Improved back button handling when note has been modified

ReactNativeClient/lib/dialogs.js

@@ -32,6 +32,30 @@ dialogs.confirm = (parentComponent, message) => {
 	});
 };
 
+dialogs.pop = (parentComponent, message, buttons) => {
+	if (!'dialogbox' in parentComponent) throw new Error('A "dialogbox" component must be defined on the parent component!');
+
+	return new Promise((resolve, reject) => {
+		Keyboard.dismiss();
+
+		let btns = [];
+		for (let i = 0; i < buttons.length; i++) {
+			btns.push({
+				text: buttons[i].title,
+				callback: () => {
+					parentComponent.dialogbox.close();
+					resolve(buttons[i].id);
+				},
+			});
+		}
+
+		parentComponent.dialogbox.pop({
+			content: message, 
+			btns: btns,
+		});
+	});
+}
+
 dialogs.error = (parentComponent, message) => {
 	Keyboard.dismiss();
 	return parentComponent.dialogbox.alert(message);