClassName := androidJavaString(env, name)
+	args := [1]C.jvalue{}
+	args[0] = C.jni_ValueObject(C.jobject(jClassName))
+	loaded := C.jni_CallObjectMethodA(env, classLoader, loadClass, &args[0])
+	if err := androidJNIError(env, "load AndroidShare class"); err != nil {
+		return zeroClass, err
+	}
+	if C.jni_IsNull(loaded) != 0 {
+		return zeroClass, fmt.Errorf("load AndroidShare class returned nil")
+	}
+	return C.jclass(loaded), nil
+}
+
+func androidJNIError(env *C.JNIEnv, action string) error {
+	if thr := C.jni_ExceptionOccurred(env); C.jni_IsNull(C.jobject(thr)) == 0 {
+		C.jni_ExceptionClear(env)
+		return fmt.Errorf("%s: Java exception", action)
+	}
+	return nil
+}
+
+func androidJavaString(env *C.JNIEnv, s string) C.jstring {
+	chars := utf16.Encode([]rune(s))
+	if len(chars) == 0 {
+		return C.jni_NewString(env, nil, 0)
+	}
+	return C.jni_NewString(env, (*C.jchar)(unsafe.Pointer(unsafe.SliceData(chars))), C.jsize(len(chars)))
+}
+
+func cString(value string) *C.char {
+	return C.CString(value)
+}