And add the Android code to access clipboard contents

internal/driver/gomobile/clipboard_android.go

@@ -2,12 +2,94 @@
 
 package gomobile
 
+/*
+#cgo LDFLAGS: -landroid -llog -lEGL -lGLESv2
+
+#include <android/log.h>
+#include <jni.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define LOG_FATAL(...) __android_log_print(ANDROID_LOG_FATAL, "GoLog", __VA_ARGS__)
+
+static jmethodID find_method(JNIEnv *env, jclass clazz, const char *name, const char *sig) {
+	jmethodID m = (*env)->GetMethodID(env, clazz, name, sig);
+	if (m == 0) {
+		(*env)->ExceptionClear(env);
+		LOG_FATAL("cannot find method %s %s", name, sig);
+		return 0;
+	}
+	return m;
+}
+
+jobject getClipboard(uintptr_t jni_env, uintptr_t ctx) {
+	JNIEnv* env = (JNIEnv*)jni_env;
+	jclass ctxClass = (*env)->GetObjectClass(env, ctx);
+	jmethodID getSystemService = find_method(env, ctxClass, "getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;");
+
+	jstring service = (*env)->NewStringUTF(env, "clipboard");
+	return (jobject)(*env)->CallObjectMethod(env, ctx, getSystemService, service);
+}
+
+char *getClipboardContent(uintptr_t java_vm, uintptr_t jni_env, uintptr_t ctx) {
+	JNIEnv* env = (JNIEnv*)jni_env;
+	jobject mgr = getClipboard(jni_env, ctx);
+
+	jclass mgrClass = (*env)->GetObjectClass(env, mgr);
+	jmethodID getText = find_method(env, mgrClass, "getText", "()Ljava/lang/CharSequence;");
+
+	jobject content = (jstring)(*env)->CallObjectMethod(env, mgr, getText);
+	if (content == NULL) {
+		return "";
+	}
+
+	jclass clzCharSequence = (*env)->GetObjectClass(env, content);
+	jmethodID toString = (*env)->GetMethodID(env, clzCharSequence, "toString", "()Ljava/lang/String;");
+	jobject s = (*env)->CallObjectMethod(env, content, toString);
+
+	const char* chars = (*env)->GetStringUTFChars(env, s, NULL);
+	const char *copy = strdup(chars);
+	(*env)->ReleaseStringUTFChars(env, s, chars);
+	return copy;
+}
+
+void setClipboardContent(uintptr_t java_vm, uintptr_t jni_env, uintptr_t ctx, char *content) {
+	JNIEnv* env = (JNIEnv*)jni_env;
+	jobject mgr = getClipboard(jni_env, ctx);
+
+	jclass mgrClass = (*env)->GetObjectClass(env, mgr);
+	jmethodID setText = find_method(env, mgrClass, "setText", "(Ljava/lang/CharSequence;)V");
+
+	jstring str = (*env)->NewStringUTF(env, content);
+	(*env)->CallVoidMethod(env, mgr, setText, str);
+}
+*/
+import "C"
+import (
+	"unsafe"
+
+	"github.com/fyne-io/mobile/app"
+)
+
 // Content returns the clipboard content for Android
 func (c *mobileClipboard) Content() string {
-	return "" // TODO implement ticket #414
+	content := ""
+	app.RunOnJVM(func(vm, env, ctx uintptr) error {
+		chars := C.getClipboardContent(C.uintptr_t(vm), C.uintptr_t(env), C.uintptr_t(ctx))
+		content = C.GoString(chars)
+		C.free(unsafe.Pointer(chars))
+		return nil
+	})
+	return content
 }
 
 // SetContent sets the clipboard content for Android
 func (c *mobileClipboard) SetContent(content string) {
-	// TODO implement ticket #414
+	contentStr := C.CString(content)
+	defer C.free(unsafe.Pointer(contentStr))
+
+	app.RunOnJVM(func(vm, env, ctx uintptr) error {
+		C.setClipboardContent(C.uintptr_t(vm), C.uintptr_t(env), C.uintptr_t(ctx), contentStr)
+		return nil
+	})
 }