Does studio have autocomletetion for basic blocks of code like
for() {} or try{} catch() {} ?
For example, when writing code you enter try and studio autocompetes the whole structure like
try {
} catch() {
}
Related
my scenario is simple:i made a game using cocos2d-x and i want to download images (FB and Google play) for multi player users and show them once the download is done as texture for a button.
in ideal world, things work as expected.
things get tricky when those buttons got deleted before the download is done.
so the callback function is in weird state and then i get signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
and the app crashes
This is how i implmented it
I have a Layout class called PlayerIcon. the cpp looks like this
void PlayerIcon::setPlayer(string userName, string displayName, string avatarUrl){
try {
//some code here
downloadAvatar(_userName, _avatarUrl);
//some code here
}
catch(... ){
}
}
void PlayerIcon::downloadAvatar(std::string _avatarFilePath,std::string url) {
if(!isFileExist(_avatarFilePath)) {
try {
auto downloader = new Downloader();
downloader->onFileTaskSuccess=CC_CALLBACK_1(PlayerIcon::on_download_success,this);
downloader->onTaskError=[&](const network::DownloadTask& task,int errorCode,
int errorCodeInternal,
const std::string& errorStr){
log("error while saving image");
};
downloader->createDownloadFileTask(url,_avatarFilePath,_avatarFilePath);
}
catch (exception e)
{
log("error while saving image: test");
}
} else {
//set texture for button
}
}
void PlayerIcon::on_download_success(const network::DownloadTask& task){
_isDownloading = false;
Director::getInstance()->getScheduler()-> performFunctionInCocosThread(CC_CALLBACK_0(PlayerIcon::reload_avatar,this));
}
void PlayerIcon::reload_avatar(){
try {
// setting texture in UI thread
}
catch (...) {
log("error updating avatar");
}
}
As i said, things works fine until PlayerIcon is deleted before the download is done.
i dont know what happens when the call back of the download task point to a method of un object that s deleted (or flagged for deletion).
i looked in the downloader implementation and it doesn't provide any cancellation mechanism
and i'm not sure how to handle this
Also, is it normal to have 10% crash rate on google console for a cocos2dx game
any help is really appreciated
Do you delete de Downloader in de destructor of the PlayerIcon?
there is a destroy in the apple implementation witch is trigered by the destructor.
-(void)doDestroy
{
// cancel all download task
NSEnumerator * enumeratorKey = [self.taskDict keyEnumerator];
for (NSURLSessionDownloadTask *task in enumeratorKey)
{
....
DownloaderApple::~DownloaderApple()
{
DeclareDownloaderImplVar;
[impl doDestroy];
DLLOG("Destruct DownloaderApple %p", this);
}
In the demo code of cocos2d-x: DownloaderTest.cpp they use:
std::unique_ptr<network::Downloader> downloader;
downloader.reset(new cocos2d::network::Downloader());
instead of:
auto downloader = new Downloader();
It looks like you are building this network code as part of your scene tree. If you do a replaceScene/popScene...() call, while the async network software is running in the background, this will cause the callback to disappear (the scene will be deleted from the scene-stack) and you will get a SEGFAULT from this.
If this is the way you've coded it, then you might want to extract the network code to a global object (singleton) where you queue the requests and then grab them off the internet saving the results in the global-object's output queue (or their name and location) and then let the scene code check to see if the avatar has been received yet by inquiring on the global-object and loading the avatar sprite at this point.
Note, this may be an intermittent problem which depends on the speed of your machine and the network so it may not be triggered consistently.
Another solution ...
Or you could just set your function pointers to nullptr in your PlayerIcon::~PlayerIcon() (destructor):
downloader->setOnFileTaskSuccess(nullptr);
downloader->setOnTaskProgress(nullptr);
Then there will be no attempt to call your callback functions and the SEGFAULT will be avoided (Hopefully).
I'm following the example from the Bot Framework pages, under 'Handle User Actions' (https://learn.microsoft.com/en-us/azure/bot-service/nodejs/bot-builder-nodejs-dialog-actions?view=azure-bot-service-3.0)
// Order dinner.
bot.dialog('orderDinner', [
function(session, args, next){
if(args && args.isReloaded){
// Reload action was triggered.
}
session.send("Lets order some dinner!");
builder.Prompts.choice(session, "Dinner menu:", dinnerMenu);
}
//...other waterfall steps...
])
// Once triggered, will restart the dialog.
.reloadAction('startOver', 'Ok, starting over.', {
matches: /^start over$/i,
dialogArgs: {
isReloaded: true;
}
});
and after reloading the dialog args.isReloadedis always undefined. That is, it doesn't seem that the framework is passing through what is put in dialogArgs. Any clues as to what I might be missing? I'm using v 3.15 (or rather, the people for whom I'm working are using 3.15) -- was this something that was introduced in a later version 3, that is, after 3.5? Or is something just going wrong?
Any help much appreciated!
Tried the code with the specified version and is working correctly. There is an errant ";" in your code (which is also in the docs) that should be removed and may be the culprit. Change the following line to the below.
Hope of help!
dialogArgs: {
isReloaded: true
}
I was trying to update the recycler view content from a background thread in Kotlin. I am not using AsyncTask.
Here is my code, i want to know if there is any better way than this:
In my MainActivity, i have progressThread as a member variable.
var progressThread = Thread()
Then in my method where i want to run the thread first i am defining it...like
progressThread = Thread (
Runnable {
kotlin.run {
try {
while (i <= 100 && !progressThread.isInterrupted) {
Thread.sleep(200)
//Some Logic
runOnUiThread {
//this runs in ui thread
}
i++
}
}catch (e:InterruptedException){
progressThread.interrupt()
}
}
})
after that i am starting it in the same method as
progressThread.start()
and for stopping it, i have a listener to cancel the progress and in the callback of that listener, i have written:
progressThread.interrupt()
Updated
Coroutines are stable now,: https://kotlinlang.org/docs/reference/coroutines-overview.html
Old Answer
Yes, you can do this using doAsync from kotlin anko library that is fairly simple and easy to use.
add following line in module level gradle file:
compile "org.jetbrains.anko:anko-commons:0.10.0"
Code example:
val future = doAsync {
// do your background thread task
result = someTask()
uiThread {
// use result here if you want to update ui
updateUI(result)
}
}
code block written in uiThread will only be executed if your Activity or Fragment is in foreground mode (It is lifecycle aware). So if you are trying to stop thread because you don't want your ui code to execute when Activity is in background, then this is an ideal case for you.
As you can check doAsync returns a Future object so you can cancel the background task, by cancel() function:
future.cancel(true)
pass true if you want to stop the thread even when it has started executing.
If you have more specialised case to handle stopping case then you can do the same thing as in your example.
You can use Kotlin Coroutines also but its in Experimental phase, still you can try it out: https://kotlinlang.org/docs/reference/coroutines.html
I try to figure out how to implement a visual studio code extension. (Based on the "Hello World!" example.)
I want to do the following:
Execute an example.cmd file in the editor in a node.js child_process (that works)
But prior to that, automatically save the file to activate the latest changes (thats the problem)
At https://code.visualstudio.com/Docs/extensionAPI/vscode-api there is description of visual studio code api.
This is the command I think to be used:
executeCommand<T>(command: string, ...rest: any[]): Thenable<T>
What I need:
The file save is asynchronous. E.g. there may show up a File Save Dialog. The user may save properly or cancel it. I need to wait til end of the user action, then in case of succeess call my command prompt.
In my code:
let disposable = vscode.commands.registerCommand('extension.sayHello', () => {
....
var retval =
vscode.commands.executeCommand('workbench.action.files.save')
.then(function(result)
{
// It should wait til end of user action,
// But it never reach here
myOutputChannel.append('workbench.action.files.save:' + result + '\n');
});
// and immediately runs the child process code below
....
});
What happens:
It runs through the code, don't wait, don't save, process the non existing file, reports an error, exit function. After all the File Save Dialog appears. :(
Can anyone give me a hint whats wrong? Is this a bug of visual studio code? Or what I am doing wrong? I am new to node.js . I guess, I didn't get how to use Thenable<T> properly?
Here's a short snippet on how to properly save the file:
let editor = vscode.window.activeTextEditor;
if (!editor) {
return;
}
let doc = editor.document;
await editor.document.save();
I have an issue with cross threading on a UI. I have read all the ways to do it and have implemented them as seen below.
public void UpdateList(object obj)
{
// do we need to switch threads?
if (listBox1.InvokeRequired)
{
MethodInvoker del = () => UpdateList(obj);
this.Invoke(del);
return;
}
// ok so now we're here, this means we're able to update the control
// so we unbox the object into a string
string text = (string)obj;
// and update
listBox1.Items.Add(text);
}
The issue comes when I try to do a
hubConnection.Start().Wait();
After that call I am trying to update my list.
Without the wait is fine. When I add the Wait it hangs on the UpdateList Invoke. There is no error...it just hangs.
I am handling this call in a button event.
Wait() is creating a deadlock on the mainthread.
Replace the hubconnection.Start.Wait() with:
await hubconnection.Start() in an async method:
public void async StartHubClickedEvent(...){
await hubconnection.Start()
}
The Microsoft Async library enables use of async/awaut on .net 4.0 and VS12.
Install-Package Microsoft.Bcl.Async
See Deadlock when thread uses dispatcher and the main thread is waiting for thread to finish
You've generated a recursive loop. Assuming an Invoke is Required, you'll call up the same method, hit if (listBox1.InvokeRequired) again (which will still pass true) and start looping as you keep calling up the same method again and again. It's better to do an If..Else pattern here where you directly invoke the change on the ListBox or simply perform the change without the invoke
An Example
if (listBox1.InvokeRequired)
{
listBox1.Invoke(()=> { listBox1.Items.Add((string)text) };
}
else
{
string text = (string)obj;
// and update
listBox1.Items.Add(text);
}